Derivation of Matrix Soil Standards for Salt under the ... · Table 7.1: Background concentrations of salt ions in groundwater within British Columbia..... 108 Table 8.1: SCHEDULE

Derivation of Matrix Soil Standards for Salt under the British Columbia

Contaminated Sites Regulation

June 2002

Report to the British Columbia Ministry of Water, Land and Air Protection, Ministry of Transportation and Highways,

British Columbia Buildings Corporation, and the Canadian Association of Petroleum Producers

Doug A. Bright, Ph.D. and Jan Addison, Ph.D.

Applied Research Division, Royal Roads University CEDAR Building

2005 Sooke Rd, Victoria, BC, V9B 5Y2

Further information contact:

© Applied Research Division Royal Roads University

CEDAR Building 2005 Sooke Road

Victoria, British Columbia V9B 5Y2

Doug A. Bright, Ph.D. Jan Addison, Ph.D.

Phone: (250) 391-2584 Phone: (250) 391-2585 E-mail: [email protected] E-mail: [email protected]

FAX: (250) 391-2560

i

Acknowledgments

This study was made possible by and substantially benefited from the contributions of several groups and individuals. Funding was provided through the Ministry of Transportation and Highways (MOTH), British Columbia Buildings Corporation (BCBC) and the Canadian Association of Petroleum Producers (CAPP). Special thanks are due to members of the Salt Standard Steering Committee (Appendix A) chaired by Dr. Glyn Fox, B.C. Ministry of Water, Land and Air Protection (WLAP) for a strong guiding hand in the study.

The Salt Standard Steering Committee provided technical and practical guidance through 2000 – 2001. Committee members included Doug Walton, (WLAP), Linda Elder (WLAP, Prince George), Narendar Nagpal (WLAP), Rob Buchanan (MOTH), George Wycherley and Nazir Jessa (BCBC), Colin McKean (independent representative for BCBC), John Ashworth (formerly of Norwest Laboratories), Doug Keyes (Norwest Laboratories, Edmonton), Adriene Bakker (CAPP) and Neil Drummond (CAPP). Their insights greatly improved the outcome of this study. In addition, members of the Petroleum Technology Alliance of Canada (PTAC) Salinity Working Group kindly provided comment on the derivation document through several drafts. We thank several technical/scientific peer reviewers. Finally, thanks to Nancy Kwong, Royal Roads University – Applied Research, who kindly coordinated communications and assisted with a myriad of issues that arose during this project.

ii

FOR DUPLEX PRINTING PURPOSES, THIS PAGE IS INTENTIONALLY LEFT BLANK

iii

Acronyms

BCBC British Columbia Building Corporation BC CSR British Columbia Contaminated Sites Regulation

BCE British Columbia Ministry of Environment (currently WLAP)

CAPP Canadian Association of Petroleum Producers CCME Canadian Council of Ministers of the Environment CCREM Canadian Council of Resource and Environment Ministers CEC Cation Exchange Capacity CEPA Canadian Environmental Protection Act

CEPA PSLII Canadian Environmental Protection Act – Priority Substance List II

COC Cocoon production (earthworm) CSST British Columbia Contaminated Sites Soils Taskgroup EC Electrical Conductivity

EC50 Median Effects Concentration (Concentration observed or calculated to result in an effect which is 50% of the control level)

ESC Exchangeable Sodium Percentage GRO Growth IC50 Median Inhibitory Concentration

ITX Immobility endpoint – equivalent to an LCx endpoint if test organisms do not recover from morbidity when placed in control medium

LC50 Median Lethal Concentration (Concentration observed or calculated to result in the death of 50% of the test organisms)

LOEC Lowest Observed Effect Concentration LOEL Lowest Observed Effects Level

MELP British Columbia Ministry of Environment, Lands and Parks (changed in late 2000 to Ministry of Water, Land and Air Protection, WLAP)

MOR Mortality MOTH British Columbia Ministry of Transportation and Highways NOEC No Observed Effect Concentration OECD Organisation for Economic Cooperation and Development POP Population

iv

Acronyms (cont’d)

PTAC Petroleum Technology Alliance of Canada REP Reproduction SAR Sodium Adsorption Ratio SSD Species Sensitivity Distribution TDI Tolerable Daily Intake TDS Total Dissolved Solids WHO Word Health Organization

WLAP British Columbia Ministry of Water, Land and Air Protection (formerly MELP and BCE)

USDA United States Department of Agriculture USEPA United States Environmental Protection Agency

v

Table of Contents

1. INTRODUCTION........................................................................... 1

1.1 Objectives ...................................................................................3

2. BRIEF OVERVIEW OF BRITISH COLUMBIA PROTOCOLS FOR THE DERIVATION OF SOIL MATRIX STANDARDS ................ 7

3. AN OPERATIONAL DEFINITION OF SALT UNDER THE BC CSR ........................................................................................... 11

4. RELEVANT SOIL, SEDIMENT, AND WATER QUALITY OBJECTIVES FOR SALT FROM OTHER JURISDICTIONS ........... 13

5. IMPORTANT ISSUES.................................................................. 15

5.1 Basic Chemistry of Salts in Soil.................................................15

5.2 Measurement of Sodium and Chloride Concentrations in Soil ........................................................................................16

5.2.1 Sodium and Chloride in Saturated Paste ....................19 5.2.2 Comparison of Saturated Paste versus Fixed-

Ratio Water:Soil Extract Methods in OECD Soil..........20 5.2.3 Recommended Protocols to Determine Levels

of Salt Ions in Soil........................................................22

5.3 Relationship Between Salt Ions and Electrical Conductivity in Soil ....................................................................23

6. DETAILED RISK-BASED CALCULATIONS .................................. 28

6.1 Human Health Protective Standards .........................................28

6.1.1 Detailed Calculations...................................................28

vi

6.1.1.1 Calculation of SQSHH ................................... 29

6.2 Ecological Effects Soil Quality Standards – Direct Pathways .................................................................................. 36

6.2.1 Soil Nutrient Cycling ................................................... 36 6.2.2 Direct Exposure by Soil Invertebrates and

Plants.......................................................................... 36 6.2.2.1 Soil Invertebrate Studies .............................. 39 6.2.2.2 Plant Toxicity Studies................................... 43 6.2.2.3 Summary of Estimated Thresholds for

the Protection of Soil Invertebrates and Plants Based on Direct Soil Contact................... 50

6.2.3 Soil and Fodder Ingestion by Livestock (Agricultural Lands Only) ............................................ 52

6.3 Soil to Groundwater Pathways – Human Health and Ecological Effects Soil Quality Standards ................................. 53

6.3.1 The Groundwater Model ............................................. 59 6.3.2 Relevant Toxicological Thresholds ............................. 60

6.3.2.1 Drinking Water and Human Health............... 61 6.3.2.2 Agricultural Water Uses................................ 61 6.3.2.3 Freshwater Aquatic Life Protection .............. 66

6.4 BC Contaminated Sites Soils Taskgroup (CSST) Model Results...................................................................................... 85

6.4.1.1 Aquatic Life Protection ................................. 87 6.4.1.2 Agricultural Land Uses – Irrigation

and Livestock Drinking Water............................. 93 6.4.1.3 Human Health – Groundwater Used

for Drinking Water .............................................. 94

7. COMPARISON WITH BACKGROUND CONCENTRATIONS OF SALT IONS IN SOIL AND WATER .......................................... 97

7.1 Background Soil Concentrations .............................................. 97

7.2 Background Groundwater Salt Ion Concentrations................. 106

8. CONCLUSIONS........................................................................ 111

vii

9. REFERENCES .......................................................................... 115

10. APPENDICES........................................................................... 124

viii


ix

List of Tables Table 2.1: Human Health and Ecological Receptors

Considered for Specific Land-use Categories in the Derivation of B.C. Matrix Soil Standards .............................................. 9

Table 5.1: Regression (Least Squares) Estimates of Nominal (Added) Versus Measured Salt Ion Concentrations ........................... 20

Table 5.2: Comparison of Recovery of Sodium and Chloride Ins in Saturated Paste versus Fixed-ratio Soil:Water Extracts in OECD Soil Samples ........................................................ 21

Table 5.3: Relationship Between Electrical Conductivity and Nominal Concentrations of NaCl (mg/kg) in Different Experimental Soils. ............................................................................ 24

Table 5.4: Comparison of the Amounts of NaCl (mg/kg) Required to Produce Specific Values of Electrical Conductivity in Different Soils. ........................................................... 25

Table 5.5: Predicted Values of Electrical Conductivity for Different Soils in Response to Contamination with NaCl.................... 26

Table 6.1: Relationship Between Percent of Soil invertebrate Species Potentially Affected and Soil NaCl Concentration (Nominal) .................................................................................... 41

Table 6.2: Comparison of Toxicity of NaCl versus Ferricyanide-Containing Commercial Road Salt to Two Species of Soil Invertebrates in Standard OECD Soil ........................ 42

Table 6.3: Comparison of Toxicity of NaCl and KCl to Selected Soil Invertebrates ................................................................ 42

Table 6.4: Summary of Soil Invertebrate Toxicity Thresholds for NaCl in Soil ................................................................................... 43

Table 6.5: Predicted Sensitivity of Plants to Salt in Soils, Measured as Electrical Conductivity (Saturated Paste Extract) .................................................................................... 46

Table 6.6: Relationship Between Percent of Plant Species Potentially Affected and Soil NaCl Concentration (Nominal) .................................................................................... 49

x

Table 6.7: Summary of Plant Toxicity Thresholds for NaCl in Soil ................................................................................................. 50

Table 6.8: Summary of Salt Ion Thresholds for Both Soil Invertebrates and Plants (converted to saturated paste equivalent concentrations).................................................................. 51

Table 6.9: Cation Exchange Capacities (CEC) for Several Clay Minerals (adapted from Johnston et al, 2000, based on Grim, 1968) ................................................................................... 54

Table 6.10: Emperically Derived, or Geometric Mean Kd values (mL/g) by Soil Type (after Sheppard and Thibault, 1990)1 ................. 57

Table 6.11: Predicted Relationships Between Salt Ions and Electrical Conductivity (EC) in Soil Solution ....................................... 63

Table 6.12: USDA (1994) Salinity Standards for Forest Nurseries ..................................................................................... 64

Table 6.13: Relative susceptibility of crops to foliar injury from saline sprinkling water1 (after Maas, 1990)......................................... 65

Table 6.14: Literature Derived Acute:Chronic NaCl Toxicity Ratios as Reported in Evans and Frick (2000) ................................... 68

Table 6.15: Lowest Observed Effects Levels – NaCl.................................. 76

Table 6.16: Final Estimated Aquatic Life Thresholds.................................. 83

Table 6.17: Default Model Input Parameters and Site-Specific Model Calibration Data ....................................................................... 86

Table 6.18: Summary of model runs for draft aquatic life standard: draft aquatic life soil standards (mg/kg chloride ion in soil) based on variations in (i) distance from the soil to the receptor, (ii) aquatic life threshold, and (iii) annual precipitation ..................................................................................... 88

Table 6.19: Model estimates of chloride soil concentration (mg/kg) thresholds for the protection of aquatic life – dependence on assumptions regarding Kd and using an aquatic life water quality threshold of 460 mg/L.................................. 90

Table 6.20: Estimated soil quality thresholds for potassium based on aquatic life protection.......................................................... 91

xi

Table 6.21: Range of estimated soil chloride thresholds for the protection of crops irrigated with groundwater on agricultural lands................................................................................ 93

Table 6.22: Range of estimated soil calcium thresholds for livestock protection (drinking water) on agricultural lands .................. 93

Table 6.23: Range of estimated soil chloride thresholds for aesthetic drinking water objectives where there is the potential for use of groundwater by humans ...................................... 94

Table 6.24: Recommended values for drinking water intake...................... 95

Table 7.1: Background concentrations of salt ions in groundwater within British Columbia ................................................ 108

Table 8.1: SCHEDULE 5 MATRIX NUMERICAL SOIL STANDARDS1 SODIUM Ion (Na+)................................................... 112

Table 8.2: SCHEDULE 5 MATRIX NUMERICAL SOIL STANDARDS1 CHLORIDE Ion (Cl-) ................................................. 113

xii


xiii

List of Figures

Figure 5.1: Relationship Between Electrical Conductivity and Nominal Concentrations of NaCl in Four Experimental Soils. .................................................................................... 25

Figure 6.1: Soil Invertebrate Species Sensitivity Distribution to NaCl (mg/kg) Based on Laboratory Toxicity Test Data ...................... 40

Figure 6.2: Plant Species Sensitivity Distribution to Soil Salinity Expressed as the Electrical Conductivity of the Saturated Paste Extract ..................................................................... 45

Figure 6.3: Plant Species Sensitivity to NaCl in Soil ................................. 48

Figure 6.4: Aquatic Life Chronic Species Sensitivity Distribution for Chloride Ion Based on Laboratory Toxicity Test Data (adapted from Evans and Frick, 2000). The upper and lower 95% confidence interval are also shown. ................ 68

Figure 6.5: Predicted chronic and actual (4 day and one week) toxicity levels for aquatic life exposed to NaCl. (upper and lower 95% CIs based on a log-logistic fit are shown). .................................................................................... 69

Figure 6.6: Approximated Species Sensitivity Distribution for NaCl effects on aquatic life – longer term exposures and mortality. .................................................................................... 74

Figure 6.7: Approximated species sensitivity distribution for NaCl (mg/L) effects on aquatic life – non-lethal endpoints (growth, reproduction, population level). ............................................ 74

Figure 6.8: Approximated species sensitivity distribution for KCl (mg/L) effects on aquatic life – longer term exposures and mortality. .................................................................... 77

Figure 6.9: Approximated species sensitivity distribution for CaCl2 (mg/L) effects on aquatic life – longer term exposures and mortality. .................................................................... 78

Figure 6.10: Approximated species sensitivity distribution for MgCl2 (mg/L) effects on aquatic life – longer term exposures and mortality. .................................................................... 78

xiv

Figure 6.11: Comparative toxicity of different chloride salts – mortality endpoints. ............................................................................ 79

Figure 6.12: Comparative toxicity of KCl and NaCl...................................... 81

Figure 6.13: Predicted soil protective levels for freely dissociable chloride ion in relation to distance of the water body from the contaminant source and maximum acceptable groundwater concentration based on aquatic life protection ..................................................................................... 89

Figure 7.1: Background soil chloride concentrations in B.C....................... 99

Figure 7.2: Background soil pH in B.C. .................................................... 100

Figure 7.3: Background soil EC (electrical conductivity) in B.C. .............. 101

Figure 7.4: Background soil total carbon concentrations in B.C. ................................................................................... 102

Figure 7.5: Background soil WAD cyanide concentrations in B.C. ................................................................................... 104

Figure 7.6: Frequency distribution of background soil concentrations of sulfate, Southern Interior region ........................... 106

xv

List of Appendices

A. Members of the Salt Standards Steering Committee, and Peer Reviewers

B. New and Revised Data Used for the Derivation of a British Columbia Salt Matrix Standard

C. Review of Existing Salt Soil and Water Guidelines in Other Jurisdictions

xvi


1

1. Introduction

Various parties with responsibility for land management within British Columbia have identified a need for risk-based, scientifically defensible investigation and remediation standards for salt contaminated soil. A variety of activities may lead to elevated levels of salt in terrestrial soils, groundwater and adjacent surface water bodies. The major focus of current management challenges for salt contamination under the BC Contaminated Sites Regulation (BC CSR) is based on the following:

1. Transportation, storage, and use of road salt to increase transportation safety and decrease human risks due to traffic accidents (including the removal of salt-affected snow to storage/melt areas);

2. Redistribution of subterranean salt brines in association with oil and gas exploration and production; and,

3. Use of various salts for dust suppression.

Two major issues within British Columbia, in particular, have catalyzed an interest in developing a soil salt standard within the framework of the BC CSR. The first of these is ongoing remediation activities at highways maintenance yards, particularly where road salt storage and handling has resulted in elevated salt concentrations in soil, surface water and/or groundwater. The second issue relates to spill response and soil remediation in northern British Columbia at sites where salt-containing produced water is released as part of oil and gas exploration and extraction activities. The lack of standardized guidance on generically protective salt concentrations in soil has made it difficult in both cases to remediate affected areas without undertaking resource-intensive detailed risk assessments at each site. In addition, current approaches have been applied inconsistently across sites and regions, and the site remediation process presently lacks predictability.

In late 2001, road salt was formally declared a CEPA “toxic” substance (Environment Canada, 2000) as part of the CEPA PSLII (Canadian Environmental Protection Act Priority Substances List II):

“Based on the available data, it is considered that road salts are entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity, and that constitute or may constitute a danger to the environment on which life depends. Therefore, it is proposed that road salts be considered “toxic” under Section 64 of the Canadian Environmental Protection Act, 1999.”

2

Under the CEPA framework, the declaration of a substance as a track II toxic substance requires that it be subjected to “life cycle management”. Under Part 5 of the Canadian Environmental Protection Act, for substances already in use within Canada and subsequently declared toxic, the Federal government has 24 months to develop preventative or control measures. Examples of such measures might include –

• voluntary arrangements; • economic instruments; • pollution prevention (P2) planning; and, • regulations.

An additional 18 months is provided as a timeline for finalizing appropriate measures. This overall timelines potentially represent a delay in the ability of various site managers in British Columbia to effectively remediate previously identified salt-contaminated sites.

The development of soil clean-up standards, and their subsequent application to remediate salt contaminated soils in British Columbia will address a subset of the environmental risks identified as part of the CEPA PSLII review of road salt. The development of salt matrix standards is specifically intended to minimize ongoing or future risks at release sites of large versus smaller masses of either road salt or produced water1. Lower magnitude but potentially cumulative environmental risks across large areas, such as might be associated with extensive road right-of-ways where road salt has been applied as a deicing agent, are best minimized using management tools other than the BC CSR; for example, the adoption of best management practices for road salt application or the handling of produced water, as well as pollution prevention planning. In response to the CEPA declaration of road salt as a CEPA toxic substance, the inclusion of salts in the province’s contaminated sites regulatory framework is only a portion of the expected solution for risk reduction, and should be seen as complimentary to other management tools.

There is very limited experience in jurisdictions outside of British Columbia with the management of anthropogenically enhanced and sometimes massive salt releases to soil and often groundwater from a toxicant/contaminant

1 Soil remediation standards for salt ions, as derived herein, are specifically intended to address potential environmental risks associated with point-source, relatively large scale introductions into the terrestrial and contiguous environment. The standards are not intended to address non-point source inputs such as road salt application and runoff.

3

perspective. Section 4 provides a brief review. While some jurisdictions such as Alberta and Saskatchewan have recently introduced soil guidelines for salt affected sites, the emphasis has been overwhelmingly on protection of or restoration of crop productivity on agricultural lands. The regulatory guidance, therefore, focuses on measures of electrical conductivity (EC: based on the known relationship between EC and decrease in plant growth or yield) and sodium adsorption ratio (SAR) in surface soils, a measure of soil ‘sodicity’.

The past focus on agronomic species and non-specific salt effects as might be mediated by osmolality-type perturbations is of interest for the protection of agricultural lands within British Columbia, but was considered insufficient to address many other potential receptors, land uses, or ecotypes. The draft salt soil matrix standards described herein, therefore, represent the first attempt internationally to define for various land use categories generically protective concentration thresholds in soil for major salt ions, beyond which there is a potential for human health and/or ecological risks.

The availability of ion-specific data for salt contaminated soils provide a means for potentially examining not just osmotically mediated effects on ecological receptors, but also various ion-specific effects across a range of land-uses and biomes. Indeed, the recently adopted Alberta guidelines set the stage for the future incorporation of environmental protection strategies that consider ion-specific fate and effects. Unfortunately, goals to protect soil ecological functioning and associated productivity as pursued herein are still limited by a disproportionate availability of salt ion toxicity data for soil invertebrates and plants that are representative of agricultural settings, but not necessarily coastal, interior, and montane temperate forests; wetlands, bogs, and riparian zones; or a large variety of other ecosystem types. For this and other reasons, it is expected that environmental quality guidelines for salt in various jurisdiction, including British Columbia, will change over time to accommodate emerging knoweldge.

A “Salt Standards Steering Committee” provided regular guidance on important issues. Members of the committee are listed in Appendix A.

1.1 Objectives

The overall objective of this study is to derive a set of soil quality standards (matrix standards) for salt ions under the framework of the British Columbia Contaminated Sites Regulation (BC CSR) and the Waste Management Act. Soil matrix standards (documented in Schedule 5 of the BC CSR) once adopted provide easily interpretable, legally enforceable contaminant investigation and remediation thresholds that are generically applicable to

4

sites that meet the definition in the Regulation of being contaminated or potentially contaminated. Generic matrix standards are intended to facilitate the resolution of contaminant issues at less-complex, smaller sites. As such, they represent a mechanism for identifying and responding to environmental risks from soil contamination that is considerably less resource intensive than would be required to conduct for each site a detailed ecological and human health risk assessment.

Additional background on the BC CSR, and policy decisions underlying it, are provided in Section 2. The development of draft soil matrix standards under the BC CSR framework for salt ions generally followed the prior policy decisions, especially as emerged from deliberations of the BC Contaminated Sites Soils Taskgroup (CSST). Given that salt ions occur naturally and are ubiquitous, however, and in light of the challenges in applying traditional toxicological concepts to salt ions, the derivation of draft matrix standards required a re-visitation of several scientific/technical issues and policy decisions.

Specific objectives of this study included:

• The establishment of a practical and scientifically defensible operational definition for “salt” in consideration of likely major sources, environmental fate processes, and known toxicological or environmental impact mechanisms for organisms targeted for protection;

• Establishment of interrelationships between different measures of salt ions in soil, based in part on soil type;

• Development of human health protective standards for salt in soil based on groundwater or soil ingestion;

• Derivation of thresholds for protection of soil ecological functioning, as manifested through soil invertebrate and plant responses, primarily through the generation and interpretation of new soil toxicity data;

• Investigations of the relative toxicity of NaCl and road salt formulations to which sodium ferrocyanide has been added as an anti-caking agent;

• Investigations of the interrelationship between soil properties and salt toxicity to soil types;

• Comparison of the toxicological thresholds of different salt ions (Na+, K+, Ca2+, Mg2+, Cl-, SO4

2-, HCO32-);

• Derivation of soil salt thresholds for the protection of aquatic life based on lateral migration via groundwater over short distances and subsequent entry into surface water bodies based on existing aquatic toxicity data;

5

• Verification of groundwater model predictions and re-visiting of standard assumptions for the transport of salt ions from soils to adjacent water bodies; and,

• Documentation on a region-by-region basis of natural ranges of major salt ions in British Columbia soils and groundwater.

6


7

2. Brief Overview of British Columbia Protocols for the Derivation of Soil Matrix Standards

The Contaminated Sites Soils Task Group (CSST) within British Columbia, following its inception in November of 1994, drew on and modified existing Canadian Council of the Ministers of Environment (CCME) guidance documents in order to establish explicit protocols for the derivation of soil quality standards for contaminated site assessment and remediation, a key component of the BC CSR. The CSST process for deriving soil quality standards for specific substances has historically relied to a large extent on CCME substance assessment documents for ecotoxicological data compilations and for human health reference values (BCE, 1996).

The overall objectives of the B.C. Matrix soil quality standards are to –

• determine when a site is considered to be contaminated; • determine when remediation has been adequately performed at a site;

and, • control the relocation of contaminated soil.

The CSST guidance recognizes four major, generic categories of land use:

(i) agricultural, (ii) residential/urban parkland, (iii) commercial, and (iv) industrial.

For the protection of non-human components of terrestrial ecosystems, the CSST procedures focus primarily on the potential for adverse effects to receptors at the primary point-of-contact. For ecological receptors, therefore, soil protective standards necessarily include a soil standard derived for the protection of soil invertebrates and plants that are in direct contact with the soils under study (Table 2.1). For agricultural lands, it is also deemed appropriate to define soil concentrations above which soil microbial functioning, and – hence – nutrient and organic cycling, may be impaired. On agricultural lands, additional consideration may be given to the potential risks to livestock from the ingestion of contaminated soil and forage materials.

The CSST procedures also contain provisions for indirect exposures, of both humans and ecological receptors, based on the transfer of substances from soil to groundwater, and subsequently to either surface water bodies (ponds,

8

lakes, streams, marine environments) or subsurface water supplies used for drinking water by humans, and/or crop irrigation or livestock watering.

For human health protection, different derivation procedures for threshold-acting and non-threshold toxicants (e.g., carcinogens) are provided. It is recognized that the expected risks to humans from a specific toxicant will undoubtedly be influenced by multi-media exposure routes, including soil intake, dermal absorption, inhalation, food ingestion, and drinking water ingestion.

For human health, CSST maintained that for the majority of substances with limited volatility, the direct ingestion of soil is likely to be the largest exposure source quantitatively. As a general rule, CSST guidance assumes that soil ingestion accounts for 20% of the tolerable daily intake (TDI) based on the receptor- and substance-specific reference dose (RfD). The CSST policy decisions also assume that soil-bound contaminants are 100% bioavailable once ingested (in other words, the entire mass of contaminant from ingested soils is internalized into humans via passage through the gastrointestinal epithelium).

9

Table 2.1: Human Health and Ecological Receptors Considered for Specific Land-use Categories in the Derivation of B.C. Matrix Soil Standards

Land Use Agricultural Residential/ Urban Parkland

Commercial Industrial

Human Health Protective Standards Intake of contaminated soil

1� � �

Groundwater used for drinking water �

� � �

Ecological Receptors - Direct Exposure Pathways Toxicity to soil invertebrates and plants:

2� (lower of LC20

or EC50-NL) � (lower of LC20

or EC50-NL) � (higher of LC20

or EC50-NL) � (higher of LC20

or EC50-NL)

Livestock ingesting soil and fodder

�

Major Microbial Function Check �

Ecological Receptors - Indirect Exposure Pathways Soil to groundwater pathway for protection of adjacent aquatic life

� (BCE model, after

Domenico and Robbins, 1984)







Soil to groundwater used for livestock watering

�

Soil to groundwater for plant irrigation

� �

Notes: 1: For a threshold-acting substance, the most sensitive receptor is deemed to be a 0.6 - 4 year old infant exposed 100% of the time at the site were the soil is being assessed (exposure term = 1.0), except for at an industrial site, where the exposure term is 0.33 rather than 1.0. This exposure pathway is assumed to account for 20% of the entire multi-media exposure for most substances.

2: Shaded cells indicate minimum calculation requirements for adoption of a matrix soil standard, under the CSST protocols.

A key issue at contaminated sites is the depth from the soil surface to which various exposure scenarios (and associated risk-based standards) should apply. This is particularly important for salt-contaminated sites, where historical and large-scale salt releases are often transported downward in higher permeability surface soils, given the high solubility of salt ions in infiltrating rain and snow melt water. The depth at which salt contaminated

10

soils occurs may be much lower than the zone where soil ecological processes are focused at many sites.

Where the salt can be transported from these subsurface soils to either an aquatic-life containing water body or an aquifer from which drinking or irrigation water is drawn, these exposure pathway/receptor combinations are expected to dictate the acceptable soil salt levels from a larger societal and sustainability perspective. Where the affected soils and aquifer does not obviously interact with a receptor organism, however, based on current conditions, there is still an expectation that residual sub-surface contamination should as a minimum be documented and the information should be accessible to all parties during land-transfer, tenancy, and re-development deliberations. This makes it challenging from a regulatory perspective to allow unconditional release of a site following remediation if residual subsurface contamination remains, regardless of the actual environmental risks.

Within British Columbia there has been precedence for the use of a “three meter rule” in consideration of some of the above-mentioned depth issues. For contaminated sites that fall under an agricultural, residential and/or urban parkland designation, application of the generic soil matrix standards at soil depths above three meters is as per the designated or anticipated future land use. For soils at greater depth, however, a remediation standard for commercial and industrial land uses is allowed.

Consideration also needs to be given to the potential for site-specific and cumulative degradation of groundwater quality, even where the affected groundwater is not likely to be used over the short term. Unlike the situation for organic contaminants, there are few mechanisms other than dilution for the loss of chloride or some other salt ions, or conversion to a toxicologically inert form. Several North American cities, including Calgary for example (K. Van Velzen, pers. com.), have begun to re-visit groundwater protection stances, based on expectations of future droughts and water shortages. Overall, soil remediation thresholds in near-surface soils may reasonably be defined based on risk-based limits, while subsurface thresholds have tended to reflect additional policy concerns.

11

3. An Operational Definition of Salt Under the BC CSR

All consulted guidelines for soil salinity standards in other jurisdictions in Canada are based on measures of Electrical Conductivity (EC) and the Sodium Adsorption Ratio (SAR) (Section 4). The Salt Standards Steering Committee agreed on a draft operational definition of “salt” for the purposes of contaminated site investigation and remediation in B.C. that departs substantially from practices in most other jurisdictions. The definition is based on the following conclusions, which in turn were based on review of the available science on salt toxicity and environmental fate.

• It may be possible to manage the environmental risks of road salt releases based on use of sodium or chloride ion or some surrogate thereof. The applicability, however, of a salt matrix standard to sites within BC that are contaminated with either produced water from the oil and gas industry or limited used salt-based dust suppressants suggests that a broader suite of salt ions needs to be considered (see a more detailed analysis, and provided in Addendum D to this report, however).

• Where Na+ and Cl- exist in combination with other salt ions either in a contaminated soil matrix or in water, the existing toxicological knowledge suggests that no single ion uniformly drives toxic responses in different living organisms. On the contrary, environmental risks might be attributed to any of the major cations or anions present – singly or in combination – depending on the organism and the environmental conditions.

• Mixtures of salt ions partition differently in surface and subsurface soils as well as in groundwater and surface water. These variations in environmental fate are important components of predicted risks, especially where a major component of salt risks is expected to be off-site transport via groundwater to surface water bodies containing aquatic life. Surrogate measures of salinity such as conductivity do not capture the differential fate of different salt ions.

• Furthermore, conductivity or other surrogate measures and individual ion concentrations across a range of surface and subsurface soil times are likely to be only weakly related to the concentrations of either individual ions or total molar concentrations of salt ions (see Section 7, below). EC is deemed to be inadequate, therefore, as a predictor of exposures to salt ions, except perhaps as a surrogate where site-specific relationships have been established.

• The quantification of several of the salt ions is required for the calculation of sodium absorption ratio, cation exchange capacity and several other measures that have been used in the past to assess salt impacts to soil ecosystems.

12

It is recommended that, for the purpose of the derivation of BC CSR soil matrix standards, an initial definition of salt should include the individually quantified anions chloride, sulfate, and bicarbonate, as well as the individually quantified cations sodium, potassium, calcium, and magnesium.

Further, it was agreed that –

• The initial focus should be on Na+ and Cl- since these are likely to be the major ions present at contaminated sites, but the possibility of developing standards for other ions should not be excluded, and

• Electrical Conductivity (EC) and Sodium Absorption Ratio (SAR) should not be discounted for inclusion in salt standards (e.g. as screening tools), but these should be subordinate to thresholds based more directly on individual salt ions.

13

4. Relevant Soil, Sediment, and Water Quality Objectives for Salt from Other Jurisdictions

A review was undertaken of the existing soil guidelines for salt in other Canadian and non-Canadian Jurisdictions. An annotated list of guidelines consulted is provided in Appendix C.

The vast majority of published guidelines for salt contamination in soil are based on measures of Electrical Conductivity (EC) and the Sodium Adsorption Ration (SAR) (Appendix C, Tables C1-C5 ). A notable exception is a recent guideline put forward by the Alberta Energy and Utilities Board (AEUB, 1999), which limits the chloride concentration of sand used in roadbed construction to 3000 mg Cl– /kg sand. In general, EC levels (dS/m) ≤ 4 and SAR values of 5-8 would be considered acceptable for most uses. Guidelines for EC in Ontario are lower than in other jurisdictions. Interestingly, only Saskatchewan has guidelines for forested lands.

Guidelines for salt contamination of the water affected by the soils are expressed in terms of the concentration of individual salt ions (Appendix D, Tables D7-D9). An environmental quality guideline for chloride (100-700 mg/L) in irrigation water is provided by CCME (1999), under the BC CSR and the Saskatchewan Guidelines. These three documents, plus the Ontario guidance also include a chloride aesthetic guideline for drinking water (250 mg/L), based on an earlier Health Canada assessment (threshold for unpleasant odors or taste). A guideline for sulphate concentrations in drinking water and for livestock (500 mg/L and 1000 mg/L respectively) is included in the BC CSR, CCME (1999) and Saskatchewan (2000) guidance. More recently, BC MELP (2000) provided a draft water quality guideline for sulphate in drinking water (500 mg/L; aesthetic guideline) and freshwater aquatic life (100 mg/L), with an alert to monitor the health of aquatic mosses at 50 mg/L.

In all four guidelines, the sodium guideline (only available for drinking water; 200 mg/L) is an aesthetic objective. No standards for magnesium or potassium are reported, and the calcium guideline (1000 mg/L) applies to water for livestock only (CCME 1999; BC CSR, 1996).

Nitrate is included in the tables in Appendix C because calcium nitrate is sometimes used to remediate sodic soils. BC CSR standards for nitrate (and nitrate + nitrate) in drinking water are lower than CCME 1999 Guidelines.

14

In light of the fact that EC and SAR have been derived primarily in consideration of effects on agricultural plants, and that much of the existing toxicity data for aquatic life, plants, or other ecological receptors is based on exposures measured as salt ion concentrations, the existing guidelines offer limited assistance toward deriving matrix salt soil standards within British Columbia.

15

5. Important Issues

5.1 Basic Chemistry of Salts in Soil

Salts are ionic compounds formed by the reaction between an acid and a base, and exist in many forms in subsurface environments. Different salts differ considerably in how soluble they are in water, but the commonly used road salts, sodium chloride (NaCl) and calcium chloride (CaCl2) are highly soluble. It is important to realize that once these salts dissolved in soil water, they dissociate into their constituent ions. Thus sodium chloride in soil consists of sodium (Na+) ions and chloride (Cl-) ions. Different ions behave very differently in soil, and the environmental fate of the different ions depends on several interacting processes including anion and cation exchanges processes, adsorption onto mineral and organic particles, and precipitation.

The chloride ion (Cl-), which is formed from the dissociation of chloride salts in water is highly soluble and mobile, does not biodegrade, does not readily precipitate, volatilise, nor does it absorb readily onto mineral surfaces. Thus it is easily transported though soils to enter groundwater and surface water.

Both sodium ion (Na+), and the calcium ion (Ca2+) although highly soluble, tend to adsorb onto negatively charged soil surfaces such as clays and particles of organic matter. The extent of the bonding depends on the cation exchange capacity (CEC) of the soil (which in turn is related to the number to negatively charged sites in soil) and the abundance and identity of other ions in the soil. Thus the fate of these cations is greatly influenced by soil texture and organic matter content. Cations that are not adsorbed or otherwise held in the soil (e.g. by precipitation or complexing) will follow the path of soil water and reach ground or surface water.

High levels of sodium on the cation exchange complex can have serious implications for soil structure. Clay particles carry a negative charge, and thus attract and hold the positively charged cations. Small hydrated ions such as calcium bind closely to the surface of the particles, neutralizing the negative charge and allowing the formation of soil aggregates. Hydrated sodium ions are large, and therefore do not bind closely enough to the surface of the clay particle to neutralize the negative charge effectively, causing the soil particles to repel each other and disperse rather than flocculate. Dispersed soils have greatly impeded drainage, resulting in puddling and erosion, and hindering remediation efforts. The potential for sodium-induced impact on soil structure is particularly high in soils with high a high percentage of sodium on the exchange complex (ESP), a high clay content (especially swelling clays, like

16

montmorillonite), in areas where the soil water has a low concentration of solutes (i.e. low electrical conductivity (EC)). An impact evaluation based on clay content and ESP (Morin et al. 2000) concluded that the susceptibility of BC soils to sodium-induced soil dispersion was low (relative to many other parts of Canada). However, the maps produced in this analysis did show certain areas (e.g. in central and northeastern BC) where the potential for damage was enhanced.

For more information on the chemistry of salt-affected soils please see Bresler et al. (1982 ), or USDA (1954).

5.2 Measurement of Sodium and Chloride Concentrations in Soil

Reported values for the toxicity of sodium chloride in soil, based on laboratory or mesocosm testing, are virtually always based on nominal (spiked) concentrations. Yet it is often difficult to relate these nominal concentrations to what is actually measured in the soil using a variety of extraction and analytical techniques. Furthermore, it is often difficult to relate measured concentrations of salt ions to the levels soil organisms (plants, microbes and invertebrates) are actually being exposed to. The more water that is added to the soil in order to extract the salt ions, the more salt ions are likely to be extracted, but the less realistically the sample reflects the concentrations of ions experienced by soil biota. In addition, as more water is used to extract the ions from the soil, there is an increasing chance that cation exchange and dissolution of slightly soluble minerals (e.g. CaCO3 and CaSO4ּ2H2O) will produce misleading results (Bresler et al. 1982).

In order to establish a common basis for comparing potential for biological responses in different soils, it has become standard procedure is to carry out chemical analyses on the water filtered from a saturated paste of the soil (Carter 1993; Alberta Environment 2001). This method involves adding just enough water to saturate the soil, and the actual amount of water added, therefore, depends on the soil type. A coarse-textured soil will require less water than a heavy clay soil. This method incorporates the theoretical knowledge that in a coarse, sandy soil, the salt ions will be concentrated in a smaller volume of water than if the same number of ions were present in a fine textured soil with a higher water holding capacity. Considerable research has shown that salt ions or electrical conductivity measured in a saturated paste extract of soils show a good relationship with the magnitude of biological response, at least for plants (Bresler et al. 1982).

17

Previous studies investigating the toxicity of NaCl to earthworms and plants (Moul, 2001) and KCl toxicity to soil invertebrates (Aquaterra, 1998a and b) used soil/water extracts for determining salt ion concentrations. In both cases, there were difficulties in encountered in relating nominal to measured concentrations. For the Aquaterra studies, considerably less than half of the spiked KCl was accounted for in measured concentrations for the majority of trials. Moul (2001) reported that measured concentrations of sodium and chloride ions exceeded the actual nominal concentrations in several instances, and there was no statistically significant relationship between nominal and measured concentration. These variable results occurred even though both studies used the same soil (the standardized OECD artificial soil).

In the present study, we investigated whether the use of the saturated paste method would improve the reliability and predictability of determining Na+ and Cl- concentrations in different soils, given the experience from previous research efforts. A limited study to explore the relationship between recoveries of these ions in soil/water extract versus saturated paste was undertaken, since it was recognised that much of the pre-existing field data for preliminary and detailed site investigations of soil salt contamination was obtained using constant ratio soil/water extracts.

Four different soils were included in this study; the standard OECD soil (OECD 1984) and three field-collected soils (Scotch Creek, Clinton and Saanichton). The OECD soil is an artificial, soil used in standardised tests to determine toxicity of contaminants to soil invertebrates. However, since it is an artificial construct, there are serious reservations concerning the relevance of results obtained in this medium to field situations. Thus the present study also included three soils obtained from different areas in BC. The Clinton and Scotch Creek soils were provided by BC-MOTH as examples of soils that were subject to contamination from road salt storage sites in central BC (an area that was expected to be more susceptible to road salt damage than other areas in BC). The Saanichton soil was used as an example of a soil that was highly productive, with a much higher CEC, but with the lower natural pH characteristic of many soils in BC. Unfortunately, it was beyond the scope of this study to include more than a limited number of soils.

A summary of the physical and chemical properties of these soil is given in Table 5.1.

18

Table 5.1: Physico-chemical characteristics of the test soils.

Parameter OECD #3 OECD #4 Saanichton Scotch Creek Clinton % C 2.89 3.75 5.7 0.76 1.51 % Nitrogen 0.06 0.08 0.32 0.04 0.06 % Saturation 84 96 64 22 19 pH 6.1 5.8 4.9 7.6 7.8 EC (dS/m) 0.35 0.32 0.43 0.43 0.99 SAR 0.4 0.3 0.4 0.4 3.6 Cation Exchange Capacity (CEC) (Cmol+/kg)

10.69 15.39 17.28 5.55 8.03

Exchangeable sodium (Cmol+/kg)

0.05 0.08 0.11 0.05 0.36

Sodium (mg/kg) 9.66 8.45 6.85 2.42 22.25 Potassium (mg/kg) 2.81 3.20 9.15 0.61 2.95 Magnesium (mg/kg) 5.63 6.07 5.90 0.83 2.45 Calcium (mg/kg) 36.71 37.82 24.70 14.04 10.96 Chloride (mg/kg) 12.94 14.11 13.44 3.85 2.60 Sulphate (mg/kg) 66.65 68.91 7.70 1.79 1.98 Bicarbonate (mg/kg) 11.17 13.06 11.14 8.21 12.31 Nitrate (mg/kg) 30.91 34.56 85.70 10.71 32.22 Soil Texture NA NA Silt Loam Sandy Loam Sandy Loam % sand 23.2 65.5 57.4 % silt 60 29.1 34.8 % clay 16.8 5.4 7.6

NOTE: All concentrations expressed per /kg oven dry wt. soil

19

5.2.1 Sodium and Chloride in Saturated Paste

Simple linear regression analysis was conducted, using Systat® 6.0, to evaluate the predictive value of nominal versus measured (saturated paste) concentration. Nominal NaCl concentrations in soil in all cases were as follows: 0, 560, 1000, 1800, 3200, 5600, 10000 mg/kg NaCl. In all cases, the model was first run with inclusion of a y-intercept term. In no case was the intercept significantly greater than zero. While there are undoubtedly naturally-occurring concentrations of extractable salt ions in the soils used, the small amount measured for soils in which no NaCl was added did not provide much influence on the overall best least-squares linear fit. The regression model used therefore was as follows:

Measured ion conc. = slope x nominal (spiked) ion conc. (1)

The slope, therefore, is a direct estimate of the proportion of the ion recovered during extraction and analysis. In all cases, there was a very good ability to predict the actual measured concentration from nominal concentration (Table 5.2).

On average, 87% of the added chloride concentration was recovered using a saturated paste procedure (range of 75 to 96% across soil types and various experiments). Similarly, in saturated paste solutions, 68% of sodium on average was recovered relative to the amount added (range = 60 to 80%).

The average of the recoveries by saturated paste for sodium and chloride ion was used to convert plant and soil invertebrate toxicity endpoints from a nominal concentration to a saturated paste equivalent concentration (Section 6.2.2).

20

Table 5.1: Regression (Least Squares) Estimates of Nominal (Added) Versus Measured Salt Ion Concentrations

Soil Type and experiment Slope of Line (measured versus

nominal)

R2 n

1) Chloride by saturated paste/ suppressed and non-suppressed HPLC/ion chromatography OECD #3-1 0.835 0.998 7 OECD #3-2 0.951 0.999 7 OECD #3-3 0.921 0.999 7 OECD #4 0.678 0.933 8 Saanichton 0.954 0.999 7 Scotch Creek 0.924 0.997 7 Clinton Creek #1 0.961 0.999 7 Clinton Creek #2 0.746 0.994 7

Average Recovery – all tests 0.871 (87%)

2) Sodium by saturated paste and ICP OECD #3-1 0.610 0.998 7 OECD #3-2 0.720 0.993 7 OECD # 3-3 0.682 0.992 7 OECD #4 0.601 0.967 7 Saanichton 0.803 0.999 7 Scotch Creek 0.704 0.998 7 Clinton Creek #1 0.599 0.999 7 Clinton Creek #2 0.686 0.997 7

Average Recovery – all tests 0.675 (68%)

5.2.2 Comparison of Saturated Paste versus Fixed-Ratio Water:Soil Extract Methods in OECD Soil

Samples of OECD soil spiked with different amounts of NaCl were divided in half, and analyses were conducted on one portion using the saturated paste method and on the other using a fixed-ratio soil:water extract (2:1 or 5:1). Two different batches of OECD soil were analysed, and two different laboratories participated in the study. Linear regression relating nominal and measured concentrations of Na+ and Cl- were carried out as described above. Thus the slope of the line can be taken as the proportion of the ion recovered.

21

Table 5.2: Comparison of Recovery of Sodium and Chloride Ins in Saturated Paste versus Fixed-ratio Soil:Water Extracts in OECD Soil Samples

Soil Saturated Paste (SP) or Soil Extract (SE)

Laboratory Slope of Line (measured versus

nominal)

R2 n

1) Chloride OECD #3 SP MoF 0.892 0.998 7 OECD #3 SP Norwest 0.618 0.958 7 OECD #3 SE soil 1: water 2 Norwest 0.930 0.960 7

OECD #4 SP MoF 0.732 0.924 7 OECD #4 SE soil 1: water 5 MoF 1.009 0.991 7

2) Sodium OECD #3 SP MoF 0.621 0.993 7 OECD #3 SP Norwest 0.644 0.993 7 OECD #3 SE soil 1: water 2 Norwest 0.898 0.956 7

OECD #4 SP MoF 0.621 0.965 7 OECD #4 SE soil 1: water 5 MoF 0.896 0.999 7

There was a very strong linear relationship (high R2) between measured and nominal concentrations of these ions in a soil/water extract over a larger range of concentrations (0 -10,000 mg NaCl/kg). A larger proportion of both ions tended to be recovered in the soil water extracts than in the saturated pastes. This was particularly evident for Na+, where ~90% of the added Na+ was recovered in fixed-ratio soil:water extracts, compared with ~60% in the saturated paste. This phenomenon is in accordance with other studies that have shown that increasing the amount of water used to extract salt ions almost invariably increases values obtained for total salt content (USDA, 1954).

Thus in this limited study, the data from soil water extracts produced values closer to the actual amounts of Na+ and Cl- added to the soils than did the saturated pastes. Yet Moul (2000), working with the same type of soil, recovered levels of metal and chloride ions in excess of what was added, and in addition found an inconsistent relationship between nominal and measured concentrations of ions. On the other hand, Aquaterra (1998a and b), also working with the OECD soil, recovered far less K+ and Cl- than was added to the soil (<50% K+ and ~20% Cl-).

22

5.2.3 Recommended Protocols to Determine Levels of Salt Ions in Soil.

The saturated paste method is an internationally recognised method for determination soil salinity, and there would need to be very good reason for proposing the official adoption of an alternative. In our study, the saturated paste method gave good, predictable recovery of the test ions over a range of soil types. Although, the soil /water extract gave excellent recovery of both Na+ and Cl- in the one soil (OECD) that was tested, its applicability to other soils was not investigated. Results based on fixed-ratio soil:water extracts are known to differ according to the amount of water added and – especially at higher moisture contents – introduce inaccuracies due to changes in hydrolysis and cation exchange.

It is also recognized that the saturated paste method has been adopted into regulatory guidance in various other jurisdictions, including Alberta and Saskatchewan, and is amenable to the calculation of various derivative measures such as sodium adsorption ratio (SAR) and cation exchange capacity (CEC). The adoption of a saturated paste methods, therefore, is also important from the perspective of regulatory harmonization within Canada.

Based on the available information, it is recommended that saturated paste be used for determining salt ions in soil.

In view of the fact that toxicity endpoints are generally based on nominal values, and saturated paste methods underestimate the concentrations of sodium and chloride in the soil, it is further recommended that:

The average of the recoveries by saturated paste for sodium and chloride ion be used to convert plant and soil invertebrate toxicity endpoints from a nominal concentration to a saturated paste equivalent concentration.

Measures of soil salinity based on techniques or surrogate measures other than ion-specific measurement using a saturated paste extract are, nonetheless, likely to be an important aspect of site investigation and remediation efforts. There is provision within the framework of the BC CSR to allow for performance-based measures in key areas. In the case of salt measures in soils, measures such as fixed-ratio soil:water extract measurements or electrical conductivity measured in either a saturated paste or fixed-ratio soil:water extract can be confidently related to a saturated paste salt ion concentration, provided that a sufficiently representative number and type soil samples have first been analyzed using both the less labour

23

intensive or less costly surrogate technique and the saturated paste techniques, and there is a clearly defined mathematical relationship between the favoured and the officially endorsed (saturated paste) technique.

Because the ratio of total salt ions present in soil or saturated paste extractable salt ions and fixed-ratio extract salt ions has been demonstrated to vary across soil types, those wishing to use alternatives to a saturated paste technique would need to demonstrate the relationship between the saturated paste and alternative salinity measurements in each major soil type at a given site. Generally, this would require the analysis of at least seven to eight soil samples from each soil type, as a basis for regression analysis. It should be expected, furthermore, that different soil types will be encountered at both different locations across any site, as well as at different soil depths.

As discussed above, fixed-ratio soil:water extraction procedures are likely to over-estimate salt ion concentrations relative to saturated paste methods. Those parties using alternative analytical techniques, therefore, are expected to either be able to confidently convert to saturated-paste equivalent values when reporting salt ion concentrations, or to confidently demonstrate that the alternative technique is a “worst-case” concentration relative to a saturated paste concentration.

5.3 Relationship Between Salt Ions and Electrical Conductivity in Soil

The literature contains a variety of predictive equations for the relationship between electrical conductivity and various salt ions in a saturated paste extract (Morin et al., 2000; Bresler et al., 1982). In fact, several jurisdictions provide remediation guidelines for contaminated soils that are based on measures of electrical conductivity (Appendix C). Bright and Addison (2000) expressed concerns about the robustness of such relationships across various soil types and soil depths, given the differences in expected fate of anions such as chloride and salt cations in soil systems. In light of the above, it was deemed important to establish the interrelationships between concentrations of salt ions and electrical conductivity in the different test soils.

Electrical conductivity was measured in the same saturated paste extracts as the sodium and chloride ions. The mathematical relationship between the amounts of NaCl added (nominal concentrations) and the EC of the saturated paste extracts of the test soils is shown in Table 5.3. For the purpose of these analyses, the data from both Clinton soil experiments were combined to produce a single regression relating nominal and measured concentration in

24

this soil type. Similarly, data from five experiments in the OECD soil were considered together.

Table 5.3: Relationship Between Electrical Conductivity and Nominal Concentrations of NaCl (mg/kg) in Different Experimental Soils.

Soil Regression R2 N

OECD EC(dS/m) = 0.0014 NaCl + 0.598 0.978 35

Scotch Creek EC(dS/m) = 0.0068 NaCl - 0.652 0.979 7

Clinton EC(dS/m) = 0.0070 NaCl + 2.32 0.978 14

Saanichton EC(dS/m) = 0.0025 NaCl + 1.12 0.997 7

For any given soil type, the electrical conductivity was strongly correlated with the amount of NaCl added to the soil (nominal concentration) (r2 ≥ 0.98). The relationship, however, was highly variable across soil types (Figure 5.1).

For the two sandy loam soils (Scotch Creek and Clinton) – both of which had low amounts of clay, organic matter or carbonate minerals – electrical conductivity increased rapidly with increasing amounts of NaCl. At the other end of the spectrum, electrical conductivity in the OECD soil was far less sensitive to increasing amounts of a salt. Thus the amount of salt that will produce a given measurement of electrical conductivity varies considerably depending on the soil (Table 5.4). In order to produce an electrical conductivity of 4 dS/m in the OECD soil, for example, it would be necessary to add ten times as much NaCl as in the Clinton soil (2,430 mg NaCl /kg as compared with 240 mg NaCl /kg).

25

0

10

20

30

40

50

60

70

80

0 2000 4000 6000 8000 10000

Nominal NaCl (mg/kg)

EC (d

S/m

)OECDClintonScotch CrSaanichton

Figure 5.1: Relationship Between Electrical Conductivity and Nominal Concentrations of NaCl in Four Experimental Soils.

Table 5.4: Comparison of the Amounts of NaCl (mg/kg) Required to Produce Specific Values of Electrical Conductivity in Different Soils.

Amount of additional NaCl (mg/kg) EC (dS/m)

OECD Soil Clinton Scotch Creek Saanichton 2 1,000 0 457 354 4 2,430 240 802 2,750 8 5,290 812 1,490 1,150 12 8,140 1,380 2,180 4,350

Using the derived relationship between nominal concentrations of NaCl and EC in the different soils, it is possible to predict the electrical conductivity that would result from the addition of different quantities of NaCl to the soil (Table 5.5). If the threshold value of 400 mg Cl-/kg (nominal-EC50 value for plant toxicity), for example, were applied to the different soils, the associated electrical conductivity values that could be expected would range from 1.6 (OECD soil) to 7.2 (Clinton soil). On the other hand, 2900 mg Cl-/kg , the LC20

26

threshold based on soil invertebrates, translates into electrical conductivity values of between 7.2 and 35, depending on the soil type.

Table 5.5: Predicted Values of Electrical Conductivity for Different Soils in Response to Contamination with NaCl

Nominal concentrations (mg/kg)

Electrical Conductivity dS/m (predicted)

NaCl Na+ Cl- OECD Clinton Scotch Creek Saanichton

500 200 300 1.3 5.8 2.7 2.4 700 300 400 1.6 7.2 4.1 2.9 1000 400 600 2.0 9.3 6.1 3.6 2000 800 1200 3.4 16 13 6.1 4000 1600 2400 6.2 30 27 11 4700 1800 2900 7.2 35 31 13 6000 2400 3600 9.0 44 40 16

The importance of soil texture in determining electrical conductivity for a given concentration of salt is well documented in the literature (US Soil Salinity Laboratory). Saturation percentage (the weight of water added to 100 g dry soil to produce a saturated paste) can be used to predict how the soil will respond to the addition of salt (USDA, 1954)

27

28

6. Detailed Risk-Based Calculations

6.1 Human Health Protective Standards

6.1.1 Detailed Calculations

The following addresses the development of a Soil Quality Matrix Standard for Salt using procedures outlined in “Overview of CSST Procedures for the Derivation of Soil Quality Matrix Standards for Contaminated Sites” January 31, 1996.

For threshold-acting substances, the derivation of a soil standard for the protection of humans is based on the following equation (BCE, 1996 – Exhibit 9A, p. 30):

( ) ( ) ( )[ ]ETSR AFDR AFIR AFBW TDI SAF SQS

SDIHH ××+×+×

××= (2)

where,

SQSHH = Daily Intake (DI)-based soil quality standard (mg/kg) SAF = soil allocation factor (default = 20%) TDI = tolerable daily intake (mg/kg bw/day)

BW = body weight (default = 13 kg; 0.6 to 4 year age class)

AFI = absorption factor for gut (default = 100%)

IR = soil ingestion rate (CSST default = 80 mg soil/d; 0.4 to 6 year age class for all land uses)

AFD = absorption factor of lung (default = 100%) DR = soil inhalation rate (default 0 kg/day) AFS = absorption factor for skin (default = 100%) SR = soil dermal contact rate (default = 0 kg/day)

ET = exposure term (default = 0.33 commercial; 1.0 for Agricultural, Residential/Urban Parkland, Industrial)

Although this equation includes parameters for multimedia exposure, ‘currently only the direct soil ingestion route in used to derive standards’ (BCE, 1996).

29

Based on CSST policy decisions (BCE, 1996) equation (1) simplifies to:

ET IR AFBW TDI SAF SQS

IHH ××

××= (3)

If published Health Canada data for both background estimated daily intake (EDI) and National generic background soil concentrations are available, however, the following equation is used to derive an additional value, PSQNHH(EDI)

( )( ) [ ]

( ) ET IR AFBSC BW SAFEDI – TDI SQS

IEDIHH ××

+××= (4)

where,

SQSHH(EDI) = human health EDI-based soil quality standard (mg/kg)

EDI = estimated daily intake (mg/kg bw/day)

BSC = national generic background soil concentration (mg/kg)

CSST noted that ‘for all substances for which matrix standards have been calculated to date, there are either no published Health Canada EDIs or background soil concentrations which would enable calculation of the PSQNHH(EDI).’ Furthermore, CSST state that ‘the final “Intake of contaminated soil” standard should be based on the “more reasonable” of the two preliminary values’.

The adjustment of acceptable dose based on intake from soil using an EDI-based approach is challenging for salt ions. The major portion of background intake is likely to be through the diet, and is expected to be highly variable between individuals, age groups, and sub-populations. A residual TDI (or RTDI, equal to the TDI minus the estimated daily intake) was not used herein for salt ions, therefore.

6.1.1.1 Calculation of SQSHH

Given the stipulation that a SQSHH(EDI) is calculated only for substances having both a Health Canada published EDI and generic background

30

concentration, the matrix standard for soil consumption was calculated using the simplified equation (2).

ET IR AFBW TDI SAF SQS

IHH ××

××= (5)

where,

SQSHH = preliminary human health TDI-based soil quality standard (mg/kg)

SAF = soil allocation factor (default = 20%) TDI = tolerable daily intake (mg/kg bw/day) (see below)

BW = body weight (default = 13 kg; 0.6 to 4 year age class)

AFI = absorption factor for gut (default = 100%) IR = soil ingestion rate (default = 0.00008 kg/d)

ET = exposure term (default = 0.33 commercial; 1.0 for Agricultural, Residential/Urban Parkland, Industrial)

Soil Allocation Factor (SAF)

The Soil Allocation Factor is the term used in the equation for threshold-acting substances to apportion a fraction of the TDI to exposure from soil. CSST recognizes that humans could be exposed to chemicals through media other than soil; i.e., via food, air, water, dermal contact, and/or consumer products. If the SQSHH were calculated using the entire TDI, humans could be exposed to the same chemical through other media resulting, theoretically, in a total exposure greater than the TDI. In order to accommodate multimedia exposure, CSST recommended that 20% of the total TDI for threshold substances be allotted to soil.

Tolerable Daily Intake (TDI)

There is no officially recommended threshold for either sodium ion or chloride ion for the protection of human health in either Canada or the United States. According to the World Health Organization (WHO, 1993) –

31

“Sodium salts (e.g., sodium chloride) are found in virtually all food (the main source of daily exposure) and drinking-water. Although concentrations of sodium in potable water are typically less than 20 mg/litre, they can greatly exceed this in some countries. The levels of sodium salts in air are normally low in relation to those in food or water. It should be noted that some water softeners can add significantly to the sodium content of drinking-water.

No firm conclusions can be drawn concerning the possible association between sodium in drinking-water and the occurrence of hypertension. Therefore, no health-based guideline value is proposed. However, concentrations in excess of 200 mg/litre may give rise to unacceptable taste.”

There is a hypothesized association between decreased sodium ingestion and lower blood pressure on the one hand, and lower blood pressure and decreased risks of cardiovascular disease on the other hand. Other factors leading to renal failure may be implicated in a subset of hypertensive individuals. WHO (1995) stated that “hypertension is a massive health problem affecting about 20% of the adult population in most countries, and is one of the major risk factors for death from cardiovascular disease”. Furthermore, excess consumption of salt was identified by the WHO as a major risk factor for hypertension.

The World Health Organization International Society of Hypertension Guidlines for the Management of Hypertension (Chalmers et al., 1999), stated -

“Reduction in salt intake

Epidemiologic studies suggest that dietary salt intake is a contributor to blood pressure elevation and to the prevalence of hypertension (Law, 1997). The effect appears to be enhanced by a low dietary intake of potassium containing foods. Randomised controlled trials in hypertensive patients indicate that reducing sodium intake by 80-100 mmol (4.7-5.8 gm) per day from an initial intake of around 180 mmol (10.5 gm) per day will reduce blood pressure by an average of around 4-6 mmHg systolic (Cutler et al., 1997). However, individuals vary considerably in their responses to changes in dietary salt, with black, obese and elderly subjects the most sensitive. A recent study in older hypertensive patients showed no adverse effects of a reduction in sodium of 40 mmol (2.3 gm) per day and after 18 months there was a significant reduction in the need for antihypertensive drug therapy

32

(Whelton et al., 1998). The aim of dietary sodium reduction should be to achieve an intake of less than 100 mmol (5.8 gm) per day of sodium or less than 6 gm per day of sodium chloride. Patients should be advised to avoid added salt, to avoid obviously salted foods, particularly processed foods, and to eat more meals cooked directly from natural ingredients. Counselling by trained dieticians and monitoring of urinary sodium are necessary in most cases. The high sodium – low potassium content of many preserved foods is drawn to the attention of the food industry.’

Regulators and medical professionals have been unable to come to a consensus on dietary sodium levels that represent a safe threshold for heart disease. In the absence of formal guidance, an upper limit for sodium ingestion for people on salt restricted diets as recommended by some physicians is around 2,400 mg/day sodium. Note that this is identical to the WHO recommended dietary intake of less than 6.0 g of NaCl (6,000 mg/day NaCl = 2,400 mg Na+/day plus 3,600 mg Cl-/day) as documented by Chalmers et al. (1999).

Individuals suffering from hypertension, or potentially from other salt related health effects, are considered to be among the more sensitive members of the population. A TDI for sodium of 2,500 mg/day was used, therefore. Note that recommended upper limits for dietary salt ion intake have routinely been expressed on a whole body weight basis, rather than on a dose/kg basis.

Body Weight (BW)

CSST recommended the use of a child receptor (0.6 to 4 years) for all land uses when developing SQSHH for threshold-acting substances. The default body weight for a child is 13 kg. Since the sodium TDI of 2,500 mg/day is not expressed based on dose/body weight, however, there is no need to make assumptions regarding the body weight of surrogate receptor groups.

Absorption Factor (AFI)

CSST recommended the assumption of 100% absorption ‘unless verifiable scientific data indicate otherwise’. For salt, an assumed absorption factor of 100% is a very reasonable estimate.

33

Ingestion Rate (IR)

The soil ingestion rate of 80 mg/day is used as per CSST’s assumption of a child receptor (0.6 to 4 year age class) for all land uses.

Exposure Term (ET)

CSST define the ET as a ratio of the assumed exposure period for any given land use versus the maximum possible lifetime exposure period. For a commercial land use and a threshold chemical, the ET is calculated as:

(unitless) 0.33 yr3.5 yr3.5

wk52 wk48

d 7d 5

hr 24hr 12 =×××

For all other land uses, a threshold chemical, the ET is calculated as:

(unitless) 01 yr3.5 yr3.5

wk52 wk52

d 7d 7

hr 24hr 24 .=×××

Using the assumed values discussed above, the SQSHH for sodium, for a Commercial Land Use can be calculated:

soil /kgNa kg 18.2 soil kg

Na mg10 1.82

0.33 day

soil kg 0.00008 1.0

dayNa mg 2,400 0.2

SQS

7

HH

+

+

+

=

×=

××

×=

Since this is an impossible value (it exceeds unity), it is concluded that it is not possible to approach or exceed dietary health limits for sodium through the ingestion of salt-contaminated soil, assuming a toddler ingestion rate of 80 mg soil/day (0.00008 kg/d) or lower.

34

For an Agricultural, Residential/Urban Parkland, or Industrial Land Use:

soil /kgNa kg 6 soil kg

Na mg10 6.00

1.0 day

soil kg 0.00008 1.0

dayNa mg 2,400 0.2

SQS

6

HH

+

+

+

=

×=

××

×=

00.

Since this is also an impossible value, it is concluded that it is not possible to approach or exceed dietary health limits for sodium through the ingestion of salt-contaminated soil, assuming a toddler ingestion rate of 80 mg soil/day (0.00008 kg/day) or lower.

Note that the calculated soil concentration would have exceeded a concentration equivalent to 100% salt even if the provisional Tolerable Daily Intake had been established at a concentration that was six times lower than the assumed 2,400 mg Na+/day for agricultural or residential/parkland lands or 18 times lower for commercial and industrial lands (i.e., 400 mg Na+/day and 132 mg Na+/day, respectively). Therefore, while debate will undoubtedly continue on ‘safe’ levels of sodium intake by humans, any change in perceptions about safe levels are unlikely to change the conclusion that human ingestion of sodium in salt affected soils is not a viable pathway for human health risks.

In light of the preceding analysis, the provisional soil standard for human health based on the ingestion of soil is set at >1 x 106mg Na+/kg soil, for all land uses.

There is no known connection between ingestion or other exposure rates for chloride ion and impaired health in human beings, or in surrogate animal species. Chloride is not deemed, therefore to be a human toxicant, or contaminant of concern in soil from a human health perspective. If, however, it is accepted that a dietary intake of 6,000 mg NaCl/day is a safe threshold for protection against hypertensive conditions in humans, and subsidiary effects, then a soil threshold of chloride can be calculated based on its presence simply as a companion ion to sodium in salt-affected soils.

35

Using a chloride maximum dietary intake value of 3,600 mg Cl-/day, based on the assumed values discussed above (human health threshold of 6 g NaCl/day), the companion ion SQSHH for chloride, for a Commercial Land Use can be calculated:

soil /kgCl kg 27 soil kg

Cl mg10 2.7

0.33 day

soil kg 0.00008 1.0

dayCl mg 3,600 0.2

SQS

–7

HH

−

−

=

×=

××

×=

For an Agricultural, Residential/Urban Parkland, or Industrial Land Use:

soil /kgCl kg 9.0 soil kg

Cl mg10 9.0

1.0 day

soil kg 0.00008 1.0

dayCl mg 2,500 0.2

SQS

6

HH

−

−

−

=

×=

××

×=

As for sodium, these are impossible values since they exceed unity.

The chloride provisional soil standard for human health based on the ingestion of soil, and based on the presence of chloride as a companion ion with no other direct human health implications, is set at >1 x 106mg Cl–/kg soil, for all land uses.

36

6.2 Ecological Effects Soil Quality Standards – Direct Pathways

6.2.1 Soil Nutrient Cycling

The CCME and CSST procedures both contain provisions for considering levels of soil contamination above which the growth, productivity, and/or metabolic functioning of soil microbes may be impaired. Soil microbes are recognized to play an important role in nutrient cycling and energy cycling and a large suite of geochemical and biochemical processes that are fundamentally important to terrestrial ecosystems.

According to BCE (1996; p. 12), –

“As a matter of policy, CSST decided to ensure additional protection for microbial functional processes in agricultural soils. In consequence, CSST has recommended simple adoption of the CCME “major microbial function check” criterion as the “Major microbial functional impairment standard. The reader is referred to the CCME Protocol document...”

A Soil Nutrient Cycling threshold for salt ions in soil has not been calculated as part of the derivation. The supporting literature is too sparse to allow a confident assessment of links between individual ions, chemical interactions between them in soils, and impairment of ecologically relevant microbial productivity.

6.2.2 Direct Exposure by Soil Invertebrates and Plants

A soil standard based on toxicity to soil invertebrates and plants is applicable to all land use scenarios under the BC CSR. This exposure scenario is one of two that must be assessed as a minimum for adoption of a new matrix standard (the other being a human health protective soil standard).

CSST and CCME (Canadian Council of Ministers of the Environment) protocols for deriving soil thresholds protective of soil invertebrates and plants differ substantially. The CCME procedure uses all data regardless of the toxicity endpoint used (excluding those of doubtful ecological relevance) and specifies a soil concentration based on the 25th percentile of the ranked concentration data for which an effect was documented.

37

The CSST protocol for the calculation of standards based on direct soil contact specify that the available toxicity data for soil invertebrates and plants be subdivided according to whether the measured effect was mortality or some other ecologically relevant, but non-lethal response. NOEC and LOEC-type endpoints are not used. Instead, LCx and ECx data are used to derive a standard (where ‘x’ is the percent response relative to controls). Further, existing CSST protocols specify that soil invertebrate and plant toxicity data be grouped together, and that a probability distribution-type approach be used to define policy-based concentrations in thresholds that are generically associated with a pre-determined level of ecological impairment. The CSST approach calls for the use a linear regression approach for each of (i) the effects data other than mortality, and (ii) the lethality data, to derive quantitative estimates of the multi-species EC50-NL (non-lethal) and LC20, respectively. Soil standards derived using the linear regression procedures are considered to be acceptable when the regression correlation co-efficient ‘r’ is greater than 0.25. The CSST policy does not make specific reference to other aspects of data distribution that may undermine predictive power of the regression approach, such as heteroscedasticity, or other non-random residual variation.

The CSST procedure for this exposure scenario was originally derived in consideration of the fact that there is often very little available toxicological data for either soil invertebrates or plants for a specific substance (see also Gaudet et al. 2001), and that the reported toxicity data in the published literature is not typically standardized around a specific range of response (for example – an EC50 or LC20)2.

A few recent exercises for the development of soil quality benchmarks have included adequate resources to develop new toxicity data and/or been based on sufficient existing information that adequate data are available for five or more individual species, reported as both an EC50-NL and an LC20. In these instances, the CSST (or CCME) procedure may not be appropriate. The pre-screening of the effects level around a 20% or 50% response level removes any variance in the response variable, and estimation of the probabilistic relationship between soil concentration and response level is not possible. On the other hand, information on the variation in soil concentrations associated with a standardized level of response was observed in different species allows a direct estimate of the species sensitivity distribution to the toxicant.

2 This tends to be less true for aquatic toxicity data, however, for which experimental and reporting protocols have been standardized for a much longer time period than for terrestrial toxicity testing.

38

The procedures used herein for deriving soil matrix standards for salt ions based on direct soil contact respect CSST guidance in that a probability distribution approach is used. Further, as per CSST policy, the matrix standard for agricultural, residential and urban parkland areas is set at the lower of the LC20 and EC50-NL response levels. For commercial and industrial land-uses, the matrix standard is set at the higher of the LC20 and EC50-NL response levels.

Because the available data allow for the estimation of the population of either LC20 or EC50-NL soil concentrations across a variety of species, the 25th percentile of the LC20 or EC50-NL was chosen as an assumed environmentally protective threshold across a variety of taxa that might be present at any given site3.

This further suggests that more sensitive taxa may not be uniformly protected in all situations. It is intended, however, that sufficient numbers and types of soil invertebrates and plants are capable of surviving and reproducing in the affected soil such that a minimum overall level of ecological functioning is maintained (for example, as might be measured as primary and secondary production, energy flow, decomposition, carbon cycling, or macronutrient and micronutrient cycling).

Finally, the following analysis includes a separate consideration of soil invertebrates and plants, since the underlying toxicological mechanisms and salt ions responsible are likely to be very different for these two groups. An underlying assumption is that the maintenance of a healthy soil invertebrate community is important over the longer term for the maintenance of functioning plant communities.

The soil matrix standard for the protection of soil invertebrates and plants for agricultural and residential/parkland sites, therefore, has been established as the concentration that is minimally protective of the more sensitive of soil invertebrates and plants.

3 The procedure used herein departs slightly from both the CCME (1996) and CSST (1996) derivation procedures. The procedure, however, is very similar to was used in the recent development of Canada-Wide Standards for Petroleum Hydrocarbons for agricultural and residential/parkland land uses.

39

6.2.2.1 Soil Invertebrate Studies

There are no existing soil quality guidelines for the protection of soil invertebrates for any of the salt ions under consideration. In addition, the lack of published information on the effects of road salt on soil invertebrates was clearly identified as a significant data gap in the CEPA PSLII road salt assessment (2001). Additional toxicology testing of soil invertebrates has been carried out as part of the present study, and details will be presented in a separate report (Addison and Bright, in preparation). A summary of the results of the present study, as well as other values derived from the published literature are shown in Appendix B-1.

Overall, the results indicate that the tested soil invertebrate species were able to tolerate relatively high levels of NaCl in the soil (> 5,000 mg/kg) over the short-term (7-14 days), especially in soils that contain high levels of organic matter and clay. This is not unexpected as soil invertebrates have a number of physiological and behavioural adaptations to survive periods of osmotic stress and drought (Wittveen et al. 1987; Hopkin 1997). It should be noted that for one of the test species (Protaphorura armata), the LC20 was not achieved even at the highest test concentration of NaCl (15,000 mg/kg).

Soil invertebrates were most susceptible to NaCl in the otherwise uncontaminated sandy field soils collected from the Clinton and Scotch Creek highways maintenance yards, both of which had low amounts of organic carbon (< 0.4%), low clay contents (~ 5%) and a low Water Holding Capacity (WHC; ~ 25% in both soils). Thus toxicity values derived from the Clinton and Scotch Creek soils are expected to provide the “worst-case” scenarios, where the contaminating NaCl is dissolved in small amounts of water, and the potential for Na+ to be bound to soil organic matter or clay particles is minimal. Since soil moisture content has been shown to be a significant factor in determining availability and toxicity of soil pollutants (Crouau et al., 1999, Løkke and van Gestel, 1998) tests on the Clinton soil were carried out at two different moisture levels (60% and 40% WHC).

The laboratory data have been used to construct preliminary species sensitivity distributions based on mortality (LCx: mostly LC20 data) and EC50 NL endpoints (Figure 6.1). Since the data set includes the effects of NaCl in different soil types and different moisture contents, the data presents a broad picture of the range of responses that can be expected.

40

Figure 6.1: Soil Invertebrate Species Sensitivity Distribution to NaCl (mg/kg) Based on Laboratory Toxicity Test Data

Table 6.1 shows the relationship between nominal levels of NaCl in the soil, and the predicted percentage of invertebrate species demonstrating lethal (LCx) or non-lethal (EC50) effects.

Mortality EndpointsLC20n=12; r-sq. = 0.97; p < 0.001

Effects Endpoints(non-lethal) EC50n=12; r-sq. = 0.94; p < 0.001

1000 100005

10

20

30

405060

70

80

90

95

Perc

ent o

f Spe

cies

Sen

sitiv

ity D

istri

butio

n

[NaCl] (mg/kg - nominal)1000 10000

5

10

20

30

405060

70

80

90

95

Perc

ent o

f Spe

cies

Sen

sitiv

ity D

istri

butio

n

[NaCl] (mg/kg - nominal)

41

Table 6.1: Relationship Between Percent of Soil invertebrate Species Potentially Affected and Soil NaCl Concentration (Nominal)

Percent of Species Sensitivity Distribution

Predicted Soil Conc. of NaCl (mg/kg soil) Corresponding to Effect Type and Level

LC20 EC50 5 3,200 660

10 3,500 770 15 3,900 890 20 4,300 1,000 25 4,700 1,200 30 5,200 1,400 35 5,700 1,600 40 6,300 1,900 45 6,900 2,200 50 7,600 2,500 55 8,300 2,900 60 9,200 3,400 65 10,000 4,000 70 11,000 4,600 75 12,000 5,300 80 13,000 6,100 85 15,000 7,200 90 16,000 8,300

A review of the literature identified several field studies on the environmental effects of NaCl (Table B-1 Other supplemental data). While it is not possible to use these data directly in calculating a thresholds effects concentration, these studies provide evidence that the protective levels suggested above are not unrealistic.

The toxicity of commercial road salt (99% NaCl, containing approximately 15 ppm ferrocyanide) was compared with that of analytical grade NaCl for two of the test species in the standard OECD soil (Table 6.2). For both species, there was no significant difference between the responses of the test organisms to NaCl as compared with commercial road salt, thus indicating the use of NaCl is a valid surrogate for road salt.

42

Table 6.2: Comparison of Toxicity of NaCl versus Ferricyanide-Containing Commercial Road Salt to Two Species of Soil Invertebrates in Standard OECD Soil

Road salt (mg/kg) NaCl (mg/kg) Species

Reproduction EC50 (95% C.L.)

F. candida 3,300 (3,000-3,7000)

2,800 (1,900-3,600)

O. folsomi 6,100 (4,900-7,300)

6,500 (5,500-7,500)

Data on the toxicity of KCl to soil invertebrates are summarized in Table B-2. Based on the limited amount of data available, KCl appears to be as toxic as NaCl (E. fetida) or less toxic than NaCl (F. candida). Unlike the situation in aquatic systems, there is no evidence that in soil KCl is more toxic than NaCl.

Table 6.3: Comparison of Toxicity of NaCl and KCl to Selected Soil Invertebrates

Species Endpoint Exposure NaCl (mg/kg)

KCl (mg/kg) Reference

Eisenia andrei LC50 14 d 8,100 7,800 Moul, 2001

Folsomia candida EC50 28 d 2,800 4,900 Addison and Bright, in prep.

A summary of the preceding thresholds for NaCl in soil is provided in Table 6.4.

43

Table 6.4: Summary of Soil Invertebrate Toxicity Thresholds for NaCl in Soil

Ecological Endpoint

Salt or Ion Concentration in Soil

(mg/kg)

Comments

NaCl Cl- Na+

1,200 728 472

Nominal concentration

EC50 -NL

Cl- Na+

630 320

Measured in Saturated Paste

NaCl Cl- Na+

4,700 2,900 1,800

Nominal concentration

LCx

Cl- Na+

2,500 1,200

Measured in Saturated Paste

6.2.2.2 Plant Toxicity Studies

There is considerable scientific knowledge on the effects of salt ions to plants, based on the enormity of the problem for agricultural practices throughout the world. Soil salinity is estimated to affect crop productivity on approximately one quarter to one third of all agricultural lands globally (Squires, 1994). According to Davenport (1998), plants can respond adversely to total salinity (or osmolality, effectively measured as EC) and to specific ion effects. Chloride is particularly toxic to some glycophytes (salt-intolerant plants) such as citrus trees and grape vines (Marschner, 1995). Sodium ions, however, are the major constituent of saline and sodic soils and sodium appears to be the major toxicant ion for many species such as wheat (Davenport, 1998).

In several studies, sodium ions have been shown to be deleterious to plants independent of the accompanying anion or overall osmotic potential of the soil (Termaat and Munns, 1986). According to Davenport (1998), the main symptoms of sodium toxicity in crop species include elevated sodium levels in

44

plant tissues, reduced potassium uptake, calcium deficiency, and an inhibition of root elongation. Specific mechanisms, however, remain poorly understood. For both glycophytic and halophytic plants, the tolerance to soil sodium ions is attributed to the ability of individual species to limit sodium uptake, and perhaps a myriad of toxic interactions of cytosolic sodium ions with various metabolic functions. Halophytic plants tend to contain higher cytosolic sodium concentrations than non-halophytes, but nonetheless tend to absorb much lower sodium concentrations relative to soil or water concentrations (Davenport, 1998).

Sodium has not been demonstrated to be required for plant function, except in micromolar amounts in the case of some C4 plants (Brownell, 1979). Conversely, chloride ion is an essential micronutrient for plants (Cain et al., 2000): An adequate chloride tissue concentration is estimated to be approximately 100 mg Cl- /kg tissue. Calcium is an essential macronutrient. An adequate calcium tissue concentration is approximately 5,000 mg Ca2+/kg tissue.

In contrast to specific ion effects of either the chloride or sodium ion (or other salt ions), osmotic stress owing to the cumulative effects of all salt ions is often important for influencing plant species presence and productivity, especially under drought conditions.

Carter et al. (1981: in Bresler et al. 1982) provide a comprehensive review of the tolerance of a wide range of plant species to soil salinity, expressed as the electrical conductivity of the soil saturated paste extract. One of the most up-to-date and comprehensive databases for salt tolerance in plants is maintained by the US Dept. of Agriculture at http://www.ussl.ars.usda.gov/saltoler.htm. Other more recent references include Howat (2000) and Mass (1996).

Figure 6.2 graphically summarizes the range of soil electrical conductivity (saturated past extract) across a wide range of plant species that is predicted to lead to either a 20% or 50% reduction in yield, based on Carter et al. (1981). The underlying data are tabulated in Appendix B.3.

http://www.ussl.ars.usda.gov/saltoler.htm

45

Figure 6.2: Plant Species Sensitivity Distribution to Soil Salinity Expressed as the Electrical Conductivity of the Saturated Paste Extract

Plants tend to exhibit a lower threshold for soil electrical conductivity, below which plant growth or crop yield is unaffected. Above this threshold, yield tends to decline linearly with increasing conductivity. While several researchers have categorized plant sensitivity to saline soils based primarily on the threshold effects level, the slope of the relationship between conductivity and declining yield is also an important aspect of plant responses (Appendix B.3).

Barley (Hordeum vulgare) is among the least sensitive of plants to soil salinity, while fruit producing trees and woody shrubs tend to be very sensitive.

Table 6.5 shows the relationship between soil electrical conductivity levels and predicted percentage of plant species experiencing either a 20% or 50% decline in yield.

EC - d

ecline i

n yield

20EC

- dec

line i

n yield

50

1 2 3 4 5 10 20Electrical Conductivity (mmho/cm - log10 scale)(saturated soil extract)

Perc

entil

e of

Rank

Dis

trib

utio

n

1

10

30

50

70

90

99

25th %ile

Barley

46

Table 6.5: Predicted Sensitivity of Plants to Salt in Soils, Measured as Electrical Conductivity (Saturated Paste Extract)

Soil Conductivity (dS/m) associated. with – % of spp. affected

20% yield reduction 50% yield reduction

5 1.7 3.3 10 1.9 3.6 15 2.1 3.9 20 2.3 4.3 25 2.5 4.6 30 2.8 5.1 35 3.0 5.5 40 3.3 6.0 45 3.7 6.5 50 4.0 7.1 55 4.4 7.7 60 4.8 8.4 65 5.3 9.2 70 5.8 10 75 6.4 11 80 7.0 12 85 7.7 13 90 8.5 14

There is unfortunately, no simple relationship between soil conductivity and salt concentration measured as individual salt anions and cations when considering the large theoretical range of soil types and salt compositions at possible salt contaminated sites (Section 5). The species sensitivity data in

Figure 6.2, therefore, cannot be confidently translated into a soil sodium, chloride, or other salt ion concentration. Nonetheless, the analysis indicates that an electrical conductivity of approximately 4.5 dS/m is estimated to be associated with a 50% loss of yield (EC50) in 25% of plant species, all other things being equal.

Cain et al. (2000) conducted an extensive review of the toxicity to plants of salt in soil measured as NaCl and CaCl2, as part of the CEPA PSLII road salt

47

assessment. This included herbaceous species, trees and wetland species. Much of the review, however, focused on endpoints resulting from aerial or foliar exposure – attributable to salt spray along road right-of-ways to which road salt was applied.

Cain et al. (2000) concluded –

“Threshold values were determined from estimates of effects concentrations providing a 25% effects level, NOEL or LOEL values and critical toxicity values estimated from experimental evaluations or field sampling following applications of NaCl or CaCl2. Threshold values for root exposure to Na ranged from 215 to 300 ppm, and for Cl was 300 ppm. Threshold values for tissue exposure to Na ranged from 575 to 650 ppm, and for Cl ranged from 800 to 1650 ppm.”

For the purpose of the BC CSR, standards for direct soil contact to plants are based on an EC50 response, as opposed to EC25, NOEL, or LOEL, as previously discussed. The thresholds provided by Cain et al. (2000), therefore, are lower than would be expected based on CSST policy decisions (BCE, 1996).

The available plant toxicity data were subsequently re-evaluated for the derivation of salt soil standards. Studies summarized in Cain et al. (2000) of NaCl toxicity in direct response to exposure via soil were deemed to be relevant for the derivation of a direct contact standard for plants under the BC CSR. Hydroponic studies were also deemed to be of limited if any relevance to determining environmentally protective thresholds for plants based on soil exposures. Data excerpted from Cain et al. (2000) and from other sources, including new data from Moul (2001) on NaCl toxicity to various plant species in summarized in Appendix B. Overall, the available data – after screening – included five species of trees, a cereal crop (barley- Hordeum vulgare), spinach, turfgrass, and mixed temperate prairies species4.

4 Harrington and Meikle (1992) as reported in Cain et al. (2000): The study evaluated germination and growth of eight prairie species, five warm grass species and three forb (broad-leaved) species, grown in soil amended with NaCl in a long-term greenhouse study. A sterilized silt-loam mix was amended with NaCl resulting in Na concentrations ranging from 0 to 2000 ppm, or 0 to 400 ppm, for the measurement of seed germination responses to NaCl.

48

The re-constructed species sensitivity distribution for the non-lethal endpoints data is provided in

Figure 6.3, below. In all cases, the concentration reported was the nominal (spiked) soil NaCl concentration. Based on this data, estimates of the number of species potentially affected at various nominal NaCl concentrations are provided in Table 6.6.

Figure 6.3: Plant Species Sensitivity to NaCl in Soil

Only two data points were found for mortality endpoints based on exposure of plants to NaCl in soil: Werkhoven (1966) provided data that allowed for the calculation of an LC20 soil concentration for Scots Pine and Colorado Blue Spruce, based on regression analyses reported in Cain et al. (2000). The NaCl concentration associated with 20% mortality in Scots Pine and Colorado Blue Spruce seedlings was estimated to be 1,400 and 500 mg/kg NaCl, respectively. The basis of the reported NaCl concentration in soil was not provided. The shortage of data points precludes any probability-type approach based on a species sensitivity distribution.

Barley (Moul, 2001)

100 1,000 10,000NaCl (mg/kg soil- nominal) (log10 scale)

Perc

entil

e of

Ran

k D

istr

ibut

ion

1

10

30

50

70

90

99

50th %ile

25th %ile

49

Table 6.6: Relationship Between Percent of Plant Species Potentially Affected and Soil NaCl Concentration (Nominal)

Percent of Plant Species Potentially Affected (50% Loss

of Yield – EC50) Soil NaCl Concentration

(mg/kg nominal)

5 330 10 400 15 480 20 580 25 700 30 840 35 1000 40 1200 45 1500 50 1800 55 2200 60 2600 65 3200 70 3800 75 4600 80 5600 85 6700 90 8100

In the absence of more toxicity data for mortality endpoints, the geometric mean of the two available points provides a provisional estimate of NaCl soil thresholds based on plant mortality. The geometric mean of 1,400 mg/kg and 500 mg/kg NaCl is approximately 840 mg/kg NaCl.

A summary of the preceding evaluation is provided in Table 6.7.

50

Table 6.7: Summary of Plant Toxicity Thresholds for NaCl in Soil

Ecological Endpoint Salt Soil Concentration Comments

electrical conductivity = 4.6 dS/m

Measured in saturated paste extract

NaCl in soil 700 mg/kg nominal;

Expressed as a nominal or total soil concentration

(or 275 mg/kg Na+, 425 mg/kg Cl-)

Non-lethal plant effects (growth, yield): 25th

percentile of Species Sensitivity Distribution Based

on EC50. Saturated Paste Conc.

Na+:190 mg/kg Cl-: 370 mg/kg

Converted to predicted recovered conc. (Section 5)1

NaCl in soil 840 mg/kg nominal;

Provisional estimate: Two data points from one study. Threshold is calculated as the geometric mean of the

two.

(or 330 mg/kg Na+, 510 mg/kg Cl-)

Plant mortality, LC20

Saturated Paste Conc. Na+:220 mg/kg Cl-: 440 mg/kg

Converted to predicted recovered conc. (Section 5)

6.2.2.3 Summary of Estimated Thresholds for the Protection of Soil Invertebrates and Plants Based on Direct Soil Contact

Sections 6.2.2.1 and 6.2.2.2 summarize estimates of soil concentrations of sodium and chloride ions for soil invertebrates and plants, respectively. The direct soil contact pathway within a matrix standard is intended to protect both soil invertebrates and plants, with a higher level of protection (lower remediation standard) for agricultural and residential/parkland than for commercial and industrial land uses.

Table 6.8 provides sodium and chloride soil thresholds deemed to allow a minimum level of ecological functioning for both soil invertebrates and plants based on the preceding analysis.

51

Table 6.8: Summary of Salt Ion Thresholds for Both Soil Invertebrates and Plants (converted to saturated paste equivalent concentrations)

Soil Invertebrates Plants

Na+ Cl- Na+ Cl- Effects Data (Non-lethal):

25th %ile of EC50 320 630 190 370

Mortality Endpoints: 25th

%ile of LC20 data unless otherwise indicated

1,200 2,500 2201 4401

Notes: 1. Based on geometric mean of toxicity data for two species.

The tabulated benchmarks suggest that plants are more sensitive overall to NaCl in soil than soil invertebrates, although the range of concentrations that lead to a 50% reproductive impairment in soil invertebrates based on longer exposure durations is similar to the NaCl concentration that results in a 50% decline in plant yield. The apparent low sensitivity of soil invertebrates to NaCl based on mortality studies is perhaps a bit misleading in the context of soil ecological functioning (see section 6.2.2.1). While different species of soil invertebrates may be able to withstand exposure to various stressors for 28 days (the maximum exposure period used in this study) or longer, an impaired ability to reproduce at the higher salt concentrations would preclude over-wintering survival of the population for most species. Few collembolans or other soil invertebrate taxa exhibit a multi-year adult life span.

For agricultural and residential/parkland land uses, therefore, the provisional direct soil contact standard is established as the lower of the soil invertebrate and plant toxicity thresholds: 190 mg/kg for sodium ion and 370 mg/kg for chloride ion. For commercial and industrial lands, the higher of the soil invertebrate or plant values was chosen: i.e. – 1,200 mg/kg of sodium and 2,500 mg/kg for chloride ion in soil.

52

6.2.3 Soil and Fodder Ingestion by Livestock (Agricultural Lands Only)

According to the CSST protocols (BCE, 1996), the recommended calculation for TRVs is a follows:

BWIR CD TRV f×= (4)

where,

TRV = Toxicity Reference Value (mg/kg-d)

CD = lower bound of high dietary concentration (mg/kg) (chemical specific)

IRf = fodder ingestion rate (CSST default value for cattle: 13.5 kg/d)

BW = body weight (CSST cattle default: 600 kg)

The “Derivation of Livestock Ingesting Soil and Fodder Standard” (Cs) is then calculated as follows:

( )[ ] AUF ED ABIR IR BvBW TRV Cs

sf ×××+××= (5)

where,

Cs = Livestock ingesting soil and fodder standard (in mg/kg)

TRV = Toxicity Reference Value (mg/kg-d)

BW = Receptor body weight (CSST default for cattle: 600 kg)

Bv = soil to plant transfer coefficient for vegetative tissue (chemical specific)

IRf = food ingestion rate (kg/d), or 0.687 x BW0.651 (CSST default of 13.5 kg/d for cattle)

IRs = Soil ingestion rate (kg/d) or 0.083 x Dry Matter Intake Rate (CSST default of 1.5 kg/d for cattle)

53

AB = Bioavailability (CSST default assumption: 100%, or 1.0)

ED = Duration of exposure annually (CSST default = 365 d/y, or 1.0)

AUF = Area use function = ratio of affected area/size of foraging range (CSST default of 100% or 1.0)

DMIR = Dry matter intake rate (CSST default of 15 kg/d for cattle)

A soil quality standard based on this exposure scenario has not been calculated, since an appropriate livestock toxicity reference value was not found.

6.3 Soil to Groundwater Pathways – Human Health and Ecological Effects Soil Quality Standards

Salt ions from NaCl-based or other de-icers and produced water, once released, readily dissolve in any available water within the soil environment. The high solubility of all of the major salt ions is of concern for off-site runoff of surface water and groundwater contamination, especially where either drinking water supplies or surface water bodies with aquatic life are found. At 0oC, 357,000 mg of NaCl will dissolve in one litre of water (Environment Canada, 1984 – cited in Johnston et al., 2000). Salt transport in overland flow is not explicitly considered in the derivation of soil matrix standards, except for the investigation and remediation of adjacent soil and aquatic environments.

The prediction of fate of any substance in subsurface terrestrial environment is strongly influenced by the mass and volume of the source. Substances are transported downward from the soil source through dissolution in rain water or snow melt water and vertical migration via voids in unsaturated soils, until the substance reaches the saturated zone at the groundwater surface. The rate of transport is influenced by the relative magnitude of transpiration versus evaporation, and mechanisms that retard the substance relative to the velocity of the infiltrating water that forms the transport medium. In addition, other attenuation mechanisms such as microbial degradation might come into play, depending on the substance of interest. For salts, upward wicking in the root zone and capillary action immediately above the seasonally variable groundwater table are also expected to play a role.

Attenuation mechanisms for salt ions can be discounted for both the unsaturated zone and deeper saturated zone, since salt ions do not biodegrade, volatilize or undergo photolysis.

54

The potential for retardation for inorganic substances and many polar organic compounds is often approximated using the “adsorption co-efficient”, Kd, a measure of the tendency of a substance to partition onto soil particles from the surrounding interstitial water. Chloride ion generally moves conservatively with the water mass. Ionic or other interactions with the surface of soil particles are sufficiently weak to be negligible (Johnston et al., 2000). Chloride ions are most often considered to be highly conservative ‘tracers’, moving at the same rate as the water in which they are dissolved. For the purpose of groundwater modeling, therefore, the Kd of Cl- is often assumed to be zero.

Associations with soil particles tend to be of much greater importance for cations, such as Ca2+, Na+, K+, and Mg2+. Soil particles, especially some clay types, exhibit a particle surface with an abundance of negatively charged functional groups. These groups contribute to the overall cation exchange capacity of the soil. For sodium, the tendency to associate with soil particles in the subsurface environment is described by equation 6:

2Na+(aq.) + Ca2+(adsorbed) = 2Na+(adsorbed) + Ca2+(aq.) (6)

The cation exchange capacity (CEC) is highly dependent on soil type, and any generalizations about CEC within a region or across the province are likely to be grossly over-simplistic. Table 6.9 summarizes typical CECs for clay minerals. Humic substances and other detrital organic matter will also contribute to the CEC.

Table 6.9: Cation Exchange Capacities (CEC) for Several Clay Minerals (adapted from Johnston et al, 2000, based on Grim, 1968)

Mineral CEC (milliequivalents/100 g soil)

Chlorite 10 – 40 Halloysite•2H2O 5 – 10 Halloysite•4H2O 40 – 50 Illite 10 – 40 Kaolinite 3 – 15 Sepiolite-Attapulgite-Palygorskite 3 – 15 Smectite 80 –150 Vermiculite 100 – 150

55

With regard to salt anions, the relative propensity to react with other substances in the subsurface environment such as metals (Stumm and Morgan, 1981) is –

CO32- > SO4

2- > PO43- > Cl-

Humic substance and some other organic ligands, including some anthropogenic substances may co-occur with salts at a contaminated site and may act as complexing agents. Dissolved phosphate can also act as a strong inorganic complexant, particularly under reducing conditions. Carbonate complexation of salt cations might also be an important factor in carbonate systems.

An estimate of adsorption coefficients (Kd) is required in order to model the fate of salt ions in the hydrogeological environment using the BC WLAP approved groundwater model and many other types of models. Kd is simply the ratio of the mass of solute species adsorbed or precipitated on the solids (soil particles) per unit of dry mass of the soil, S, to the solute concentration in the surrounding liquid, C:

Kd = S (g/g dry) / C (g/mL) (7)

One of the major limitations in using Kd to calculate retardation terms is that it accurately describes solute partitioning between groundwater and the solid phase for only one set of environmental conditions. Kd values do not describe intrinsic properties of a substance; rather, they are empirical measures that summarize complex ecosystem-specific properties, especially soil type and heterogeneity.

An excellent discussion of the derivation and interpretation of Kd values is provided in Krupka et al. (1999). There has been considerable emphasis on evaluating Kd for radionuclides; much less so for salt ions.

According to Krupka et al. –

“Clearly, the greatest limitation of using Kd values to calculate retardation terms… …is that it describes solute partitioning between the aqueous and solid phases for only 1 set of environmental conditions. Such homogeneity does not exist in nature and therefore greatly compromises the usefulness of the constant. For example,

56

when the aqueous phase chemistry was varied, americium Kd values in a Hanford sediment ranged from 0.2 to 53 ml/g, roughly a 200-fold range (Delegard and Barney, 1983). Additional variability in the americium Kd values, albeit less, were observed when slightly different Hanford sediments were used: 4.0 to 28.6 ml/g.

…Using similar aqueous phases but diverse soils, Sheppard et al. (1976) measured americium Kd values ranging from 125 to 43,500 ml/g.”

Kd values are generally determined experimentally in batch5 or flow-through column set ups6, or may alternatively be estimated empirically. For example Sheppard and Thibault (1990) proposed that Kd can be estimated for cases where the soil-to-plant concentration ratio is known, based on an assertion that Kd and plant-soil partitioning are strongly correlated, as follows:

ln Kd = a + b (ln Biv) (8)

where,

Biv is the soil-to-plant concentration ratio

and a, b are constants. On the basis of experimental data, Sheppard and Thibault (1990) proposed that the value for the coefficient b is –0.5 based on experimental data. The value for a is expected to vary across soil types (sandy soil: 2.11; clayey soil: 3.78; loamy soil: 3.36; organic rich soils: 4.62). Using this approach, Kd estimates for a range of elements were derived, as summarized in Table 6.10.

5 An ASTM D4319 test method has been developed as a standard short-term batch method to measure the distribution co-efficient under steady-state conditions. 6 Standardized column studies have been developed in draft within British Columbia by SoilCon Laboratories Ltd.

57

Table 6.10: Emperically Derived, or Geometric Mean Kd values (mL/g) by Soil Type (after Sheppard and Thibault, 1990)1

Element Sand Loam Clay Organic

Bromine 15 50 75 180 Carbon 5 20 1 70 Calcium 5 30 50 90 Cadmium 80 40 560 900 Cobalt 60 1,300 550 1,000 Chromium 70 30 1,500 270 Iron 220 800 16 600 Iodine 1 5 1 25 Potassium 15 55 75 200 Manganese 50 750 180 150 Nickel 400 300 650 1,100 Phosphorus 5 25 35 90 Lead 270 16,000 550 22,000 Selenium 150 500 740 1,800 Tin 130 450 670 1,600 Zinc 200 1,300 2,400 1,600

Note: 1. Several values were obtained from literature as opposed to being empirically derived from soil-plant concentration data.

As part of concerted efforts in the United States to predict risks of radionuclide releases and disposal7, “RESRAD” default Kd values for major ions of interest herein were as follows:

• chloride 0.1 mL/g • sodium 20 mL/g • potassium 5 mL/g • calcium 50 mL/g

7 http://web.ead.anl.gov/resrad/home2/index.cfm

58

Returning to chloride ion, the lack of potential for retardation or attenuation relative to the other ions suggests that chloride ion mobility is most likely to influence risks to aquatic life, via drinking water ingestion, or via irrigation water, where chloride is the major anion present in a salt release. Actual risks at the point of exposure, therefore, are expected to be dependent only on the potential for dilution along the groundwater transport pathway. If it is further assumed that the surface contaminated soils represent a potentially infinite, non-depleting source8, then there is theoretically no potential for dilution via infiltration in the contaminated zone. The available dilution mechanisms, therefore, include mixing (via dispersion and diffusion) with the surrounding groundwater in the saturated zone, immediately below the contaminated soil source, and down-gradient along the flow path. Dispersion tends to be the major process that influences mixing and plume migration in higher permeability environments, while diffusion may be important in very fine-grained soils with very low flow rates. According to Domenico and Swartz (1990, as cited in Johnston et al., 2000), dispersion in other than fine-textures soils across the major flow direction is often an order of magnitude lower than the longitudinal dispersion, and vertical dispersion (beneath the plume) is a further order of magnitude lower (i.e., approximately 1% of longitudinal dispersion). The potential for mixing and dilution of chloride ion via dispersion or dilution in the saturated zone over relatively short travel distances, therefore, is very low.

In addition to the mixing that occurs in the subterranean environment, CSST policy decision allows for an additional ten-fold dilution between the groundwater outflow point and the point of exposure in the aquatic receiving environment. This assumption may not be sufficiently protective of some water bodies with very long water residence times, seasonally low flows, and/or where short term evaporation rates exceed transpiration rates. It is easy to imagine several situations were chronic salt loading to a surface water body could be concentrated over time, rather than diluted.

Finally, density effects may influence the subsurface fate of groundwater salt plumes of high concentration. Density-related effects would result in the sinking of the water mass in the surrounding groundwater. Few groundwater models have been constructed to account for this possibility.

8 The derivation of generically applicable guidance generally requires the assumption of an infinite, non-depleting source. While this assumption may be very conservative (and over-predict groundwater fluxes) it is difficult to envision an alternate set of assumptions that would be sufficiently protective across all possible sites of application.

59

6.3.1 The Groundwater Model

The approach developed by the Contaminated Sites Soil Task Group (CSST) was used initially to develop the salt soil quality matrix standard for groundwater flow to surface water used by aquatic life. The CSST approach is outlined in “Overview of CSST Procedures for the Derivation of Soil Quality matrix Standards for Contaminated Sites” (BCE, 1996). Soil quality guidelines presented in that document were derived using an analytical groundwater transport model developed a half-decade ago by BC Environment with the assistance of Golder Associates Ltd. and approved by CSST. The model adopted by CSST considers the major transport processes.

The model simulates contaminant partitioning from the soil to groundwater, transport of contaminants to the water table, and subsequent transport of contaminants in the saturated zone to the receptor. The model assumes one-dimensional groundwater flow, but may include transport mechanisms such as dispersion, biodegradation (based on an assumed saturated zone and unsaturated zone environmental half life), adsorption-desorption, and dilution (between contaminated leachate and groundwater). The US EPA draft document “Soil Screening Guidance” (1994 draft; subsequent released in final in 1996) was used as the framework for the model and the mathematical simulation for the saturated groundwater transport was based on work by Domenico (1987).

The CSST groundwater model includes four main components as follows:

(i) Contaminant partitioning between soil particles, soil pore air, and soil pore water;

(ii) Groundwater flow and contaminant leachate transport in the unsaturated zone;

(iii) Mixing of unsaturated and saturated groundwater at the water table; and,

(iv) Groundwater flow and contaminant transport in the saturated zone to a receptor.

Numerous assumptions are incorporated into the model. They are as follows:

• the soil is physically and chemically homogeneous; • the moisture content is uniform throughout the unsaturated zone; • the infiltration rate is uniform throughout the unsaturated zone; • decay of the contaminant source is not considered (i.e., infinite source

mass);

60

• flow in the unsaturated zone is assumed to be one dimensional and downward only, with dispersion, sorption-desorption, and biological degradation;

• the contaminant is not present as a free product phase (not relevant for salts);

• the maximum concentration in the leachate is equivalent to the solubility limit of the chemical in water under the defined site conditions;

• the groundwater aquifer is unconfined; • groundwater flow is uniform and steady; • co-solubility and oxidation/reduction effects are not considered; • attenuation of the contaminant in the saturated zone is assumed to be

one dimensional with respect to sorption-desorption, dispersion, and biological degradation;

• dispersion is assumed to occur in the longitudinal and transverse directions only and diffusion is not considered;

• mixing of the leachate with the groundwater is assumed to occur through mixing of leachate and groundwater mass fluxes; and,

• dilution of the plume by groundwater recharge down-gradient of the source is not included.

The model is constructed by specifying the contaminant concentration in groundwater (saturated zone) at the source. The model then back calculates the soil concentration at the source and forward calculates the groundwater concentration at the receptor. The model derives soil concentration standards to ensure that the contaminant concentrations in the groundwater discharging to the surface aquatic receptor are less than or equal to the Canadian Water Quality Guideline criteria for the receptor, or another benchmark of groundwater quality, as may be adopted into Schedule 6 of the B.C. Contaminated Sites Regulation.

6.3.2 Relevant Toxicological Thresholds

Existing Canadian and British Columbia water-based environmental quality guidelines were used, where available, as target concentrations at the point of exposure. From these, the BCE groundwater model was used to back-calculate corresponding upper limit concentrations of various salt ions in soil that could be introduced into groundwater. Little existing guidance was available for risk-based thresholds for aquatic life, for the majority of salt ions addressed herein. A more in-depth aquatic life effects assessment is included below, therefore.

61

6.3.2.1 Drinking Water and Human Health

CCME (1999) summarizes current guidelines for Canadian drinking water quality. Guidelines of relevance to the calculation of a salt soil matrix standard include –

• chloride: Aesthetic drinking water objective -250 mg/L • sodium: Aesthetic drinking water objective - 200 mg/L

In addition, the guidelines include an aesthetic objective for total dissolved solids (TDS) of Aesthetic drinking water objective of 500 mg/L.

6.3.2.2 Agricultural Water Uses

Canadian water quality guidelines for the protection of agricultural water uses, where salt-contaminated sites are located on or immediately adjacent to agricultural lands, encompass two exposure scenarios. The first includes irrigation water, which – if contaminated – could adversely affect crop yield. The underlying protocol is designed to protect sensitive crop species (CCME, 1999). The guidelines account for the expected maximum irrigation water use for specific crops and the overall sensitivity of such crops. The second scenario addresses livestock watering, in consideration of (i) livestock tolerable daily intake (TDI), (ii) daily intake rates, (iii) livestock body weights, and (iv) potential for bioaccumulation. The intent of the guidelines is to protect the livestock as opposed to their consumers.

Relevant guidelines to the calculation of a salt soil matrix standard include –

• chloride: Irrigation water guideline – 100 – 700 mg/L Foliar damage endpoints:

100-178 mg/L for almonds, apricots, plums 178-355 mg/L for grapes, peppers, potatoes, tomatoes 355-710 mg/L for alfalfa, barley, corn, cucumbers 710 mg/L for cauliflower, cotton, safflower, sesame, sorghum, sugar beets. sunflowers

Rootstock endpoints: 180-610 mg/L for stone fruit 710-900 mg/L for grapes

Cultivar endpoints: 110-180 mg/L for strawberries 230-460 mg/L for grapes 250 mg/L for boysenberries, raspberries, blackberries

62

• sulphate: Livestock watering guideline – 1,000 mg/L • calcium: Livestock watering guideline –

(from CCREM, 1987) 1,000 mg/L

• TDS (salinity): Irrigation water guideline – 500 –3,500 mg/L TDS guideline =

500 mg/L for strawberries, raspberries, beans and carrots 500-800 mg/L for boysenberries, currants, blackberries,

gooseberries, plums, grapes, apricots, peaches, pears, cherries, apples, onions, parsnips, radishes, peas, pumpkins, lettuce, peppers, muskmelons, sweet potatoes, sweet corn, potatoes, celery, kohlrabi, cauliflower, cowpeas, broad beans, flax

800-1,500 mg/L for spinach cantaloupe, cucumbers, tomatoes, squash, brussels sprouts, broccoli, turnips, smooth brome, alfalfa, big trefoil, beardless wildgrass, vetch, timothy, crested wheat grass, sunflowers, and corn

1,500-2,500 mg/L for beets, zucchini, canola, sorghum, oat hay, wheat hay, mountain broam, tall fescue, sweet clover, reed canary grass, birdsfoot trefoil, perennial rye grass

3,500 mg/L for asparagus, soybeans, safflowers, oats, rye, wheat, sugar beets, barley, barley hay, tall wheat grass.

• TDS (salinity): livestock water – 3,000 mg/L

Morin et al. (2000; Figure 2) provide a summary of various equations used to convert between various expressions of salt concentration. In particular –

EC (dS/m) = TDS (mg/L)/640

Further, EC can be converted to NaCl concentrations in soil solution, provided that it is controlled by the presence of sodium and chloride ions only as –

Cl- (mEq/L) = Na+ (mEq/L) ≅ 10 • EC (dS/m)

(adapted from Morin et al., 2000).

This allows the above-mentioned thresholds to be approximated as EC concentrations of salt ion concentrations (see however comments in Section 5 regarding the variable influence of soil type).

63

Bresler et al. (1982) provided as series of predictive relationships between EC and ion concentration, based on a summary of Marion and Babcock (1977; see Bressler et al, 1982) who used experimental data and applied a modified Onsager-Fuoss equation (Table 6.11).

Table 6.11: Predicted Relationships Between Salt Ions and Electrical Conductivity (EC) in Soil Solution

Solution Equation r2 Std. Dev.

pure salts log Conc. (mEq/L) = 0.926 + 1.037 log EC (dS/m)

0.9998 0.012

NaCl log ionic strength (mmol/L, 25oC) = 0.932 + 1.028 log EC (dS/m)

0.9999 0.009

CaCl2 log ionic strength (mmol/L, 25oC) = 1.101 + 1.051 log EC (dS/m)

0.9998 0.011

MgSO4 log ionic strength (mmol/L, 25oC) = 1.215 + 1.022 log EC (dS/m)

1.000 0.002

The CCME guidance on thresholds of effect for chloride in drinking water (100 – 700 mg/L chloride) was subjected to a more critical evaluation given that the lower end of the range approaches the upper limits of observed chloride concentrations in relatively pristine groundwater aquifers (see Table 7.1, Section 7.2).

Maynard et al. (1996) estimated a 50% reduction in the growth of white spruce in greenhouse-grown trees irrigated with 93 mg/L sodium, applied as Na2CO3 (at an EC of 0.5 dS/m). While the researchers had no way of assigning the observed growth reduction to the cation or the anion, this nonetheless underscores weaknesses in research on either irrigation of foliar exposures to NaCl. There is always the potential to mis-assign toxicity to the chloride ion. A follow-up study by Maynard et al. (submitted) demonstrated that reduced growth occurred at a higher sodium concentration and growth medium electrical conductivity when the spruce seedlings were exposed to sodium acetate (acetate is rapidly metabolized by soil microbes under aerobic conditions, and is less likely to exert toxic effects as the companion anion).

Banuls and Primo-Miio (1992) exposed potted Citrus plants to salt solutions through addition of saline solutions to a sand growing medium (at 0, 15, 30,

64

45 or 60 mM NaCl) The 60 mM (~3,500 mg/L NaCl) solution resulted in a 33% reduction in plant dry weight relative to the controls.

The United States Department of Agriculture (1994) published salinity standards for forest nursery irrigation water as shown in the following table (Table 6.12). The supporting rationale was not provided in the document. The standards, however, are also reported in Landis et al. (1989), modified from several other authors, especially Ayers (1977).

Table 6.12: USDA (1994) Salinity Standards for Forest Nurseries

Water Quality Index Do Not Exceed Limit1

Salinity (EC) 1.5 dS/m

Toxic Ions Sodium ion 50 ppm; 2.2 mEq Chloride ion 70 ppm; 2.0 mEq Boron 0.75 ppm; N/A

Accessory Ions Calcium ion 100 ppm; 5.0 mEq Magnesium ion 50 ppm; 4.3 mEq Sulfate ion 250 ppm; 5.2 mEq

Foliar Staining Ions Bicarbonate 60 ppm; 1.0 mEq Total hardness 206 ppm; –

Note: 1. These values assume a porous and free draining growing medium. Water with much lower salt concentrations can cause serious problems if poor drainage or irrigation practices allow salts to accumulate. 1 ppm = 1 mg/L. the conversion between mg/L and mEq varies with atomic weight and the electrical charge of the ion.

For a variety of horticultural species, Hanan et al. (1978) suggested that as a rule-of-thumb irrigation water should contain less than 200 mg/L calcium (10 mEq/L), 140 mg/L chloride (4 mEq/L), or 184 mg/L sodium (8 mEq/L).

65

Table 6.13 includes summarized data on the sensitivity of various species to foliar injury when directly sprayed with salt-containing irrigation water.

Table 6.13: Relative susceptibility of crops to foliar injury from saline sprinkling water1 (after Maas, 1990)

Na or Cl conc (mmolc/L) causing foliar injury2 < 5

(<177 mg/L Cl-)

5-10 (177-354 mg/L Cl-)

10-20 (354-709 mg/L Cl-)

> 20 (>709 mg/L Cl-)

Almond Grape Alfalfa Cauliflower Apricot Pepper Barley Cotton Citrus Potato Cucumber Sugarbeet Plum Tomato Maize Sunflower

Safflower Sesame Sorghum

Notes: 1. Susceptibility based on direct accumulation of salts through the leaves. 2. Foliar injury is influenced by cultural and environmental conditions. These data are presented only as general guidelines for day-time sprinkling.

According to Bresler et al. (1982) –

“When foliage is wetted, leaves may also absorb salts directly. This becomes important under sprinkler irrigation. Even sodium, which is not translocated to the leaves of some species, may be taken up directly by the leaves of these same species. .. …When plans absorb salts readily through their leaves, tolerance to salinity of sprinkler-irrigated plant is greatly reduced. As little as 5 mEq salt/L foliar-applied irrigation water can lead to chloride or sodium accumulation to damaging levels in fruit crops. Intermittent wetting by rotating sprinklers allows the salt concentration of water films to further increase by evaporation, so that as little as 2 to 3 mEq/L of sodium or chloride in the irrigation water can cause severe leaf damage.” (p. 169-170).

A concentration of 2-3 mEq/L equates to a chloride concentration in irrigation water of 70 to 105 mg/L.

66

Overall, this brief review of the literature confirms that toxicity through foliar absorption occurs at much lower concentrations than through soil absorption, particularly under conditions of high evapotranspiration. it should be noted, however that this is not necessarily applicable to the effects of winter-time road salt spray on adjacent trees and herbs. Trees tend to be less sensitive than the species shown in Table 6.12 since the salt exposure is generally during periods of dormancy, which no foliar growth and very limited foliar uptake occurs (for conifers). Annual and perennial herbaceous plants tend to have limited above-ground biomass during the winter months.

A threshold of effects for the application of irrigation water to foliar surfaces (e.g. through use of sprinklers as opposed to drip irrigation) as provided in CCME (1999) of 100 mg/L Cl- is deemed appropriate based on the underlying science.

6.3.2.3 Freshwater Aquatic Life Protection

There are no existing Canadian nor British Columbia water quality guidelines for the protection of freshwater aquatic life for the majority of salt ions addressed herein. Within British Columbia, “working water quality guidelines” for only sulphate currently exist, among the seven major salt ions encompassed in the operational definition (Section 3). The Ministry of Water, Land and Air Protection has established a sulphate aquatic life guideline of 100 mg/L overall, and a provisionally lower guideline (50 mg/L) for the protection of aquatic mosses.

In the absence of formal guidance, we considered four options for establishing a surface water/aquatic life protective threshold concentration especially for chloride ions, since this was deemed to be the ion with the greatest potential for mobility in the subsurface environment and potential for contaminating adjacent surface water bodies. The four options considered were –

1. Use of the chloride concentration threshold for the protection of aquatic life (213 mg/L Cl-) as derived by by Evans and Frick (2000) toward an assessment of road salt environmental risks as part of the CEPA PSLII road salt assessment;

2. The independent derivation of a provisional chloride water quality guideline based on a collation and re-analysis of the available toxicity data;

67

3. Use the value of 230 mg/L chloride ion as an aquatic life water quality guideline developed for and adopted by the USEPA (1988); and

4. Use a chronic water quality guideline of 147 mg/L chloride that was under development and review as at the time of production of this provisional soil matrix standard, but had yet to be approved (Nagpal et al., June 2002 draft).

Each of these approaches is briefly discussed herein, and the relevant soil quality guidelines provided based on a back-calculation from the aquatic life guidance using the BC WLAP approved groundwater model, along with generic assumptions.

CEPA PSL II Aquatic Life Protective Threshold for Chloride

There is a wealth of published information on the toxicity of salt to aquatic organisms. Evans and Frick (2000) undertook a literature review as part of the CEPA PSLII road salt assessment. They provided an estimated aquatic species sensitivity to chloride ion based on a chronic exposure, as illustrated in Figure 6.4.

Evans and Frick (2000) estimated that the 5th percentile of the sensitivity distribution for aquatic life occurs at around 213 mg/L Cl-. Similarly, the estimated 10th, 25th and 50th percentile of the effects distribution was estimated to occur at 240, 330, and 560 mg/L, respectively. The reconstructed species sensitivity distribution was developed by first categorizing the exposure period used in the original studies into < 1 day, 1 day, 4 days, and 1 week. The extent to which these represent chronic versus acute exposure periods depends on the life history of the specific test organism used. Evans and Frick (2000) further standardized the data for exposure period, to reflect longer-term (> 1 week) chronic exposure periods, using empirically derived acute:chronic toxicity ratios from a limited number of studies on NaCl toxicity.

68

Figure 6.4: Aquatic Life Chronic Species Sensitivity Distribution for Chloride Ion Based on Laboratory Toxicity Test Data (adapted from Evans and Frick, 2000). The upper and lower 95% confidence interval are also shown.

The acute:chronic ratios consulted are tabulated below (Table 6.14). The authors used a uniform acute:chronic ratio of 6.98 to extrapolate 96-h toxicity data to a longer term toxicity endpoint.

Table 6.14: Literature Derived Acute:Chronic NaCl Toxicity Ratios as Reported in Evans and Frick (2000)

Exposure period Ratio of

acute:chronic toxicity

Organism Type Reference

48 h: 21 day 3.95 Daphnia pulex (NOEC, LOEC) Birge et al. (1985)

96 h: 32 day 22.1 Fathead minnow (NOEC, LOEC) Birge et al. (1985)

Not provided 7.31 Rainbow trout LCx USEPA (1988) after Spehar (1987)

100

50

0100 200 1,000

213 mg/L

Perc

ent o

f Aqu

atic

Spp

. Affe

cted

Chloride conc. (mg/L)

69

The results of the re-construction of chronic toxicity sensitivity distributions for aquatic life, as carried out by Evans and Frick (2000), are provided in Figure 6.5.

Figure 6.5: Predicted chronic and actual (4 day and one week) toxicity levels for aquatic life exposed to NaCl. (upper and lower 95% CIs based on a log-logistic fit are shown).

One short-coming of the Evans and Frick (2000) derivation was the use of numerical values to convert acute to chronic data (ACR: Acute-to-chronic ratio) based on very little experimental data, and no information on the expected variations of ACR across species, water properties, time frames, toxicological endpoints, and exposure types. Another shortcoming was that much of the toxicity data used to derive a toxicity threshold was from the very poorly accessible grey literature, which is not readily available for critical review. A strength of their approach, however, was the use of a multi-species, probability distribution-type approach. The authors chose the lower 95% confidence interval of the 5th percentile of the reconstructed species sensitivity distribution, based on a linear regression of extent of chronic response in relation to the logarithm of the chloride concentration.

100 1,000 10,000

Chloride conc. (mg/L)

TaxaAffected(%)

Predicted chronic1 week

0

50

100

4 day

70

The use of an estimate around the 5th percentile of the estimated species sensitivity distribution represents a departure from current CCME protocols for the derivation of water quality guidelines, which establish through policy a zero percentile of species effected (i.e. lower than the lowest LOEC). A 5th percentile, however, is consistent with regulatory practice in an increasing number of jurisdictions internationally, including the United States, Netherlands, Australia and New Zealand.

Independent Royal Roads University Derivation

One of the challenges in assessing the toxicity of salt ions is that the toxicity is usually arbitrarily assigned to either the cation or anion, without knowledge of the actual toxicological mechanisms or mitigating factors.

Perhaps one of most definitive studies of the relative toxicity of different major salt ions to freshwater aquatic organisms is that of Mount et al. (1997). These researchers conducted approximately 2,900 individual toxicity tests (24 to 96 h LC50) on salt ion pairs using fathead minnows (Pimephales promelas) and two species of daphnids (Daphnia magna and Ceriodaphnia dubia). A major objective was to develop an ability to predict the aquatic toxicity of produced water releases, which commonly contain a diverse and variable mixture of major ions. The researchers used multiple logistic regression to relate mixed ion composition to survival for the three test species. Ion toxicity, when expressed on the basis of mg/L ion decreased in the following order:

K+ > HCO3- = Mg2+ > Cl- > SO4

2-

The other two cations, Na+ and Ca2+, were not deemed to be significant predictors of toxicity for any of the three species, suggesting that the toxicity of salts containing these cations was due primarily to the accompanying anions. The final regression equation derived for the Fathead minnow was –

Survival (%) (96-h) = 4.70 – 0.00987[K+] – 0.00327[Mg2+] – 0.0012[Cl-] –

0.00075[SO42- ] – 0.00443 [HCO3

- ] (9)

(R2 = 0.767)

71

Mount et al. (1997) found that the fit was improved for the two daphnids if a numerical descriptor of the relative concentration of cations (0, 1, or 2 for each ionic mixture) was included. This suggests indirect effects of the cations Na+ and Ca2+, in particular, probably based on their influence on availability of the other five major salt ions. The final predictive regression equation for the D. magna 48 h LC50 was –

48-h survival (%) = 5.83 – 0.0185[K+] – 0.003510[Mg2+] – 0.00395[Cl-] –

0.00225[SO42- ] – 0.00397 [HCO3- ] – 0.511(NumCat)

+ 0.00677(NumCat*K+) + 0.00146 (NumCat*Cl-) +

0.00132(NumCat*SO42-) (10)

(R2 = 0.799)

The final predictive regression equation for the C. dubia 48 h LC50 was –

48-h survival (%) = 8.83 – 0.0299[K+] – 0.00668[Mg2+] – 0.00813[Cl-] –

0.00439[SO42- ] – 0.00775 [HCO3

- ] – 0.446(NumCat) +

0.00870(NumCat*K+) + 0.00248(NumCat*Cl-) +

0.00140(NumCat*SO42-) (11)

(R2 = 0.842)

One of the implications of the Mount et al. (1997) study is the relative unimportance of Na+ and Ca2+ for acute aquatic toxicity. This, coupled with the lower mobility in groundwater than Cl-, suggests that a draft soil quality standard for the protection of aquatic life that is based on the transport of chloride ion is likely to be sufficiently protective against adverse effects of sodium ion, at least for organisms that respond in a similar fashion to P. promelius and the two daphnids. Another major implication, especially where salt soil contamination is due to a produced water or other release with appreciable potassium ion concentration, is that the effects of the K+ ion on aquatic life in nearby surface water bodies merits careful examination.

A similar analysis is reported herein to that carried out by Evans and Frick (2000) for chloride ion, and by Singleton (2000) for sulphate ion toxicity. Considerable data on salt ion aquatic toxicity, as found in the “Acquire” on-

72

line database was not referenced by Evans and Frick. In fact, few of the studies included herein were used by Evans and Frick. In addition, a slightly different approach was taken. This allows an appreciation of the differences in toxicity endpoints derived, using different approaches and endpoints, and – hence – the robustness of environmental protection endpoints to the underlying methodology.

The mortality-type (LCx) and non-lethal endpoints (ECx) were separated for an analysis of each of NaCl, KCl, CaCl2 and MgCl2 laboratory based exposures. NOEC and LOEC data were excluded from the analysis, since there was deemed to be adequate aquatic toxicity data for the majority of salt ion pairs. Where data for more than one exposure period was available, the longest available period was used. Where more than one replicate endpoint for the same species and exposure duration occurred, a toxicity endpoint for these taxa was estimated as the arithmetic mean of the available data points.

Approximately 25% of the toxicity endpoints, as reported in the Acquire database, were checked against the original references, with a strong emphasis on the studies that reported toxicity at lower salt ion concentrations. A study on the toxicity of NaCl to mayflies (Stenonema modetum) by Diamond et al. (1992) was erroneously summarized in the Acquire database: NaCl was measured using a salinometer, and reported as “parts-per-thousand”, whereas the NOEC and LOEC data in Acquire were reported as parts-per-trillion.

The vast majority of available toxicity studies did not measure exposure concentrations at any time during the experiments; rather, greater than 95% of the literature is based on nominal (spiked) concentrations. Furthermore, methods for endpoint estimation were generally inadequately described. Important exposure conditions such as pH or hardness of the test media generally were not provided.

These problems notwithstanding, the available data used to re-construct a species sensitivity distribution are summarized in Appendix B-4, and in Figure 6.5 to Figure 6.9. Exposure periods were not standardized, since the uncertainty not accounted for in the use of simple extrapolation techniques was deemed to be inappropriate. Furthermore, especially for the KCl and NaCl data set, at least some longer term (chronic) toxicity data were included, which would have a strong influence on the lower end of the distribution curve. The sensitivity distributions were re-constructed using a simple ranks-based approach, with graphical summaries. While the technique makes no major assumptions about the underlying data distribution, the tendency of the ranked data to plot along a straight line when the salt concentration is plotted on a logarithmic scale and the rank percentile is plotted on a probability scale

73

suggests that the re-constructed species sensitivity is consistent with a log-normal distribution.

An actual statistical estimate of the approximated species sensitivity distributions of aquatic life to NaCl, KCl, MgCl2 or CaCl2 was calculated as a linear least-squares fit between the log10 concentration of dissolved salt concentration as the independent variable, and the cumulative percent of species in the database affected as the dependent variable.

For the purpose of defining an environmentally protective threshold for aquatic life, the lower 95% confidence interval around the linear fit was used as a conservative estimate of toxicity thresholds, taking into account probablistic uncertainty. Whereas the majority of jurisdictions internationally establish target protective levels at the 5th percentile of the approximated species distribution, the current CCME and B.C. guidance sets water quality guidelines at a level that necessarily protects all species that may be present; in other words, at the zero percentile of the species distribution – assuming that such a threshold exists.

74

Figure 6.6: Approximated Species Sensitivity Distribution for NaCl effects on aquatic life – longer term exposures and mortality.

Figure 6.7: Approximated species sensitivity distribution for NaCl (mg/L) effects on aquatic life – non-lethal endpoints

1,000 10,000

Log10[NaCl]

0

20

40

60

80

100

%ileof SSD

% of species affected (EC50 level) = 59.8 log10[NaCl] - 173

p = 0.043, r = 0.792

1,000 10,000

Log10[NaCl]

0

20

40

60

80

100

%ileof SSD

% of species affected (LC50 level) = 80.2 log10[NaCl] - 254

p < 0.001, r = 0.962

75

(growth, reproduction, population level).

The limited amount of toxicity data for other than mortality-type endpoints (including invertebrate immobility without recovery) as summarized in Figure 6.7 results in a large amount of uncertainty in the prediction of percent of species affected at a given NaCl concentration.

A summary of the regression-based zero percent effects (or mortality) concentration or NaCl is as follows:

Mortality studies:

• Zero percentile based on the least-squares fit as shown: 1,450 mg/L NaCl;

• Zero percentile based on lower 95% C.I. of the least-squares fit: 1,260 mg/L NaCl.

Non-lethal endpoints:

• Zero percentile based on the least-squares fit as shown: 760 mg/L NaCl.

The large amount of uncertainty around the species sensitivity distribution reconstructed from the non-lethal endpoints precludes a reasonable estimate of a threshold of effects based on statistical uncertainty.

A lower value of 760 mg/L NaCl is equivalent to a water-borne concentration of 461 mg/L chloride ion.

The literature-derived toxicity database was scrutinized to identify experimental results wherein toxicological effects were observed at lower than 760 mg/L NaCl. We examined all available toxicity data, including studies for which effects were reported as LOECs or E(L)Cx, where x was less than 50%. The toxicity data scrutinized include the tabulated information in Appendix B, as well as the data collated by Evans and Frick (2001), also reproduced in Appendix B.

Table 6.14 summarizes the endpoints from the literature wherein a biological response was observed at a nominal NaCl concentration of less than 760 mg/L. The ecological relevance of all three of these is doubtful.

76

Table 6.15: Lowest Observed Effects Levels – NaCl

Taxon Observed Effect

Exposure Time

Conc. (mg/L NaCl)

Test water and misc. Reference

aquatic hyphomycetes (fungi)

increased sporulation above controls

48 h 659 soft water Sridhar & Barlocher, 1997

Paramecium tetrourelia

17% reduction in cell division

2 h 562 Tris Buffer Ito et al., 1977

Pimephales promelas (fathead minnow fry)

smaller size 3 d 734 unknown Birge et al, 1985

The lowest observed effects concentration for the other chloride salts are actually lower than this, as discussed below.

The estimated species sensitivity distributions for aquatic organisms exposed directly to KCl, CaCl2 and MgCl2 are illustrated in Figure 6.8, 6.9, and 6.10, respectively. These suggest that the toxicity of the salts is different depending on the ion pairs involved. In other words, toxicity does not appear to simply be a response to the salinity or osmolality of the exposure medium.

77

Figure 6.8: Approximated species sensitivity distribution for KCl (mg/L) effects on aquatic life – longer term exposures and mortality.

Log10[KCl]

0

20

40

60

80

100

%ileof SSD

% of species affected (LC50 level) = 60.6 log10[KCl] - 121

p < 0.001, r = 0.922

10 100 1,000

100 mg/L

70 mg/L

78

Figure 6.9: Approximated species sensitivity distribution for CaCl2 (mg/L) effects on aquatic life – longer term exposures and mortality.

Figure 6.10: Approximated species sensitivity distribution for MgCl2 (mg/L) effects on aquatic life – longer term exposures and mortality.

0

20

40

60

80

100

%ileof SSD

1,000 10,000100

Log10[CaCl2]

% of species affected (LC50 level) = 45.3 log10[CaCl2] - 98.3

p < 0.001, r = 0.972

100 mg/L

150 mg/L

0

20

40

60

80

100

%ileof SSD

1,000 10,000100

% of species affected (LC50 level) = 53.3 log10[MgCl2] - 95.6

p < 0.001, r = 0.962

Log10[MgCl2]

30 mg/L

60 mg/L

79

Figure 6.11: Comparative toxicity of different chloride salts – mortality endpoints.

Figure 6.11, in particular, suggests that the toxicity of the chloride ion in aquatic environments is influenced by the accompanying cation. KCl appears to be far more toxic to aquatic organisms on a molar or milliequivalent basis than NaCl or the other chloride salt pairs. This is, in fact, consistent with the research by Mount et al. (1997) as described previously.

The lower end of the data distribution for lethality in response to MgCl2 or CaCl2 exposure was similar: The 5th percentile of the ranked mortality data occurred at around 100 to 200 mg/L Cl-, while the 5th percentile for NaCl was an order of magnitude higher than this. While these are mortality as opposed to non-lethal effects data, the most sensitive endpoints in the data distribution

100 1,000 10,000

[Chloride ionl] (mg/L)

99

1

50

95

5

90

10

30

70

Ran

k Pe

rcen

tNaClKClCaCl

2

MgCl2

80

were generally based on longer-term exposures (Appendix B-4). The lowest LC50 for calcium chloride was observed in Daphnia magna (Biesinger et al., 1972) based on a 4.2 d exposure. The lowest LC50 for magnesium chloride was observed in the crayfish Austropotamobius pallipes pall (Boutet and Chaisemartin, 1973) based on a 21 day exposure.

Based on the available data, the toxicity of different chloride salts when expressed on the basis of equivalent chloride concentrations is –

KCl > MgCl2 > CaCl2 > NaCl

Evans and Frick (2000) estimated a threshold chloride toxicity to aquatic life of around 210 mg/L chloride ion, based on NaCl literature-derived toxicity data. We conclude herein that this is perhaps conservative based on all available NaCl aquatic toxicity data, taking into account chronic endpoints. When all chloride salts are considered, however, a limited number of the toxicity data provided in Appendix B-4 are lower than this when expressed on the basis of nominal chloride concentration. These include:

• MgCl2 (as Cl- conc) 21 day reproduction – EC50 for Daphia magna of 93 mg/L;

• MgCl2 (as Cl- conc) 21 day immobility – EC50 for Daphia magna of 141 mg/L;

• MgCl2 (as Cl- conc) 48 h immobility – EC50 for the calanoid copepod Eudiaptomus padanus padanus of 134 mg/L.

Dowden and Bennett (1965) and Mount et al. (1997) observed 50 h or 48 h LC50 values for D. magna that were consider higher than this (702 mg/L Cl- and 990 mg/L Cl-, respectively).

81

Figure 6.12: Comparative toxicity of KCl and NaCl

1:1

Fathead minnow7-d LOEC (mortality)

0 4,000 8,0006,0002,000NaCl LC50 (mg/L)

KCl LC50(mg/L)

0

1,000

2,000

3,000

4,000

5,000

1:1KCl as ChlorideLC50

(mg/L)

0

1,000

2,000

NaCl as Chloride: LC50 (mg/L)

1,000 2,000 3,000 4,0000

82

There are a limited number of studies wherein both KCl and NaCl were used as reference toxicants. These allow a direct comparison of the toxicity of the two different salts. It appears that KCl is a special case with regard to salt ion toxicity to aquatic life. Given that the vast majority of road salt and produced water releases have very minor contributions of potassium ion, the KCl toxicity data reviewed herein were not deemed to be representative of salt related soil contamination issues where sodium and chloride are the dominant ions.

Overall, it is concluded that the relative aquatic toxicity of various salts is not fully explainable based on the measurement in isolation of either than cation or anion. Toxic effects to various organisms are more likely associated with ion imbalances; for example, extreme ranges in calcium:potassium ratios relative to typical environmental and physiological conditions. In addition, the importance of ion imbalance as opposed to single ion concentrations in the ambient environment is probably greater for KCl, MgCl2 and CaCl2 than for NaCl.

Even though effects on aquatic organisms might be more influenced by ion imbalances than the absolute concentrations of individual ions, it is nonetheless necessary for the purpose of deriving a matrix soil standard to define a minimum concentration in the aquatic environment for chloride, above which risks to aquatic life might occur. It was assumed, therefore, that the NaCl aquatic toxicity data best reflects the toxicity of salt releases with the least confounding influence of toxicity more directly associated with ion imbalances, and the effects of the cation. This is deemed to be appropriate since the cation from salt releases has only limited potential to migrate in groundwater to surface water bodies relative to chloride ions. In addition, NaCl is anticipated to represent 80% or more of the salt contamination at sites in the province of British Columbia, based on the presence of road salt release sites in particular.

Given this assumption, a chloride aquatic life threshold was derived as shown in Table 6.16. This was derived as the regression-based estimate of the 0%ile of the estimated species sensitivity distributions, using a log-linear regression approach.

83

Table 6.16: Final Estimated Aquatic Life Thresholds

Salt ion Toxicity as - O% of SSD (mg/L)

Lower 95% C.I. of

regression (mg/L)

Threshold as (anion, cation) conc. (mg/L)

chloride NaCl 760 NU1 460 mg/L Cl- potassium KCl 100 70 37 mg/L K+

Note: 1. not used due to limited non-lethality endpoint data.

A similar estimate is provided for potassium ion, based on the assumption that the cation alone contributes to the aquatic life toxicity. This is provided herein for illustrative purposes only. The extrapolation of this result from the collated laboratory toxicity test data to the field setting is likely to be inappropriate, in light of the preceding discussion.

USEPA (1988) Aquatic Life Guideline for Chloride

The USEPA (1988) developed a chloride water quality guideline that was deemed to be protective of locally important aquatic species, provided that longer–term (> 4 day average) concentrations do not exceed 230 mg/L more than once every three years. Further, the USEPA specified that the 1 hour average chloride concentration should not exceed 860 mg/L more than once every three years.

Policy guidance in British Columbia allows for the use of a formally adopted guideline from another jurisdiction in the absence of formal guidance from within Canada.

Draft Ambient Water Quality Guideline for Chloride

Following the final derivation of a provisional aquatic life threshold as described above, the Water, Air and Climate Branch of BC WLAP sponsored the independent derivation of an “ambient water quality guideline for chloride”

84

(Nagpal et al. 2002 draft) using approved British Columbia and CCME protocols for the derivation of water quality guidelines. The derivation had not been subjected to a technical or public review at the tie of finalization of this report, so there is some uncertainty about what a final approved chloride guideline for surface waters might look like. Nonetheless, the draft chronic guideline was used to calculate a corresponding soil standard that is protective of aquatic life, in anticipation of future developments.

The origin of the draft chronic (30-d average) chloride guideline is briefly reviewed herein; however, interested readers are directed to the original documents.

The most sensitive toxicity endpoint for chronic, non-mortality-type responses was identified from the peer-reviewed and grey literature on aquatic toxicity of chloride compiled by Evans and Frick (2000) and based on the salt matrix standard derivation described herein. Degreave et al. (1992) estimated that an average concentration of 735 mg/L chloride (based on 14 separate trials, involving many different laboratories) after 7 days of exposure resulted in a 50% reduction in reproduction. This is the lowest Lowest Observed Effect Concentration (LOEC) available from the existing literature. A five-fold safety factor was applied to this toxicity endpoint to arrive at a chronic chloride water quality guideline of 147 mg/L. Whereas the CCME protocol prescribes the application of a 10-fold safety factor to convert a lowest LOEC based on a chronic response to a water quality guideline, British Columbia by policy and precedent prescribes the use of a safety factor in the range of 2 to 10, depending on the availability of relevant toxicity information.

85

6.4 BC Contaminated Sites Soils Taskgroup (CSST) Model Results

Table 6.16 presents the default model input parameters adopted by CSST, based on a ‘generic’ site. Given the nature of Tier I guidance within Canadian jurisdictions, the default site parameters assume that conditions are optimal, or “worst-case” for the exposure of aquatic life (or other receptors) from a mass of salt contaminated soils on site, based on groundwater transport. No attempt was made to calibrate the model for salt ions; however, the model accounts for the known primary influences on the groundwater fate of chloride ion. The CSST default values are considered typical of the conditions for the lower Fraser River/Vancouver area of British Columbia.

In deriving modified estimates of site parameters, it is important to note that some of the properties are linked. The modification of one parameter in the suite must be carried out in careful consideration of the values of the rest of the suite, otherwise the modeling predictions are invalid:

Suite 1 Suite 2 Suite 3 source soil

volume climatic conditions subsurface environ.

X source dimension length

P precipitation rate x distance from source to receptor

Y source dimension width

(RO + EV)

run-off and evaporation

n contaminated soil porosity

Z source dimension depth

D1/2US days when ground surface temp is below 0o C.

nu water-filled porosity

ne effective porosity foc soil org. C. fraction V Darcy velocity in

saturated zone d depth to unconfined

aquifer da depth of unconfined

aquifer ρρρρb soil dry bulk density pH(s) soil pH pH(gw) groundwater pH

The default assumptions used herein are based on salt-contaminated soils at a generic site with a biota-containing surface water body, livestock watering

86

dugout, or drinking water well that is within 10 m in a down-gradient direction. The site is assumed to have a 3 m unsaturated zone, which is contaminated throughout its entire depth at the source. As a worst case, the soil is assumed to have limited organic carbon content (0.5%), is highly permeable, and the subsurface environment remains unfrozen throughout the year.

Table 6.17: Default Model Input Parameters and Site-Specific Model Calibration Data

Parameter Units Default CSST Value

Contaminant Source Width m 30

Contaminant Source Depth m 3

Contaminant Source Length m 5

Distance to Receptor m 10

Precipitation m/yr 1.000

Runoff & Evaporation m/yr 0.454

Precipitation minus Runoff and Evaporation m/yr

Depth to Groundwater (water table) m 3.0

Half-life in unsaturated zone days substance specific

Partition Coefficient, Kd and KOC mL/g substance specific

Weight fraction of organic carbon in soil, foc [/] 0.006

H2O-filled porosity (unsaturated) [/] 0.1

Air filled porosity (unsaturated) [/] 0.2

Henry's Constant = H*42.3 [/] substance specific

Days with surface temp. < 0 deg. C days 0

Darcy velocity in saturated zone m/yr 12.6

Depth of unconfined aquifer m 5

Total porosity (saturated) [/] 0.3

Effective porosity (saturated) [/] 0.2

Soil bulk density g/cm3 1.74

Maximum solubility of contaminant mg/L substance specific

Half-life in saturated zone days substance specific

87

The distance between the contaminated soil mass and the nearest down-gradient surface water body that supports aquatic life is obviously an important aspect of the fate predictions based on the groundwater model.

6.4.1.1 Aquatic Life Protection

The above-described standardized (CSST) assumptions were used along with the BC Environment approved groundwater model to estimate the concentrations of available/extractable chloride ion in soil beyond which there might be elevated risks to aquatic life.

Section 6.3.2.3 summarizes options for establishing a threshold concentration for chloride in water that is protective of aquatic life, as a pre-requisite to the calculation of chloride concentrations in soil beyond which aquatic life might be at risk. Possible chloride thresholds in water examined herein include –

1. 460 mg/L Cl-: derived herein

2. 147 mg/L Cl-: [Nagpal et al., 2002 (draft)]

3. 213 mg/L Cl-: from Evans and Frick (2000) contribution to the CEPA review.

4. 230 mg/L Cl-:[USEPA, 1988]

A water benchmark of 460 mg/L was initially used as an input to the groundwater model, and to conduct a variety of sensitivity analysis (see also Addendum A to this report). The results of this analysis follow.

After detailed model calculations were completed, they were repeated to arrive at Kd-dependent soil quality standards, assuming a chloride aquatic life protective threshold of 147 mg/L and 230 mg/L.

For the initial evaluation of soil Cl- concentrations for aquatic life protection, the following estimates were used initially:

• Aquatic life protective threshold at point of exposure = 460 mg/L Cl- • Allowing for a ten-fold dilution between groundwater and the receiving

environment at the point of exposure, the maximum acceptable groundwater concentration of Cl- is 4,600 mg/L

88

• Cl- Kd value = 0 • Results of various model runs are provided in Table 6.7

Table 6.18: Summary of model runs for draft aquatic life standard: draft aquatic life soil standards (mg/kg chloride ion in soil) based on variations in (i) distance from the soil to the receptor, (ii) aquatic life threshold, and (iii) annual precipitation

(i) D

ista

nce

to

Rec

epto

r

(ii) Assumed freshwater life threshold x 10

(iii) Annual precip. (m/yr) assume FWAL x 10= 4600

mg/L Precip (m/y);

(ro + evap = 45% of precip.)

(m) 25 mg/L

100 mg/L

200 mg/L

500 mg/L

1000 mg/L

4,600 mg/L 0.1m/y 0.63

m/y 1 m/y 6.3 m/y

5 4.8 19 38 95.1 190 875 10 4.8 19 38 95.1 190 875 1440 919 875 707 20 4.8 38 875 50 4.9 19.7 39 98.4 197 906 100 6.7 26.7 53 134 267 1230 2030 1290 1230 994 200 11.8 47 94 235 470 2170 300 400 500 28.3 113 226 566 1130 5210 750

1000 56.3 225 450 1130 2250 10400 17100 10884 10400 8370 2000 3000 5000 281 1120 2250 10000 562 2250

At a distance of 10 m between a surficial mass of salt-contaminated soil and an affected surface water body, the BCE groundwater model, along with standardized assumptions, predicts that a soil concentration of 875 mg/kg freely dissociable chloride ion would lead to a concentration in the surface water body, after a further ten-fold dilution of the affected groundwater of 460 mg/L – the assumed threshold level for aquatic life protection.

89

The interrelationship between acceptable soil concentration and assumed distance between the source and receptor area is explored in Table 6.17, as well as in Figure 6.12 Chloride ion is expected to move conservatively with the groundwater, without any appreciable retardation, and without any potential for reduction through mechanisms other than the mixing of the groundwater with uncontaminated adjacent water masses. Because of this, an increase in the groundwater travel distance from 10 meters to 100 meters or greater is not accompanied by large differences in the allowable concentration of the source soils.

10 100 1000 100000

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

25 mg/L

100 mg/L

210 mg/L

500 mg/L

1000 mg/L

2100 mg/L

Calc

ulat

ed A

quat

. Life

Soi

l Qua

lity

Leve

l (m

g/kg

Cl- )

Distance from Source to Surface Water Body (m)

Figure 6.13: Predicted soil protective levels for freely dissociable chloride ion in relation to distance of the water body from the contaminant source and maximum acceptable groundwater concentration based on aquatic life protection

The generic modeling assumptions also include an infinite contaminant source. Based on this, it would be expected that any increase in surface infiltration with the contaminated zone (e.g. through an increase in the

90

predicted annual rainfall) would be accompanied not by any further potential for dilution once the salt ions are introduced to groundwater, but rather by enhanced salt mass transfer to the underlying groundwater. As shown in Table 6.17, therefore, the model under some conditions predicts an inverse relationship between annual precipitation rates and environmentally acceptable chloride concentrations in soil. This is the one aspect of the model wherein the theoretical construct is at odds with expected environmental fate. Since infiltrating precipitation or snow melt along the offset path does not pass through the contaminated soil mass, dilution through infiltration would be expected to more than offset the increased leaching at the source. For most contaminants, concentration declines along the flow path are likely to be attributed primarily to degradation and dispersion. In the case of chloride ion, however, additional mixing and dilution due to infiltration along the flow path may be the major contributor to dilution at many sites.

The groundwater modeling predictions were found to be highly sensitive to the choice of Kd values for chloride or the other salt ions. Table 6.19 provides calculated aquatic life protective soil concentration thresholds for chloride, based on different assumptions regarding soil-groundwater partitioning.

Table 6.19: Model estimates of chloride soil concentration (mg/kg) thresholds for the protection of aquatic life – dependence on assumptions regarding Kd and using an aquatic life water quality threshold of 460 mg/L.

Kd Distance (m) 0 0.1 0.25 0.5 1

10 875 2400 4680 8490 16100

20 875 2400 4680 8490 16100

50 906 2480 4850 8780 16700

100 1230 3370 6580 11900 22600

200 2170 5930 11600 21000 33800

500 5210 14300 27900 50500 95800

1000 10400 28400

Reasonable chloride Kd estimates for coarse-textured sandy soils are probably within the range from 0 to 0.1; however, an assumed Kd of even 0.1 results in an apparently acceptable chloride soil concentration that is more than 2.5 times higher than when assuming no potential for interactions with soil particles.

91

It was noted in Section 6.3.2.3 than KCl appears to be far more toxic to aquatic organisms than the other chloride-containing salts, probably due to toxic effects of the potassium ion. In spite of the greater toxicity of potassium to aquatic life when introduced directly to experimental units, the much lower groundwater mobility suggests that soil values for potassium which are protective of aquatic life are not likely to drive remedial or risk management efforts at salt contaminated sites.

Based on Figure 6.7, a threshold effects level in the receiving environment of 37 mg/L KCl as potassium ion is likely to be protective of the vast majority of aquatic species in a given locale. Assuming that an acceptable groundwater concentration is ten times the acceptable exposure concentration, an aquatic life based ground water value of 370 mg/L K+ was put into the groundwater model, along with Kd values in the range previously described. The model results, shown in Table 6.19, suggest that potassium effects on aquatic life in adjacent water bodies are unlikely to be of concern at the vast majority of salt-contaminated sites.

Table 6.20: Estimated soil quality thresholds for potassium based on aquatic life protection

Assumed K+ Kd Soil Type (see Table 6.9) Estimated soil quality threshold (mg/kg K+)

5 RESRAD default 6,190 15 Sand 18,400 55 Loam 67,400 75 Clay 91,900

200 Organic 245,000

The model runs for chloride ion and aquatic life protection were repeated assuming an applicable chloride ion water quality guideline for the protection of aquatic life of 147 mg/L (Nagpal et al., 2002 draft) or 230 mg/L (USEPA, 1988). The results are provided in Table 6.21.

92

Table 6.21: Model estimates of chloride soil concentration (mg/kg) thresholds for the protection of aquatic life – dependence on assumptions regarding Kd and using an aquatic life water quality threshold of 147 mg/LA or 230 mg/LB.

Kd Distance (m) 0 0.1 0.25 0.5 1

Aquatic Life Guideline = 147 mg/L Cl-; corresponding groundwater conc. = 1,470 mg/L assuming a 10-fold dilution in the surface water body prior to point of interaction with the receptor.

10 280 520 770 1000 1300

20 280 520 770 1000 1300

50 290 540 790 1000 1300

100 390 740 1100 1400 1800

200 690 1300 1900 2500 3100

500 1700 3100 4600 6000 7500

1000 3300 6200 9100 11900 15000

Aquatic Life Guideline = 230 mg/L Cl-; corresponding groundwater conc. = 1,470 mg/L assuming a 10-fold dilution in the surface water body prior to point of interaction with the receptor.

10 440 820 1200 1600 2000

20 440 820 1200 1600 2000

50 450 850 1250 1600 2000

100 620 1200 1700 2200 2800

200 1100 2000 3000 3900 5000

500 2600 4900 7100 9400 11700

1000 5200 9700 14200 19000 23000

A: Based on Nagpal et al. (2002 draft)l B: Based on USEPA (1988).

93

6.4.1.2 Agricultural Land Uses – Irrigation and Livestock Drinking Water

A lower threshold occurs at a chloride concentration of 100 mg/L in irrigation water for foliar damage in more sensitive plant species (CCME, 1999). Based on this toxicological threshold, appropriate soil chloride levels are provided in Table 6.21, estimated using the BCE groundwater model and a range of Kd values. As previously mentioned, Kd values for chloride in the range of 0 to 0.1 are deemed to be reasonable, given the generic nature of estimates provided herein.

Table 6.21: Range of estimated soil chloride thresholds for the protection of crops irrigated with groundwater on agricultural lands

Kd estimate Associated soil quality threshold estimate (mg/kg chloride)

0 19 0.05 36 0.1 52 0.2 85 0.5 190 1 350 2 680 5 1,700

Table 6.22 provides similar groundwater modeling estimates based on a livestock watering threshold for calcium of 1,000 mg/L.

Table 6.22: Range of estimated soil calcium thresholds for livestock protection (drinking water) on agricultural lands

Assumed Ca2+ Kd (mL/g) Soil Type (see Table 6.9) Estimated soil quality threshold (mg/kg Ca2+)

5 Sand 16,700 10 33,300 30 Loam 99,500 50 Clay (RESRAD default) 166,000 90 Organic 298,000

94

6.4.1.3 Human Health – Groundwater Used for Drinking Water

The aesthetic drinking water guidelines for chloride (250 mg/L) and sodium (200 mg/L) were used to estimate threshold soil ion concentrations applicable at sites where there is current or future potential to use groundwater as a drinking water source.

For sodium ions, assuming a Kd value of 20 ml/g, a soil quality threshold was estimated from the groundwater modelling exercise to be 13,300 mg/kg Na+. For chloride, Table 6.23 provides the range of estimates based on different assumed scenarios for soil-water partitioning of chloride ions, as estimated by the Kd value.

Table 6.23: Range of estimated soil chloride thresholds for aesthetic drinking water objectives where there is the potential for use of groundwater by humans

Kd soil quality threshold (mg/kg Cl-) 0 47

0.05 89 0.1 130 0.2 210 0.5 460 1 880 2 1,700 5 4,200

At the majority of sites in British Columbia, drinking water – when used – is drawn from deeper aquifers, as opposed to nearsurface groundwater supply. It is likely, therefore, that the groundwater model assumptions are unrealistic relative to fate processes influenced by the possible presence vertically of one or more aquitards. For this reason, the protection of drinking water supplies should be based on direct measurements in groundwater of major ion concentrations, and on monitoring over time in areas where there is concern about future introductions of salt ions to drinking water supplies from salt-contaminated sites. A set of soil numbers for the protection of human drinking water supplies was not carried forward into the draft matrix standard, therefore.

95

In addition to the aesthetic drinking water objectives discussed above, a health based soil quality threshold for sodium ingestion via drinking water was calculated.

Health Canada provides recommended values for drinking water intake by average Canadians as shown in Table 6.24.

Table 6.24: Recommended values for drinking water intake

Age (yr)

Body Wt. (kg)

Air Intake (m3/d)

Water Intake (L/d)1

Soil Intake (mg/d)

0-6 mo. 7 2 0 for breast-fed; 0.75 others 35

7 mo. – 4 13 5 0.2/0.8 50 5-11 27 12 0.3/0.9 35

12-19 57 21 0.5/1.3 20 20+ 70 23 0.4/1.5 20

Notes: 1. first number is for tapwater only; second is for tapwater plus beverages prepared from tapwater

As noted in Section 6.1.1.1, a recommended upper limit for sodium ingestion for people on salt restricted diets is 2,500 mg/day sodium. Individuals suffering from hypertension, or potentially from other salt related health effects, are considered to be among the more sensitive members of the population.

If 20% of the tolerable daily intake of 2,500 mg/day sodium is allocated to drinking water, then this exposure pathway should not contribute more than 500 mg Na+/day. In this case, the most sensitive age group will be that which consumes on average the greatest amount of water daily. Adults (20+ years) are estimated to consume an average of 1.5 L/d of drinking water, directly and through the preparation of other beverages. A health-based limit for sodium in drinking water, therefore may be calculated as –

96

( )

LNa mg 333

day waterdrinking L 1.5

dayNa mg 500

DW Na Health

+

+

=

= (11)

This figure was then used as a maximum allowable groundwater concentration, without further allowance for a ten-fold dilution. Assuming a Kd of 20 ml/g, a human health based sodium concentration threshold in soils of 22,100 mg/kg was calculated using the BCE groundwater model.

A human health-based standard for chloride ion cannot be calculated for either the drinking water or soil ingestion pathway, since a TDI estimate for chloride ion is not available from any guiding toxicological literature or regulatory agency.

97

7. Comparison with Background Concentrations of Salt Ions in Soil and Water

The natural, or background, concentrations of salt ions in soils and groundwater were reviewed in order to put the above-described toxicity based soil protective thresholds in the larger context.

7.1 Background Soil Concentrations

British Columbia Water, Land and Air Protection (BC WLAP) has developed a database of substance concentrations in soils for the different administrative regions of the province. This database, publicly available through the BC WLAP website9, was used as an indication of the naturally occurring concentrations of salt ions and related soil properties within surface soils believed to be relatively uninfluenced by human activities. The data were derived from background soil sampling studies for each region, with some geographical differences in intensity of sampling.

The collated results are amalgamated from two sampling depths at all sampling sites: 0-10 cm depth and 50-60 cm depth. Overall, the data are based on 63 sites from across the province, and 504 individual samples overall (not all substances may be available for all samples). Sampling and analytical methodologies for metals have been clearly documented. Since the samples were analyzed by ICP, the database includes results for the major cations calcium, potassium, magnesium and sodium. Unfortunately, the available results are based on pre-digestion of the soil using either an aqua regia or perchloric-nitric strong acid digestion. Such digestion would be expected to release these ions from various minerals (the major portion present) in addition to the extractable salt portion of the soil mass. The results, therefore, are not relevant to the naturally occurring concentrations of salt cations in soils, and therefore have not been provided herein. No data were found for saturated paste extractable salt cations.

The database also contains “miscellaneous” parameters, including pH, EC, total C, hardness, cyanide (strong and weak acid dissociable), Cl-, Br-, F-, nitrate, nitrite, total Kjeldahl nitrogen, phosphate, and sulphate. Unfortunately, the detailed methods are not provided in the accompanying literature. We

9http://wlapwww.gov.bc.ca/epd/epdpa/contam_sites/guidance/technical/bgsq/affbgsq.html

98

could not ascertain, therefore, that Cl- measurements would be equivalent to concentrations measured using a saturated paste method. Figure 7.1 shows estimated background soil concentrations for chloride ion. Figures providing the background concentrations of pH, EC, total carbon, weak acid dissociable cyanide, and sulfate are provided as Figure 7.2 to Figure 7.5.

99

Figure 7.1: Background soil chloride concentrations in B.C.

Chl

orid

e (m

g/kg

)

0

10

20

30

40

50

Lowe

r Mai

nlan

d

Vanc

ouve

r Isl

and

Vanc

ouve

rSo

uthe

rn In

terio

r

Koot

enay

Carib

ou

Omen

ica-

Peac

e

Skee

naN

o Da

ta

St.dev.

Upper 95% C.I.

Average

All <25 mg/kg

(N=43) (N=38)

(N=30)

(N=12)

(N=21)

(N=46)

(N=25)

60

70 Max.

142 mg/kg142 mg/kg 84 mg/kg 78 mg/kg

100

Figure 7.2: Background soil pH in B.C.

Lowe

r Mai

nlan

d

Vanc

ouve

r Isl

and

Vanc

ouve

rSo

uthe

rn In

terio

r

Koot

enay

Carib

ou

Omen

ica-

Peac

e

Skee

na

pH

3

4

5

6

7

8

9

St.dev.

Upper 95% C.I.

Average

Max.

(N=39) (N=46)

(N=28)

(N=38)

(N=36)

(N=12)

(N=24)

(N=30)

101

Figure 7.3: Background soil EC (electrical conductivity) in B.C.

Lowe

r Mai

nlan

d

Vanc

ouve

r Isl

and

Vanc

ouve

rSo

uthe

rn In

terio

r

Koot

enay

Carib

ou

Omen

ica-

Peac

e

Skee

na

0

1.00

2.00

ElectricalConductivity(mS/cm) St.dev.

Upper 95% C.I.

Average

Max.

(N=39) (N=46) (N=29)

(N=38) (N=36)

(N=12) (N=23) (N=30)

102

Figure 7.4: Background soil total carbon concentrations in B.C.

53% 51% 53%

0

10

20

30

40

Lowe

r Mai

nlan

d

Vanc

ouve

r Isl

and

Vanc

ouve

rSo

uthe

rn In

terio

r

Koot

enay

Carib

ou

Omen

ica-

Peac

e

Skee

na

TotalCarbon(%)

St.dev.

Upper 95% C.I.

Average

Max.

(N=39)

(N=46)

(N=27)

(N=38)(N=36)

(N=12)

(N=24)

(N=30)

103

Figure 7.5: Background soil sulfate concentrations in B.C.

Lowe

r Mai

nlan

d

Vanc

ouve

r Isl

and

Vanc

ouve

rSo

uthe

rn In

terio

r

Koot

enay

Carib

ou

Omen

ica-

Peac

e

Skee

naNo

Dat

a

No D

ata

No D

ata

4,800 mg/kg

0

200

400

600

800

1,000

Sulfate(mg/kg)

(N=43)

(N=38)

(N=22)(N=12) (N=30)

104

Figure 7.5: Background soil WAD cyanide concentrations in B.C.

Lowe

r Mai

nlan

d

Vanc

ouve

r Isl

and

Vanc

ouve

r

Sout

hern

Inte

rior

Koot

enay

Carib

ou

Omen

ica-

Peac

e

Skee

na

0.0

0.5

1.0

1.5C

yani

de(W

eak

Aci

d D

isso

ciab

le)

(mg/

kg)

All <5 mg/kg

No D

ata

No

Data

(N=43)

(N=10)(N=27)

(N=10)

(N=22)

(N=8)

105

Surficial soils in most regions of British Columbia tend to be naturally acidic (Figure 7.2), with average pHs on Vancouver Island of around 4.8. Soil pH around urban and semi-urban areas of Vancouver tends to be even lower, with an average of around 4.0. Surficial soil pH in the Southern Interior and Caribou region approaches near-neutral pH (average pH of 6.8 for both).

Freely dissociable chloride concentrations in British Columbia soils that are unaffected by human activities very rarely exceed 30 mg/kg (upper 95% confidence interval for chloride concentration distribution for the Lower Mainland, which was the highest of any region). Even though the coastal areas of the province might be expected to have salt-affected soils due to a recent and/or historical marine influence, this is not reflected in the background soil concentrations. Nor would it be expected to, since the transient nature of chloride ions in soil systems would result in their rapid removal after marine inputs (through geological uplift) or wet deposition of marine aerosols) have stopped. The presence of naturally saline areas in the Southern Interior does not appear to be reflected by elevated soil chlorinity either, although this might be a reflection of the sampling locations chosen, which may have avoided naturally sodic or saline soils.

The relative background soil sulfate concentrations across regions (Figure 7.5) suggests that at least some naturally saline soils were included in the samples collected based on several samples in the database with highly elevated sulfate concentrations (Figure 7.6).

106

Figure 7.6: Frequency distribution of background soil concentrations of sulfate, Southern Interior region

Electrical conductivity in background soil samples in all regions is generally low, with averages for the six regions between 0.10 and 0.20 dS/m. The upper 95% confidence limits for the dataset are also uniformly less than 0.50 dS/m. As for sulfate, EC was elevated in 2 of 38 Southern Interior background samples.

7.2 Background Groundwater Salt Ion Concentrations

Information on ambient groundwater concentrations of total or dissolved metals, major ions, pH and electrical conductivity has been compiled by Wagner (1996) on behalf of BC WLAP. Sample data were available for a number of groundwater monitoring wells in aquifers that were minimally to heavily exploited for drinking water use. The report distinguishes between different aquifer types, especially surface versus bedrock aquifers, where sufficient information was available by region, and across the province. The data available up to 1996 within Ministry records provided groundwater quality information for Regions 1 – 4, but not for 5 (Caribou), 6 (Skeena) or 7 (Omineca-Peace).

Table 7.1 provides statistical estimates of the concentration distribution of major ions, pH, and EC for regions 1 – 4. The upper range concentration of

0 20 40 60 80 100 120 1400

2

4

6

8

10

12

14

>150

mg/

kg(4

50, 4

300,

480

0 m

g/kg

)

No. o

f Sam

ples

Soil sulfate concentration (mg/kg)

107

choride ions in groundwater (e.g. 95th percentile) was 31 to 109 mg/L, depending on the region. Whereas the upper 95th percentile of chloride concentrations was higher in the Southern Interior than in regions 1, 2 or 4, the average chloride concentration was lower than for other regions. This is probably attributable to the localized influence of naturally saline soils in limited areas within the Region.

108

Table 7.1: Background concentrations of salt ions in groundwater within British Columbia

Region No.

SamplesNon-

Detects Units Mean Median Min. Max. St.Dev.95%

Conf.90th %ile

95th %ile

99th %ile

pH

1(Vancouver Island)- Bedrock Aquifers 17 0 pH

units 7.6 7.7 6.5 8.4 0.58 0.28 8.1 8.2 8.4

1(Vancouver Island)- Surficial Aquifers 17 0 pH

units 7.5 7.5 6.7 8.4 0.50 0.24 8.0 8.2 8.4

2 (Lower Mainland)- Surficial Aquifers 17 0 pH

units 7.5 7.7 6.7 8.2 0.43 0.20 7.9 8.0 8.2

3 (Southern Interior)- Bedrock (3) and Surficial

(24) Aquifers 27 0 pH

units 7.8 8 6.8 8.5 0.54 0.20 8.3 8.4 8.5

4 (Kootenay)- Bedrock (1) and Surficial (3)

Aquifers 4 0 pH

units 8.0 8.1 7.5 8.3 0.38 0.38 8.3 8.3 8.3

EC 1(Vancouver Island)- Bedrock Aquifers 17 0 dS/m 0.424 0.445 0.113 0.650 0.172 0.082 0.634 0.648 0.650 1(Vancouver Island)- Surficial Aquifers 17 0 dS/m 0.278 0.267 0.058 0.695 0.165 0.079 0.434 0.539 0.664 2 (Lower Mainland)- Surficial Aquifers 17 0 dS/m 0.166 0.154 0.067 0.342 0.076 0.036 0.256 0.275 0.329


(24) Aquifers 27 0 dS/m 0.294 243 61 610 182 69 565 581 604


Aquifers 4 0 dS/m 0.428 477 110 648 244 239 629 639 646

Chloride ion 1(Vancouver Island)- Bedrock Aquifers 17 0 mg/L 36 30 5.1 81 25 12 70 78 80 1(Vancouver Island)- Surficial Aquifers 15 0 mg/L 25 20 1.7 97 26 13 53 74 92 2 (Lower Mainland)- Surficial Aquifers 17 0 mg/L 7.7 8.5 1.1 13 3.7 1.8 12 12 13


(24) Aquifers 27 1 mg/L 10 3.9 0.35 142 27 10 14 15 109


Aquifers 4 0 mg/L 14 12 0.8 32 13 13 27 29 31

Cont’d.

109

Table 7.1: Background concentrations of salt ions in groundwater within British Columbia (cont’d)

Region No.

SamplesNon-


Conf.90th %ile

95th %ile

99th %ile

Sulfate 1(Vancouver Island)- Bedrock Aquifers 17 0 mg/L 21 18 2.8 76 18 8.3 34 46 70 1(Vancouver Island)- Surficial Aquifers 17 4 mg/L 9.5 6.0 0.7 43 11 5.3 19 24 40 2 (Lower Mainland)- Surficial Aquifers 17 7 mg/L 8.0 3.4 0.7 26 9.1 4.3 21 24 25


(24) Aquifers 27 7 mg/L 17 11 0.7 75 21 7.7 50 53 70


Aquifers 4 2 mg/L 9.1 8.0 0.7 20 9.2 9.0 18 19 19

Calcium (dissolved) 1(Vancouver Island)- Bedrock Aquifers 10 0 mg/L 30 25 2.1 71 26 16 69 70 71 1(Vancouver Island)- Surficial Aquifers 8 0 mg/L 17 14.9 3.6 33 10 7.1 29 31 33 2 (Lower Mainland)- Surficial Aquifers 16 0 mg/L 16 10 4.4 44 12 5.8 31 36 43


(24) Aquifers 16 0 mg/L 35 34 7.6 92 24 12 65 73 88


Aquifers 2 0 mg/L 61 61 12 110 70 97 100 105 109

Potassium (dissolved) 1(Vancouver Island)- Bedrock Aquifers 14 2 mg/L 1.3 0.6 0.1 10.9 2.8 1.5 1.2 4.7 9.7 1(Vancouver Island)- Surficial Aquifers 15 2 mg/L 2.1 1.9 0.28 3.9 1.3 0.65 3.6 3.7 3.9 2 (Lower Mainland)- Surficial Aquifers 12 0 mg/L 1.9 1.9 0.90 4.9 1.1 0.65 2.8 3.7 4.7


(24) Aquifers 17 0 mg/L 2.7 2.4 0.8 5.2 1.4 0.68 4.6 4.9 5.1


Aquifers 4 0 mg/L 2.5 2.5 0.7 4.2 1.6 1.6 3.9 4.1 4.2

Cont’d.

110

Table 7.1: Background concentrations of salt ions in groundwater within British Columbia (cont’d)

Region No.

SamplesNon-


Conf.90th %ile

95th %ile

99th %ile

Magnesium (dissolved) 1(Vancouver Island)- Bedrock Aquifers 10 0 mg/L 5.9 3.4 0.23 19 6.7 4.1 15 17 19 1(Vancouver Island)- Surficial Aquifers 8 0 mg/L 6.0 6.1 0.68 13 4.6 3.2 11 12 13 2 (Lower Mainland)- Surficial Aquifers 15 0 mg/L 4.3 3.4 1.1 13 3.2 1.6 7.7 9.5 12

3 (Southern Interior)- Bedrock (3) and Surficial(24) Aquifers 17 0 mg/L 11 5.9 1.5 31 9.2 4.4 24 26 30

4 (Kootenay)- Bedrock (1) and Surficial (3)Aquifers 2 0 mg/L 9.5 9.5 6.7 12 3.9 5.4 12 12 12

Sodium (dissolved) 1(Vancouver Island)- Bedrock Aquifers 14 0 mg/L 36 33 4.2 65 20 10 62 63 64 1(Vancouver Island)- Surficial Aquifers 15 0 mg/L 22 18 5.0 64 18 8.9 48 55 62 2 (Lower Mainland)- Surficial Aquifers 2 0 mg/L 5.1 5.13 4.2 6.0 1 1.8 5.9 5.9 6.0

3 (Southern Interior)- Bedrock (3) and Surficial(24) Aquifers 20 0 mg/L 12 7.15 2.1 59 13 5.7 21 30 53

4 (Kootenay)- Bedrock (1) and Surficial (3)Aquifers 4 0 mg/L 8.8 8.65 3.2 15 4.9 4.8 13 14 14

111

8. Conclusions

The derivations provided in Section 5, and substantiated in prior sections are summarized Tables 8-1, 8-2 and 8-3.

In addition, recommendations specific to soil matrix standards for salt, for modifications to existing CSST procedures, or for new procedures for naturally occurring ions are provided throughout the text in italics. The majority of these are summarized in the notes.

112

Table 8.1: SCHEDULE 5

MATRIX NUMERICAL SOIL STANDARDS1

SODIUM Ion (Na+)

COLUMN I COLUMN II COLUMN III COLUMN IV COLUMN V COLUMN VI Note

SOIL STANDARD FOR PROTECTION OF SITE-SPECIFIC FACTOR

Site-specific Factor

Agricultural (AL)

Urban Park

(PL)

Residential

(RL)

Commercial

(CL)

Industrial

(IL)

2

HUMAN HEALTH PROTECTION Intake of contaminated soil Groundwater used for drinking water

>1 000 mg/g

13 000

>1 000 mg/g

13 000

>1 000 mg/g

13 000

>1 000 mg/g

13 000

13 000

3

ENVIRONMENTAL PROTECTION Toxicity to soil invertebrates and plants Livestock ingesting soil and fodder Major microbial functional impairment Groundwater flow to surface water used by aquatic life Groundwater used for livestock watering Groundwater used for irrigation watering

190

NS

NS

NS

NS

NS

190

NS

190

NS

1 200

NS

1 200

NS

4

4

5

5

5

Notes

1. All values in ug/g unless otherwise stated. Substances must be analyzed using methods specified in protocols approved under section 53 or alternate methods acceptable to the director. 2. The site-specific factors of human intake of contaminated soil and toxicity to soil invertebrates and plants specified in this matrix apply at all sites. 3. Intake pathway of exposure modeled is inadvertent ingestion of soil. 4. NS - no standard. Insufficient acceptable scientific data exists, so no standard is calculated. 5. NS - no standard. No appropriate standard, guideline or criterion exists to use to develop a soil quality standard.

113

Table 8.2: SCHEDULE 5

MATRIX NUMERICAL SOIL STANDARDS1

CHLORIDE Ion (Cl-)

COLUMN I COLUMN II COLUMN III COLUMN IV COLUMN V COLUMN VI Note SOIL STANDARD FOR PROTECTION OF SITE-SPECIFIC FACTOR

Site-specific Factor

Agricultural (AL)

Urban Park

(PL)

Residential

(RL)

Commercial

(CL)

Industrial

(IL)

2

HUMAN HEALTH PROTECTION Intake of contaminated soil Groundwater used for drinking water Kd < 0.05 Kd 0.05 - < 0.1 Kd 0.1 - <0.15 Kd 0.15 - <0.2 Kd > 0.2

>1 000 mg/g

50 90

130 170 210

>1 000 mg/g

50 90

130 170 210

>1 000 mg/g

50 90

130 170 210

>1 000 mg/g

50 90

130 170 210

50 90

130 170 210

3,4

5 5 5 5 5

ENVIRONMENTAL PROTECTION Toxicity to soil invertebrates and plants

Livestock ingesting soil and fodder

Major microbial functional impairment

Groundwater flow to surface water used by aquatic life Kd < 0.05 Kd 0.05 - < 0.1 Kd 0.1 - <0.15 Kd 0.15 - <0.2 Kd > 0.2

Groundwater used for livestock watering

Groundwater used for irrigation watering Kd < 0.05 Kd 0.05 - < 0.1 Kd 0.1 - <0.15 Kd 0.15 - <0.2 Kd > 0.2

370

NS

NS

440 820

1200 1600 2000

NS

20 35 50 70 85

370

440 820

1200 1600 2000

20 35 50 70 85

370

440 820

1200 1600 2000

20 35 50 70 85

2 500

440 820

1200 1600 2000

2 500

440 820

1200 1600 2000

6

7

5,8 5,8 5,8 5,8 5,8

6

5 5 5 5 5

114

Notes

1. All values in ug/g unless otherwise stated. Substances must be analyzed using methods specified in protocols approved under section 53 or alternate methods acceptable to the director. 2. The site-specific factors of human intake of contaminated soil and toxicity to soil invertebrates and plants specified in this matrix apply at all sites. 3. Intake pathway of exposure modeled is inadvertent ingestion of soil. 4. Standard established based on toxic reference dose (Tolerable Daily Intake) derived for NaCl. Toxicity attributed primarily to cation (Na+), not anion (Cl-). 5. The Kd is the Kd of the soil at a site. 6. NS - no standard. No appropriate standard, guideline or criterion exists to use to develop a soil quality standard. 7. NS - no standard. Insufficient acceptable scientific data exists, so no standard is calculated. 8. Standard to protect freshwater aquatic life, based on USEPA (1988) chloride water quality guideline of 230 mg/L.

115

9. References

AEUB, 1999. Use of Produced Sand in Road Construction. Information Letter 99-02. Alberta Energy and Utilities Board. Calgary, Alberta.

Addison, J.A. and D.A. Bright. In prep. Toxicity of NaCl to Soil Inverterbrates. Draft manuscript .

Alberta Environment. 2001. Salt Contamination Assessment and Remediation Guidelines. Environmental Sciences Division, Environmental Service, Edmonton, Alberta. 88 pp.

Aquaterra Environmental. 1998a. Development of a reproduction toxicity test with Onychiurus folsomi for assessment of contaminated soils. Report prepared for Method Development and Application Section , Environmental Technology Centre, Environments Canada, Ottawa, Ontario. 28 pp+ appendices.

Aquaterra Environmental. 1998b. Development of earthworm toxicity tests for assessment of contaminated soils. Report prepared for Method Development and Application Section, Environmental Technology Centre, Environment Canada, Ottawa, Ontario. 28 pp + appendices.

Ayers, R.S. 1977. Quality of water for irrigation. J. Irrig. Drainage Div. Proc. American Society Div. Engineers 103: pp 135-154.

Bañuls, J., and E. Primo-Millo, 1992. Effects of chloride and sodium on gas exchange parameters and water relations of Citrus plants. Physiol. Plant. 86: 115-123.

BCE (British Columbia Ministry of Environment, Lands and Parks). 1996. Overview of CSST Procedures for the Derivation of Soil Quality Matrix Standards for Contaminated Sites (January 31, 1996).

Biesinger, K.E. and G.M. Christensen. 1972. Effects of various metals on survival, growth, reproduction, and metabolism of Daphnia magna. J. Fish Res. Board Can. 29(12): 1691-1700.

116

Birge, W.J., J.A. Black, A.G. Westerman and J.E. Hudson. 1980. Aquatic toxicity tests on inorganic elements occurring in oil shale. In: C. Gale (Ed ) Oil Shale Symposium: Sampling, Analysis and Quality Assurance, March 1979; EPA-600/9-80-022, US EPA, Cincinnati, OH: pp. 519-534.

Bresler, E., B.L. McNeal and D.L. Carter. 1982. Saline and Sodic Soils: Principles-Dynamics-Modeling. Springer-Verlag, NY. p. 166-193.

Bright, D.A. and J.A. Addison. 2000. Derivation of Salt Soil Quality Standards Under the British Columbia Contaminated Site Regulation (BC CSR): 1. Problem Formulation and Discussion Document. Report to the Salt Steering Committee, Government of British Columbia. 38 pp.

Brownell, PF. 1979. Sodium as an essential micronutrient element for plants and its possible role in metabolism. Adv. Bot. Res., 7: 117-224.

Boutet, C. and C. Chaisemartin. 1973. Specific toxic properties of metallic salts in Austropotamobius pallipes pallipes and Orconectes limosus. C R Soc. Biol. (Paris) 167(12):1933-1938 (in French).

Cain, N.P., B. Hale, E. Berkalaar and D. Morin. 2000. Review of the Effects of NaCl and Other Road Salts on Terrestrial Vegetation in Canada. Report to Environment Canada. 70 pp plus appendices.

Carter, M. R., Ed. 1993. Soil Sampling and Methods of Analysis. Canadian Society of Soil Science. Lewis Publishers, Boca Raton, FL. 823 pp.

Canadian Council of Ministers of the Environment (CCME). 1999. Canadian Environmental Quality Guidelines. Canadian Council of Ministers of the Environment, Winnipeg.

Canadian Council of Resource and Environment Ministers (CCREM). 1987. Canadian Water Quality Guidelines. Prepared by the Task Force on Water Quality Guidelines.

Chalmers J et al. (WHO-ISH Hypertension Guidelines Committee). 1999. World Health Organization - International Society of Hypertension Guidelines for the Management of Hypertension. J. Hypertens., 1999, 17:151-185.

117

Crouau, Y., R. Chenon and C. Gisclard. 1999. The use of Folsomia candida (Collembola, Isotomidae) for the bioassay of xenobiotic substances and soil pollutants. Appl. Soil Ecol. 12: 103-111.

Cutler J.A., D. Follman and P.S. Alexander. 1997. Randomised controlled trials of sodium reduction: An overview. Am. J. Clin. Nutr. 65 (Suppl): 643S-651S.

Davenport, R., 1998. Non-selective cation channels in wheat roots. Ph.D. Thesis. Cambridge University, Cambridge, UK

Delegard, C. H. and G. S. Barney. 1983. Effects of Hanford High-Level Waste Compounds on Sorption of Cobalt, Strontium, Neptunium, Plutonium, and Americium of Hanford Sediments. RHO-RE-ST-1 P, Rockwell Hanford Operations, Richland, Washington.

Diamond, J.M., E.L. Winchester, D.G. Mackler and D. Gruber. 1992. Use of the mayfly Stenonema modestum (Heptageniidae) in suacute toxicity assessments. Environ. Toxicol. Chem. 11(3):415-425.

Domenico, P. A. 1987. An analytical model for multidimensional transport of a decaying contaminant species. J of Hydrology, 91.

Domenico, P.A. and G.A. Robbins, 1984. A new method of contaminant plume analysis. Ground Water, 23: 476-485.

Domenico, P.A. and F.W. Schwartz. 1990. Physical and Chemical Hydrogeology. John Wiley and Sons. 824 pp.

Dowden. B.F. and H.J. Bennett, 1965. Toxicity of selected chemicals to certain animals. J. Water Pollut. Control Fed. 37(9): 1308-1316.

Environment Canada. 1984. Sodium Chloride. Environmental and Technical Information for Problem Spills. Technical Services Brand, Environmental Protection Programs Directorate, Environmental Protection Services, Ottawa, Ontario.

118

Environment Canada. 2000. Canadian Environmental Protection Act, 1999. Priority Substances List Assessment Report Road Salts. Environment Canada and Health Canada, Ottawa, Ontario. 105 pp. plus appendices

Evans, M. and C. Frick. 2000. The Effects of Road Salts on Stream, Lake and Wetland Ecosystems. CEPA Supporting Document. 207 pp.

Fischer, E. and L. Molnár. 1997. Growth and reproduction of Eisenia fetida (Oligochaeta, Lumbricidae) in semi-natural soil containing various metal chlorides. Soil Biol. Biochem. 29: 667-670.

Gaudet, C., D. Bright, K. Adare and K. Potter. 2001. A rank-based approach for deriving Canadian soil and sediment quality guidelines, in The Use Of Species Sensitivity Distributions (SSD) In Ecotoxicology. L. Posthuma and G.W.Suter, editors. CRC Press, Boca Raton, FL. pp. 255-274.

Hanan, J.J., W.D. Holley, and K.L. Goldsberry. 1978. Greenhouse Management. Springer-Verlag, NY.

Höbel, S., J. Gerdsmeier, A. Mellin and H. Greven. 1992. Die Wirkung zweier Streusalze auf Enchytraeiden eines Wiesenbodens. Zool. Anz. 228:107-128.

Hopkins, S.P. 1997. Biology of Springtails (Insecta: Collembola) Oxford University Press. N.Y. 330 pp.

Howat, D. 2000. Acceptable salinity, sodicity and pH values for boreal forest reclamation. Alberta Environment, Environmental Sciences Division, Edmonton, Alberta. Report #ESD/LM/00-2. (http://www3.gov.ab.ca/env/info/infocentre/publist.cfm)

Johnston, C.T., R.C. Sydor and C.L.S. Bourne. 2000. Impact of Winter Road Salting on the Hydrogeological Environment – An Overview. Prepared for Environmental Resource Group on Road Salts, Ottawa, Ontario. 50 pp.

Kaplan, D.L., R. Hartenstein, E.F. Neuhauser and M.R. Malecki. 1980. Physicochemical requirements in the environment of the earthworm Eisenia foetida. Soil Biol. Biochem. 12:347-352

http://www.gov.ab.ca/env/info/infocentre/index.cfm

119

Krupka, K.M., D.I. Kaplan, G. Whelan, R.J. Serne and S.V. Mattigod. 1999. Understanding Variation in Partition Co-efficient, Kd, Values. Volume I: The Kd Model, Methods of Measurement, and Application of Chemical Reaction Codes. USEPA Office of Air and Radiation Report EPA 402-R-99-004A, August 1999. 212 pp.

Landis, T.D., R.W. Tinus, S.E. McDonald and J.P Bounett. 1989. Quantity and Quality of Irrigation Water, in Seedling Nutrition and Irrigation. Vol. 4. The Container Tree Nursery Manual, Agricultural Handbook 674, Washington, D.C. 119 pp.

Law, M.R. 1997. Epidemiological evidence on salt and blood pressure. Am J Hypertens. 10:42S-45S.

Løkke, H. and C.A.M. van Gestel. 1998. Soil Toxicity tests in risk assessment of new and existing chemicals. pp.3-20 In: Løkke, H. and C.A.M. van Gestel (eds.) Handbook of Soil Invertebrate Toxicity Tests. John Wiley and Sons. UK. 281 pp.

Maas E.V. 1990. Crop salt tolerance. In: Agricultural Salinity Assessment and Management Manual. K.K. Tanji (ed.). ASCE, New York. pp. 262-304.

Marschner, H. 1995. Mineral Nutrition of Higher Plants, 2nd ed. Academic Press.

Martikainen, E.A.T. and P.H. Krogh. 1999. Effects of soil organic matter content and temperature on toxicity of dimethoate to Folsomia fimetaria (Collembola: Isotomidae). Environ. Toxicol. Chem. 18: 865-872.

Maas, M.V. 1996. Plant response to soil salinity. 4th National Conference and Workshop on the Productive use and Rehabilitation of Saline Lands. March 5-30. Albany, Western Australia. Pp. 385-391.

Maynard, D.G., K.I. Mallett and C.L Myrholm. 1996. Sodium carbonate inhibits emergence and growth of green-house grown white spruce. Can. J. Soil Sci. 77: 99-105.

Maynard, D.G., K.I. Mallett and C.L. Myrholm, submitted. Growth and nutrient uptake response of white spruce seedlings to salinity derived from acetate soils.

120

Morin, D., W. Snodgrass, J. Brown and P.A. Arp. 2000. Impacts evaluation of road salt loads on soils and surface waters. Report submitted to the Environment Canada CEPA Priority Substances List Environmental Resource Group on Road Salts. June 2000. Environment Canada, Commercial Chemicals Evaluation Branch, Hull, Quebec.

Moul, D.J. 2001. Inorganic chloride salt (road salt) toxicity tests - impacts on terrestrial organisms. Report prepared by the Pacific Environmental Sciences Centre, Environment Canada, Vancouver BC. 22 pp + attachments.

Mount, D.R., D. Gulley, J.R. Hockett, T.D. Garrison and J.M. Evans. 1997. Statistical models to predict the toxicity of major ions to Ceriodaphnia dubia, Daphnia magna and Pimephales promelas (Fathead minnows). Environ. Toxicol. Chem. 16: 2009-2019.

Nagpal, N.K., D.A. Levy an D.D. MacDonald, 2002 (Draft). Ambient Water Quality Guidelines for Chloride. 33 pp.

Rösgen, Ch., J. Gerdsmeier and H. Greven. 1991. Laboruntersuchungen zur Wirkung zweier Streusalze auf Folsomia candida (Collembola). Z. angew. Zool. 78: 445-463.

Rösgen, Ch., J. Gerdsmeier and H. Greven. 1993. Die Wirkung zweier Streusalze auf Collembolengemeinschaften eines Wiesenbodens. Pedobiologia 37: 107-121.

Saskatchewan Upstream Petroleum Sites Remediation Guidelines. 2000.Guideline No. 4- Update1, September 2000. Saskatchewan Petroleum Industry/Government Environmental Committee. 24pp.

Schrader, G., K. Metge and M. Bahadir. 1998. Importance of salt ions in ecotoxicological tests with soil arthropods. Appl. Soil Ecol. 7: 189-193.

Sheppard, M.I. and D.H. Thibault, 1990. Default soil solid/liquid partition coefficients, Kds, for four major soil types: A compendium. Health Physics 59:471–482.

Sheppard, J.C., J.A. Kittrick and T.L. Hart. 1976. Determination of Distribution Ratios and Diffusion Coefficients of Neptunium, Americium, and Curium in

121

Soil-Aquatic Environments. RTO-221-T-12-2, Rockwell Hanford Operations, Richland, Washington.

Singleton, H.J. 2000. Ambient Water Quality Guidelines for Sulphate. Water Management Branch, Ministry of Environment, Lands and Parks. 52 pp.

Spehar, R.L. 1987. U.S. EPA, Duluth, MN. (Memorandum to C. Stephan. U.S. EPA, Duluth, MN. June 24). (In U. S. EPA 1988)

Squires, V. 1994. Overcoming salinity with seawater: saltbushes as a useful crop. Search 2: 9-12.

Stumm, W. &J. J. Morgan 1981. Aquatic Chemistry , 2nd edition. John Wiley & Sons, New York, 780 pp.

Termaat, A & Munns, R, 1986. Use of concentrated macronutrient solutions to separate osmotic from NaCl-specific effects on plant growth. Australian Journal of Plant Physiology, 13: 509-522.

United States Deptarment of Agriculture (USDA). 1954. Saline and Alkali Soils. Diagnosis and Improvement. Out of print. (http://www.ussl.ars.usda.gov/hb60/hb60/htm)

United States Department of Agriculture (USDA). 1994. Forest Nursery Notes – Water as a Limiting Factor. 26 pp.

United States Environmental Protection Agency (USEPA). 1988. Ambient water quality criteria for chloride. USEPA, Washington, D.C.

Wagner, M. 1996. Study of Groundwater Quality in British Columbia. Final Report. Unpublished report for the Ministry of Environment, Lands and Parks. 22pp + appendices.

Whelton PK, L.J. Appel, M.A. Espeland, W.B. Applegate, W.H. Ettinger, J.B. Kostis, S. Kumanylaka, C.R. Lacy, K.C. Johnson, S. Folmar and J.A. Cutler, for TONE Collaborative Research Group. 1998. Sodium reduction and weight loss in the treatment of hypertension in older persons. A randomized controlled trial of nonpharmacologic interventions in the elderly (TONE). JAMA 279: 839846.

http://www.ussl.ars.usda.gov/hb60/hb60/htm

122

Werkhoven, C.H.E. 1966. Germination and survival of colorado spruce, scots, pine, caragana, and siberian elm at four salinity and two moisture levels. Can. J. Plant. Sci. 46: 1-7

World Health Organization (WHO). 1995. High Blood Pressure: The "Silent Killer" that Threatens One in Five Adults. WHO Experts Prepare New Recommnedations on Prevention and Control. Press Release WHO/85 – 2 November 1994 (http://www.who.int/archives/inf-pr-1994/pr94-85.html)

World Health Organization (WHO). 1993. Guidelines for drinking-water quality, 2nd ed. Vol. 1. Recommendations. Geneva, World Health Organization. p. 55.

Witteveen, J., H.A. Verhoef and J.P.W. Letschert. 1987. Osmotic and ionic osmoregulation in marine littoral Collembola. J. Insect Physiol. 33:59-66.

Yeardley, R.B.Jr., J.M. Lazorchak and M.A. Pence. 1995. Evaluation of alternative reference toxicants for use in the earthworm toxicity test. Environ. Toxicol. Chem.14: 1189-1194.

http://www.who.int/archives/inf-pr-1994/pr94-85.html

123

124

10. Appendices

List of Appendices

A. Appendix A: Members of the Salt Standards Steering Committee, and Peer Reviewers.......................................................A-1

B. Appendix B: New and Revised Data Used for the Derivation of a British Columbia Salt Matrix Standard...............................................B-1

C. Appendix C: Review of Existing Salt Soil and Water Guidelines in Other Jurisdictions.........................................................................C-1

List of Tables

Table B.1: Studies of the Effects of NaCl on Soil Invertebrates .............B-2

Table B.2: Studies of the Effects of KCl on Soil Invertebrates ................B-5

Table B.3: Studies of the Effects of Soil Salinity (Electrical Conductivity of Saturated Paste Extract) on Plants (Adapted from Bresler et al, 1982).......................................................................B-7

Table B.4: Studies of the Effects of NaCl in Soil on Plants ...................B-10

Table B.5: Studies of the Effects of KCl in Soil on Plants......................B-14

Table B.6: Studies of the Effects of NaCl on Aquatic Life (Excluding Marine and Brackish Water Taxa) ....................................B-16

Table B.7: Studies of the Effects of KCl on Aquatic Life (Excluding Marine and Brackish Water Taxa) ....................................B-27

Table B.8: Studies of the Effects of MgCl2 on Aquatic Life (Excluding Marine and Brackish Water Taxa) ....................................B-32

Table B.9: Studies of the Effects of CaCl2 on Aquatic Life (Excluding Marine and Brackish Water Taxa) ....................................B-34

Table B.10: Studies of the Effects of Other Salt Ion Pairs on Aquatic Life (Excluding Marine and Brackish Water Taxa) ................B-38

Table C.1: Overview................................................................................C-2

Table C.2: Soil Quality Relative to Disturbance and Reclamation (Alberta Agriculture 1987, as reported in Environmental Sciences Division, Environmental Service, Alberta Environment, 2000). Soils to be remediated to background levels or better .....................................................................................C-3

Table C.3: Saskatchewan Upstream Petroleum Sites Remediation Guidelines for Soil (2000). (a) must monitor crop growth and yield for minimum of 3 y. (b) must monitor crop growth and yield for a minimum of 5 y..................................................C-3

Table C.4: CCME Commercial/Industrial (CCME, 1991. Interim Canadian Environmental Quality Criteria for Contaminated Sites) ...............................................................................................C-3

Table C.5: Guideline for use at contaminated sites in Ontario, 1997 .............................................................................................. C-4

Table C.6: Canadian Environmental Quality Guidelines – CCME, 1999 ........................................................................................ C-4

Table C.7: Saskatchewan Upstream Petroleum Sites Remediation Guidelines (2000) ........................................................... C-5

Table C.8: BC Contaminated Site Regulation (1996; Schedule 6, Generic Water Standards) ............................................................... C-5

A-1

A. Appendix A: Members of the Salt Standards Steering Committee, and Peer Reviewers

Glyn A. Fox, Ph.D. (Committee Chair) Ministry of Water, Land, and Air Protection Victoria, BC

Doug Walton, Ministry of Water, Land, and Air Protection Victoria, BC

Narender Nagpal, Ministry of Water, Land, and Air Protection Victoria, BC

Linda Elder, Ministry of Water, Land, and Air Protection Prince George, BC

Rob Buchanan, P.Geo. Ministry of Transportation and Highways Victoria, BC

Nazir Jessa, P.Eng., CMA British Columbia Buildings Corporation Victoria, BC

Colin McKean, M.Sc. Independent Consultant

John Ashworth, Ph.D. formerly of Norwest Laboratories, Edmonton, AB

Doug Keyes, Norwest Laboratories, Edmonton, AB

Adriene Bakker, Canadian Association of Petroleum Producers

Alan Kennedy, Canadian Association of Petroleum Producers

Neil Drummond, Canadian Association of Petroleum Producers

A-2

B-1

B. Appendix B: New and Revised Data Used for the Derivation of a British Columbia Salt Matrix Standard

B-2

Table B.1: Studies of the Effects of NaCl on Soil Invertebrates Effect Endpoint Test

Duration NaCl

(mg/kg)Cl-

(mg/kg)EC

(dS/m) Soil pH Medium A Author Year

Data used in derivation of species sensitivity distribution in section 6.2.2.1

Foslsomia candida EC50 REP 28 d 487 301 6.3 7.8 Field soil (Clinton, B.C.,40% WHC)

Addison, J.A. and D.A. Bright. In prep

Folsomia candida EC50 REP 28 d 913 563 9.0 7.8 Field soil (Clinton, B.C., 60% WHC)

Addison, J.A. and D.A. Bright. In prep

Folsomia candida EC50 REP 28 d 935 577 5.9 7.6 Field soil (Scotch Creek, B.C.) Addison, J.A. and D.A. Bright. In prep E.fetida/andrei EC50 REP 28 d 1884 1199 3.27 5.8 OECD Soil Addison, J.A. and D.A. Bright. In prep Protaphorura armata

EC50 REP 28 d 2151 1327 14.3 7.6 Field soil (Scotch Creek, B.C.) Addison, J.A. and D.A. Bright. In prep

Folsomia candida EC50 REP 28 d 2765 1706 4.1 6.1-6.3 OECD Soil Addison, J.A. and D.A. Bright. In prep Folsomia candida EC50 REP 28 d 3338* 2060 5.6 6.1-6.3 OECD Soil Addison, J.A. and D.A. Bright. In prep Folsomia candida LC20 MOR 28 d 3098 1912 25.0 7.8 Field soil (Clinton, B.C)) Addison, J.A. and D.A. Bright. In prep Folsomia candida EC50 REP 28 d 3717 2294 10.4 4.9 Field soil (Saanichton, Victoria

Area, B.C.) Addison, J.A. and D.A. Bright. In prep

Folsomia candida LC20 MOR 28 d 5503 3396 37.4 7.6 Field soil (Scotch Creek, B.C) Addison, J.A. and D.A. Bright. In prep Folsomia candida LC20 MOR 28 d 4313* 2661 7.0 6.1-6.48 OECD Soil Addison, J.A. and D.A. Bright. In prep Eisenia fetida/andrei

EC50 GRO 28 d 4681 2888 7.2 5.8 OECD Soil Addison, J.A. and D.A. Bright. In prep

Onychiurus folsomi LC20 MOR 28 d 5524 3409 8.4 6.1-6.3 OECD Soil Addison, J.A. and D.A. Bright. In prep Onychiurus folsomi EC50 REP 28 d 6061B 3740 9.4 6.1-6.3 OECD Soil Addison, J.A. and D.A. Bright. In prep Proisotoma minuta EC50 REP 14 d 6415 3958 9.6 6.1-6.3 OECD Soil Addison, J.A. and D.A. Bright. In prep Onychiurus folsomi EC50 REP 28 d 6521 4024 9.8 6.1-6.3 OECD Soil Addison, J.A. and D.A. Bright. In prep Eisenia andrei LC50 MOR 14 d 8100 4998 NA 7.5±0.5 OECD soil Moul, D.J. Inorganic chloride salt (road

salt) toxicity tests - impacts on terrestrial organisms. Report prepared by the Pacific Environmental Sciences Centre, Environment Canada, Vancouver BC. 22 pp + attachments

2001

Folsomia candida LC50 MOR 1 d 9000 5554 0.98 6.0-6.5 OECD Soil Rösgen, Ch., J. Gerdsmeier and H. Greven. Laboruntersuchungen zur Wirkung zweier Streusalze auf Folsomia candida (Collembola). Z. angew. Zool. 78: 445-463.

1991

B-3

Effect Endpoint Test Duration

NaCl (mg/kg)

Cl- (mg/kg)

EC (dS/m)

Soil pH Medium A Author Year

Folsomia candida LC20 MOR 7 d 9507 5866 24.9 4.9 Field soil (Saanichton, Victoria

Area, B.C.) Addison, J.A. and D.A. Bright. In prep

Folsomia candida LC20 MOR 7 d 9589 5917 14.1 5.8 OECD Soil Addison, J.A. and D.A. Bright. In prep Onychiurus folsomi LC20 MOR 28 d 11227B 6928 16.6 6.6-6.13 OECD Soil Addison, J.A. and D.A. Bright. In prep Protaphorura armata

LC20 MOR 7 d 16117 9945 23.2 5.8 OECD Soil Addison, J.A. and D.A. Bright. In prep

Onychiurus folsomi LC20 MOR 7 d 16450 10151 23.7 5.8 OECD Soil Addison, J.A. and D.A. Bright. In prep Other Supplemental data (These data were not used sin the species sensitivity distributions in 6.2.2.1) Enchytraeids (total) 87%

reduction POP 16 wk ~1500 ~916 1.77 NA field soil, meadow Höbel, S., J. Gerdsmeier, A. Mellin

and H. Greven.. Die Wirkung zweier Streusalze auf Enchytraeiden eines Wiesenbodens. Zool. Anz. 228:107-128.

1992

Collembola (total) Reduction (p=0.025)

POP 16 wk ~1500 ~916 NA 6.5 field soil, meadow Rösgen, Ch., J.Gerdsmeier and H. Greven. Die Wirkung zweier Streusalze auf Collembolenmeinschaften eines Wiesenbodens. Pedobiologia 37:107-120.

1993

Folsomia candida Inhibition REP 28d 2539 1550 NA NA LUFA 2 Schrader, G., K. Metge and M. Bahadir. Importance of salt ions in ecotoxicological tests with soil arthropods. Appl. Soil Ecol. 7: 189-193.

1998

Eisenia fetida Reduction (p=0.001)

COC 10 wk 3833 2300 NA NA Manure and peaty soil Fischer, E. and L. Molnár.1997. Growth and reproduction of Eisenia fetida (Oligochaeta, Lumbricidae) in semi-natural soil containing various metal chlorides. Soil Biol. Biochem. 29: 667-670

1997

Eisenia fetida LC100 MOR 14 d 5000 3085 NA NA Buss Bedding +15% Silt loam Kaplan, D.L., R. Hartenstein, E.F. Neuhauser and M.R. Malecki. Physicochemical requirements in the environment of the earthworm Eisenia foetida. Soil Biol. Biochem. 12:347-352

1980

B-4

Effect Endpoint Test Duration

NaCl (mg/kg)

Cl- (mg/kg)

EC (dS/m)

Soil pH Medium A Author Year

B-5

Table B.1: Studies of the Effects of KCl on Soil Invertebrates Organism End-

point Effect Test

DurationKCl conc.(mg/kg)

Cl- (mg/kg)

Soil pH Medium Author Year

Lumbricus terrestris LC50 MOR 14 d 3370 2005 6.6 OECD soil

Aquaterra Environmental. Development of earthworm toxicity tests for assessment of contaminated soils. Report prepared for Method Development and Application Section, Environmental Technology Centre, Environment Canada, Ottawa Ontario. 28pp + appendices

1998b

Lumbricus terrestris LC50 MOR 14 d 3730 2219 5.5 Delacour Orthic Black Chernozem As above 1998b Lumbricus terrestris LC50 MOR 7 d 4230 2516 6.6 OECD soil As above 1998b

Eisenia fetida LC50 MOR 28 d 5760 3426 5.61 OECD soil As above 1998b Eisenia fetida LC50 MOR 21 d 5840 3474 5.61 OECD soil As above 1998b Eisenia fetida LC50 MOR 21 d 5990 3563 6.17 Delacour Orthic Black Chernozem As above 1998b Eisenia fetida LC50 MOR 14 d 6030 3587 5.61-5.9 OECD soil As above 1998b Eisenia fetida LC50 MOR 7 d 6060 3605 6.17 Delacour Orthic Black Chernozem As above 1998b Eisenia fetida LC50 MOR 14 d 6070 3611 6.17 Delacour Orthic Black Chernozem As above 1998b Eisenia fetida LC50 MOR 14 d 6340 3771 5.3-7.7 OECD soil Yeardley, R.B.Jr., J.M. Lazorchak and

M.A. Pence. Evaluation of alternative reference toxicants for use in the earthworm toxicity test. Environ. Toxicol. Chem.14: 1189-1194

1995

Eisenia fetida LC50 MOR 7 d 6340 3771 5.3-7.7 OECD soil As above 1995 Folsomia candida EC50 REP 28 d 4909 2338 NA OECD soil Addison, J.A. and D.A. Bright In prep. Eisenia fetida LC50 MOR 28 d 6662 3963 6.17 Delacour Orthic Black Chernozem Aquaterra Environmental.

Development of earthworm toxicity tests for assessment of contaminated soils. Report prepared for Method Development and Application Section , Environmental Technology Centre, Environment Canada, Ottawa Ontario. 28pp + appendices

1998b

Lumbricus terrestris LC50 MOR 7 d 6880 4092 5.5 Delacour Orthic Black Chernozem As above 1998b Eisenia fetida LC50 MOR 8 d 6960 4140 5.61-5.9 OECD soil As above 1998b

B-6

Organism End-point

Effect Test Duration

KCl conc.(mg/kg)

Cl- (mg/kg)

Soil pH Medium Author Year

Other supplemental data

Onychiurus folsomi LC50 MOR 14 d >15000 >8922 OECD Soil Aquaterra Environmental. Development of a reproduction toxicity test with Onychiurus folsomi for assessment of contaminated soils. Report prepared for Method Development and Application Section, Environmental Technology Centre, Environments Canada, Ottawa, Ontario. 28pp +

1998a

Onychiurus folsomi LC50 MOR 14 d >15000 >8922 Delacour Orthic Black Chernozem As above 1998a

B-7

Table B.2: Studies of the Effects of Soil Salinity (Electrical Conductivity of Saturated Paste Extract) on Plants (Adapted from Bresler et al, 1982)

Plant Name Scientific Name Salinity Threshold

Slope - Decrease in % prod.

EC50 (dS/m)

EC20 (dS/m)

A) Non-tolerant (‘sensitive’) plant species Algerian Ivy Hedera cariensis 1.0 3.44 4.43 Almond Prunus dulcis 1.5 18 4.28 2.61 Apple Malus sylvestris 1.0 5.00 1.69 Apricot Prunus ameriaca 1.6 23 3.77 2.47 Avocado Persea americana 1.0 4.00 2.50 Bean Phaseolus vulgaris 1.0 18.9 3.65 2.06 Blackberry Rubus spp. 1.5 22.5 3.72 2.39 Boysenberry Rubus ursinus 1.5 22.5 3.72 2.39 Burford Holly Ilex cornuta 1.0 3.39 1.09 Carrot Daucus carota 1.0 14.1 4.55 2.42 Celery Apium graveolens 1.0 2.67 Grapefruit Citrus paradisi 1.8 16.1 4.91 3.04 Heavenly Bamboo Handina domestica 1.0 4.79 2.62 Hibiscus Hibiscus rosa-sinensis 1.0 4.5 2.43 Lemon Citrus limon 1.0 2.69 Onion Allium cepa 1.2 16.1 4.31 2.44 Orange Citrus sinensis 1.7 15.9 4.84 2.96 Peach Prunus persica 3.2 18.8 4.10 2.67 Pear Pyrus spp. 1.0 2.68 Pineapple Guava Feijoa sellowiana 1.2 2.57 1.66 Plum Prunus domesticus 1.5 18.2 4.25 2.60 Pittosporum Pittosporum tobira 1.0 6.00 2.90 Raspberry Rubus idaeus 1.0 2.00 Rose Rosa spp. 1.0 1.77 Strawberry Fragaria 1.0 33.3 2.50 1.60 Star Jasmine Trachelospermum

jasminoides 1.6 3.53 2.14

B) Moderately sensitive plants Alfalfa Medicago sativa 2.0 7.3 8.85 4.74 Arborvitae Thuja orientaus 2.0 8.90 4.10 Bottlebrush Callistemon viminalis 1.5 7.00 2.50 Boxwood Buxux microphylla var. 1.7 10.8 6.33 3.55

B-8



EC50 (dS/m)

EC20 (dS/m)

Japonica Broadbean Vicia faba 1.6 9.6 6.81 3.68 Cabbage Brassica oleracea var.

capitata 1.8 9.7 6.95 3.86

Clover, alsike ladino, red, strawberry

Trifolium spp. 1.5 12 5.67 3.17

Corn, forage Zea mays 1.8 7.4 8.56 4.50 Cowpea Vigna unguiculata 1.3 14.3 4.80 2.70 Cucumber Cucumis sativus 2.5 13 6.35 4.04 Dodonea Dedonia viscosa var.

Atropurpurea 1.0 7.8 7.41 3.56

Flax Vinum usitatissumum 1.7 12 5.87 3.37 Grape Vitus spp. 1.5 9.5 6.76 3.61 Juniper Juniper chinensis 1.5 9.5 6.76 3.61 Latana Latana camera 1.8 6.00 3.10 Lettuce Latuca sativa 1.3 13 5.15 2.84 Lovegrass Eragroslis spp. 2.0 8.5 7.88 4.35 Meadow foxtail Alopecurus pratensis 1.5 9.7 6.65 3.56 Muskmelon Cucumis melo 2.5 4 Oleander Nerium oleander 2.0 9.14 4.86 Peanut Arachis hypogaca 3.2 28.6 4.95 3.90 Pepper Capsicum annum 1.5 14.1 5.05 2.92 Potato Solanum tuberosum 1.7 12 5.87 3.37 Pyracantha Pyracantha braperi 2.0 9.1 7.49 4.20 Radish Raphanus sativus 1.2 13 5.05 2.74 Rice, Paddy Oryza sativa 3.0 12.2 7.10 4.64 Sesbania Sesbania exaltata 2.3 7 9.44 5.16 Spinach Spinacia oleracea 2.0 7.6 8.58 4.63 Squash Cucurbita maxima 2.5 3.63 Sugar cane Saccharum officinarum 1.7 5.9 10.2 5.09 Silverberry Elaeagnus pungens 1.6 7.00 3.78 Sweet potato Ipomoea batata 1.5 11 6.05 3.32 Texas Privet Ligustrum lucidum 2.0 9.1 7.49 4.20 Tomato Lycopersicon

escuulentum 2.5 9.9 7.55 4.52

Trefoil, Big Lotus uliginosus 2.3 18.9 4.95 3.36 Vetch, Common Vicia sativa 3.0 11.1 7.50 4.80 Viburnum viburnum spp. 1.4 13.2 5.19 2.92 Xylosma Xylosma senticosa 1.5 13.3 5.26 3.00

B-9



EC50 (dS/m)

EC20 (dS/m)

C) Moderately tolerant plants Barley, forage Hordeum vulgare 6.0 7 13.1 8.86 Beet, garden Beta vulgaris 4.0 9 9.56 6.22 Brocolli Brassica oleracea var.

capitata 2.8 9.1 8.29 5.00

Clover, berseem Trifolium alexandrium 1.5 5.8 10.1 4.95 Dracaena Dracaena endivisa 4.0 9.1 9.49 6.20 Euonymus Euonymus japonica var.

grandiflora 7.0 9.08 7.87

Fescue Festuca clatior 3.9 5.3 13.3 7.67 Hardinggrass Phalaris tuberosa 4.6 7.6 11.2 7.23 Orchardgrass Dactylis glomerata 1.5 6.2 9.56 4.73 Ryegrass, perennial Lolium perenne 5.6 7.6 12.2 8.23 Safflower Carthamus tinctorius 6.5 12.0 10.0 Sorghum Sorghum bicolor 4.8 12.0 7.77 Soybean Glycine max 5.0 20 7.50 6.00 Sudangrass Sorghum sudanese 2.8 4.3 14.4 7.45 Trefoil, Birdsfoot Lotus corniculatus 5.0 10.0 10.0 7.00 Wheat Triticum aestivum 6.0 7.1 13.0 8.82 Wildrye, beardless Elymus triticoides 2.7 6.0 11.0 6.03 D) Highly tolerant plants Barley, grain Hordeum vulgare 8.0 5.0 18.0 12.0 Bermuda grass Cyneden dactylon 6.9 6.4 14.7 10.0 Cotton Gossypium hirsutum 7.7 5.2 17.3 11.5 Date Phoenix dactylifera 4.0 3.6 17.9 9.56 Sugarbeet Beta vulgaris 7.0 5.9 15.5 10.4 Wheatgrass, crested Agropyron desertorum 3.5 4.0 16.0 8.50 Wheatgrass, fairway Agropyron cristatum 7.5 6.9 14.7 10.4 Wheatgrass, tall Agropyron elongatum 7.5 4.2 19.4 12.3

B-10

Table B.3: Studies of the Effects of NaCl in Soil on Plants Scientific Name, variety

Effect Duration (days)

Observed Response

Mean

Observed Response

Units

Ion Soil Conc. (nominal unless

otherwise indicated)

Units Soil Clay %

Soil Sand

%

Soil Silt %

Soil pH

Mean

Media Organic Matter (% dry)

Comments/ Citation

From "Phytotox"

Spinacia oleracea Population - Biomass

49 4.78 g/eu NR 0 mg/kg soil

25 53 25 6.9* 1.10* Monette, L.K., 1978. The Effects of Salinity as Sodium Chloride and the Absorption of Zinc and Cadmium by Barley and Spinach. Ph.D. Thesis, University of California, Davis, CA: 99 p.

49 3.78 g/eu NR 500 mg/kg il

25 53 25 6.9* 1.10* As above 49 2.94 g/eu NR 1500 mg/kg

il25 53 25 6.9* 1.10* As above

49 2.57 g/eu NR 2250 mg/kg il

25 53 25 6.9* 1.10* As above Spinacia oleracea Population -

Biomass 49 EC50 est. g/exp. unit NR 2,900 mg/kg

soil 25 53 25 6.9* 1.10* Model: biomass (g) = 8.73 -

1.83(lo g10[NaCl]); r2=0.99; Ref as above .

Hordeum vulgare, var. California Mariout-72

Population - Biomass

30 4.46 g/eu NR 0 mg/kg soil

25 53 25 6.9* 1.10* Monette, L.K., 1978. The Effects of Salinity as Sodium Chloride and the Absorption of Zinc and Cadmium by Barley and Spinach. Ph.D. Thesis, University of California, Davis, CA: 99 p.

30 4.04 g/eu NR 500 mg/kg il


il25 53 25 6.9* 1.10* As above

30 1.49 g/eu NR 2250 mg/kg il


il25 53 25 6.9* 1.10* As above

30 3.17 g/eu NR 500 mg/kg il


il25 53 25 6.9* 1.10* As above

30 1.2 g/eu NR 2250 mg/kg il


il25 53 25 6.9* 1.10* As above

B-11

Scientific Name, variety


Observed Response

Mean

Observed Response

Units



Units Soil Clay %

Soil Sand

%

Soil Silt %

Soil pH

Mean


Comments/ Citation

30 4.12 g/eu NR 500 mg/kg 25 53 25 6.9* 1.10* As above 30 2.27 g/eu NR 1500 mg/kg

il25 53 25 6.9* 1.10* As above

30 1.5 g/eu NR 2250 mg/kg il

25 53 25 6.9* 1.10* As above

Hordeum vulgare, var. California Mariout-72

Population - Biomass

30 EC50 est. g/exp. unit NR 1,300 mg/kg soil

25 53 25 6.9* 1.10* Model: biomass (g) = 13.6 - 3.62(log10[NaCl]); r2=0.92 (n=9);Ref. as above

Spinacia oleracea Population -

Biomass 49 4.95 g/eu NR 0 mg/kg

soil 25 53 25 6.9* 1.10* Monette, L.K., 1978. The Effects

of Salinity as Sodium Chloride and the Absorption of Zinc and Cadmium by Barley and Spinach. Ph.D. Thesis, University of California, Davis, CA: 99 p.

49 4.22 g/eu NR 500 mg/kg il


il25 53 25 6.9* 1.10* As above

49 2.45 g/eu NR 2250 mg/kg il

25 53 25 6.9* 1.10* As above

Spinacia oleracea Population - Biomass

49 EC50 est. g/exp. unit NR 2,300 mg/kg soil

25 53 25 6.9* 1.10* Model: biomass (g) = 11.6 - 2.73(log10[NaCl]); r2=0.99; Ref. as above

From Moul (May, 2001) Hordeum vulgare Chapais (Barley)

Shoot Length 7 IC50 g NaCl 3420 mg/kg soil

OECD soil (24% moisture); Logistic (ESG Int'l); Moul, D.J., 2001. Inorganic Chloride Salt Toxicity Tests: Impacts on Terrestrial Organisms. Unpublished report of BC WLAP, 22 pp + appendices.

Hordeum vulgare Ch i (B l )

Root Length 7 IC50 g NaCl 2750 mg/kg il

OECD soil; Gompertz (ESG Int'l); R f b

B-12



Observed Response

Mean

Observed Response

Units



Units Soil Clay %

Soil Sand

%

Soil Silt %

Soil pH

Mean


Comments/ Citation

Chapais (Barley) soil Ref. as above. Hordeum vulgare Chapais (Barley)

Shoot Length 7 IC20 g NaCl 2490 mg/kg soil

OECD soil (24% moisture); Logistic (ESG Int'l); Ref. as above

Hordeum vulgare Chapais (Barley)

Root Length 7 IC20 g NaCl 1180 mg/kg soil

OECD soil ; Gompertz (ESG Int'l); Ref. as above.

Hordeum vulgare Chapais (Barley)

Germination 7 IC50 g NaCl 5000 mg/kg soil

OECD soil (24% moisture); Logistic (ESG Int'l); Ref. as above

Turf Grass growth IC50 (Qualitative)

~18000 mg/kg soil

Ref as above

From Cain et al., 2001 Mixed temperate prairie spp.

shoot growth EC25 NaCl 232 ppm soil sol'n

Harrington and Meikle, 1992

Mixed temperate prairie spp.

shoot growth EC50 NaCl 370 ppm soil sol'n

As above

Mixed temperate prairie spp.

root growth EC50 NaCl 320 ppm soil sol'n

As above

Betula alleghaniensis (yellow birch)

% germination 30 EC50 NaCl 1800 ppm soil sol'n

As above

Catalpa bignoides (southern catalpa)


As above

Betula alleghaniensis (yellow birch)


As above

Catalpa bignoides (southern catalpa)


As above

Pinus rigida (pitch pine)

% germination 6 EC50 NaCl 2100 ppm soil Logit germ =2.49 - 12.2 (% NaCl); r2 = 0.77; Bicknell and Smith, 1975

Thuja occidentalis (eastern white cedar)

% foliar discoloration

EC50 Na 4300 mg/kg soil

Foster and Maun, 1977

B-13



Observed Response

Mean

Observed Response

Units



Units Soil Clay %

Soil Sand

%

Soil Silt %

Soil pH

Mean


Comments/ Citation

Thuja occidentalis (eastern white cedar)

% foliar discoloration

EC50 Cl 850 mg/kg soil

As above

Picea pungens (Colorado blue spruce)

pot biomass (dry)

58 EC50 NaCl 1100 mg/kg soil

15% rel. humidity; Werkhoven et al. , 1990


pot biomass (dry)


22% rel. humidity; ref. as above


% survival (mortality)

58 LC20 NaCl 500 mg/kg soil


Pinus sylvestris (Scots pine)

pot biomass (dry)



Pinus sylvestris (Scots pine)

% survival (mortality)

58 LC20 NaCl 1400 mg/kg soil

15% rel. humidity; ref as above

B-14

Table B.4: Studies of the Effects of KCl in Soil on Plants Scientific Name, variety

Effect Duration (d)

Observed Response

Mean

Units Ion Conc. Units Type Soil Clay

%

Soil Sand

%

Soil Silt %

Soil pH

Mean


Author

Pennisetum glaucum - var. 83-104

Growth - Biomass

50 4.6 g/eu K+ 76 ppm NR NR NR NR 7.8 0.08 Singh, M., N. Singh, and R.K. Tewatia, 1992. Potassium and zinc interactions in pearlmillet and corn grown in sandy soils. CROP RES (HISAR) 5(1):43-49


Growth - Biomass

50 5.2 g/eu K+ 50 ppm NR NR NR NR 7.8 0.08 as above


Growth - Biomass



Growth - Biomass



Growth - Biomass

50 EC50 est. g/eu K+ >> 200 ppm NR NR NR NR 7.8 0.08 as above

Zea mays - var. VIJAI Growth -

Biomass 50 5.25 g/eu K+ 76 ppm NR NR NR NR 7.8 0.08 as above

50 7.34 g/eu K+ 50 ppm NR NR NR NR 7.8 0.08 as above 50 7.42 g/eu K+ 100 ppm NR NR NR NR 7.8 0.08 as above 50 6.27 g/eu K+ 200 ppm NR NR NR NR 7.8 0.08 as above

Zea mays - var. VIJAI Growth -

Biomass 50 EC50 est. g/eu K+ >> 200 ppm NR NR NR NR 7.8 0.08 as above

Oryza sativa -var. SAKEL 4

Growth - Biomass

NA (ma) 22.1 g/eu K+ 0 ppm NR NR NR NR 7.2 0.41 Prasad, J., and R.S. Singh, 1988. Effect of potassium and iron on yields and phosphorus, calcium and magnesium content of paddy (Oryza sativa L.). Agric.Sci.Dig. 8(4):207-209

NA (ma) 24.8 g/eu K+ 25 ppm NR NR NR NR 7.2 0.41 as above NA (ma) 26.55 g/eu K+ 50 ppm NR NR NR NR 7.2 0.41 as above NA (ma) 18.35 g/eu K+ 0 ppm NR NR NR NR 7.2 0.41 as above

B-15


Effect Duration (d)

Observed Response

Mean

Units Ion Conc. Units Type Soil Clay

%

Soil Sand

%

Soil Silt %

Soil pH

Mean


Author

NA (ma) 22.4 g/eu K+ 25 ppm NR NR NR NR 7.2 0.41 as above NA (ma) 31.45 g/eu K+ 50 ppm NR NR NR NR 7.2 0.41 as above

Oryza sativa -var. SAKEL 4

Growth - Biomass

NA (ma) EC50 est. g/eu K+ >>50 ppm NR NR NR NR 7.2 0.41 as above

Phaseolus vulgaris (tendergreen)

Growth - Biomass

56 EC72 NR 22722 mg/kg soil NR 10 NR NR 6.0/ 8.1 Miller, R.W., S. Honarvar, and B. Hunsaker, 1980. Effects of Drilling Fluids on Soils and Plants 1. Individual Fluid Components. J.Environ.Qual. 9(4):547-552.

56 EC100 NR 68333 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above Zea mays - var. Saccharate 'Bailey

Growth - Biomass

56 EC78 NR 22722 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above

56 EC99 NR 68333 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above 56 EC100 NR 29214 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above 56 EC100 NR 87857 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above 56 EC100 NR 29214 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above 56 EC100 NR 87857 mg/kg soil NR 10 NR NR 6.0/ 8.1 as above

B-16

Table B.5: Studies of the Effects of NaCl on Aquatic Life (Excluding Marine and Brackish Water Taxa)

Scientific Name Common Name Endpoint Effect NaCl Conc.

(mg/L) Cl- conc. (mg/L)

#Independent Results if Average

Test Duration

(days)

Ref. No.(Full ref. At

end of table)

1. Endpoints used in final analysis (longest exposure duration available for a specific taxon) 1a. Non-lethal endpoints Ceriodaphnia dubia Water flea IC50 REP 1,211 735 (n=14) 7 7

Lemna minor Duckweed EC50 POP 5,193 3,150 (n=4) 7 3 Myriophyllum spicatum Eurasian watermilfoil EC50 POP 7,073 4,291 (n=2) 32 21

Myriophyllum spicatum Eurasian watermilfoil EC50 GRO 7,716 4,681 (n=2) 32 21

Brachydanio rerio Zebrafish EC50 Terat. 12,009 7,290 2 51 1b. Mortality endpoints Ceriodaphnia dubia Water flea LC50 MOR 1,581 959 (n=14) 7 7

Tubifex tubifex Tubificid worm EC50A ITX 1,985 1,204 4 12

Nitzschia linearis Diatom LC50 MOR 2,430 1,474 5 18 Stenonema rubrum Mayfly LC50 MOR 2,500 1,517 2 19

Nais variabilis Oligochaete LC50 MOR 2,569 1,558 2 9 Microhyla ornata Frog LC50 MOR 2,711 1,645 4 17

Morone saxatilis Striped bass LC50 MOR 3,000 1,820 (n=2) 4 11 Streptocephalus rubricaudatus Fairy shrimp LC50 MOR 3,070 1,862 1 6

Daphnia magna Water flea LC50 MOR 3,114 1,889 4.2 8

Gyraulus circumstriatus Flatly coiled gyraulus LC50 MOR 3,200 1,941 10 24 Daphnia pulex Water flea EC50 ITX 3,297 2,000 1 13

Lymnaea Pond snail LC50 MOR 3,388 2,055 2 8 Brachionus calyciflorus Rotifer LC50 MOR 3,665 2,223 1 4

Daphnia magna Water flea EC50 ITX 3,680 2,232 2.67 1

B-17




Test Duration

(days)


end of table)

Carassius auratus Goldfish LC50 MOR 4,324 2,623 10 22

Physa heterostropha Pond snail, pneumonate snail LC50 MOR 4,725 2,866 (n=4) 4 24 Daphnia magna Water flea LC50 MOR 4,746 2,879 2 2

Microhyla ornata Frog LC50 MOR 5,027 3,050 4 17 Physa heterostropha Pond snail, pneumonate snail LC50 MOR 5,100 3,094 10 24

Baetis tricaudatus Mayfly EC50 ITX 5,378 3,262 (n=4) 2 h 14 Limnodrilus hoffmeisteri Tubificid worm, Oligochaete LC50 MOR 5,800 3,518 10.9 24

Asellus communis Aquatic sowbug LC50 MOR 6,150 3,731 7 24

Helisoma campanulatum Ramshorn snail LC50 MOR 6,150 3,731 10 24 Cricotopus trifasciatus Midge LC50 MOR 6,221 3,774 2 9

Pimephales promelas Fathead minnow LC50 MOR 6,390 3,876 4 15 Hydroptila angusta Caddisfly LC50 MOR 6,621 4,016 2 9

Streptocephalus proboscideus Fairy shrimp LC50 MOR 6,897 4,184 1 4

Microhyla ornata Frog LC50 MOR 6,929 4,203 4 17 Erpobdella punctata Red leech LC50 MOR 7,500 4,550 4 24

Erpobdella punctata Red leech LC50 MOR 7,500 4,550 10 24 Hydropsyche Caddisfly LC50 MOR 9,000 5,460 2 19

Culex Mosquito LC50 MOR 10,200 6,188 2 8 Hypophthalmichthys molitrix Silver carp LC50 MOR 11,300 6,855 0.167 20

Gambusia holbrooki Eastern mosquitofish LC50 MOR 11,540 7,000 4 16

Cyprinus carpio Common, mirror, colored, carp LC50 MOR 12,300 7,461 0.167 20 Lepomis macrochirus Bluegill LC50* MOR 12,946 7,853 4 18

Carassius carassius Crucian carp LC50* MOR 13,750 8,341 1 8 Poecilia latipinna Sailfin molly LC50 MOR 16,595 10,067 2 8

Gambusia affinis Western mosquitofish LC50 MOR 17,550 10,646 4 23

Anguilla rostrata American eel LC50 MOR 19,665 11,929 (n=2) 4 10 Poecilia reticulata Guppy LC50 MOR 20,000 12,133 1 25

B-18




Test Duration

(days)


end of table)

Caenorhabditis elegans Nematode LC50 MOR 20,728 12,574 (n=3) 2 5

Argia Damselfly LC50 MOR 23,500 14,256 (n=2) 4 24 2. Indiviudal endpoints for studies with multiple estimates (e.g. interlaboratory comparisons, factorial experiments) Ceriodaphnia dubia Water flea IC50 REP 300 182 7 7

Ceriodaphnia dubia Water flea IC50 REP 650 394 7 7 Ceriodaphnia dubia Water flea IC50 REP 720 437 7 7

Ceriodaphnia dubia Water flea IC50 REP 730 443 7 7

Ceriodaphnia dubia Water flea IC50 REP 740 449 7 7 Ceriodaphnia dubia Water flea IC50 REP 1,290 783 7 7

Ceriodaphnia dubia Water flea IC50 REP 1,340 813 7 7 Ceriodaphnia dubia Water flea IC50 REP 1,340 813 7 7

Ceriodaphnia dubia Water flea IC50 REP 1,390 843 7 7

Ceriodaphnia dubia Water flea IC50 REP 1,510 916 7 7 Ceriodaphnia dubia Water flea IC50 REP 1,600 971 7 7

Ceriodaphnia dubia Water flea IC50 REP 1,690 1,025 7 7 Ceriodaphnia dubia Water flea IC50 REP 1,760 1,068 7 7

Ceriodaphnia dubia Water flea IC50 REP 1,900 1,153 7 7 Lemna minor Duckweed EC50 POP 4,880 2,961 7 3

Lemna minor Duckweed EC50 POP 5,000 3,034 7 3

Lemna minor Duckweed EC50 POP 5,390 3,270 7 3 Lemna minor Duckweed EC50 POP 5,500 3,337 7 3

Baetis tricaudatus Mayfly EC50 ITX 4,740 2,876 2 h 14 Baetis tricaudatus Mayfly EC50 ITX 5,330 3,234 2 h 14

Baetis tricaudatus Mayfly EC50 ITX 5,440 3,300 2 h 14

Baetis tricaudatus Mayfly EC50 ITX 6,000 3,640 2 h 14 Myriophyllum spicatum Eurasian watermilfoil EC50 GRO 7,423 4,504 32 21

B-19

Scientific N

ame

Com

mon N

ame

Endpoint Effect

NaC

l Conc.

(mg/L)

Cl - conc. (m

g/L)

#Independent R

esults if Average

Test D

uration (days)

Ref. N

o.(Full ref. At

end of table)

M

yriophyllum spicatum

Eurasian w

atermilfoil

EC50

GR

O

8,008 4,859

32

21

M

yriophyllum spicatum

Eurasian w

atermilfoil

EC50

POP

5,962 3,617

32

21

Myriophyllum

spicatum

Eurasian waterm

ilfoil EC

50 PO

P 8,183

4,965

32 21

C

eriodaphnia dubia W

ater flea LC

50 M

OR

280

170

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

910

552

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,170

710

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,430

868

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,640

995

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,710

1,037

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,740

1,056

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,830

1,110

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,830

1,110

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,830

1,110

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,940

1,177

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,940

1,177

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,940

1,177

7 7

C

eriodaphnia dubia W

ater flea LC

50 M

OR

1,940

1,177

7 7

M

orone saxatilis Striped bass

LC50

MO

R

1,000 607

4

11

M

orone saxatilis Striped bass

LC50

MO

R

5,000 3,034

4

11

Physa heterostropha

Pond snail, pneumonate snail

LC50

MO

R

3,500 2,123

4

24

Physa heterostropha Pond snail, pneum

onate snail LC

50 M

OR

4,100

2,488

4 24

Physa heterostropha

Pond snail, pneumonate snail

LC50

MO

R

5,100 3,094

4

24

Physa heterostropha Pond snail, pneum

onate snail LC

50 M

OR

6,200

3,762

4 24

Anguilla rostrata

American eel

LC50

MO

R

17,880 10,848

4

10

Anguilla rostrata

American eel

LC50

MO

R

21,450 13,014

4

10

Argia D

amselfly

LC50

MO

R

23,000 13,954

4

24

B-20




Test Duration

(days)


end of table)

Argia Damselfly LC50 MOR 24,000 14,561 4 24

3. NOEC, LOEC and Other Endpoint Types (not used)

Carassius auratus Goldfish LETC MOR 7,322 4,442 6 27 Pimephales promelas Fathead minnow LETC MOR 7,650 4,641 6 27

Chlorella vulgaris Green algae LOEC POP 680 413 NR 31

Stenonema modestum Mayfly LOEC DVP 2,700 1,638 14 30

Stenonema modestum Mayfly LOEC GRO 3,500 2,123 14 30 Stenonema modestum Mayfly LOEC MOR 3,500 2,123 14 30

Stenonema modestum Mayfly LOEC DVP 6,000 3,640 14 30 Stenonema modestum Mayfly LOEC DVP 6,000 3,640 7 30

Baetis tricaudatus Mayfly LOEC ITX 6,000 3,640 2 14

Baetis tricaudatus Mayfly LOEC ITX 6,000 3,640 2 14 Stenonema modestum Mayfly LOEC DVP 7,000 4,247 7 30

Stenonema modestum Mayfly LOEC GRO 7,000 4,247 14 30 Stenonema modestum Mayfly LOEC MOR 7,000 4,247 14 30

Baetis tricaudatus Mayfly LOEC DVP 8,000 4,854 1 14 Baetis tricaudatus Mayfly LOEC DVP 8,000 4,854 2 14

Baetis tricaudatus Mayfly LOEC DVP 8,000 4,854 2 14

Baetis tricaudatus Mayfly LOEC ITX 8,000 4,854 1 14 Baetis tricaudatus Mayfly LOEC ITX 8,000 4,854 1 14

Baetis tricaudatus Mayfly LOEC ITX 8,000 4,854 1 14 Pimephales promelas Fathead minnow LOEC MOR 8,000 4,854 7 26

Pimephales promelas Fathead minnow LOEC MOR 8,000 4,854 7 26

Pimephales promelas Fathead minnow LOEC MOR 8,000 4,854 7 26 Pimephales promelas Fathead minnow LOEC MOR 8,000 4,854 7 26

B-21




Test Duration

(days)


end of table)

Pimephales promelas Fathead minnow LOEC MOR 8,000 4,854 7 26

Pimephales promelas Fathead minnow LOEC MOR 8,000 4,854 7 26 Polycelis nigra Planarian LT50 MOR 11,104 6,737 2 33

Pimephales promelas Fathead minnow MATC POP 5,700 3,458 7 26

Pimephales promelas Fathead minnow MATC POP 5,700 3,458 7 26 Pimephales promelas Fathead minnow MATC POP 5,700 3,458 7 26

Pimephales promelas Fathead minnow MATC POP 5,700 3,458 7 26

Pimephales promelas Fathead minnow MATC POP 5,700 3,458 7 26 Pimephales promelas Fathead minnow MATC POP 5,700 3,458 7 26

Chlorella vulgaris Green algae NOEC POP 590 358 NR 31

Ceriodaphnia dubia Water flea NOEC MOR 1,500 910 7 7

Stenonema modestum Mayfly NOEC DVP 2,000 1,213 14 30 Stenonema modestum Mayfly NOEC GRO 2,700 1,638 14 30

Stenonema modestum Mayfly NOEC MOR 2,700 1,638 14 30 Stenonema modestum Mayfly NOEC DVP 4,000 2,427 14 30

Stenonema modestum Mayfly NOEC DVP 4,000 2,427 7 30 Stenonema modestum Mayfly NOEC DVP 4,000 2,427 7 30

Stenonema modestum Mayfly NOEC GRO 4,000 2,427 14 30

Pimephales promelas Fathead minnow NOEC MOR 4,000 2,427 7 26 Pimephales promelas Fathead minnow NOEC MOR 4,000 2,427 7 26

Pimephales promelas Fathead minnow NOEC MOR 4,000 2,427 7 26 Pimephales promelas Fathead minnow NOEC MOR 4,000 2,427 7 26

Pimephales promelas Fathead minnow NOEC MOR 4,000 2,427 7 26

Pimephales promelas Fathead minnow NOEC MOR 4,000 2,427 7 26 Pimephales promelas Fathead minnow NOEC GRO 4,000 2,427 7 26

B-22




Test Duration

(days)


end of table)

Pimephales promelas Fathead minnow NOEC GRO 4,000 2,427 7 26

Pimephales promelas Fathead minnow NOEC GRO 4,000 2,427 7 26 Pimephales promelas Fathead minnow NOEC GRO 4,000 2,427 7 26

Pimephales promelas Fathead minnow NOEC GRO 4,000 2,427 7 26 Pimephales promelas Fathead minnow NOEC GRO 4,000 2,427 7 26

Stenonema modestum Mayfly NOEC MOR 5,600 3,398 14 30

Epischura baikalensis Copepod NR-ZERO MOR 6 4 1 36

Daphnia magna Water flea NR-ZERO MOR 58 35 1 36 Chimarra marginata Caddisfly NR-ZERO MOR 255-313 155-190 4 29

Hydropsyche bulbifera Caddisfly NR-ZERO MOR 255-313 155-190 4 29 Hydropsyche exocellata Caddisfly NR-ZERO MOR 255-313 155-190 4 29

Hydropsyche lobata Caddisfly NR-ZERO MOR 255-313 155-190 4 29

Hydropsyche pellucidulla Caddisfly NR-ZERO MOR 255-313 155-190 4 29 Chimarra Caddisfly NR-ZERO MOR 520 315 0.5 32

Tricorythus Mayfly NR-ZERO MOR 520 315 1.5 32 Microhyla ornata Frog NR-ZERO MOR 2,000 1,213 4 17

Rana breviceps Frog NR-LETH MOR 2,400 1,456 6 34 Rana breviceps Frog NR-LETH MOR 2,800 1,699 5 34

Rana breviceps Frog NR-LETH MOR 3,600 2,184 6 34

Rana breviceps Frog NR-LETH MOR 4,000 2,427 3.16 34 Rana breviceps Frog NR-LETH MOR 4,200 2,548 5 34

Stizostedion lucioperca Pikeperch NR-LETH MOR 5,000 3,034 0.38 36 Chimarra Caddisfly NR-LETH MOR 5,650 3,428 4 32

Rana breviceps Frog NR-LETH MOR 6,000 3,640 3.16 34

Microhyla ornata Frog NR-LETH MOR 7,000 4,247 1 17 Anguilla anguilla Common eel NR-ZERO MOR 20,000 12,134 1 28

B-23




Test Duration

(days)


end of table)

Stizostedion lucioperca Pikeperch NR-LETH MOR 40,000 24,268 0.17 h 35

Notes: A) EC50 – immobility (ITX) is not strictly speaking a mortality-based endpoint, since organisms have been known to recover if placed in water without toxicant. Prolonged exposures to the test medium, however, would likely result in death and ITX endpoints, therefore, are considered herein as mortality endpoints.

Ref. No.

Authors Title Journal

1 Anderson, B.G., 1948. The Apparent Thresholds of Toxicity to Daphnia magna for Chlorides of Various Metals When Added to Lake Erie Water.

Trans. Am. Fish Soc. 78:96-113.

2 Arambasic, M.B., S. Bjelic and G. Subakov, 1995. Acute Toxicity of Heavy Metals (Copper, Lead, Zinc), Phenol and Sodium on Allium cepa L., Lepidium sativum L. and Daphnia magna.

Water Res. 29(2):497-503.

3 Buckley, J.A., K.P. Rustagi and J.D. Laughlin, 1996. Response of Lemna minor to Sodium Chloride and a Statistical Analysis of Continuous Measurements for EC50 and 95 % Confidence Limits Calculation.

Bull. Environ. Contam. Toxico. 57(6):1003-1008.

4 Calleja, M.C., G. Persoone and P. Geladi, 1994. Comparative acute toxicity of the first 50 multicentre evaluation of in vitro cytotoxicity chemicals to aquatic non-vertebrates.

Arch. Environ. Contamin. Toxicol. 26: 69-78.

5 Cressman, C.P. III and P.L. Williams, 1994. Reference Toxicants for Toxicity Testing Using Caenorhabditis elegans in Aquatic Media

In: F J Dwyer, T R Doane, and M L Hinman (Eds ), Environmental Toxicology and Risk Assessment: Modeling and Risk Assessment, 6th Volume, ASTM STP 1317, Philadelphia, PA:518-532 :.

6 Crisinel, A., L. Delaunay, D. Rossel, J. Tarradellas, H. Meyer, H. Saiah, P. Vogel, C. Delisle and C. Blaise, 1994.

Cyst-Based Ecotoxicological Tests Using Anostracans: Comparison of Two Species of Streptocephalus.

Environ. Toxicol. Water Qual. 9(4):317-326.

7 Degreave, G.M., J.D. Cooney, B.H. Marsh, T.L. Pollock, N.G. Reichenbach, 1992.

Variability in the performance of the 7-d Ceriodaphnia dubia survivial and reproduction test: an intra- and inter-laboratory comparison.

Environ. Toxicol. Chem. 11: 851-866.

8 Dowden, B.F. and H.J. Bennett, 1965. Toxicity of Selected Chemicals to Certain Animals J. Water Pollu. Control Fed. 37(9):1308-1316.

9 Hamilton, R.W., J.K. Buttner and R.G. Brunetti, 1975. Lethal levels of sodium chloride and potassium chloride for an oligochaete, a chironomid midge, and a caddisfly of Lake Michigan.

Environ. Entomol. 4: 1003-1006

10 Hinton, M.J. and A.G. Eversole, 1978. Toxicity of Ten Commonly Used Chemicals to American Eels. Proc. Annu. Conf. Southeast Assoc.

B-24

Ref. No.


Fish Wildl. Agencies 32:599-604.

11 Hughes, J.S., 1973. Acute Toxicity of Thirty Chemicals to Striped Bass (Morone saxatilis). La Dep. Wildl. Fish. 318-343-2417:15 p

12 Khangarot, B.S., 1995. Toxicity of Metals to a Freshwater Tubificid Worm, Tubifex tubifex (Muller). Bull. Environ. Contam. Toxicol. 46:906-912.

13 Lilius, H., T. Hastbacka, and B. Isomaa (1995) A comparison of the toxicity of 30 reference chemicals to Daphnia magna and Daphnia pulex.

Environ. Toxicol. Chem. 14: 2085-2088

14 Lowell, R.B., J.M. Culp and F.J. Wrona (1995). Toxicity testing with artificial streams: effects of differences in current velocities. Environ. Toxicol. Chem. 14: 1209-1217.

15 Mount, D.R., D.D. Gulley, J.R. Hockett, T.D. Garrison and J.M. Evans, 1997.

Statistical models ot predict the toxicity of major ions to Ceriodaphia dubia, Daphnia magna, and Pimephales promelas (Fathead minnows).


16 Newman, M.C.and M.S. Aplin, 1992. Enhancing Toxicity Data Interpretation and Prediction of Ecological Risk with Survival Time Modeling: An Illustration Using Sodium Chloride Toxicity.

Aquat Toxicol 23(2):85-96.

17 Pahdye, A.D. and H.V. Ghate, 1992. Sodium chloride and potassium chloride tolerance of different stages of the frog, Microhyla ornata.

Herpetological Journal 2: 18-23.

18 Patrick, R., J. Cairns, J and A. Scheier, 1968. The Relative Sensitivity of Diatoms, Snails, and Fish to Twenty Common Constituents of Industrial Wastes

Prog Fish-Cult 30(3):137-140

19 Roback, S.S., 1965. Environmental Requirements of Trichoptera. In: C M Tarzwell (Ed ), Biological Problems in Water Pollution, Trans 3rd Seminar, Aug 13-17, 1962, Tech Rep 999-WP25, U S Public Health Service, R A Taft Sanitary Engineering Center, Cincinnati, OH:118-126 :

20 Rosicky, P., J. Kouril and I. Prikryl, 1987. The Effect of the Length of Short-Term Exposure to NaCl on the Tolerance of Early Common Carp and Silver Carp Fry to NaCl Baths.

Bul Vyzk Ustav Ryb Hydrobiol Vodnany 23(1):8-13 (CZE) (ENG ABS) :

21 Stanley, R.A., 1974. Toxicity of Heavy Metals and Salts to Eurasian Watermilfoil (Myriophyllum spicatum L.).

Arch Environ Contam Toxicol 2(4):331-341.

22 Threader, R.W. and A.H. Houston. 1983. Use of NaCl As a Reference Toxicant for Goldfish, Carassius auratus. Can J Fish Aquat Sci 40(1):89-92.

23 Wallen, I.E., W.C. Greer and R. Lasater, 1957. Toxicity to Gambusia affinis of Certain Pure Chemicals in Turbid Waters. Sewage Ind Wastes 29(6):695-711 (Author Communication Used).

24 Wurtz, C.B. and C.H. Bridges, 1942. Preliminary results from macroinvertebrate bioassays. Proc. Pennsylvania Academy of Science, 35:51-56

25 Yarzhombek, A.A., A.E. Mikulin and A.N. Zhdanova, 1991. Toxicity of Some Substances to Fish in Relation to Form of Exposure. (Toksichnost Vestichestv diya ryb v Zavisimosti ot Sposoba Vozdejstviya).

J Ichthyol 31(7):99-106; Vopr Ikhtiol 31(3):496-502 (RUS) :

B-25

Ref. No.


26 Pickering, Q.H., J.M. Lazorchak and K.L. Winks, (1996. Subchronic sensitivity of one-, four-, and seven-day-old fathead minnow (Pimephales promelas) larvae to five toxicants.


27 ADELMAN, I.R., L.L. SMITH, J, AND G.D. SIESENNOP, 1976. Acute Toxicity of Sodium Chloride, Pentachlorophenol, Guthion, and Hexavalent Chromium to Fathead Minnows (Pimephales promelas) and Goldfish.

J Fish Res Board Can 33(2):203-208.

28 BUCHMANN, K., A. FELSING, AND H.C. SLOTVED, 1992. Effects of Metrifonate, Sodium Chloride and Bithionol on an European Population of the Gill Parasitic Monogeneans Pseudodactylogyrus spp. and the Host.

Bull Eur Assoc Fish Pathol 12(2):57-60.

29 CAMARGO, J.A. AND J.V. TARAZONA, 1990. Acute Toxicity to Freshwater Benthic Macroinvertebrates of Fluoride Ion (F-) in Soft Water.

Bull Environ Contam Toxicol 45(6):883-887.

30 DIAMOND, J.M., E.L. WINCHESTER, D.G. MACKLER, AND D. GRUBER, 1992.

Use of the Mayfly Stenonema modestum (Heptageniidae) in Subacute Toxicity Assessments.

Environ Toxicol Chem 11(3):415-425.

31 DOOREN DE JONG LE, 1965 Tolerance of Chlorella vulgaris for Metallic and Non-Metallic Ions. Antonie Leeuwenhoek J Microbiol Serol 31:301-313.

32 GOETSCH, P.A. AND C.G. PALMER, 1997. Salinity Tolerances of Selected Macroinvertebrates of the Sabie River, Kruger National Park, South Africa.

Arch Environ Contam Toxicol 32(1):32-41.

33 JONES, J.R.E., 1941. A Study of the Relative Toxicity of Anions, with Polycelis nigra As Test Animal. J Exp Biol 18:170-181.

34 MAHAJAN, C.L., S.D. SHARMA, AND S.P. SHARMA, 1979. Tolerance of Aquatic Organisms to Chloride Salts. Indian J Exp Biol 17(11):1244-1245.

35 STANGENBERG, M., 1975. The Influence of the Chemical Composition of Water on the Pike Perch (Lucioperca lucioperca L.) Fry From the Lake Gopio.

Limnologica 9(3):421-426.

36 STOM, D.I. AND L.D. ZUBAREVA, 1994. Comparative Resistance of Daphnia and Epischura to Toxic Substances in Acute Exposure.

Hydrobiol J 30(3):35-38; Gidrobiol J 29(2):31-34 (1993)

37 BENGTSSON, B.E., 1978. Use of a Harpacticoid Copepod in Toxicity Tests. Mar Pollut Bull 9:238-241.

38 BIESINGER, K.E. AND G.M. CHRISTENSEN, 1972. Effects of Various Metals on Survival, Growth, Reproduction, and Metabolism of Daphnia magna.

J Fish Res Board Can 29(12):1691-1700.

39 BOUTET, C. AND C. CHAISEMARTIN, 1973. Specific Toxic Properties of Metallic Salts in Austropotamobius pallipes pallipesand Orconectes limosus.

C R Soc Biol (Paris) 167(12):1933-1938 (FRE) (ENG TRANSL).

40 Burton, G.A., T.J. Noberg-King, C.G. Ingersoll, D.A. Benoit, G.A. Ankley, P. V. Winger, J. Kubitz, J.M. Lazorchak, M.E. smith, E. Greer, F. J. Dwyer, D.J. Call, K.E. Day, P. Kennedy, M. Stinson, 1996.

Interlaboratory study of precision: Hyalalla azteca and Chironomus tentans freshwater sediment toxicity assays.


41 DURAND-HOFFMAN, M.E., 1995. Analysis of Physiological and Toxicological Effects of Potassium on Dreissena polymorpha and Toxicological Effects on Fish.

M S Thesis, Ohio State University, Columbus, OH

B-26

Ref. No.


42 FISHER, S.W., P. STROMBERG, K.A. BRUNER, AND L.D. BOULET, 1991.

Molluscicidal Activity of Potassium to the Zebra Mussel, Dreissena polymorphia: Toxicity and Mode of Action.

Aquat Toxicol 20:219-234.

43 Waller, D.L., J.R. Rach, W.G. Cope and L.L. Marking (1993). Toxicity of candicate molluscicides to zebra mussels (Dreissena polymorpha) and selected non-traget organisms.

J. Great Lakes Res. 19: 695-702.

44 BAUDOUIN, M.F. AND P. SCOPPA, 1974. Acute Toxicity of Various Metals to Freshwater Zooplankton. Bull Environ Contam Toxicol 12(6):745-751.

45 BIRGE, W.J., J.A. BLACK, A.G. WESTERMAN, AND J.E. HUDSON, 1980.

Aquatic Toxicity Tests on Inorganic Elements Occurring in Oil Shale. In: C Gale (Ed ) Oil Shale Symposium: Sampling, Analysis and Quality Assurance, March 1979; EPA-600/9-80-022, U S EPA, Cincinnati, OH:519-534

46 TATARA, C.P., M.C. NEWMAN, J.T. MCCLOSKEY, AND P.L. WILLIAMS. 1997.

Predicting Relative Metal Toxicity with Ion Characteristics: Caenorhabditis elegans LC50.

Aquat Toxicol 39(3/4):279-290.

47 TSUJI, S., Y. TONOGAI, Y. ITO, AND S. KANOH, 1986. The Influence of Rearing Temperatures on the Toxicity of Various Environmental Pollutants for Killifish (Oryzias latipes).

J Hyg Chem /Eisei Kagaku 32(1):46-53 (JPN) (ENG ABS).

48 CAIRNS, J.C.J. AND A. SCHEIER, 1959. The Relationship of Bluegill Sunfish Body Size to its Tolerance for Some Common Chemicals.

Proc 13th Ind Waste Conf , Purdue Univ Eng Bull 96:243-252.

49 Lange, M., W. Gebauer, J. Markl and R. Nagel, 1995. Comparison of testing acute toxicity on embryo of zebrafish, Brachydanio rerio and RTG-2 cytotoxicity as possible alternatives to the acute fish test.

Chemosphere 30: 2087-2102.

50 SEALS, C., C.J. KEMPTON, J.R. TOMASSO, J, AND T.I.J. SMITH

Environmental Calcium Does Not Affect Production or Selected Blood Characteristics of Sunshine Bass Reared Under Normal Culture Conditions.

Prog Fish-Cult 56(4):269-272.

51 Lange, M., W. Gebauer, J. Markl and R. Nagel, 1995. Comparison of testing acute toxicity on embryo of zebrafish, Brachydanio rerio and RTG-2 cytotoxicity as possible alternatives to the acute fish test.

Chemosphere 30: 2087-2102.

B-27

Table B.6: Studies of the Effects of KCl on Aquatic Life (Excluding Marine and Brackish Water Taxa)

Scientific Name Common Name Endpoint Effect KCl (mg/L)

Cl- (mg/L)

K+ (mg/L)

No. of ReplicateEndpoints

Test Duration

(d)

Ref. (see end of Table

B.5)

1. Effects Endpoints (freshwater)

1a. Non-lethal Endponts

Daphnia magna Water flea EC50 REP 61 29 32 21 38

Daphnia magna Water flea EC50 ITX 97 46 51 21 38

Daphnia magna Water flea EC50 ITX 228 108 120 2.67 1

Tubifex tubifex Tubificid worm EC50 ITX 813 387 426 4 12

1b. Mortality Endpoints

Anodonta imbecillis Mussel LC50 MOR 76 36 40 1 42

Dreissena polymorpha Zebra mussel LC50 MOR 138 66 72 1 42

Dreissena polymorpha Zebra mussel LC50 MOR 149 71 78 2 43

Hyalella azteca Scud LC50 MOR 274 130 144 (n=13) 4 40

Daphnia magna Water flea LC50 MOR 340 162 178 (n=2) 4.2 8

Austropotamobius pallipes pall Crayfish LC50 MOR 370 176 194 4 39

Orconectes limosus Crayfish LC50 MOR 370 176 194 (n=4) 30 39

Nitocra spinipes Harpacticoid copepod LC50 MOR 450 214 236 4 37

Gambusia affinis Western mosquitofish LC50 MOR 460 219 241 (n=2) 4 23

Stizostedion canadense Sauger LC50 MOR 500 238 262 1 41

B-28


Cl- (mg/L)

K+ (mg/L)


Test Duration

(d)


B.5)

Morone saxatilis Striped bass LC50 MOR 508 242 266 1 41

Lymnaea Pond snail LC50* MOR 520 247 273 4 8

Ceriodaphnia dubia Water flea LC50 MOR 630 300 330 2 15

Daphnia magna Water flea LC50 MOR 660 314 346 2 15

Ictalurus punctatus Channel catfish LC50 MOR 720 342 378 2 43

Stizostedion vitreum Walleye LC50 MOR 724 344 380 1 41

Notemigonus crysoleucas Golden shiner LC50 MOR 816 388 428 1 41

Pimephales promelas Fathead minnow LC50 MOR 880 418 462 4 15

Physella acuta european physa, bladder snail LC50 MOR 940 447 493 4 18

Nitzschia linearis Diatom LC50 MOR 1,337 636 701 5 18

Microhyla ornata Frog LC50 MOR 1,414 672 742 4 13

Cricotopus trifasciatus Midge LC50 MOR 1,487 707 780 (n=2) 2 9

Microhyla ornata Frog LC50 MOR 1,593 758 835 4 13

Oncorhynchus mykiss Rainbow trout,donaldson trout LC50 MOR 1,610 766 844 2 43

Brachionus calyciflorus Rotifer LC50 MOR 1,692 805 888 1 4

Streptocephalus proboscideus Fairy shrimp LC50 MOR 1,871 890 981 1 4

Obliquaria reflexa Three-horned wartyback LC50 MOR 2,000 951 1,049 2 43

Lepomis macrochirus Bluegill LC50 MOR 2,010 956 1,054 4 18

B-29


Cl- (mg/L)

K+ (mg/L)


Test Duration

(d)


B.5)

Hydroptila angusta Caddisfly LC50 MOR 2,197 1,045 1,152 (n=2) 2 9

Microhyla ornata Frog LC50 MOR 2,539 1,207 1,332 4 13

Morone saxatilis Striped bass LC50 MOR 3,499 1,664 1,835 1 41

Chironomus tentans Midge LC50 MOR 4,677 2,224 2,453 (n=17) 4 40

Caenorhabditis elegans Nematode LC50 MOR 36,883 17,540 19,345 (n=2) 2 5

2. NOEC, LOEC and Other Endpoint Types (not used)

Musculium transversum Long fingernail clam LOEC MOR 275 131 144 42 1

Musculium transversum Long fingernail clam LOEC MOR 275 131 144 NR 1

Pimephales promelas Fathead minnow LOEC GRO 500 238 262 7 26

Chlorella vulgaris Green algae LOEC POP 670 319 351 NR 31

Pimephales promelas Fathead minnow LOEC MOR 1,000 476 524 7 26






Pimephales promelas Fathead minnow MATC GRO 353 168 185 7 26

B-30


Cl- (mg/L)

K+ (mg/L)


Test Duration

(d)


B.5)

Pimephales promelas Fathead minnow MATC GRO 707 336 371 7 26

Pimephales promelas Fathead minnow MATC POP 707 336 371 7 26






Musculium transversum Long fingernail clam NOEC MOR 184 87 97 NR 1

Musculium transversum Long fingernail clam NOEC MOR 195 93 102 42 31

Pimephales promelas Fathead minnow NOEC GRO 250 119 131 7 26






Pimephales promelas Fathead minnow NOEC MOR 500 238 262 7 26



B-31


Cl- (mg/L)

K+ (mg/L)


Test Duration

(d)


B.5)




Chlorella vulgaris Green algae NOEC POP 600 285 315 NR 31

Rana breviceps Frog NR-LETH MOR 1,400 666 734 5 34

Rana breviceps Frog NR-LETH MOR 1,600 761 839 5 34

Rana breviceps Frog NR-LETH MOR 2,400 1,141 1,259 1 34

Rana breviceps Frog NR-LETH MOR 2,600 1,236 1,364 1 34

Rana breviceps Frog NR-LETH MOR 4,700 2,235 2,465 0.33 34

Rana breviceps Frog NR-LETH MOR 5,300 2,520 2,780 0.33 34

B-32

Table B.7: Studies of the Effects of MgCl2 on Aquatic Life (Excluding Marine and Brackish Water Taxa)

Scientific Name Common Name Endpoint Effect MgCl2 conc. (mg/L)

Cl- (mg/L)

Mg2+ (mg/L)

Duration (days) Ref. No.

1. Endpoints used in final analysis (longest exposure duration available for a specific taxon) Daphnia magna Water flea EC50 REP 125 93 32 21 38 Eudiaptomus padanus padanus Calanoid copepod EC50 ITX 180 134 46 2 44 Daphnia magna Water flea EC50 ITX 190 141 49 21 38 Cyclops abyssorum prealpinus Cyclopoid copepod EC50 ITX 280 209 71 2 44 Daphnia hyalina Water flea LC50 MOR 32 24 8 2 44 Austropotamobius pallipes pall Crayfish LC50 MOR 315 235 80 30 39 Orconectes limosus Crayfish LC50 MOR 505 376 129 30 39 Ceriodaphnia dubia Water flea LC50 MOR 880 655 225 2 15 Daphnia magna Water flea LC50 MOR 888 662 227 4.2 8 Oncorhynchus mykiss Rainbow trout,donaldson trout LC50 MOR 1,355 1,009 346 28 45 Pimephales promelas Fathead minnow LC50 MOR 2,120 1,579 541 4 15 Gambusia affinis Western mosquitofish LC50 MOR 4,210 3,135 1,075 4 23 Caenorhabditis elegans Nematode LC50 MOR 17,195 12,805 4,390 1 46 2. Endpoints rejected as being of shorter duration Daphnia magna Water flea EC50 ITX 140 104 36 2 38 Eudiaptomus padanus padanus Calanoid copepod EC50 ITX 180 134 46 2 44 Cyclops abyssorum prealpinus Cyclopoid copepod EC50 ITX 183 136 47 2 44

B-33

Scientific Name Common Name Endpoint Effect MgCl2 conc. (mg/L)

Cl- (mg/L)

Mg2+ (mg/L)

Duration (days) Ref. No.

Daphnia magna Water flea EC50 ITX 190 141 49 2.67 1 Daphnia magna Water flea EC50 ITX 322 240 82 2 38 Ceriodaphnia dubia Water flea LC50 MOR 127 95 32 1 15 Daphnia magna Water flea LC50 MOR 133 99 34 2 15 Daphnia magna Water flea LC50 MOR 156 116 40 1 15 Pimephales promelas Fathead minnow LC50 MOR 284 212 73 2 15 Austropotamobius pallipes pall Crayfish LC50 MOR 480 357 123 4 39 Orconectes limosus Crayfish LC50 MOR 760 566 194 4 39

Daphnia magna Water flea LC50 MOR 865 644 221 1 8 Daphnia magna Water flea LC50 MOR 943 702 241 2.1 8 Pimephales promelas Fathead minnow LC50 MOR 3,520 2,621 899 1 15 Gambusia affinis Western mosquitofish LC50 MOR 4,530 3,374 1,157 2 23 Gambusia affinis Western mosquitofish LC50 MOR 4,780 3,560 1,220 1 23 3. NOEC, LOEC and other endpoints None found

B-34

Table B.8: Studies of the Effects of CaCl2 on Aquatic Life (Excluding Marine and Brackish Water Taxa)

Scientific Name Common Name Endpoint Effect CaCl2 conc

(mg/L) as Cl- (mg/L)

as Ca2+

(mg/L) Duration

(days)

Ref. No. (see end of Table

B.5)

1. Endpoints used in final analysis (longest exposure duration available for a specific taxon) 1a. Non-lethal endpoints Daphnia magna Water flea EC50 REP 220 141 79 21 38 Tubifex tubifex Tubificid worm EC50 ITX 281 180 102 4 12 Daphnia magna Water flea EC50 ITX 330 211 119 21 38 Eudiaptomus padanus padanus Calanoid copepod EC50 ITX 4,000 2,556 1,444 2 44 Cyclops abyssorum prealpinus Cyclopoid copepod EC50 ITX 7,000 4,472 2,528 2 44 1b. Mortality endpoints 0 Daphnia magna Water flea LC50 MOR 649 415 234 4.2 8 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 2 47 Ceriodaphnia dubia Water flea LC50 MOR 1,830 1,169 661 2 15 Lymnaea Pond snail LC50 MOR 2,573 1,644 929 4 8 Daphnia hyalina Water flea LC50 MOR 3,000 1,917 1,083 2 44 Nitzschia linearis Diatom LC50 MOR 3,130 2,000 1,130 5 18 Pimephales promelas Fathead minnow LC50 MOR 4,630 2,958 1,672 4 15 Lepomis macrochirus Bluegill LC50 MOR 9,500 6,069 3,431 4 48 Lepomis macrochirus Bluegill LC50 MOR 10,650 6,804 3,846 5 18 Gambusia affinis Western mosquitofish LC50 MOR 13,400 8,561 4,839 4 23

B-35



as Ca2+

(mg/L) Duration

(days)


B.5) 2. Endpoints rejected as being of shorter duration. 2a. Non-lethal endpoints Daphnia magna Water flea EC50 REP 220 141 79 21 38 Tubifex tubifex Tubificid worm EC50 ITX 389 249 140 2 12 Daphnia magna Water flea EC50 ITX 464 296 168 2 38 Daphnia magna Water flea EC50 ITX 573 366 207 1 12 Tubifex tubifex Tubificid worm EC50 ITX 814 520 294 1 12 Daphnia magna Water flea EC50 ITX 920 588 332 2.67 1 2b. Mortality endpoints Chlorella vulgaris Green algae LOEC POP 280 179 101 90 31 Daphnia magna Water flea LC50 MOR 759 485 274 2 8 Daphnia magna Water flea LC50 MOR 759 485 274 2 8 Daphnia magna Water flea LC50 MOR 759 485 274 3 8 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 1 47 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 1 47 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 1 47 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 2 47 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 2 47 Oryzias latipes Medaka, high-eyes LC50 MOR 1,000 639 361 2 47 Daphnia magna Water flea LC50 MOR 1,838 1,174 664 1 8

B-36



as Ca2+

(mg/L) Duration

(days)


B.5) Daphnia magna Water flea LC50 MOR 1,838 1,174 664 1 8 Ceriodaphnia dubia Water flea LC50 MOR 2,260 1,444 816 1 15 Daphnia magna Water flea LC50 MOR 2,770 1,770 1,000 2 15 Daphnia magna Water flea LC50 MOR 3,005 1,920 1,085 2.1 8 Lymnaea Pond snail LC50 MOR 3,094 1,977 1,117 2 8 Daphnia magna Water flea LC50 MOR 3,250 2,076 1,174 1 15 Lymnaea Pond snail LC50 MOR 3,308 2,113 1,195 3 8 Daphnia magna Water flea LC50 MOR 3,526 2,253 1,273 1.02 8 Lymnaea Pond snail LC50 MOR 4,485 2,865 1,620 1 8 Pimephales promelas Fathead minnow LC50 MOR 6,560 4,191 2,369 2 15 Pimephales promelas Fathead minnow LC50 MOR 6,660 4,255 2,405 1 15 Lepomis macrochirus Bluegill LC50 MOR 8,350 5,335 3,015 1 8 Lepomis macrochirus Bluegill LC50 MOR 9,500 6,069 3,431 4 48 Lepomis macrochirus Bluegill LC50 MOR 9,500 6,069 3,431 4 48 Lepomis macrochirus Bluegill LC50 MOR 11,300 7,219 4,081 4 48 Gambusia affinis Western mosquitofish LC50 MOR 13,400 8,561 4,839 1 23 Gambusia affinis Western mosquitofish LC50 MOR 13,400 8,561 4,839 2 23 Caenorhabditis elegans Nematode LC50 MOR 413,318 264,063 149,255 1 46

3. NOEC, LOEC and Other Endpoint Types (not used) Morone saxatilis x chrysops Sunshine bass NR-ZERO MOR 5-80 42 50

B-37



as Ca2+

(mg/L) Duration

(days)


B.5) Chlorella vulgaris Green algae LOEC POP 280 179 101 90 31 Stizostedion lucioperca Pikeperch NR-LETH MOR 7,500 4,792 2,708 20 min 35 Rana breviceps Frog NR-LETH MOR 10,000 6,389 3,611 0.33 34

B-38

Table B.9: Studies of the Effects of Other Salt Ion Pairs on Aquatic Life (Excluding Marine and Brackish Water Taxa)

Scientific Name Common Name End-point Effect

Salt Conc

(mg/L) as anion(mg/L)

as cation (mg/L)

Dura-tion

(days) Author Year

1. Calcium sulphate

Lepomis macrochirus Bluegill LC50 MOR 2980 2,102 878 4 PATRICK, R., J. CAIRNS, J, AND A. SCHEIER 1968

Nitzschia linearis Diatom LC50 MOR 3200 2,258 942 5 As above 1968

Ceriodaphnia dubia Water flea LC50 MOR >1,940 > 1368 >571 1 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Ceriodaphnia dubia Water flea LC50 MOR >1,910 >1,350 >563 2 As above 1997

Ceriodaphnia dubia Water flea LC50 MOR >1,970 >1,390 >580 2 As above 1997

Daphnia magna Water flea LC50 MOR >1,970 >1,390 >580 1 As above 1997

Pimephales promelas Fathead minnow LC50 MOR >1,970 >1,390 >580 1 As above 1997



Gambusia affinis Western mosquitofish LC50 MOR >56,000 >39,500 >16,500 1 WALLEN, I.E., W.C. GREER, AND R. LASATER 1957

Gambusia affinis Western mosquitofish LC50 MOR >56,000 >39,500 >16,500 2 As above 1957

Gambusia affinis Western mosquitofish LC50 MOR >56,000 >39,500 >16,500 4 As above 1957

2. Potassium sulphate

Dreissena polymorpha Zebra mussel LC50 MOR 112 62 50 1 FISHER, S.W., P. STROMBERG, K.A. BRUNER, AND L.D. BOULET

1991

Ceriodaphnia dubia Water flea LC50 MOR <680 <375 <305 2 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Pimephales promelas Fathead minnow LC50 MOR 680 375 305 4 As above 1997



Daphnia magna Water flea LC50 MOR 720 397 323 2 As above 1997

Ceriodaphnia dubia Water flea LC50 MOR 770 424 346 1 As above 1997

B-39


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year


Lepomis macrochirus Bluegill LC50 MOR 3550 1,957 1,593 4 TRAMA, F.B. 1954

3. Magnesium sulphate

Tubifex tubifex Tubificid worm EC50 ITX 158 126 32 4 KHANGAROT, B.S. 1991

Tubifex tubifex Tubificid worm EC50 ITX 165 132 33 2 As above 1991

Tubifex tubifex Tubificid worm EC50 ITX 303 242 61 1 As above 1991

Daphnia magna Water flea EC50 ITX 344 275 69 2 KHANGAROT, B.S. AND P.K. RAY 1989

Daphnia magna Water flea EC50 ITX 406 324 82 1 As above 1989

Daphnia magna Water flea LC50 MOR 158 126 32 4 DOWDEN, B.F. AND H.J. BENNETT 1965





Daphnia magna Water flea LC50 MOR 1,820 1,453 367 2 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Daphnia magna Water flea LC50 MOR 2,360 1,884 476 1 As above 1997

Lymnaea Pond snail LC50 MOR 1,250 998 252 4 DOWDEN, B.F. AND H.J. BENNETT 1965

Lymnaea Pond snail LC50 MOR 1,260 1,006 254 3 As above 1965



Ceriodaphnia dubia Water flea LC50 MOR 1,770 1,413 357 1 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

B-40


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year

Ceriodaphnia dubia Water flea LC50 MOR 1,770 1,413 357 2 As above 1997

Pimephales promelas Fathead minnow LC50 MOR 2,820 2,251 569 4 As above 1997



Gambusia affinis Western mosquitofish LC50 MOR 3,100 2,474 626 1 WALLEN, I.E., W.C. GREER, AND R. LASATER 1957

Gambusia affinis Western mosquitofish LC50 MOR 3,100 2,474 626 2 As above 1957

Gambusia affinis Western mosquitofish LC50 MOR 3,100 2,474 626 4 As above 1957

Lepomis macrochirus Bluegill LC50 MOR 3,800 3,033 767 1 DOWDEN, B.F. AND H.J. BENNETT 1965

Oryzias latipes Medaka, high-eyes LC50 MOR >1,000 >798 >202 1 TSUJI, S., Y. TONOGAI, Y. ITO, AND S. KANOH 1986

Oryzias latipes Medaka, high-eyes LC50 MOR >1,000 >798 >202 1 As above 1986



Oryzias latipes Medaka, high-eyes LC50 MOR >1,000 >798 >202 2 TSUJI, S., Y. TONOGAI, Y. ITO, AND S. KANOH 1986


Chlorella vulgaris Green algae NOEC POP 980 782 198 NR DOOREN DE JONG LE 1965

Chlorella vulgaris Green algae LOEC POP 1,230 982 248 NR As above 1965

4. Sodium sulphate

Nitzschia fonticola Diatom EC50 POP >800 >542 >304 NR YAMANE, A.N., M. OKADA, AND R. SUDO 1984

Selenastrum capricornutum

Green algae EC50 POP >800 >542 >304 NR As above 1984

Microcystis aeruginosa Blue-green algae EC50 POP >800 >542 >304 NR As above 1984

Myriophyllum spicatum Eurasian watermilfoil EC50 GRO 928 628 353 32 STANLEY, R.A. 1974

Myriophyllum spicatum Eurasian watermilfoil EC50 GRO 1,335 904 508 32 As above 1974

Myriophyllum spicatum Eurasian watermilfoil EC50 POP 2,113 1,431 804 32 As above 1974

Myriophyllum spicatum Eurasian watermilfoil EC50 POP 2,305 1,561 877 32 As above 1974

B-41


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year

Myriophyllum spicatum Eurasian watermilfoil EC50 GRO 2,337 1,583 889 32 As above 1974

Myriophyllum spicatum Eurasian watermilfoil EC50 POP 3,037 2,057 1,155 32 As above 1974

Myriophyllum spicatum Eurasian watermilfoil EC50 POP 3,313 2,244 1,260 32 As above 1974

Myriophyllum spicatum Eurasian watermilfoil EC50 GRO 3,360 2,276 1,278 32 As above 1974

Daphnia magna Water flea EC50 ITX 4,547 3,079 1,730 4.2 FREEMAN, L. AND I. FOWLER 1953

Morone saxatilis Striped bass LC50 MOR 56 38 21 4 HUGHES, J.S. 1973

Morone saxatilis Striped bass LC50 MOR 81 55 31 4 As above 1973










Morone saxatilis Striped bass LC50 MOR 790 535 301 1 HUGHES, J.S. 1973

Morone saxatilis Striped bass LC50 MOR 1,100 745 418 4 As above 1973




Daphnia magna Water flea LC50 MOR 142 96 54 4 DOWDEN, B.F. AND H.J. BENNETT 1965




B-42


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year



Daphnia magna Water flea LC50 MOR 1,024 693 390 4 As above 1965







Daphnia magna Water flea LC50 MOR 2,716 1,839 1,033 1 As above 1965

Daphnia magna Water flea LC50 MOR 4,580 3,102 1,742 2 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Daphnia magna Water flea LC50 MOR 6,290 4,260 2,393 1 As above 1997

Daphnia magna Water flea LC50 MOR 8,384 5,678 3,189 1 DOWDEN, B.F. 1961

Daphnia magna Water flea LC50 MOR 9,115 6,173 3,467 2 ARAMBASIC, M.B., S. BJELIC, AND G. SUBAKOV 1995

Amphipoda Scud order LC50 MOR 200 135 76 3 DOWDEN, B.F. AND H.J. BENNETT 1965

Amphipoda Scud order LC50 MOR 200 135 76 4 As above 1965







Tricorythus Mayfly LC50 MOR 660 447 251 4 GOETSCH, P.A. AND C.G. PALMER 1997

Lymnaea Pond snail LC50 MOR 799 541 304 4 DOWDEN, B.F. AND H.J. BENNETT 1965

Lymnaea Pond snail LC50 MOR 1,151 780 438 4 As above 1965


B-43


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year






Nitzschia linearis Diatom LC50 MOR 1,900 1,287 723 5 PATRICK, R., J. CAIRNS, J, AND A. SCHEIER 1968

Gambusia affinis Western mosquitofish LC50 MOR 2,200 1,490 837 6 WALLEN, I.E., W.C. GREER, AND R. LASATER 1957

Gambusia affinis Western mosquitofish LC50 MOR 3,200 2,167 1,217 6 As above 1957







Culex Mosquito LC50 MOR 2,572 1,742 978 1 DOWDEN, B.F. AND H.J. BENNETT 1965

Culex Mosquito LC50 MOR 3,004 2,034 1,143 2 As above 1965



Lepomis macrochirus Bluegill LC50 MOR 3,040 2,059 1,156 4 TRAMA, F.B. 1954

Lepomis macrochirus Bluegill LC50 MOR 3,940 2,668 1,499 1 DOWDEN, B.F. AND H.J. BENNETT 1965

Lepomis macrochirus Bluegill LC50 MOR 4,380 2,966 1,666 4 TRAMA, F.B. 1954

Lepomis macrochirus Bluegill LC50 MOR 5,670 3,840 2,157 1 DOWDEN, B.F. AND H.J. BENNETT 1965

Lepomis macrochirus Bluegill LC50 MOR 12,500 8,465 4,755 4 CAIRNS, J.C.J. AND A. SCHEIER 1959

Lepomis macrochirus Bluegill LC50 MOR 12,750 8,635 4,850 4 As above 1959

Lepomis macrochirus Bluegill LC50 MOR 13,000 8,804 4,945 4 As above 1959

Lepomis macrochirus Bluegill LC50 MOR 13,500 9,143 5,135 4 PATRICK, R., J. CAIRNS, J, AND A. SCHEIER 1968

B-44


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year

Ceriodaphnia dubia Water flea LC50 MOR 3,080 2,086 1,172 2 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Ceriodaphnia dubia Water flea LC50 MOR 3,590 2,431 1,366 1 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Poecilia latipinna Sailfin molly LC50 MOR 3,599 2,437 1,369 2 DOWDEN, B.F. AND H.J. BENNETT 1965

Poecilia latipinna Sailfin molly LC50 MOR 4,510 3,054 1,716 1 As above 1965



Polycelis nigra Planarian LT50 MOR 6,818 4,617 2,594 2 JONES, J.R.E. 1941

Pimephales promelas Fathead minnow LC50 MOR 7,960 5,391 3,028 4 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Pimephales promelas Fathead minnow LC50 MOR >7690 >5,210 >2,930 2 As above 1997

Pimephales promelas Fathead minnow LC50 MOR >8080 >5,470 >3,070 1 As above 1997

Daphnia magna Water flea LETC ITX 5,960 4,036 2,267 2 ANDERSON, B.G. 1946

Tricorythus Mayfly NR-ZERO

MOR 7,340 4,971 2,792 0.5 GOETSCH, P.A. AND C.G. PALMER 1997

5. Sodium carbonate

Daphnia magna Water flea EC50 ITX 524 297 227 4.2 FREEMAN, L. AND I. FOWLER 1953

Microcystis aeruginosa Blue-green algae EC50 POP >800 >454 >346 NR YAMANE, A.N., M. OKADA, AND R. SUDO 1984

Nitzschia fonticola Diatom EC50 POP > 800 >454 >346 NR As above 1984

Selenastrum capricornutum

Green algae EC50 POP > 800 >454 >346 NR As above 1984

Amphipoda Scud order LC50 MOR 67 38 29 3 DOWDEN, B.F. AND H.J. BENNETT 1965



B-45


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year


Nitzschia linearis Diatom LC50 MOR 242 137 105 5 PATRICK, R., J. CAIRNS, J, AND A. SCHEIER 1968

Poecilia latipinna Sailfin molly LC50 MOR 297 168 129 2.1 DOWDEN, B.F. AND H.J. BENNETT 1965

Poecilia latipinna Sailfin molly LC50 MOR 405 230 175 1.04 As above 1965

Lepomis macrochirus Bluegill LC50 MOR 300 170 130 4 CAIRNS, J.C.J. AND A. SCHEIER 1959

Lepomis macrochirus Bluegill LC50 MOR 300 170 130 4 As above 1959

Lepomis macrochirus Bluegill LC50 MOR 300 170 130 4 As above 1959

Lepomis macrochirus Bluegill LC50 MOR 320 181 139 4 PATRICK, R., J. CAIRNS, J, AND A. SCHEIER 1968

Lepomis macrochirus Bluegill LC50 MOR 385 218 167 1 DOWDEN, B.F. AND H.J. BENNETT 1965

Dugesia Turbellarian, flatworm LC50 MOR 341 193 148 4 As above 1965








Daphnia magna Water flea LC50 MOR 607 344 263 1.04 As above 1965

Daphnia magna Water flea LC50 MOR 1640 930 710 2 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Daphnia magna Water flea LC50 MOR 2380 1,350 1,030 1 As above 1997

Lymnaea Pond snail LC50 MOR 395 224 171 3 DOWDEN, B.F. AND H.J. BENNETT 1965

Lymnaea Pond snail LC50 MOR 403 229 174 1 As above 1965



Culex Mosquito LC50 MOR 600 340 260 2 As above 1965

Culex Mosquito LC50 MOR 1820 1,032 788 1 DOWDEN, B.F. AND H.J. BENNETT 1965

B-46


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year

Gambusia affinis Western mosquitofish LC50 MOR 740 420 320 4 WALLEN, I.E., W.C. GREER, AND R. LASATER 1957

Gambusia affinis Western mosquitofish LC50 MOR 840 476 364 2 As above 1957

Gambusia affinis Western mosquitofish LC50 MOR 1200 681 519 1 As above 1957

Ceriodaphnia dubia Water flea LC50 MOR 1020 578 442 4 MOUNT, D.R., D.D. GULLEY, J.R. HOCKETT, T.D. GARRISON, AND J.M. EVANS

1997

Ceriodaphnia dubia Water flea LC50 MOR 1420 805 615 1 As above 1997

Pimephales promelas Fathead minnow LC50 MOR 2500 1,418 1,082 2 As above 1997

Pimephales promelas Fathead minnow LC50 MOR 4850 2,750 2,100 1 As above 1997

Pimephales promelas Fathead minnow LC50 MOR <850 <482 <368 4 As above 1997

Daphnia magna Water flea LETC ITX <424 <240 <184 2 ANDERSON, B.G. 1946

Micropterus salmoides Largemouth bass NR-LETH

MOR 200 113 87 NR SANBORN, N.H. 1945


MOR 500 284 216 NR As above 1945


MOR 500 284 216 NR As above 1945

Cyprinidae Minnow,carp family NR-LETH

MOR 482 273 209 0.25 TUROBOYSKI, L. 1960

Cyprinidae Minnow,carp family NR-LETH

MOR 628 356 272 0.25 As above 1960

Lepomis macrochirus Bluegill NR-LETH

MOR 500 284 216 NR SANBORN, N.H. 1945

Micropterus salmoides Largemouth bass NR-ZERO

MOR 100 57 43 7 SANBORN, N.H. 1945

B-47


Salt Conc


as cation (mg/L)

Dura-tion

(days) Author Year

Micropterus salmoides Largemouth bass NR-ZERO

MOR 200 113 87 7 As above 1945

Lepomis macrochirus Bluegill NR-ZERO

MOR 200 113 87 7 As above 1945

Carassius auratus Goldfish NR-ZERO

MOR 500 284 216 7 As above 1945

Carassius auratus Goldfish NR-ZERO

MOR 500 284 216 7 As above 1945

C-1

C. Appendix C: Review of Existing Salt Soil and Water Guidelines in Other Jurisdictions

C-2

Table C.1: Overview

Generic Guidelines for Salt Contaminated Soil

Comments

Soil Quality Relative to Disturbance and Reclamation (adapted from Alberta Agriculture 1987)

Developed to provide physical, chemical and biological guidelines for evaluating the suitability of the soil for revegetation. Remediation to generic guidelines (Table 2), is expected for topsoil and subsoil. Soil parameters used are EC and SAR. Requires comparison with off site controls. Concerned with Agricultural Soils

Saskatchewan Upstream Petroleum Sites Remediation Guidelines (2000)

Developed to provide remediation criteria for oil and gas companies, surface landowners and regulators. Soil parameters used are EC and SAR. (Table 3)

Guideline for use at contaminated sites in Ontario1997. Ministry of Environment and Energy.

Generic soil criteria are provided for two depths and for two soil textures. (Table 4) Provides advice and information to determine whether or not soil remediation is required, and to determine the kind of restoration needed to allow continued use or re-use of the site. In theory differentiates between sites with potable or non-potable water, and gives values for surface and sub-soil. (not necessarily available for salts). Also provides background levels. NB anion and cations expressed /g soil

CCME 1991. Interim Canadian Environmental Quality Criteria for Contaminated Sites

(Table 5). In Alberta, the CCME Industrial/Commercial Criteria for EC and SAR may be used at sites zoned for industrial use.

Canadian Environmental Quality Guidelines CCME (1999)

Addresses the protection of air quality, marine quality freshwater and marine sediment quality, tissue quality for the protection of wildlife consumers of aquatic life, and soil quality for agricultural, residential/parkland, commercial and industrial land uses. In reality, there are no soil standards for any relevant ions. Some water standards are given (Table 6). Alberta uses these guidelines in considering water quality of salt affected water.

Saskatchewan Upstream Petroleum Sites Remediation Guidelines (2000)

Water Quality Objectives (background water quality data for the site considered to be primary clean-up criteria). (Table 7).

BC Contaminated Sites Regulation (1996)

Generic Water Quality Guidelines (Table 8).

C-3

Table C.2: Soil Quality Relative to Disturbance and Reclamation (Alberta Agriculture 1987, as reported in Environmental Sciences Division, Environmental Service, Alberta Environment, 2000). Soils to be remediated to background levels or better

Rating Categories Parameter

Good Fair Poor UnsuitableEC dS/m < 2 2 to 4 4 to 8 > 8

Topsoil SAR < 4 4 to 8 8 to 12 > 12

EC dS/m < 3 3 to 5 5 to 10 > 10 Subsoil

SAR < 4 4 to 8 8 to 12 > 12

Table C.3: Saskatchewan Upstream Petroleum Sites Remediation Guidelines for Soil (2000). (a) must monitor crop growth and yield for minimum of 3 y. (b) must monitor crop growth and yield for a minimum of 5 y

Parameter Agricultural Residential Forest Subsoil

Unconditional use 2 2 2 8

Moderately tolerant crops

3-5 a 3-5 a 3-5a 9-12a >12b

EC@25°C dS/m

Tolerant crops 6-8 a 6-8 a 6-8 a

Unconditional use 5 5 5 8 SAR

Conditional use 6-8 a 6-8 a 6-8 a 9-13a >13 b

Note: According to SPIGEC 2000, data pertaining to salt tolerance on forest vegetation are not readily available.

Table C.4: CCME Commercial/Industrial (CCME, 1991. Interim Canadian Environmental Quality Criteria for Contaminated Sites)

Parameter Agricultural Residential/Parkland Commerical/Industrial EC 2 dS/m 2 dS/m 4 dS/m

SAR 5 5 12

C-4

Table C.5: Guideline for use at contaminated sites in Ontario, 1997

Soil remediation criteria (µg/g) Potable groundwater criteria(µg/L)

Parameter Agricultural Residential/Parkland

Commerical/ Industrial

All land use categories

EC (mS/cm) 0.70 0.70 1.4 N/A

SAR 5.0 5.0 12 N/A

Chloride N/V N/V N/V 250 000

Nitrate N/V N/V N/V 10 000

Sodium N/V N/V N/V 200 000 Notes: N/V No Value (mS/cm = dS/m) Soil criteria only apply where surface soil pH is 5.0 to 9.0 and for full depth use, the subsurface soil pH is 5.0-11.0 No values derived for any land use categories where non-potable groundwater conditions applied.

Table C.6: Canadian Environmental Quality Guidelines – CCME, 1999

Substance Aquatic Life Irrigation Livestock Drinking water Calcium 1 000 000 µg/L

Chloride 100 000 – 700 000 µg/L

≤ 250 000 µg/ La

Nitrate (as N)

Concentrations that stimulate weed growth should be avoided

45 000 µg/L

Nitrate and Nitrite (as N)

100 000 µg/L 100 000 µg/L

Sodium ≤ 200 000 µg/La Sulphate 1 000 000 µg/L ≤ 500 000 µg/La Total Dissolved Solids

500 000 – 3 500 000 µg/L

3 000 000 µg/La ≤ 500 000 µg/La

a Aesthetic objective No standards for soil for any of the above ions Road salts (calcium chloride, sodium chloride) are listed in the CCME 1999 document under “additional priority” substances ie standards to be developed for protection of Aquatic Life

C-5

Table C.7: Saskatchewan Upstream Petroleum Sites Remediation Guidelines (2000)

Substance Aquatic Life Irrigation Livestock Drinking waterCalcium NA

Chloride 100-700 mg/L ≤ 250 mg/L

Nitrate (as N) 45 mg/L

Nitrate and Nitrite (as N) 100mg/L

Sodium 200 mg/L

Sulphate 1000 mg/L ≤ 500 mg/L

Total Dissolved Solids NA

Table C.8: BC Contaminated Site Regulation (1996; Schedule 6, Generic Water Standards)

Substance Aquatic Life Irrigation Livestock Drinking water

Calcium 1000 mg/L

Chloride 100-700 mg/L 250 mg/L

Nitrate (as N) 400 000µg/L 100 000µg/L 10 000µg/L

Nitrate + Nitrite (as N) 400 000µg/L 100 000µg/L 10 000µg/L

Sodium 200 mg/L

Sulphate 1 000 mg/L 1 000 mg/L 500 mg/L Notes: No K, Mg

Documents

Derivation of Matrix Soil Standards for Salt under the ... · Table 7.1: Background concentrations of salt ions in groundwater within British Columbia..... 108 Table 8.1: SCHEDULE