VERTICAL SCREENING DISTANCES FOR ETHYLENE DIBROMIDE …neiwpcc.org/tanks2015old/tanks2015presentations/2... · us from including in filings with the SEC. U.S. Investors are urged

Copyright 2015 Shell Global Solutions (US), Inc.

VERTICAL SCREENING DISTANCES FOR ETHYLENE DIBROMIDE (EDB) AND 1,2 DICHLOROETHANE (1,2 DCA) AT PETROLEUM UNDERGROUND STORAGE TANK (UST) SITES 25th National Tanks Conference and Expo September 14 – 16, 2015 Phoenix, Arizona

Matthew Lahvis – Shell Global Solutions (US), Inc. June Lu – SNC Lavalin, Inc. Janice Paslawski – SNC Lavalin, Inc.

1 September 2015


DEFINITIONS AND CAUTIONARY NOTE Reserves: Our use of the term “reserves” in this presentation means SEC proved oil and gas reserves.

Resources: Our use of the term “resources” in this presentation includes quantities of oil and gas not yet classified as SEC proved oil and gas reserves. Resources are consistent with the Society of Petroleum Engineers 2P and 2C definitions.

Organic: Our use of the term Organic includes SEC proved oil and gas reserves excluding changes resulting from acquisitions, divestments and year-average pricing impact.

Resources plays: Our use of the term ‘resources plays’ refers to tight, shale and coal bed methane oil and gas acreage.

The companies in which Royal Dutch Shell plc directly and indirectly owns investments are separate entities. In this presentation “Shell”, “Shell group” and “Royal Dutch Shell” are sometimes used for convenience where references are made to Royal Dutch Shell plc and its subsidiaries in general. Likewise, the words “we”, “us” and “our” are also used to refer to subsidiaries in general or to those who work for them. These expressions are also used where no useful purpose is served by identifying the particular company or companies. ‘‘Subsidiaries’’, “Shell subsidiaries” and “Shell companies” as used in this presentation refer to companies in which Royal Dutch Shell either directly or indirectly has control. Companies over which Shell has joint control are generally referred to as “joint ventures” and companies over which Shell has significant influence but neither control nor joint control are referred to as “associates”. The term “Shell interest” is used for convenience to indicate the direct and/or indirect ownership interest held by Shell in a venture, partnership or company, after exclusion of all third-party interest.

This presentation contains forward-looking statements concerning the financial condition, results of operations and businesses of Royal Dutch Shell. All statements other than statements of historical fact are, or may be deemed to be, forward-looking statements. Forward-looking statements are statements of future expectations that are based on management’s current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. Forward-looking statements include, among other things, statements concerning the potential exposure of Royal Dutch Shell to market risks and statements expressing management’s expectations, beliefs, estimates, forecasts, projections and assumptions. These forward-looking statements are identified by their use of terms and phrases such as ‘‘anticipate’’, ‘‘believe’’, ‘‘could’’, ‘‘estimate’’, ‘‘expect’’, ‘‘intend’’, ‘‘may’’, ‘‘plan’’, ‘‘objectives’’, ‘‘outlook’’, ‘‘probably’’, ‘‘project’’, ‘‘will’’, ‘‘seek’’, ‘‘target’’, ‘‘risks’’, ‘‘goals’’, ‘‘should’’ and similar terms and phrases. There are a number of factors that could affect the future operations of Royal Dutch Shell and could cause those results to differ materially from those expressed in the forward-looking statements included in this presentation, including (without limitation): (a) price fluctuations in crude oil and natural gas; (b) changes in demand for Shell’s products; (c) currency fluctuations; (d) drilling and production results; (e) reserves estimates; (f) loss of market share and industry competition; (g) environmental and physical risks; (h) risks associated with the identification of suitable potential acquisition properties and targets, and successful negotiation and completion of such transactions; (i) the risk of doing business in developing countries and countries subject to international sanctions; (j) legislative, fiscal and regulatory developments including potential litigation and regulatory measures as a result of climate changes; (k) economic and financial market conditions in various countries and regions; (l) political risks, including the risks of expropriation and renegotiation of the terms of contracts with governmental entities, delays or advancements in the approval of projects and delays in the reimbursement for shared costs; and (m) changes in trading conditions. All forward-looking statements contained in this presentation are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. Readers should not place undue reliance on forward-looking statements. Additional factors that may affect future results are contained in Royal Dutch Shell’s 20-F for the year ended 31 December, 2015 (available at www.shell.com/investor and www.sec.gov ). These factors also should be considered by the reader. Each forward-looking statement speaks only as of the date of this presentation, 14 September, 2015. Neither Royal Dutch Shell nor any of its subsidiaries undertake any obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information. In light of these risks, results could differ materially from those stated, implied or inferred from the forward-looking statements contained in this presentation. There can be no assurance that dividend payments will match or exceed those set out in this presentation in the future, or that they will be made at all.

We use certain terms in this presentation, such as discovery potential, that the United States Securities and Exchange Commission (SEC) guidelines strictly prohibit us from including in filings with the SEC. U.S. Investors are urged to consider closely the disclosure in our Form 20-F, File No 1-32575, available on the SEC website www.sec.gov. You can also obtain this form from the SEC by calling 1-800-SEC-0330.

2 September 2015


use EDB = lead additive; soil fumigant

1,2 DCA = lead additive; commercial chemical/solvent, paints, etc.

chemical properties

BACKGROUND EDB

1,2 DCA

Br Br

Compound Henry’s Law

Constant 25oC

Effective Solubility – Gasoline b

(µg/L)

Vapor Pressure (mm Hg)

25oC

Effective Air-Phase Saturation

(µg/L)

EDB 0.027 1,900 11 51

1,2 DCA 0.048 3,700 79 178

benzene 0.23 15,000 95 3450

a VISL calculator - http://www.epa.gov/oswer/vaporintrusion/documents/VISL-Calculator.xlsm

b Falta, 2004. Ethylene Dibromide and 1,2-Dichloroethane Contamination from Leaded Gasoline Releases, Ground Water Management - Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Assessment, and Remediation Conference, , pp. 252-260

3 September 2015

http://www.epa.gov/oswer/vaporintrusion/documents/VISL-Calculator.xlsm



persistence aerobic biodegradation EDB: t1/2 = days – weeks 1,2 DCA: t1/2 = days – > several months

anaerobic: EDB: t1/2 = months 1,2 DCA: t1/2 = months– years; sulfate,

methanogenic conditions only

co-metabolic biodegradation demonstrated (methane), yet biodegradation may be slowed in the field by the presence of other hydrocarbons

BACKGROUND: BIODEGRADATION EDB

1,2 DCA

Br Br

KEY POINT

• EDB and 1,2 DCA biodegrade aerobically • biodegradation rates less well

understood than BTEX 4 September 2015


BACKGROUND: ANALYTICAL METHODS

Method

EDB

1,2

DCA

Screening Level*

EDB 1,2 DCA GROUNDWATER (µg/L)

8260B 3 3 0.18 2.2

8011 0.01

SOIL GAS (µg/m3) 8260B 200 100

0.047

1.1 TO-15 7.5 – 15 4 - 8

TO-15 (sim) 0.4 0.2

KEY POINT

• separate analytical methods required for groundwater • analytical detection limits (DLs) and reporting limits (RLs) in

soil gas are generally above risk-based screening levels

5 September 2015

* VISL calculator - http://www.epa.gov/oswer/vaporintrusion/documents/VISL-Calculator.xlsm





From Wilson and Adair, 2008

BACKGROUND: OCCURRENCE (EDB)

KEY POINT

• EDB concentrations in GW > DLs are a relatively common occurrence in South Carolina and other states

6 September 2015

Copyright 2015 Shell Global Solutions (US), Inc. 7 August 2015

Modified from Wilson and Adair, 2008 EDB risk

greater

Natural Attenuation of the Lead Scavengers 1,2 Dibromoethane (EDB) and 1,2 Dichloroethane (1,2-DCA) at Motor Fuel Release Sites and Implications for Risk Management (EPA/600/R-08/107)

BACKGROUND: RISK (EDB)

KEY POINT

• EDB represented a greater risk than benzene in groundwater at 25% of sites investigated


2010 US EPA OUST Memo: begin/continue to monitor:

- used pre-1986, continued to be stored

- threat to DW resources

analyze using appropriate methods (Method 8011 – EDB)

remediate if threat exists

share information

BACKGROUND: REGULATORY

KEY POINT

• EPA/Falta studies prompt US EPA OUST to recommend additional risk assessment for EDB and 1,2 DCA

8 September 2015


BACKGROUND: OCCURRENCE

# of states w/ %’s based on

estimates or hard data

# of states monitoring for lead scavengers

ASTSWMO, 2014. Lead Scavengers Survey Report: Prepared by LUST Task Force, August 2014.

KEY POINT

• EDB and 1,2 DCA in ground water is a common occurrence, yet states generally do not have hard data to support risk assessment


new methodology developed for PVI site screening based on use of vertical screening distances

approach recommended in ITRC, US EPA OUST, and California Low Threat Tank Closure Policy

historical leaded gasoline releases defined as “precluding factor” in US EPA OUST & ITRC guidance

potential re-opener for sites closed by California Low-Threat Tank Closure Policy

BACKGROUND/MOTIVATION

10

Incorporating ITRC doc or referring to directly

Staff using, by not formally endorsed

Early use of ITRC PVI document (3/26/15) From ITRC PVI Classroom Training (Sept, 2015)

September 2015


OBJECTIVES

assess PVI risk develop risk-based exclusion

distance criteria for use in PVI assessments at petroleum-hydrocarbon release sites based on sound science

11 September 2015


DATABASE – UST SITES WESTERN CANADA

SNC-Lavalin 139 UST sites – Western Canada

Sites % of database

Pb scavengers in groundwater (analyzed) 66 47 Pb scavengers > DLs in groundwater EDB = 0.5 µg/L;1,2-DCA = 0.5 µg/L

7 5 *

KEY POINT

• few sites in Western Canada with EDB and 1,2 DCA > DLs/RLs in groundwater

12 September 2015

Copyright 2015 Shell Global Solutions (US), Inc. 13 March 2012

County # Total Site (extracted)

# Sites w/ Pb Scavengers Analyzed

GW Detections Soil

Gas Detections GW and

Soil Gas

Paired points

EDB 1,2

DCA EDB 1,2 DCA Alameda 767 109 7 30 51 2 5 10 3 Butte 102 6 2 7 3 0 0 1 0 Contra Costa 277 48 19 29 9 0 Orange 796 796 0 796 156 0 24 156 Riverside 351 352 0 99 65 0 9 65 San Luis Obispo 158 158 10 41 3 0 0 3 0 Fresno 209 209 19 60 14 0 7 14 0 Salano 750 686 0 219 62 0 10 51 0 Santa Cruz 173 173 5 39 18 0 2 18 0 Shasta 40 32 2 4 2 0 0 1 0 Sutter 42 37 3 11 3 0 0 3 0 Tuolumne 43 38 2 13 8 0 1 7 0 Kings 49 36 0 18 12 0 2 10 1 Lake 46 28 2 7 2 0 0 1 0 Los Angeles 2161 255 17 110 114 3 22 12 3 Mariposa 22 12 0 0 2 0 0 2 0 Merced 150 150 9 48 33 0 5 33 0 Napa 115 115 2 20 8 1 1 8 0 Sacramento 395 40 0 20 34 1 10 4 0 San Bernardino 211 27 2 11 11 0 2 5 0 San Diego 1000 170 1 22 68 0 2 2 0 Santa Barbara 352 88 8 47 10 1 2 1 0 Sonoma 457 81 3 29 15 0 3 4 0 Ventura 390 59 1 18 10 0 0 3 0

Total (%) 9056 3705 (41%)

95 (3%)

1688 (46%)

733 (8%)

8 (1%)

107 (15%)

423 (11%) 7 (.1%)

KEY POINT

• 41% GW data, 8% soil-gas data • EDB rarely detected at GW locations where analyzed (3%); 1,2 DCA

more common (46%) • EDB rarely detected in soil gas (1% of sites) as compared to 1,2

DCA (15% of sites) • very few (0.1%) sites with groundwater detections for EDB and 1,2

DCA and complementary soil gas data

DATABASE – UST SITES CALIFORNIA (GEOTRACKER)


DATABASE DEVELOPMENT GENERAL ELEMENTS: groundwater and soil gas concentrations soil gas sampling method (vapor probe, monitoring well head space) soil type (presence of fractured rock) surface cover (asphalt, open, building) source type (LNAPL, dissolved) water-table elevation facility type (UST, industrial) sampling dates presence of fractured rock (excluded) vertical separation distances lateral offset (source, monitoring well) analytical method (detection and reporting limits) site operational history (release pre-1986, operating pre-1986) remediation history QA/QC (including leak testing, no on-going remediation, GW wells

screened across water table) 14 September 2015


MW Headspace

- LNAPL

5 ft from waste oil

tank

source soil (railroad siding)

10 ft from waste oil

tank

1,2 DCA – ALL DATA

15 March 2012

DISTRIBUTION OF GROUNDWATER

CONCENTRATIONS

KEY POINT

• vast majority of concentrations of 1,2 DCA in soil-gas are ND at source separation distances > ~6 ft, even for relatively significant concentrations in groundwater (i.e., > 100 µg/L)

• data indicate that PVI risk (screening) at UST sites is likely bounded by benzene (vertical screening distance = 15 ft)


1,2 DCA – PAIRED DATA DISTRIBUTION OF GROUNDWATER

CONCENTRATIONS PAIRED DATA • < 30 days between sample events • < 30 ft between sample locations • vapor probe only • > 10 ft from source areas (waste-oil tanks)

KEY POINT

• empirical data insufficient for derivation of vertical screening distances for 1,2 DCA

16 September 2015


1,2 DCA – PAIRED DATA

KEY POINT

• soil-gas concentrations orders of magnitude less than predicted by equilibrium partitioning likely an indicator of 1,2 DCA biodegradation in the vadose zone

17

within 3 feet of source


KEY POINT • NDs in soil gas indicate that PVI is likely not an issue; however,

lower soil-gas screening levels are necessary to confirm

EDB – WESTERN CANADA SITES W/ HISTORICAL USE OF LEADED GASOLINE

18 September 2015


EDB – PAIRED DATA

KEY POINT

• again, soil-gas concentrations orders of magnitude below those in equilibrium w/ groundwater are a potential indicator of EDB biodegradation in the vadose zone

19


CONCLUSIONS

inability to assess screening distances lots of ND data (method DLs and RLs above soil-gas screening

levels, especially for EDB) few sites w/detections in groundwater and complementary soil-gas data (i.e., data pairs)

empirical data (to date) indicate limited PVI risk biodegradation likely contributing to lack of detections

for EDB and1,2 DCA consistent with previous empirical studies showing that the PVI risk

is limited above low-concentration (dissolved or weathered LNAPL) sources

20 September 2015


PATH FORWARD

research opportunities further data collection at sites with known impacts modeling of soil-gas profiles laboratory column studies

new API project (Golder Associates, Scissortail Environmental Solutions, LLC) lit review empirical database evaluation (request for data)

21 September 2015

Documents

VERTICAL SCREENING DISTANCES FOR ETHYLENE DIBROMIDE …neiwpcc.org/tanks2015old/tanks2015presentations/2... · us from including in filings with the SEC. U.S. Investors are urged