U. S. DEPARTMENT OF THE INTERIOR

U. S. GEOLOGICAL SURVEY

The effect of acidic, metal-enriched drainage from the Wightman Fork and Alamosa River on the composition of selected wetlands in the San Luis Valley, Colorado

by

Laurie S^Balistrieri,* Larry P. Gough,** R. C. Severson,**Maria Montour,** P. H. Briggs,** Betty Adrian,**

Joe Curry,**David Fey,** Phil Hageman,** and Clara Papp**

Open-File Report 95-568

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. Any use of trade names is for descriptive purposes only and does not imply endorsement by the USGS.

*USGS, University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195-7940**USGS, Box 25046, MS 973, Denver Federal Center, Denver, CO 80225-0046

1

U.S. Department of the Interior Bruce Babbitt, Secretary U.S. Geological Survey Gordon Eaton, Director

For additional information write to:Branch ChiefBranch of GeochemistryBox 25046, MS 973Denver Federal CenterDenver, CO 80225

Copies of this report can be purchased from:Books and Open-File ReportsU.S. Geological SurveyBox 25046Denver Federal CenterDenver, CO 80225-0046

Abstract

The biogeochemistry of selected wetlands in the San Luis Valley, Colorado, was examined to assess the effect of acidic, metal-enriched water draining mineralized areas near and around the Summitville Mine. The sampling protocols, analytical methods, and chemical composition of water and stream bed sediment from the Wightman Fork and Alamosa River as well as water, surface sediment or cores, and rooted aquatic vegetation from wetland sites within and west of the Alamosa National Wildlife Refuge are presented. The data indicate that As, Co, Cr, Cu, Ni, and Zn are tracers of drainage from mineralized areas around the Summitville Mine. Sediments and aquatic plants in wetlands in the San Luis Valley that receive surface water from the Alamosa River tend to have larger concentrations of certain tracer elements (e.g., Co and Cu) than wetlands that receive water from other sources. Larger concentrations of Cu, Ni, and Zn in the sediments of wetlands receiving Alamosa River water appear to be related to the presence of larger amounts of Fe oxyhydroxides. However, there is little to no variation in the concentrations of tracer elements with depth in wetlands that receive Alamosa River water. This observation suggests that the geochemistry of these wetlands has not been significantly affected by recent mining activities at the Summitville Mine.

Introduction

Underground workings and open-pit gold mining activities at the Summitville Mine located in the southwestern San Juan Mountains of Colorado have produced acidic (pH 1.2- 3.2) and metal-enriched waters (e.g., As, Be, Cd, Cr, Co, Cu, Ga, Ge, Li, Ni, Se, Te, Th, V, Zn and rare-earth elements) (Plumlee and others, 1993). Some of this water enters the Wightman Fork. This stream and other tributaries draining mineralized areas south and southeast of Summitville flow into the Alamosa River and downstream to the San Luis Valley (Fig. 1). Within the Valley, this water is used for irrigation of alfalfa, barley, and other crops (Erdman and others, 1995) and is a source of water for livestock and certain wetlands near the Alamosa National Wildlife Refuge. Because these wetlands are seasonal hosts to migratory birds such as the endangered whooping crane, the U.S. Fish and Wildlife Service is concerned about the possible impact of metal-enriched drainage on the stability, productivity, and quality of these wetland ecosystems.

This work was part of the U. S. Geological Survey Environmental Geoscience Studies of the Summitville Mine (Posey and others, 1995). Our particular study was designed to assess the impact of acid drainage on selected wetlands in the San Luis Valley, particularly those located in the Alamosa National Wildlife Refuge, and provide useful information for management of wildlife within this area. To make this assessment, our plan was to compare the biogeochemistry of wetlands that receive surface water from the Alamosa River with wetlands that receive surface water from sources that carry little or no drainage from mineralized areas (e.g., Rio Grande River). We collected and analyzed water and stream-bed sediment from the Wightman Fork and Alamosa River to identify elements that are indicative of drainage from mineralized areas (i.e., indicator or tracer elements) and to assess the extent

of their transport throughout the Alamosa River system. We also collected and analyzed water, sediment, and rooted aquatic vegetation from wetlands that receive surface water from several sources - Alamosa River, La Jara Creek, and Rio Grande River. This report summarizes field and analytical methods and biogeochemical results. A preliminary assessment is made of the impact of acidic, metal-enriched drainage carried by the Alamosa River on selected wetlands in the San Luis Valley.

Field Methods

River samplesStream-bed sediment and water were collected from the Wightman Fork and ten

locations along the Alamosa River during June 24-26, 1993 (Fig. 1; Table 1). Site B was in the Wightman Fork just above the confluence with the Alamosa River. Site C was in the Alamosa River just above the confluence with the Wightman Fork, whereas site D was in the Alamosa River just below the confluence. Sites E, F, and G were located in the Alamosa River between Wightman Fork and Terrace Reservoir. Jasper, Burnt, and Silver Creeks enter the Alamosa River between sites E and F. Sites H, A, I, J, and K were located in the Alamosa River downstream of Terrace Reservoir. The Alamosa River begins to be diverted into canals downstream of site A and does not flow in a single, well-defined channel between site J and the Rio Grande River.

Stream-bed sediments were collected by scooping the upper 2 centimeters into polyethylene specimen containers. The sediment was allowed to settle, the supernatant was decanted, and the containers were packed in plastic bags for return to the laboratory. The sediments in the Alamosa River downstream of the confluence with the Wightman Fork were "panned" for the heavy fraction. Qualitative observations suggested decreasing concentrations of pyrite downstream. Stream-bed sediments at site H were collected from a small pool away from the main channel and are likely influenced by natural sorting.

River water was collected near the bank and placed in 60 mL polyethylene bottles (2/site) that were well rinsed with river water and 250 mL polyethylene bottles (I/site) that were acid cleaned and well rinsed with both distilled, de-ionized water and river water. Field measurements of pH were made using a model 290A Orion pH meter and Ag^AgCl combination electrode following standardization with pH buffers of 4.0, 7.0, and 10.0. Conductivity was also measured in the field using a model 124 Orion conductivity meter with a 4-electrode conductivity cell after standardization with 1,000 and 10,000 (iS/cm solutions. Water samples in the 250 mL bottles were filtered through 47 mm, 0.22 um Nuclepore filters within 10 hours of collection. Subsamples were taken for chloride and sulfate determinations and placed in clean 60 mL polyethylene bottles. The remaining solution was acidified to pH 2 using ultra-clean, concentrated nitric acid. Distilled, deionized water was run through the filtering system, acidified in the same manner as the river samples, and treated as a filter blank. All sample containers were packed in plastic bags for return to the laboratory.

Wetland samplesSediment, water, and aquatic wetland plants were collected from nine areas within

wetlands just west of (sites O, PI, P2, Q, and R) or within (sites L, M, N, and S) the

Alamosa National Wildlife Refuge during June 27-29, 1993 (Fig. 1; Table 2). The character of the wetlands was variable and included permanent (M and S) and small evaporative (P2) ponds, wetlands along sloughs (L), oxbows (O), ditches (PI), or canals (N and R), and flooded fields (Q). The wetlands received surface water from different sources. The wetlands within the Refuge appeared to be topographically isolated from receiving surface water from the Alamosa River or La Jara Creek and, most likely, received surface water from the Rio Grande River. The wetlands west of the Refuge appeared to receive surface water from the Alamosa River or a combination of Alamosa River and La Jara Creek waters.

Surface sediments at wetland sites L, PI, and P2 were collected by scooping the upper 2 centimeters into polyethylene specimen containers. The surface water was decanted and the containers packed in plastic bags for transport to the laboratory. Qualitative observations during sampling indicated that surface sediments at sites L and PI were black, organic-rich material with plant roots, whereas a reddish floe (possibly iron oxyhydroxides) was present on the surface sediments at site P2.

Sediment cores were collected at sites O, M, and N by pushing a 10.2 centimeter diameter, acrylic butyrate core liner into the sediments. About 30 centimeters of sediment were collected in the core liner at the sites; a deeper sample (33-42 centimeters) was obtained at site O using a peat corer. The cores were maintained in an upright position and then extruded and sectioned into 2 or 5 centimeter intervals and placed into polyethylene specimen containers within 8 hours of collection. Subsamples of cores from sites O and M were taken in the field for 210Pb analyses. All specimen containers were packed in plastic bags for transport to the laboratory.

Sediment samples from sites Q and R were collected with a tiling spade as it was impossible to push the core liner into the sediments. The sediments at these sites fell into distinct intervals and smelled strongly of hydrogen sulfide. Samples at site Q were taken from a black, organic-rich root mat (0-5 cm), a grey-black silt (10-15 cm), and a grey-green silt with red mottles (15-25 cm). Samples at site R included a black, organic-rich root mat (0-10 cm), a mixed organic-rich and sandy mineral layer with red staining (10-15 cm), a sandy layer with red staining (12-22 cm), and a silt and salt (gypsum ?) layer with red staining (22-32 cm). Samples were placed in polyethylene specimen containers and packed in plastic bags for transport to the laboratory.

Water samples from the wetlands were collected, processed, and packaged exactly the same as the water samples from the Wightman Fork and Alamosa River.

The aquatic wetland plant Persicana amphibia (L.) S. Gray (smartweed) was collected at sites L, S, O, PI, Q, and R In addition, the aquatic wetland plant Potamogeton natans L. (pondweed) was collected at sites L, M, N, and PI. The stems, leaves, and flowers were rinsed during collection and placed in cloth Hubco bags for transport to the laboratory. Roots, rhizomes, and attached sediment were removed during collection. Each plant sample was composed of five to ten individual plants.

Laboratory Methods

The methods for preparation and analyses of the sediment (excluding 210Pb analyses), water (excluding chloride and sulfate analyses), and plant samples are summarized in

Arbogast (1990). Only brief descriptions are given here.Sediment samples were dried overnight in a forced-air drying oven set at 30°C. The

sediment was disaggregated in a ceramic mortar and passed through a 10-mesh (1.7 mm) sieve. The material passing the sieve was pulverized in an agate shatter box to 100-mesh or less (<150 um). The pulverized material was decomposed using a mixture of acids (HC1, HNO3, HC1O4, and HF) and analyzed for 40 major and trace elements by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Concentrations of As and Se in the digested samples were measured by flow injection hydride generation atomic absorption spectrophotometry (HG-AAS). Mercury concentrations were determined in digested samples by continuous flow-cold vapor-atomic absorption spectrophotometry (CV-AAS). Total sulfur and total carbon contents of sediments were determined by Wgh-temperature combustion in an oxygen atmosphere. The evolved sulfur and carbon dioxides were measured by infrared detection using a LECO sulfur or carbon analyzer. Carbonate carbon was determined by coulometric titration of carbon dioxide evolved upon acidification of the sample. Organic carbon was determined as the difference between total and carbonate carbon.

The moisture contents of selected wetland cores (site O core 1 and site M core 2) were determined by the difference between wet and dried (100°C) sediment weights. Portions of these dried sediment samples were analyzed for 210Pb following the method of Flynn (1968). Briefly, a yield tracer (^Po) was added to the sediment samples. The sediment was leached using a series of hot acids (HNO3, HC1O4, HC1) and then made up in -0.3N HC1. Ascorbic acid was added to complex iron. 210Po (the daughter of 210Pb) was autoplated onto silver disks and counted by alpha spectrometry.

The major, minor, and trace element composition of the filtered and acidified water samples was determined by ICP-AES. Samples were not concentrated. Dissolved chloride concentrations were determined by silver nitrate titrations using an automated chloridometer (Grasshoff, 1976). Dissolved sulfate concentrations were determined by barium sulfate precipitation (Grasshoff, 1976). Excess dissolved barium was measured by atomic absorption spectrophotometry.

The aquatic plant samples were washed of any visible sediment in tap water (about 5 rinses) and then rinsed twice with distilled water. The washed plants were placed in clean Hubco bags and dried in a forced-air oven at 35-40°C for 24 hours. The dried material was then ground in a Wiley mill to pass a 2 mm sieve. The samples were ashed in Vicor crucibles at 450-500°C for 18 hours. Subsamples of the ashed plants were digested in hot acids, like the sediment samples, and the elemental composition of the ash was determined by ICP-AES. Using unashed, digested plant samples, concentrations of As were measured by HG-AAS whereas Hg concentrations were determined by CV-AAS.

Chain of Custody, Quality Control, and Quality Assurance

Chain of custody procedures were followed during the collection, transport, analysis, and storage of these samples.

The quality control (QC) and quality assurance (QA) procedures of the USGS Analytical Chemistry Services Group are summarized in Arbogast (1990). In addition to the laboratory QA/QC procedures, the field study quality control included submission of

procedural blanks for the water samples, splits of sediment and aquatic plant samples, and NIST standard reference materials (SRM) (sediments and plants) to the laboratory. These samples were analyzed in the same manner as the respective field samples.

The concentrations of elements in the procedural blanks for water sampling are generally below detection limits (Table 3). The laboratory splits of sediment and plant samples indicate very good reproducibility (Tables 4, 6-10, 12-13). In general, there is also good agreement between the laboratory analyses for NIST standard reference materials for sediments and plants and the certified values from the NIST Certificate of Analysis (Tables 14 and 15).

Results and Discussion

River samplesWater. The composition of water in the Wightman Fork and Alamosa River during

June 1993 is summarized in Table 3. Water in the Wightman Fork (site B) was characterized by low pH values and elevated concentrations of dissolved major (Na, Ca, Mg, Cl, and SO4) and minor (Al, B, Co, Cu, Fe, Mn, Ni, Sr, and Zn) ions relative to water in the Alamosa River above the confluence with the Wightman Fork (site C). The Wightman Fork had a distinct influence on the composition of Alamosa River water downstream of the confluence. Values of pH were lower and dissolved concentrations of major (Na, Ca, Cl, and SO4) and minor (Al, Cu, Fe, Mn, Sr, and Zn) ions were elevated in the Alamosa River just below (site D) as compared to above (site C) the confluence. Elevated dissolved concentrations of major (Na, Ca, Cl, and SO4) and certain minor (Cu, Mn, Sr, and Zn) ions persisted far downstream (at least 49 km) in Alamosa River water. Dilution plays the major role in attenuating dissolved concentrations of ions downstream of the confluence; however, dissolved Cu concentrations far downstream also appear to be affected by a removal process such as sorption (Balistrieri and others, 1995). The dissolved chemical characteristics of the Wightman Fork and Alamosa River are variable with time and highly dependent on pH (Ward and Walton-Day, 1995; Walton-Day and others, 1995). Hence, our sampling during June 1993 only provides a single, instantaneous picture of the dissolved chemical characteristics of these rivers.

Sediment: The composition of stream-bed sediments from the Wightman Fork and Alamosa River is summarized in Table 4. The data indicate that sediments in the Wightman Fork (site B) have higher concentrations of Fe, S, As, Cr, Cu, Hg, Pb, and Zn relative to sediments in the Alamosa River above the confluence with the Wightman Fork (site C). Of these elements, Cu and As show the greatest enrichment (13.5 to 14.2 x). Sediments in the Alamosa River downstream of the confluence with the Wightman Fork tend to have higher concentrations of As, Co, Cr, Cu, Ni, and Zn relative to sediments above the confluence (site C) (Fig. 2). Higher concentrations of Co, Ni, and Zn in Alamosa River sediments tend to occur much farther downstream (>18-29 km from the confluence) than the other elements.

The composition of water and sediments in the Wightman Fork most likely reflects drainage from the Summitville Mine; however, enrichments of elements in the Alamosa River downstream of the confluence with the Wightman Fork also include elements supplied by other streams (e.g., Jasper and Burnt Creeks) and from diffuse runoff. Based on the

compositional data of Wightman Fork and Alamosa River, the following elements appear to be indicative of drainage from mineralized areas in this watershed: Al, As, B, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S, Sr, Zn. Some of the minor elements (e.g., As, Co, Cr, Cu, Ni, and Zn) are enriched far downstream of the confluence with the Wightman Fork. This latter group of elements is used as potential tracers or indicator elements for assessing the impact of drainage from mineralized areas on wetlands in the San Luis Valley.

Wetland samplesWater: The composition of surface water in selected wetlands in the San Luis Valley

is summarized in Table 5. In June 1993, the wetlands were basic (pH > 7), had variable dissolved major ion (e.g., Na, K, Ca, Mg, Cl, and SO4) concentrations, and low concentrations of many minor ions (e.g., Co, Cu, Ni, and Zn). Variations in the major ion chemistry of the water and our observations of salt crusts in the vicinity of many wetlands suggest that evaporation was occurring and causing the concentration and precipitation of certain dissolved elements. The low concentrations of the minor cations are consistent with their ability to sorb onto particles or precipitate at higher pH values (Stumm and Morgan, 1981). In contrast, the mobility of anions, like As, is usually greater at the higher pH values observed in the wetlands due to lower sorption of anions at high pH (Pierce and Moore, 1982). Dissolved concentrations of As tended to be higher in wetlands within the Refuge as compared to wetlands outside of the Refuge. This observation may, in part, reflect different source waters as well as the effects of evaporative concentration.

Differences in the ratio of two conservative elements, Na and Cl, between the wetlands and Alamosa River water below Terrace Reservoir provide support for different source waters (Fig. 3). The ratio in Alamosa River water (Na/Cl = 100+4) is less than half of the ratio in wetland waters within the Alamosa National Wildlife Refuge (Na/Cl = 229+19). The ratio for wetlands west of the Refuge ranges from 114 to 189 and suggests input from the Alamosa River.

Sediment: The composition of wetland sediments is summarized in Tables 6-10. The concentrations of the indicator elements (i.e., As, Co, Cr, Cu, Ni, and Zn) are plotted for selected wetland sediments that receive water from different sources (Fig. 4). The plots indicate that sediments in wetlands that receive some Alamosa River water clearly have higher concentrations of Cu, Ni, and Zn than wetlands receiving surface water from other sources. In addition, the metal contents of sediments in wetlands receiving Alamosa River water do not significantly change with depth. If wetlands receiving Alamosa River water received additional metals from drainage derived from open-pit mining activities at Summitville, then the downcore composition of wetland sediments should change significantly - provided that the collected sediment represents a timeframe that brackets the beginning of open-pit mining activities at Summitville Mine (i.e., before and after 1984-1986) (Pendleton and others, 1995).

Two wetland cores (site O core 1 and site M core 2) were age dated using 210Pb techniques. Mass accumulation rates were determined from 210Pb activity and water content as a function of depth using a one-dimensional, two-layer, steady-state sedimentation model in which mixing occurs only in the surface mixed layer (Robbins and Edgington, 1975; Carpenter and others, 1982). The model assumptions are that (1) the sedimentation rate is

8

constant; (2) there is no post-depositional mobility of 210Pb; (3) the flux of unsupported 210Pb to the interface is constant; and (4) the deepest sample represents the amount of supported 210Pb in this area and is constant throughout the core. The porosities (O) of the two cores were calculated from water-content data and by assuming that the density (p) of the dried sediment was 2.5 g cm"3 . The supported 210Pb in the sediments was estimated to be 0.8 dpm g" 1 . The accumulation rate of the sediment, S (g cm"2 y" 1), was determined from the equation S = -A/m, where m is the slope of the line defined by the natural log of unsupported 210Pb (i.e., excess 210Pb) versus sediment accumulation, A (g cm"2), in the core as a function of depth below the surface mixed layer and A, is the decay constant for 210Pb (0.03113 y l ) (Fig. 5). Sediment accumulation was determined from the equation A = z*(l-O)*p and accounts for the natural compaction of the sediment as a function of depth. The resulting accumulation rates are 0.74 g cm"2 y" 1 at site M (core 2) and 0.70 g cm"2 y" 1 at site O (core 1). Sedimentation rates in cm y"1 do not include natural compaction and, hence, decrease with depth. The sedimentation rates are between 0.33 and 0.52 (average = 0.38) cm yr" 1 for site M (core 2) and 0.33 and 0.43 (average = 0.35) cm yr" 1 for site O (core 1). Table 11 includes the approximate age of the depth intervals for the two cores.

Accumulation rates of the indicator elements were calculated by multiplying the metal content at a given depth by the mass accumulation rates and plotted for two time periods at sites M and O (Fig. 6). These time periods represent pre- and post-open pit mining activities at Summitville Mine. Only site O receives surface water from the Alamosa River. The first observation is that variations in the metal contents of the two cores collected at a given site result in a range of element accumulation rates for that site (also see Tables 7 and 9). Second, the site that receives Alamosa River water (site O) tends to have higher accumulation rates of As, Co, Cu, Ni, and, possibly, Zn. And third, there is little difference between accumulation rates at the site receiving Alamosa River water (site O) for pre- and post-open pit mining activities at Summitville Mine because there are no significant changes in metal contents downcore.

Increases in certain indicator elements (i.e., Co, Cr, Cu, and Ni) in the wetlands receiving Alamosa River water compared to those that receive surface water from other sources may be related to the accumulation of Fe in the wetlands. Iron oxyhydroxides have a strong affinity for many elements and, thus, can sequester trace elements in the sediments. Higher Fe contents and accumulation rates are observed for wetlands receiving Alamosa River water (Fig. 7). There are good correlations between the concentrations of Fe and certain indicator elements in almost all wetland sediments (Fig. 8).

Aquatic plants: The chemical composition of the aquatic wetland plants, P. amphibia and P. natans, is tabulated in Tables 12 and 13. The same species of aquatic plant was not present in all of the wetlands; however, each species came from wetlands that received water from different sources.

Rooted aquatic macrophytes can assimilate dissolved metals from the water through their leaves, but most uptake is thought to occur through their roots. Therefore, their chemical composition often reflects the geochemistry of the sediments in the wetlands (Pip and Stepaniuk, 1992; Flessa, 1994).

The concentrations of the indicator elements on a dry weight basis in the aquatic wetland plants are compared for wetlands receiving surface water from different sources in

figures 9 and 10. Both P. amphibia and P. natans tend to have higher concentrations of Co and Cu, if they are growing in wetlands receiving Alamosa River water. Zn also appears to be enriched in P. amphibia in wetlands receiving Alamosa River water. These observations are consistent with the enrichment of these elements, particularly Cu and Zn, in the sediments of wetlands receiving Alamosa River water. In contrast, aquatic plant concentrations of As tend to be higher in wetlands receiving water from other sources. Dissolved concentrations of As also tended to be higher in these wetlands.

Summaiy

The chemical composition of water and sediment from the Wightman Fork and Alamosa River during June 1993 was used to identify the following elements - As, Co, Cr, Cu, Ni, and Zn - as possible tracers of acidic, metal-enriched drainage from mineralized areas in the Alamosa River watershed. These elements appeared to be transported throughout the Alamosa River system downstream of its confluence with the Wightman Fork.

The composition of surface water in selected wetlands in the San Luis Valley appeared to be affected by evaporation during June 1993. These waters tended to be basic and have low dissolved concentrations of all of the indicator elements, except As.

The chemical composition of sediments in wetlands receiving surface water from the Alamosa River or Alamosa River and La Jara Creek tended to be enriched in Fe, Cu, Ni, and Zn relative to sediments of wetlands receiving surface water from other sources. A comparison of metal accumulation rates in two wetlands receiving water from different sources indicates that the wetland receiving surface water from the Alamosa River has higher accumulation rates of Fe, As, Co, Cu, and Ni. The higher concentrations and accumulation rates of certain indicator elements in wetlands receiving some surface water from the Alamosa River appear to be related to the content and accumulation of Fe. However, there are no major differences in the accumulation rates or downcore concentrations of indicator elements during the past 70 to 100 years in wetlands receiving Alamosa River water. Unless the age dating of the wetland cores is incorrect, the effects of recent mining activities (e.g., open-pit mining at Summitville) on wetland sediment geochemistry is not readily apparent.

Aquatic wetland plants (i.e., Persicaria amphibia and Potamogeton natans) tend to have higher concentrations of certain indicator elements (i.e., Co, Cu, and Zn) in wetlands receiving Alamosa River water. These enrichments reflect similar enrichments observed in the sediments of these wetlands.

Finally, a direct link between specific mining activities at the Summitville Mine and the geochemistry of the studied wetlands was not found. However, the studied wetlands west of the Alamosa National Wildlife Refuge that receive Alamosa River water tended to have higher concentrations of indicator elements, except As, in their sediment and aquatic plants relative to the studied wetlands within the Refuge that receive surface water from other sources. In addition, Cu appears to be the best overall indicator element for wetlands that receive water from the Alamosa River.

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Acknowledgements

Andrew Archuleta of the U.S. Fish and Wildlife Service acted as our guide in our initial trip to the San Luis Valley and assisted us in identifying wetlands of interest. Jim Kilburn provided a helpful review of this manuscript.

References

Arbogast, B. F., 1990, Quality assurance manual for the Branch of Geochemistry, U. S. Geological Survey: U. S. Geological Survey Open-File Report 90-668, 184 p.

Balistrieri, L. S., Gough, L. P., Severson, R. C., and Archuleta, A, 1995, Thebiogeochemistry of wetlands in the San Luis Valley, Colorado: the effects of acid drainage from natural and mine sources: Proceedings: Summitville Forum '95, Colorado Geological Survey, Special Publication 38, pp. 219-226.

Carpenter, R., Peterson, M L., and Bennett, J. T., 1982, 210Pb-derived sediment accumulation and mixing rates for the Washington continental slope: Marine Geology, v. 48, pp. 135-164.

Erdman, J. A, Smith, K. S., Dillon, M A, and Kuile, M T., 1995, Impact of Alamosa River water on alfalfa, southwestern San Luis Valley, Colorado: Proceedings: Summitville Forum '95, Colorado Geological Survey, Special Publication 38, pp. 263-271.

Flessa, H., 1994, Plant-induced changes in the redox potential of the rhizDspheres of the submerged vascular macrophytes Myriophyllum verticillatum L. and Rcmmculus circinatus L.: Aquatic Botany, v. 47. pp. 119-129.

Flynn, W. W., 1968, The determination of low levels of polonium-210 in environmental materials: Analytical Chimica Acta, v. 43, pp. 221-227.

Grasshoff, K., 1976, Methods of Seawater Analysis: Verlag Chemie, 317 p.

Pendleton, J. A, Posey, H. H., and Long, M B., 1995, Characterizing Summitville and its impacts: setting the scene: Proceedings: Summitville Forum '95, Colorado Geological Survey, Special Publication 38, pp. 1-12.

Pierce, M L. and Moore, C. B., 1982, Adsorption of arsenite and arsenate on amorphous iron hydroxide: Water Res., v. 16, pp. 1247-1253.

Pip, E. and Stepaniuk, J., 1992, Cadmium, copper, and lead in sediments and aquaticmacrophytes in the lower Nelson River system, Manitoba, Canada-1. Interspecific differences and macrophyte-sediment relations: Archiv fur Hydrobiologie, v. 124, pp. 337-355.

11

Plumlee, G. S., Smith, K. S., and Ficklin, W. H., 1993, Empirical studies of diverse mine drainages in Colorado: implications for the prediction of mine drainage chemistry: Proceedings, 1993 Mined Land Reclamation Symposium, Billings, Montana, Montana State University Reclamation Research Unit Publication no. 9301, v. 1, pp. 176-186.

Posey, H. H., Pendleton, J. A., Van Zyl, D., 1995, Proceedings: Summitville Forum '95, Colorado Geological Survey, Special Publication 38, 375 p.

Robbins, J. A. and Edgington, D. N., 1975, Determination of recent sedimentation rates inLake Michigan using Pb-210 and Cs-137: Geochim. Cosmochim. Acta, v. 39. pp. 285- 304.

Stumm, W. and Morgan, J. J., 1981, Aquatic Chemistry, John Wiley & Sons, 780 p.

Walton-Day, K., Ortiz, R F., and von Guerard, P. B., 1995, Sources of water having low pH and elevated metal concentrations in the upper Alamosa River from the headwaters to the outlet of Terrace Reservoir, South-Central Colorado, April - September 1993: Proceedings: Summitville Forum '95, Colorado Geological Survey, Special Publication 38, pp. 160-170.

Ward, E., C., and Walton-Day, K., 1995, Seasonal variations in water quality on Wightman Fork of the Alamosa River, 1993: Proceedings: Summitville Forum '95, Colorado Geological Survey, Special Publication 38, pp. 183-190.

12

Table 1. Location of river sampling sites during June 1993.

Site

B

C

D

E

F

G

H

A

I

J

K

Latitude deg min sec

37

37

37

37

37

37

37

37

37

37

37

24

24

24

24

23

22

19

19

19

17

17

22

04

27

49

46

48

52

52

03

15

46

Longitude deg min sec

106

106

106

106

106

106

106

106

106

106

106

31

31

30

30

25

20

13

12

10

05

02

21

30

54

09

30

51

48

45

21

24

15

Description

Wightman Fork (WF) 0.1 km upstream of AR

Alamosa River (AR)0.5 km upstream of WF

Alamosa River0.5 km downstream of WF

Alamosa River 2 km downstream of WF

Alamosa River 11 km downstream of

Alamosa River 18 km downstream of

Alamosa River 29 km downstream of

WF

WF

WF

Alamosa River31.5 km downstream of WF

Alamosa River36.5 km downstream of WF

Alamosa River 44 km downstream of

Alamosa River

WF

49 km downstream of WF

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Table 2. Location of wetland sampling sites during June 1993.

Site Latitude Longitudedeg min sec deg min sec

Description

M

N

O

PI

P2

37 2237

37 23 09

37 26 15

37 27 10

37 22 21

37 23 04

37 23 04

37 22 45

37 22 16

105 45 25

105 46 27

105 45 55

105 46 19

105 47 51

105 49 12

105 49 12

105 49 15

105 53 37

southern ANWRa Big Slough

southern ANWR kidney-shaped pond

northern ANWRmain feeder canal just westof road

northern ANWRpond just north of NorthRefuge Road, east of maincanal

2.3 km due west of ANWR old oxbow of La Jara Creek

3.8 km due west of ANWR North Seamans Ditch

3.8 km due west of ANWR small evaporative pond just north of Seamans Ditch

3.8 km due west of ANWR flooded field north of South Seamans Ditch

11.2 km due west of ANWR seasonal wetland between Alamosa River and its old channel

aAlamosa National Wildlife Refuge

14

Tabl

e 3.

W

ater

com

posi

tion

of W

ight

man

For

k (s

ite B

) an

d A

lam

osa

Riv

er, C

O in

Jun

e 19

93.

DU

P =

dup

licat

e fie

ld s

ampl

e

Site

pH

Cond

uct.

uS/cm

B 4.

54

654

B DUP

4.55

85

1C

7.18

56

D 5.03

246

E 5.

61

142

F 5.

96

145

G

6.28

13

8H

. 6.08

139

A no

water

sam

ple

I 5.98

139

J 5.88

139

K 5.

83

158

Filter Bla

nk

Na

Kppm

ppm

48

<147

5

1 <1

13

<18

<17

<16

<15

<1

5 <1

5 <1

5 <1

<1

<1

Ca ppm 44 44 7 18 12 15 13 14 14 14 17 <1

M%

ppm 8 8 1 3 2 2 2 2 2 2 3 <1

Clppm

8.9

8.9

0.81 3.1

1.6

1.3

1.6

1.7

1.9

1.8

1.7

SO4

Alppm

ppm

380

12390

1226

<112

0 3

74

<175

<167

<164

<1

65

<162

<166

<1 <1

As ppb <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2

Bppb

110

110

<50

<50

<50

<50

<50

<50

<50

<50

<50

<50

Ba ppb 24 29 <20 20 <20 22 <20 24 24 24 28 <20

Co

ppb 97 92 <40

<40

<40

<40

<40

<40

<40

<40

<40

<40

Cu

ppb

8500

8600 <40

2800

1100 890

360

490

480

420

260

<40

Fe

Mnppm

ppb

17

2400

17

2400

<1

656

810

3 400

2 40

0<1

31

0<1

380

<1

390

<1

380

<1

370

<1

<40

Nippb

100 95 <40

<40

<40

<40

<40

<40

<40

<40

<40

<40

Sippm 6 8 4 5 4 5 4 5 5 5 5 <1

Sr

Znppb

ppb

170

1700

170

1700

64

<40

96

540

80

250

100

220

93

180

100

190

110

190

110

180

130

160

<40

<40

All samples be

low detection

limi

ts for

the

following elements:

Ag

<40 ppb

Be

<20 ppb

Bi

<200 ppb

Cd

<40 ppb

Cr

<40 ppb

Ga

<80 ppb

Li

<40 ppb

Mo

<80 ppb

Pb

<80 ppb

Sn

<100 ppb

Ti

< 100

ppb

V <40 ppb

Zr

<40 pp

b

Table

4.

Co

mp

osi

tion

of

bed

sedim

ents

fro

m t

he W

ightm

an F

ork

(site

B)

and

Ala

mosa

Riv

er in

Jun

e 19

93.

(Bas

ed o

n dr

y w

eig

hts

) D

UP

= d

up

lica

te f

iled

sam

ple;

s =

labora

tory

sp

lit

Site

A

lw

t%

B

7.5

B D

UP

7.

5C

7.

9C

s

7.9

D

7.3

E

7.3

F 7.

3G

7.

2H

6.

4A

7.

5A

DU

P

7.4

I 7.

4J

7.2

Js

7.2

K

7.3

Site

G

a pp

m

B

16B

DU

P

16C

17

Cs

17D

16

E

16F

15G

17

H

19A

15

A D

UP

15

I 16

J 15

Js

15K

15

Ca

wt%

0.61 0.

61.

81.

8 10.

60.

730.

88 1.3

1.2

1.2

1.2

1.1

1.1

1.3

Hg

ppm

0.16 0.

20.

040.

040.

060.

02<

0.0

20.

02<

0.0

2<

0.0

20.

060.

02<

0.0

2<

0.0

2<

0.0

2

Fe

Kw

t%

wt%

6.5

2.2

6.3

2.3

4.5

24.

5 2

5.5

2.1

5.5

2.1

4 2.

35.

8 2.

213

2.

14.

2 2.

44

.7

2.2

4.9

2.1

4.4

2.3

4.3

2.3

4.4

2.3

La

Li

ppm

pp

m

36

1336

12

34

1034

10

33

937

20

37

1139

11

40

1140

12

39

1239

11

38

1138

12

38

11

Mg

wt%

0.47

0.48

0.84

0.85 0.

70.

730.

680.

730.

730.

680.

720.

740.

690.

680.

69 Nb

ppm 12 13 12 12 11 17 11 12 15 14 13 14 14 12 12

Na

wt% 1.

61.

61.

21.

2 11.

21.

31.

21.

51.

71.

61.

51.

51.

61.

6

Nd

ppm 27 29 27 28 26 31 28 31 34 30 29 33 31 30 31

P

Ti

wt%

w

t%

0.19

0.

40.

18

0.4

0.12

0.

390.

12

0.41

0.13

0.

410.

12

0.42

0.12

0.

380.

14

0.55

0.12

1.

30.

11

0.4

0.11

0.4

60.

11

0.51

0.11

0.

440.

11

0.43

0.11

0.

46

Ni

Pb

ppm

pp

m

7 70

8 66

6 25

6 23

5 25

4 37

6 31

9 40

23

2710

32

10

33

10

4011

32

10

2810

32

Mn

ppm

600

580

660

660

540

430

550

620

1600 86

079

071

079

076

062

0

Se

ppm 0.8

0.8

1.5

1.5

2.3 2

1.3

1.3

0.5

0.7

0.8

0.8

0.7

0.7

0.8

SW

t%

0.51

0.48

0.39

0.41

0.76

0.38

0.21

0.27 0.1

0.13

0.21

0.14

0.15

0.14

0.16 S

c pp

m 10 10 11 11 11 11 10 11 12 9 10 11 10 10 10

As

ppm 50 70 5.1

3.8

8.3 15 12 8.5

8.2

7.2 13 11 8.1

7.7 13 Sr

ppm

410

400

420

420

330

270

360

380

400

450

44

045

044

044

049

0

Ba

ppm

670

680

590

670

690

690

720

880

840

800

79

076

076

075

083

0

Th

ppm 10 11 10 10 7 15 10 12 10 8 8 11 11 9 12

Ce

ppm 68 67 69 69 66 72 71 75 81 73 74 77 71 71 73 V

pp

m

110

110

110

110

120

120

100

160

410

100

110

130

110

110

110

Co

ppm 13 13 14 13 13 6 12 15 40 23 21 18 21 20 16 Y

pp

m 13 13 16 17 14 14 15 15 16 18 18 17 16 16 16

Cr

Cu

ppm

pp

m

13

330

15

310

6 23

9 2

210

20

010

30

09

290

16

43

050

31

010

34

016

3

80

16

300

14

310

11

310

14

41

0

Yb

Zn

ppm

pp

m

1 11

01

110

2 76

1 76

1 76

1 71

1 75

1 11

02

290

2 11

02

120

2 12

01

110

1 11

02

120

All

sam

ple

s be

low

de

tect

ion

lim

its f

or

the

follo

win

g el

emen

ts:

Ag

<2

ppm

Au

<8

ppm

Bi

<1

0p

pm

Cd

<2

ppm

Eu

<2

ppm

Ho

<4

ppm

Mo

<2

ppm

Sn

<5 p

pmT

a <

40 p

pmU

<

10

0p

pm

Tab

le 5

. W

ate

r co

mpo

sitio

n of

wet

lend

s in

San

Lui

s V

alle

y, C

O d

urin

g Ju

ne 1

993.

D

UP

= d

uplic

ate

field

sam

ples

Site L

LDUP

M N S O P1 P2 Q R

pH

Cond

uct.

9.89

9.94

10.46

8.77

no water

sample

7.56

7.45

9.34

8.01

8.19

uS/c

m

412

422

168

2444 716

771

1928

1259 369

Nappm 75 74 11 560 45 47 190

130 13

Kppm 6 6 <1 23 6 7 44 16 3

Ceppm 16 16 13 28 80 92 180

100 47

Mg ppm 2 2 1 8 17 17 35 32 7

Clppm 12 12 1.5 89 14 11 49 24 2.7

SO4

Alppm

ppm

43

<138

<1

19

<1270

<1

200

<1300

<1900

<1450

<111

0 <1

As ppb 51 33 3 90 3 <2 2 <2 <2

Bppb

880

880

<50

3600 <50

<50

210 78 <50

Ba ppb 33 34 21 79 37 33 70 30 23

Co ppb

<40

<40

<40

<40

<40

<40

<40

<40

<40

Cu

Fepp

b ppm

<40

<1<40

<1<4

0 <1

<40

<1

<40

<1<40

<1<40

<1<40

<1<40

<1

Mn ppb

<40

<40

<40

<40 83 50 73 79 <40

Nippb

<40

<40

<40

<40

<40

<40

<40

<40

<40

Sippm 9 9 5 22 10 8 6 9 4

Sr ppb

140

140

110

350

640

790

2300

1100 380

Zn ppb

<40

<40

<40

<40

<40

<40

<40

<40

<40

Site

s O

, P1

, P

2, Q

, an

d R

rec

eive

som

e su

rfac

e w

ater

from

the

Ala

mos

a R

iver

, S

ites

L, M

, N

, an

d S

rec

eive

sur

face

wate

r fro

m o

ther

sou

rces

.

See

Tab

le 3

for

filte

r bl

ank.

All

sam

ples

bel

ow d

etec

tion

limits

for

the

follo

win

g el

emen

ts:

Ag

<40

ppb

Be

<2

0p

pb

Bi

<200

ppb

Cd

<40

ppb

Cr

<40

ppb

Ga

<80

ppb

Li

<40

ppb

Mo

Pb

Sn Ti

V

Zr

<60

ppb

<80ppb

<100

ppb

<1

00 p

pb

<40

ppb

<40

ppb

Tabl

e 6.

C

ompo

sitio

n of

wet

land

sur

face

sed

imen

ts a

t site

s L,

P1,

and

P2

in J

une

1993

. (Ba

sed

on d

ry w

eigh

ts)

DU

P =

dupl

icat

e fie

ld s

ampl

e; s

= la

bora

tory

spl

it

Site

D

epth

A

l cm

w

t%

L 0-

2 8.

2L

DU

P

0-2

8L

DU

P s

0-

2 7.

9

P1

0-2

7.6

P2

0-2

6.8

Site

D

epth

C

ucm

pp

m

L 0-

2 8

L D

UP

0-2

8L

DU

P s

0-2

7

P1

0-2

170

P2

0-2

31

Ca

Fe

wt%

w

t%

2.1

2.1

2.1

2.3

2.2

2.4

1.3

4.4

3 3.

6

Ga

Hg

ppm

pp

m

16

<0.0

215

<0

.02

16

<0.0

2

16

0.28

14

<0.0

2

KW

t%

32.

9 3

2.1

2.3 La

ppm 50 53 48 33 30

Mg

wt%

0.41

0.43

0.42

0.87 1.

2 Lipp

m 13 14 14 20 14

Na

wt% 2.

42.

22.

3

1.1

1.4

Nb

ppm 11 11 13 13 13

P

wt%

0.07

0.08

0.08

0.19

0.18 Nd

ppm 39 40 36 29 27

Ti

wt%

0.27

0.27

0.28

0.37 0.

4 Ni

ppm 4 4 5 12 12

Mn

ppm

340

540

550

500

870

Pb

ppm 28 30 33 110 31

Sw

t%

0.15

0.27

0.27

0.26

0.57 S

cpp

m 7 8 7 11 9

totC

w

t% 0.3

0.98

0.87

3.44 2.1 Se

ppm

<0.1

<0.1

<0.1 1.2

1.6

org

C

wt% 0.

30.

950.

84

3.42

1.62 S

rpp

m

500

480

490

410

540

As

ppm 7.1

5.9

7.3 26 4.9 Th

ppm 15 15 13 6 7

Ba

ppm

1000

1000

1000 670

760 V

ppm 45 49 50 100

100

Ce

ppm 88 91 82 64 58 Y

ppm 22 22 22 17 13

Co

Cr

ppm

pp

m

14

816

8

17

8

18

18

15

18

Yb

Znpp

m

ppm

2 52

2 62

2 62

1 17

0

1 97

All s

ampl

es b

elow

det

ectio

n lim

its fo

r the

follo

win

g el

emen

ts:

Ag

<2 p

pm

Au

<8 p

pm

Bi

<10p

pm

Cd

<2 p

pm

Eu

<2 p

pm

Ho

<4 p

pm

Mo

<2 p

pm

Sn

<5 p

pm

Ta

<40

ppm

U

<100

ppm

00

Tabl

e 7.

C

ompo

sitio

n of

wet

land

sed

imen

ts a

t site

M in

Jun

e 19

93 (

Base

d on

dry

wei

ghts

) A,

B =

fiel

d sp

lits;

s =

labo

rato

ry s

plits

Site

D

epth

A

lcm

w

t%

M c

ore

1 0-

2A

7.8

M c

ore

1 0-

2B

7.9

M c

ore

1 2-

4A

7.7

M c

ore

1 2-

4B

7.9

M c

ore

1 4-

6A

7.9

M c

ore

1 4-

6B

7.9

M c

ore

1 6-

1 1A

7.

8M

core

l 6-

1 1B

8.

2M

core

l 11

-16A

8.

1M

core

l 11

-16B

8

M c

ore

1 16

-21A

8

M c

ore

l 16

-21A

s 8.

1M

co

rel

16-2

1 B

8.1

M c

ore

2 0-

2B

7.2

M c

ore

2 2-

4B

7 4

M c

ore

2 4-

6B

7.3

M c

ore

2 6-

8B

7.5

M c

ore

2 8-

1 O

B 7.

6M

cor

e 2

10-1

2B

7.8

M c

ore

2 12

-14B

7.

7M

cor

e 2

14-1

9B

7.8

M c

ore

2 19

-24B

8.

1

Site

D

epth

C

ucm

pp

m

M c

ore

l 0-

2A

12M

core

l 0-

2B

13M

cor

e 1

2^»A

1 1

M c

ore

l 2-

4 B

12M

core

l 4-

6A

12M

core

l 4-

6B

12M

core

l 6-

1 1A

10

M c

ore

l 6-

1 1B

10

M c

ore

l 11

-16A

16

M c

ore

l 11

-16B

14

M c

ore

l 16

-21A

18

M c

ore

l 16

-21A

S

15M

core

l 16

-21B

15

M c

ore

2 0-

2B

25M

cor

e 2

2-4B

23

M c

ore

2 4-

6B

23M

cor

e 2

6-8B

24

M c

ore

2 8-

1 O

B 23

M c

ore

2 10

-12B

22

M c

ore

2 12

-14B

25

M c

ore

2 14

-1 9

B

16M

cor

e 2

19-2

4B

16

Ca

Few

t%

wt%

1.9

2.2

2.1

2.3

1.9

2.2

2 2.

21.

9 2.

21.

7 1.

91.

7 1.

91.

5 1.

71.

5 2.

91.

6 2.

61.

5 3

1.5

31.

6 2.

9

1.7

3.5

17

3.4

1.6

3.3

1.6

3.1

1.5

3.3

1.5

3.2

1.5

3.2

1.4

2.9

1.5

3.1

Ga

Hg

ppm

pp

m

17

<0.0

218

<0

.02

16

<0.0

216

<0

.02

17

<0.0

215

<0

.02

15

<0.0

214

<0

.02

18

<0.0

217

<0

.02

18

<0.0

218

<0

.02

18

<0.0

2

15

<0.0

216

<0

.02

17

<0.0

216

<0

.02

17

<0.0

218

<0

.02

17

<0.0

218

<0

.02

18

<0.0

2

Kw

t% 2.9

2.8

2.9

2.9

3.1

2.9

3.1 3

2.8

2.8

2.8

2.8

2.8

2.1

2.2

2.1

2.2

2.2

2.4

2.3

2.8

2.9 La

ppm 42 41 42 41 44 48 46 44 47 46 46 47 46 39 40 40 41 42 42 43 45 48

Mg

wt%

0.48

0.57

0.46

0.48

0.46 0.

40.

370.

360.

570.

540.

540.

540.

56

0.76

0.75

0.75

0.71

0.73

0.69

0.71

0.56

0.53 Li

ppm 17 17 17 17 17 14 14 13 20 20 19 20 20 23 23 23 22 23 22 23 19 19

Na

wt% 2.

12.

12.

12.

12.

1 22.

1 21.

81.

81.

81.

81.

8

1.2

1.3

1.3

1.4

1.4

1.5

1.4

1.8

1.9

Nb

ppm 15 14 15 17 15 9 14 8 16 16 17 16 16 16 16 16 17 16 16 17 16 17

Pw

t%

0.08

0.07

0.08

0.09

0.09

0.08

0.07

0.06

0.05

0.05

0.06

0.06

0.05 0.1

0.09

0.07

0.07

0.07

0.06

0.06

0.05

0.05 N

dpp

m 31 32 32 32 33 36 35 38 37 35 36 37 36 32 32 32 32 35 33 35 33 38

Tiw

t%

0.31

0.32 0.

30.

310.

310.

260.

260.

230.

360.

330.

340.

340.

34 0.4

0.4

0.4

0.38

0.39

0.37 0.

40.

340.

36 Ni

ppm 4 4 3 3 4 3 3 2 5 5 4 4 5 8 7 7 7 7 6 6 5 5

Mn

ppm

350

400

360

380

380

320

310

270

320

310

340

340

330

1100

750

560

460

420

400

410

350

380

Pb

ppm 46 49 45 45 45 34 34 28 24 29 26 27 27 61 62 68 68 69 66 66 32 27

Sw

t%

0.13

0.12

0.17

0.19

0.17

0.16

0.15

0.14

0.06

0.07

<0.0

5<0

.05

<0.0

5

014

0.13

0.13

0.13 0.1

0.09

0.08

0.06

<0.0

5 Sc

ppm 8 8 8 8 7 8 7 8 11 10 10 10 10 12 12 12 12 13 12 13 10 10

totC

wt%

1.84

1.85

1.81

2.02

1.61

1.27

0.94

0.64

1.36

1.34

1.21

1.28

1.36

3.94

3.72

3.82

3.58 3.

32.

382.

511.

33 0.8 Se

ppm 0.1

0.1

0.1

0.1

0.1

<0.1

<0.1

<0.1

"0.

20.

10.

20.

20.

2

0.3

03

0.3

0.3

0.3

0.2

0.2

0.2

0.2

org

Cw

t%

1.62 1.

81.

812.

021.

611.

270.

940.

641.

361.

341.

211.

281.

36

3.91

3.72

3.82

3.58 3.

32.

382.

511.

33 0.8 Sr

ppm

440

450

440

460

430

420

410

390

370

380

370

370

390

310

330

330

340

330

340

330

350

380

As

ppm 3 3

3.4

4.7 4

3.9

4.3

3.2

3.7

3.1

3.5

5.8

2.9

6.5

4.9

8.3

8.8

6.9

6.4

3.8

4.6 4 Th

ppm 12 11 11 11 13 16 14 18 13 11 13 12 12 10 11 9 10 10 10 11 12 13

Ba

ppm

900

910

900

930

920

870

930

870

840

850

840

850

870

680

690

680

710

700

740

730

820

870 V

ppm 55 59 54 56 55 43 42 36 82 73 76 75 77 86 86 90 87 89 81 86 70 74

Ce

ppm 73 72 72 71 74 82 79 80 83 81 81 82 81 73 74 75 75 77 76 78 79 85 Y

ppm 20 20 20 20 21 21 20 19 25 24 24 24 25 23 23 24 25 25 23 25 23 25

Co

Cr

ppm

pp

m

7 11

6 12

7 10

7 11

7 11

5 8

5 7

4 6

7 16

7 13

7 15

8 14

7 12

11

2011

20

10

2011

18

10

209

1810

19

8 14

9 14

Yb

Znpp

m

ppm

2 84

2 90

2 82

2 87

2 83

2 65

2 60

2 50

3 79

3 76

3 74

2 75

3 76

2 15

02

150

2 15

02

150

2 15

02

140

3 15

02

922

78

All s

ampl

es b

elow

det

ectio

n lim

its fo

r the

follo

win

g el

emen

ts:

Ag

<2 p

pmA

u <8

ppm

Bi

<10

ppm

Cd

<2 p

pmE

u <2

ppm

Ho

<4 p

pmM

o <2

ppm

Sn

<5 p

pmTa

<4

0 pp

mU

<

100p

pm

Tab

le 8

. C

ompo

sitio

n of w

etla

nd s

edim

ents

at

site

N i

n Ju

ne 1

993.

(B

ased

on

dry

wei

ghts

) s

= la

bora

tory

spl

it

Site

D

epth

A

lcm

w

t%

N c

ore

1 0-

2 8

N c

ore

1 2-

4 8

N c

ore

1 4-

6 8.

2N

cor

e 1

6-8

8.1

N c

ore

1 8-

10

8N

cor

e 1

10-1

2 8.

2N

cor

e 1

12-1

4 8.

1N

cor

e 1

14-1

9 8.

2N

co

rel

14-1

9 s

8.2

N c

ore

1 19

-24

8

N c

ore

2 0-

2 8.

1N

cor

e 2

2-4

8.1

N c

ore

2 4-

6 8.

3N

cor

e 2

6-1

1 8.

4N

cor

e 2

11-1

6 8.

2N

cor

e 2

16-2

1 8.

3

Site

D

epth

C

ucm

pp

m

N c

ore

1 0-

2 12

N c

ore

1 2-

4 10

N c

ore

1 4-

6 9

Nco

rel

6-8

11N

cor

e 1

8-10

9

Ncore

l 10

-12

11N

cor

e 1

12-1

4 16

Ncore

l 14

-19

12N

co

rel

14-1

9 s

10N

cor

e 1

19-2

4 9

N c

ore 2

0-2

11

N c

ore

2 2-

4 13

N c

ore

2 4-

6 10

N c

ore

2 6-

11

11N

cor

e 2

11-1

6 9

N c

ore

2 16

-21

13

Ca

Fe

wt%

w

t%

2.8

2.3

2.6

2.5

2.3

2.7

2.2

2.9

2.3

2.7

2.1

2.9

2 4

2 3.

12.

1 3.

21.

9 2.

6

2.7

2.7

2.6

3.3

2.8

32.

8 3.

12.

6 3.

12.

7 3.

3

Ga

Hg

ppm

pp

m

17

<0.

0218

<

0.02

19

<0.

0219

<0

.02

18

<0.

0219

<0

.02

19

<0.0

221

<0

.02

20

<0.0

219

<0

.02

18

<0.0

218

<0

.02

19

<0.0

219

<0

.02

19

<0.0

219

<0

.02

Kw

t% 2.8 3

3.2

2.8

2.9

2.9

2.4

2.9

2.9

3.3

2.8

2.6

2.6

2.6

2.7

2.7 La

ppm 42 45 45 45 42 46 44 48 48 51 43 44 42 42 44 44

Mg

wt%

0.57

0.53

0.53

0.59

0.55 0.

60.

85 0.6

0.6

0.43

0.64

0.77

0.71

0.73

0.67

0.72 Li

ppm 16 16 17 18 16 18 23 19 18 15 18 21 19 19 19 20

Na

wt% 2.

52.

52.

62.

42.

52.

4 22.

32.

42.

5

2.5

2.3

2.4

2.4

2.3

2.3

Nb

ppm 16 16 15 16 16 15 16 16 17 17 17 17 14 14 15 18

Pw

t%

0.09

0.08

0.08

0.08

0.07

0.08 0.

10.

080.

080.

08

0.09 0.

10.

090.

090.

090.

09 Nd

ppm 33 34 35 35 35 37 36 36 37 38 32 35 33 33 34 35

Ti

wt%

0.33 0.

30.

330.

350.

340.

350.

450.

360.

360.

32

0.35

0.38

0.38

0.39

0.37

0.39 N

ipp

m 4 3 5 5 5 6 9 7.

6 4 5 6 6 5 5 6

Mn

ppm

560

610

570

630

680

850

1300

1000

1000 650

650

880

760

800

820

850

Pb

ppm 22 25 23 24 24 17 24 21 24 26 20 21 21 21 21 23

Sw

t%

0.13

0.14

0.13

0.08

0.05

<0.0

5<0

.05

<0.0

5<0

.05

<0.0

5

0.08

0.07

0.06

0.06

0.06

0.06 S

cpp

m 7 7 7 8 8 8 12 9 9 7 8 9 9 9 9 9

totC

wt% 1.

30.

820.

890.

750.

540.

430.

650.

380.

310.

17

0.72

0.64 0.

60.

50.

480.

53 Se

ppm 0.1

<0.1 0.1

0.1

<0.1

<0.1 0.1

0.1

<0.1 0.2

0.1

0.1

<0.1

<0.1 0.1

0.1

org

Cw

t%

1.14

0.69

0.84

0.73

0.52

0.42

0.63

0.36 0.

30.

17 0.6

0.52

0.48 0.

40.

36 0.4 Sr

ppm

570

540

520

520

520

510

460

470

480

460

570

530

580

580

530

540

As

ppm 4.7

4.3

8.6

3.8

3.5

3.5

7.3

5.3

5.1

7.9

5.6

4.6 4

5.5

3.4

4.3

Th

ppm 10 12 13 14 12 13 12 13 14 14 10 12 11 11 12 12

Ba

ppm

980

1000

1000 960

980

980

880

970

990

1000 980

910

970

950

950

950 V

ppm 57 52 59 62 58 62 81 65 66 51 60 73 67 70 66 73

Ce

ppm 73 77 84 80 79 80 82 86 88 89 77 79 76 76 80 79 Y

ppm 20 20 21 22 20 22 25 23 23 23 21 22 21 21 21 22

Co

Cr

ppm

pp

m

9 13

10

1012

12

12

1412

13

13

1516

18

14

1314

14

9 10

11

1413

16

12

1512

14

11

1413

14

Yb

Zn

ppm

pp

m

2 53

2 56

2 58

3 63

3 58

2 63

3 89

2 67

2 67

2 53

2 60

2 76

2 68

3 70

2 70

2 73

All

sam

ples

bel

ow d

etec

tion

limits

fo

r th

e fo

llow

ing

elem

ents

:

Ag

<2 p

pmA

u <8

ppm

Bi

< 10

ppm

Cd

<2 p

pmE

u <2

ppm

Ho

<4 p

pmM

o <2

ppm

Sn

<5 p

pmT

a <

40 p

pmU

<

10

0p

pm

Tabl

e 9.

C

ompo

sitio

n of

wet

land

sed

imen

ts a

t site

0 in

Jun

e 19

93.

(Bas

ed o

n dr

y w

eigh

ts)

B =

field

spl

it; s

= la

bora

tory

spl

it

Site

D

epth

A

lcm

w

l%

0 c

ore

1 0-

2B

7.8

0 c

ore

1 2-

4B

8.1

0 c

ore

1 4-

6B

8O

co

rel

6-8B

8.

10 c

ore

1 8-

10B

8

Oco

rel

10-1

28

8.1

0 c

ore

1 10

-128

s

8O

co

rel

12-1

48

8.1

Oco

rel

14-1

98

8.6

Oco

rel

19-2

48

8.4

0 c

ore 20-2

80 c

ore

2 2-

4 7.

7O

cor

e 2

4-6

8.2

0 c

ore

2 6-

11

8.1

0 c

ore

2 6-

1 1

s 8.

10 c

ore

2 11

-16

8.3

O c

ore

2 16

-21

8.4

O c

ore

2 33

-42

7.8

Site

D

epth

C

ucm

pp

m

0 c

ore

1 0-

2B

430 c

ore

1 2-

4B

440 c

ore

1 4-

6B

440 c

ore

1 6-

8B

44O

co

rel

8-1

OB

44O

core

l 10

-128

43

Oco

rel

10-1

28 s

44

0 c

ore

1 12

-148

44

0 c

ore

1 14

-198

44

0 c

ore

1 19

-248

43

0 c

ore

2 0-

2 39

0 c

ore

2 2-

4 40

0 c

ore

2 4-

6 42

0 c

ore 26-11

420 c

ore

2 6-

1 1

s 41

0 c

ore

2 11

-16

420 c

ore

2 16

-21

420 c

ore

2 33

-42

44

Ca

Few

l%

wl%

1.5

4.9

1.3

4.8

1.3

4.6

1.3

4.7

1.3

51.

3 4.

81.

3 4.

71.

3 4.

81.

2 5.

11.

2 5.

3

1.4

6.2

1.1

6.1

1.3

5.8

1.2

5.3

1.2

5.3

1.2

5.8

1.2

5.8

1.1

5.2

Ga

Hg

ppm

pp

m

18

<0.0

219

<0

.02

17

0.02

19

0.02

18

0.02

18

0.02

18

0.02

18

0.02

20

0.02

20

<0.

02

17

<0.

0216

<

0.02

17

<0.

0218

<

0.02

17

<0.

0218

<

0.02

18

<0.

0218

<

0.02

Kw

l%

22.

22.

12.

22.

12.

12.

12.

12.

22.

1 2 22.

1 22.

12.

12.

12.

1 Lapp

m 35 37 36 37 36 37 37 36 38 38 36 39 37 37 37 38 38 38

Mg

wt%

0.86

0.88

0.87

0.89

0.86

0.86

0.85

0.86

0.88

0.86

0.83 0.

80.

860.

850.

850.

840.

84 0.8 Li

ppm 16 17 16 17 16 16 16 16 17 17 15 16 16 16 16 16 16 15

Na

wl%

0.98

10.

981

0.98

10.

991

0.99

0.99

0.99

0.97

10.

991

0.98

11.

1 Nb

ppm 11 10 12 13 11 13 11 12 12 12 12 11 12 11 11 13 11 11

Pw

l%

0.18

0.16

0.16

0.16

0.18

0.17

0.17

0.17

0.18

0.19

0.22

0.21 0.

20.

190.

190.

210.

210.

17 Nd

ppm 30 34 30 33 33 30 33 32 34 35 32 34 32 33 32 34 32 30

Tiw

t%

0.37

0.39

0.39

0.39

0.39

0.41

0.39

0.38

0.38 0.

4

0.38

0.37

0.38

0.39 0.

40.

38 0.4

0.39 N

ipp

m 13 11 11 11 12 11 12 12 12 12 11 11 11 11 12 12 12 13

Mn

ppm

1600 900

660

610

780

630

620

830

710

770

670

820

670

640

630

700

640

870 Pb

ppm 30 29 32 27 30 33 31 32 27 29 27 27 30 30 31 31 30 28

Sw

t%

0.16

0.12

0.13

0.13

0.13

0.12

0.12

0.11

0.11

0.11

0.11

0.11

0.11

0.11

0.12

0.11

0.11 0.

1 Sc

ppm 12 13 12 13 12 12 12 12 13 13 13 12 13 13 13 13 13 12

totC

Wt%

3.24

2.66

3.22

3.17 2.

82.

682.

652.

281.

891.

66

1.72

1.38

1.95 2

2.14

1.66

1.36

0.96 S

epp

m 0.9

0.8

0.9 1

1.1

1.2 1 1

1.3

1.6

1.4

1.5

1.3

1.3

1.3

1.7

1.6

0.7

orgC wt%

3.19

2.66

3.21

3.17 2.

82.

682.

652.

271.

891.

66

1.67

1.36

1.93 2

2.12

1.66

1.36

0.96 S

rpp

m

400

410

400

400

400

410

400

400

400

400

400

400

400

400

400

400

400

410

As

ppm 6.3

3.4

3.3

5.5

4.8

6.4

4.6

8.3

7.3

9.9 11 6.9

4.6

4.7

5.3

9.9

7.1

5.5 Th

ppm 9 9 8 10 10 10 10 10 11 10 9 10 10 9 9 11 10 9

Ba

ppm

680

690

660

670

660

680

670

680

700

660

620

660

650

650

650

650

650

700 V

ppm

110

120

120

120

120

120

110

120

120

130

120

130

120

120

120

130

130

120

Ce

ppm 67 73 70 69 70 72 70 69 71 73 70 74 70 71 70 70 73 74 Y

ppm 19 20 20 20 20 21 20 20 20 22 20 18 20 20 20 20 21 16

Co

Cr

ppm

pp

m

27

2020

22

17

2017

21

20

2117

21

16

2218

20

15

2120

20

18

2018

19

20

2018

20

17

2220

19

18

2020

20

Yb

Znpp

m

ppm

2 13

02

130

2 13

02

130

2 13

02

130

2 13

02

130

2 14

02

140

2 14

01

130

2 14

02

130

2 13

02

140

2 14

01

120

All

sam

ples

bel

ow d

etec

tion

limits

for t

he fo

llow

ing

elem

ents

:

Ag

<2p

pmA

u <8

ppm

Bi

<10

ppm

Cd

<2 p

pmEu

<2

ppm

Ho

<4

ppm

Mo

<2 p

pmSn

<5

ppm

Ta

<40

ppm

U

<100

ppm

Tab

le 1

0.

Com

posi

tion

of w

etla

nd s

edim

ents

at s

ites

Q a

nd R

in J

une

1993

. (B

ased

on

dry

wei

ghts

) s

= la

bora

tory

spl

it

Site Q Q Q Q R R R R Site Q Q Q Q R R R R

Dep

thcm 0-

50-

5 s

10-1

515

-25

0-10

10-1

515

-22

22-3

2

Dep

thcm 0-

50-

5 s

10-1

515

-25

0-10

10-1

515

-22

22-3

2

Al

wt% 3.

13.

37.

17.

5 67.

37.

6 8

Cu

ppm 32 32 42 46 48 31 38 44

Ca

Fe

K

Mg

wt%

w

t%

wt%

w

t%

2.3

1.3

0.98

0.

512.

4 1.

4 1.

1 0.

521.

9 3.

7 2.

5 0.

972.

7 4.

2 2.

5 1.

1

1.5

2.5

2 0.

661.

2 4.

2 2.

6 0.

761.

3 4.

5 2.

7 0.

632.

5 4.

6 2.

7 1

Ga

Hg

La

Lipp

m

ppm

pp

m

ppm

7 <0

.02

13

77

<0.0

2 13

8

15

<0.0

2 30

13

15

<0.0

2 32

15

13

<0.0

2 24

13

16

<0.0

2 34

14

16

<0.0

2 34

15

17

<0.0

2 32

17

Na

wt%

0.54

0.61 1.

21.

1

1.2

1.6

1.5

1.3

Nb

ppm 4 5 11 11 6 13 12 13

Pw

t%

0.17

0.17

0.24

0.21

0.12

0.16

0.18

0.16 N

dpp

m 12 12 27 30 21 26 27 29

Tiw

t%

0.12

0.12

0.34

0.34 0.

30.

460.

41 0.4 Ni

ppm 5 6 13 17 9 11 13 14

Mn

ppm

160

190

400

640

300

430

860

1100 Pb

ppm 19 16 31 29 28 26 26 26

Sw

t% 1.1

1.05

0.16

0.14

0.53

0.13

0.12

0.11 S

cpp

m 4 4 9 10 7 9 10 11

tOtC

Wt%

28.3

26.3 2.5

1.86

11.5

1.62

1.02 0.9

Se

ppm 0.8

1.3

1.5

1.2

0.6

0.6

0.8

0.8

org

Cw

t%

28.2

26.2

2.34

1.44

11.5

1.62

0.99

0.52 S

rpp

m

260

270

440

430

380

450

440

430

As

ppm 0.6 1

4.1

6.1

1.2

2.7 5

5.2

Th

ppm <4 <47 7 6 9 8 7

Ba

ppm

270

300

770

730

570

610

800

730 V

ppm 36 41 96 110 84 120

120

120

Ce

ppm 25 25 59 61 47 64 65 64 Y

ppm 7 7 15 17 11 15 15 15

Co

Cr

ppm

pp

m

5 9

6 10

16

1722

17

9 16

14

2020

17

25

15

Yb

Zn

ppm

pp

m

<1

99<1

10

01

110

1 12

0

1 11

02

110

1 11

01

120

All

sam

ples

bel

ow d

etec

tion

limits

for

the

follo

win

g el

emen

ts:

Ag

N3

Au

ho

B

iC

dE

u

<2

pp

m<

8ppm

<10ppm

<2ppm

<2

pp

m

Ho

<4 p

pmM

o <2

ppm

Sn

<5 p

pmT

a <4

0 pp

mU

<

10

0p

pm

Table 11. Pb-210 and water content of cores at wetland sites O and M in June 1993. (Based on dry weights) s = laboratory split

Site

O core 1O core 1O core 1O core 1O core 1O core 1O core 1O core 1O core 1O core 1O core 1O core 2

M core 2M core 2M core 2M core 2M core 2M core 2M core 2M core 2M core 2M core 2M core 2

Depthcm

0-22-4

2-4 s4-66-88-1010-1212-14

12-14 s14-1919-2433-42

0-22-4

2-4 s4-66-88-1010-1212-14

12-14 s14-1919-24

supportedPb-210dpm/g

1.681.55

1.51.851.861.671.291.221.26

0.9690.9170.819

2.622.522.962.321.981.931.941.441.54

0.8750.865

fraction estimatedof water date

0.702 1988-19930.627 1983-1988

0.624 1977-19830.617 1971-19770.609 1966-19710.589 1960-19660.589 1953-1960

0.586 1938-19530.587 1923-1938

0.743 1986-19930.663 1977-1986

0.652 1968-19770.621 1958-19680.616 1948-19580.602 1938-19480.593 1927-1938

0.5630.762

Site O core 1 was compacted during collection.Uncompacted depths = (1.36 x sampled depth), assuming uniform compaction.

Estimated dates from analysis of Pb-210 data (see text).

23

Table 12. Composition of aquatic plant, Persicaria amphibia (smartweed), in wetlands in June 1993. (Based on dry weight) DUP = duplicate field sample; s = laboratory split

Site

L sample 1L sample 1 DUPL sample 2

S sample 1S sample 2S sample 2 DUP

O sample 1O sample 1 DUPO sample 1 DUP sO sample 2O sample 2 DUP

P1P1 DUP

QQDUP

R sample 1R sample 2R sample 2 s

Site

L sample 1L sample 1 DUPL sample 2

S semple 1S sample 2S sample 2 DUP

O sample 1O sample 1 DUPO sample 1 DUP sO sample 2O sample 2 DUP

P1P1 DUP

QQDUP

R sample 1R sample 2R sample 2 s

ashwt%

9.679.338.33

98.67

9

8.337.677.676.677.67

99

10.310

88.678.67

Bappm

14011092

837678

2923232325

1414

2322

151414

Alppm

220210130

81150140

2531774723

1845

4140

162626

Coppm

0.581.3

0.67

1.61.61.5

1.91.71.71.31.5

2.12.5

1.91.9

2.22.52.5

Cawt%

1.91.91.5

0.990.950.99

1.2111

1.1

1.31.4

1.11.1

11.41.4

Crppm

0.2<0.2

0.2

<0.2<0.2<0.2

<0.2<0.2

0.2<0.2<0.2

0.20.3

<0.2<0.2

0.2<0.2

0.2

Feppm

270310270

230250250

270210210220230

350380

310350

180180180

Cuppm

4.22.73.2

4.87.36.9

7.45.65.84.34.8

1312

8.47.3

139.510

Kwt%

1.41.21.4

1.31.11.3

22

2.11.71.9

2.42.2

2.72.7

2.22.22.2

Lappm

<0.4<0.4<0.4

0.40.40.5

<0.4<0.4<0.4<0.4<0.4

<0.4<0.4

<0.4<0.4

<0.4<0.4<0.4

Mgwt%

0.360.350.34

0.320.310.32

0.280.250.250.230.26

0.30.32

0.390.37

0.260.330.32

Lippm

0.80.80.7

0.50.50.5

<0.3<0.3<0.3<0.3<0.3

0.50.5

0.5<0.3

0.30.60.7

Nawt%

0.570.570.49

10.95

1.1

0.160.150.150.130.15

0.170.17

0.490.45

0.0670.0870.087

Moppm

2.52.92.3

0.450.430.45

0.920.920.92

1.11.2

1.61.8

0.720.6

0.881.51.6

Pwt%

0.350.310.34

0.40.390.41

0.360.350.380.280.32

0.490.55

0.430.46

0.540.430.44

Nippm

<0.3<0.3

0.3

<0.30.80.8

0.40.40.40.30.4

0.50.5

0.4<0.3

0.642

Tippm

109

<9

<999

<9<9<9<9<9

<9<9

<9<9

<9<9<9

Pbppm

2.82.11.3

<0.8<0.8<0.8

<0.8<0.8<0.8<0.8<0.8

<0.8<0.8

<0.8<0.8

<0.8<0.8<0.8

Mnppm

780550550

410045004400

15001200110011001200

490410

14001600

290470470

Srppm

290260210

130120140

120110110110120

140130

140120

96110110

total Swt%

0.1630.1590.155

0.2570.19

0.267

0.2280.1890.1960.1660.189

0.280.314

0.6220.653

0.3260.27

0.273

Vppm

1.51.41.1

0.360.520.45

1.51.21.21.51.9

0.540.81

<0.36<0.36

0.40.430.52

AsPPm

1.21.10.7

0.60.70.7

0.60.40.40.50.4

0.40.3

0.30.3

0.10.10.1

Znppm

181317

182021

2118191517

3340

2528

413940

Sites O, P1, Q, and R receive some surface water from the Alamosa River. Sites L and S recaive surface water from other sources.

All samples below detection limits for the following elements: (Assumes ash weight of 9%)

Ag Au Be Bi Cd Ce Eu Ga Hg Ho

<0.4 ppm <2ppm

<0.2 ppm <2ppm

<0.4 ppm <0.7 ppm <0.4 ppm <0.7 ppm

<0.02 ppm <0.7 ppm

Nb Nd Sc Sn Ta Th U Y

Yb

<0.7 ppm <0.7 ppm <0.4 ppm <1 ppm <7 ppm

<0.06 ppm <18ppm <0.4 ppm <0.2 ppm

24

Table 13. Composition of aquatic plant, Potamogeton natans (pondweed), in wetlands in June 1993. (Based on dry weights) DUP = duplicate field sample

Site

L sample 1L sample 1 DUPL sample 2

M sample 1M sample 1 DUPM sample 2M sample 2 DUP

N sample 1N sample 1 DUPN sample 2

P1

Site

L sample 1L sample 1 DUPL sample 2

M sample 1M sample 1 DUPM sample 2M sample 2 DUP

N sample 1N sample 1 DUPN sample 2

P1

ashwt%

99.679.67

99.679.67

10

88.678.67

9

Bappm

7713097

83754142

626149

68

Alppm

430330390

890360400400

380430

78

140

Coppm

0.630.770.58

0.720.580.68

0.6

0.40.520.26

8.3

Cawt%

1.71.81.7

2.11.8

0.840.89

1.51.31.3

1.7

Crppm

0.30.30.3

0.50.40.10.4

0.20.30.2

<0.2

Feppm

460410500

650380390400

880510170

1700

Cuppm

6.36.77.1

96.95.25.5

3.73.64.9

14

Kwt%

1.41.71.7

0.761.52.62.7

0.961.41.9

1.3

Lappm

0.50.5

<0.4

0.6<0.4

0.40.5

0.50.5

<0.4

<0.4

Mgwt%

0.320.31

0.3

0.340.320.240.26

0.190.210.23

0.32

Lippm

<0.30.40.4

0.5<0.3<0.3<0.3

0.40.5

<0.3

<0.3

Nawt%

0.360.430.36

0.230.390.710.75

0.440.65

0.6

0.17

Moppm

2.734

1.31.2

0.971.1

3.84.7

5

1.6

Pwt%

0.320.360.42

0.480.620.450.49

0.30.350.37

0.36

Nippm

0.5<0.3

0.6

0.5<0.3

22

<0.30.50.6

<0.3

Tippm

302020

50202020

2030<9

<9

Pbppm

4.75

4.3

1.30.8

11.3

<0.80.8

<0.8

<0.8

Mnppm

710730670

1601509293

770950290

3000

Srppm

220230200

20018097

100

230230210

170

totalswt%

0.2030.1830.177

0.2220.275

0.280.3

0.2140.31

0.3

0.292

Vppm

3.73.1

7

1.60.97

33.2

4.54.7

2

1.6

Asppm

1.21.11.5

0.50.50.80.9

5.64.22.7

1.4

Znppm

253430

47483638

223628

38

Site P1 receives some surface water from the Alamosa River. Sites L, M, and N receive surface water from other sources.

All samples below detection limits for the following elements: (Assumes ash weight of 9%)

Au Be Bi Cd Ce Eu Ga Hg Ho

<0.4 ppm <2ppm

<0.2 ppm <2 ppm

<0.4 ppm <0.7 ppm <0.4 ppm <0.7 ppm

<0.02 ppm <0.7 ppm

Nb Nd Sc Sn Ta Th U Y

Yb

<0.7 ppm <0.7 ppm <0.4 ppm <1 ppm <7 ppm

<0.06 ppm <18ppm <0.4 ppm <0.2 ppm

25

Tabl

e 14

. C

ompo

sitio

n of

Sta

ndar

d R

efer

ence

Mat

eria

ls (

SR

M)

for

sedi

men

ts.

(Bas

ed o

n dr

y w

eigh

t)

(^

SR

M 2

709

Ele

men

t Al

Ca Fe K

Mg

Na P Ti Mn S

tota

l Cor

gC As

Ba Ce

Co Cr

Cu

Ga Hg La Li Nb

Nd Nl

Pb

Se Sc Sr

Th V Y Yb Zn

wt%

wt%

wt%

wt%

wt%

wt%

wt%

wt%

ppm

wt%

wt%

wt%

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

This

wor

kA

ve o

f 3

7.43 23.

61.

971.

53 1.2

0.07

0.34 56

00.

09 1.2

0.94

16.3

933 46

15.7

126.

7 35 16 1.4

24.3

56.7

11.7 20 87 21

1.43 12

240

11.3

117

15.7 1.3

103

Std

.D

ev.

0.09

00.

080.

050.

050 0 0 8 0

0.03

0.02 2.

4 19 2.2

0.5

4.7 0

0.8 0

1.2

0.5

0.5

0.8

2.2 1

0.12

0 01.

7 50.

50.

5 5

NIS

Tva

lue

7.5

1.89 3.5

2.03

1.51

1.16

0.06

20.

342

0.08

9(1

.2)

17.7

968

(42)

13.4

130

34.6

(14) 1.4

(23)

(19) 88

18.9

1.57

(12)

231

(11)

112

(18)

(1.6

) '

106

SR

M 2

710

Thi

s w

ork

Ave

of 3

6.43

1.33

3.47

2.03

0.87

1.17

0.12

0.27

1030

00.

243.

143.

13 600

700

59.7

11.7

34.3

3000

40.3

26.7 33 41 13 24

12.7

4933 0.

6 934

0 1175

.720

.7 267

67

Std

.D

ev.

0.17

0.05

0.12

0.05

0.02

0.05

0 049

70.

010.

050.

050 8

2.9

0.9

0.9

163

2.4

0.9

2.2

0.8

0.8

0.8

0.5

368 0 0 0

0.8

1.2

0.5 0

287

NIS

Tva

lue

6.44

1.25

3.38

2.11

0.85

31.

140.

106

0.28

310

100

0.24 (3

)

626

707

(57)

(10)

(39)

2950

(34)

32.6

(34)

(23)

14.3

5532

(8.7

)(2

40)

(13)

76.6

(23)

(1.3

)69

52

SR

M 2

711

Thi

s w

ork

Ave

of

3

6.6 3

2.97

2.47

1.07

1.23

0.09

0.28 66

7<

0.05

1.88

1.36

76.7

730

76.3 12

48.7

117

17.3 5.2 41 28

17.3

32.7

20.3

1053 1.

3 1025

714

.7 8525

.3 2.7

353

Std

.D

ev.

0.22

0.08

0.12

0.05

0.05

0.05

00.

01 19

0.03

0.03 4.7 0

2.9

0.8

2.1 5

0.5

0.7

2.2

1.4

0.5

0.5

0.5

105

0.08

0 52.

1 20.

50.

5 17

NIS

Tva

lue

6.53

2.88

2.89

2.45

1.05

1.14

0.08

60.

306

638

0.04

2(2

)

105

726

(69)

(10)

(47)

114

(15)

6.25

(40)

(31)

20.6

1162

1.52 (9

)24

513

.681

.6(2

5)(2

.7)

350.

4

NIS

T va

lues

from

Cer

tific

ate

of A

naly

sis

for

each

ref

eren

ce m

ater

ial;

pare

nthe

ses

indi

cate

non

-cer

tifie

d va

lues

Table 15. Composition of Standard Reference Material (SRM) for plants (SRM 1515, apple leaves, based on dry weight)

SRM 1515This study NIST

n=1 value

ashAl

CaFeK

MgNa

PTi

Mntotal S

AsBaCoCrCuHgLaLi

MoNi

PbSrV

Zn

wt%ppmwt%ppmwt%wt%ppmwt%ppmppmwt%ppmppmppmppmppmppmppmppmppmppmppmppmppmppm

72601.5701.6

0.2535

0.171050

0.110.06

460.210.42

5.50.04

20<4<4

0.91<725<411

2861.526

(80)1.61

0.27124.4

54(0.18)0.038

49(0.09)

(0.3)5.64

0.044(20)

0.0940.910.47

250.2612.5

NIST value from Certificate of Analysis for the reference material; parentheses indicate non-certified values

27

sr30'

Approximate easternboundary of San Juan

Mountains

Monte VistaNational Wildlife

Refuge

A Wetland Site River Site

Alamosa National Wildlife Refuge

10 20 KILOMETERS

Farmlands irrigated atleast in part with

Alamosa River water

Wildlife habitat potentially affected by Alamosa River water

Fig. 1. Map of the study area showing river and wetland sampling locations.

28

o£ (75 16

.O

1

O)

95

Input of Wightman Fork20-

15-

10-

0 4-

^

^s CU */ ^^ /

/ W i

11

///

no enrichmenti

3-

1 2-

8 1-

0CDEFGAIJK

Alamosa River site

Input ofWightman Fork

2.0-,

1.5-

1.0-

0.5-

0.03-

0

Co

CDEFGAIJK Alamosa River site

Fig. 2. Enrichment of elements in Alamosa River bed sediments at sites downstream of the confluence with the VMghtman Fork relative to bed sediments at a site above the confluence (site C) during June 1993. A value of 1 indicates no enrichment relative to site C.

29

o IB

200-

10

0-

0

AN

WR

Ala

mos

a R

iver

be

low

Ter

race

R

eser

voir V\\I

I I

Vfe

st

ANV\

II

of

/R II

II

^^ I

II

HIJ

K

RP

1P

2Q

O

MLN

Site

Fig.

3.

Rat

io o

f Na

to C

l con

cent

ratio

ns in

Ala

mos

a R

iver

wat

ers

belo

w T

erra

ce R

eser

voir

and

in w

etla

nd w

ater

s w

est o

f and

with

in

the

Ala

mos

a N

atio

nal W

ildlif

e R

efug

e (A

NW

R) d

urin

g Ju

ne 1

993.

As

in s

edim

ent (

ppm

) C

o in

sed

imen

t (pp

m)

Cr i

n se

dim

ent (

ppm

) 0

5 10

15

0

10

20

30

0 10

20

30

Cu

in s

edim

ent (

ppm

) 0

20

40

60

B Ni in

sed

imen

t (pp

m)

Zn in

sed

imen

t (pp

m)

0 10

20

0

50

100

150

Fig.

4.

Con

cent

ratio

ns o

f ind

icat

or e

lem

ents

in s

elec

ted

wet

land

se

dim

ents

dur

ing

June

199

3. C

lose

d sy

mbo

ls in

dica

te w

etla

nds

rece

ivin

g A

lam

osa

Riv

er w

ater

; op

en s

ymbo

ls in

dica

te w

etla

nds

rece

ivin

g w

ater

from

oth

er s

ourc

es.

-3

21 n In (excess Pb, dpnVg)

-2 -1 0

25 z°-

OJ

50-

75 J

-30

o1

CB

25-

50-

75-J

B

Site M core 2

S = 0.74 g cmV1

210In (excess Pb, dpnVg) -2-10 1

Site O core 1 S = 0.70 g cm'V1

210rFig. 5. Excess Pb as a function of mass accumulation at wetland sites M and O. The slope of the solid line is used to calculate the accumulation rate (see text).

32

ee

o-

Cu accumulation rate (Mg cm"2 y"1)

-A |0 CO<~> Cj CO

o

As accumulation rate (Mgcm-2y1)

roi

O)i

O)I_

N accumulation rate (Mgcm-2y1)

Co accumulation rate (Mgcrn2y1)

W O)I . , I

COI

m

(ftI

oI

OlI

CD z

Zn accumulation rate (Mgcm'2/1)

Cr accumulation rate (Mgcm'2y1)

#*" 'o

88OlI

oI

v\i

o ^

<D

030

Fe in sediment (wt %) 02468

50-, 1986-1993 1923-1938

10

0

-

B

^ i

^

i^^^

777

J

x^

^ ^ O O 4

^7%> */ V

^ 00

V V *7 V

Fig. 7. a) Fe content and b) accumulation rate in selected wetlands in the San Luis Valley, Co during 1993. Site O and wetlands denoted by closed symbols receive Alamosa River water, site M and wetlands denoted by open symbols receive surface water from other sources.

34

9-

6-

E 4? c 3

60

n

40

-

20-

AS

;

30-n

20-

10- o

i?

\

201

15-

10-

Cu

:5

5-

r2 =

0.8

0Z

02468

Fe in

sed

imen

t (w

t %)

20

-

10-

200

1

150-

100-

1N

-5

50

-r2

= 0

.74

fi

> l

| r

| i

| i

|

02468

Fe in

sed

imen

t (w

t %)

r2 =

0.6

4

i '

r

02468

Fe in

sed

imen

t (w

t %)

Fig.

8.

Cor

rela

tions

bet

wee

n co

ncen

tratio

ns o

f Fe

and

indi

cato

r ele

men

ts

in a

ll w

etla

nd s

edim

ents

exc

ept t

hose

at s

ite P

2 an

d th

ose

havi

ng >

4%

orga

nic

C.

1.0

-

0.5

-

0.0

-

15 10

-

5-

0-

o-

<>

^ S

*

*

* L

~*

As

t i , ?

i ,

0-

30

0^

I .

?2

oo-

W

<T>

^*

T S- 8:

10

0-

Co

i i i . i i

0-

50

-,10

00-

T

75

0-

^

ll

50

0-

^ft

T -^

3 ^i

^^

L1

^^

§

250-

Cu

r,

_

40-

1

30

-

t

-

O

°~1

0-

Ni

0-

O

I <>

Cr

T

f

*

^

*

Zni

i i

i i

i

O

P1

Q

R L

S Vt

etla

nd s

iteO

P1

Q

R

L \A

fetla

nd s

iteO

P1

Q

R

L

Vtet

land

site

Fig.

9.

Con

cent

ratio

ns o

f ind

icat

or e

lem

ents

in th

e aq

uatic

wet

land

pl

ant P

ersi

caria

am

phib

ia (

smar

twee

d) in

sel

ecte

d w

etla

nds

in th

e Sa

n Lu

is V

alle

y, C

o du

ring

June

199

3. C

lose

d sy

mbo

ls d

enot

e w

etla

nds

rece

ivin

g A

lam

osa

Riv

er w

ater

; ope

n sy

mbo

ls d

enot

e w

etla

nds

rece

iyin

g su

rface

wat

er fr

om o

ther

sou

rces

. Er

ror b

ars

deno

te s

tand

ard

devi

atio

n of

ele

men

t con

cent

ratio

ns o

f all

plan

ts a

t a g

iven

site

.

D-

4- -

2-

0-

15

-

10

-

5-

0-

<

<^

&

i i

i

<t>

c>

$

10

-

8-

^ ^~

,I

6"

i 4"

As

2"

.

o-

2000

-,

1500

-

f 1; 100

0-^3 ^^

^

500-

Cu

0-

500

-,

*

400-

?

300-

t -

£200-

100-

i i \ $ i

0-

40

-

U

3°-

°

|^

2°-

s.§

1

10-

Ni0-

T <>

0

T

Cr

I f

Zn

P1

L M

N

\A

fetla

nd s

iteP1

L

M

N

Wte

tland

site

P1

L M

N

\A

fetla

nd s

ite

Fig.

10.

Con

cent

ratio

ns o

f ind

icat

or e

lem

ents

in th

e aq

uatic

wet

land

pl

ant P

otam

oget

on n

atan

s (p

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