Metals in the Benthic Macroinvertebrates in Coal Creek, Crested Butte, CO

Transcription

1 Metals in the Benthic Macroinvertebrates in Coal Creek, Crested Butte, CO Scarlett E. Graham July 1, 26 University of Colorado at Boulder Environmental Engineering REU Summer Student Overview Motivation Background Hypotheses Methods Results Conclusions Comparisons to Water and Sediments

2 Motivations Coal Creek Watershed Coalition Standard Mine is an EPA Superfund Site Coal Creek is a drinking water supply Recreation is a major contributor to the economy Acid Mine Drainage (AMD) 1/3 of EPA Superfund Sites in Colorado are devoted to cleaning up abandoned mines. Characteristics: -low ph - high metal concentrations - elevated sulfate levels - excessive suspended solids Heavy Metals: Fe, Mn, Al

3 Geochemical processes: (1) 4FeS 2 (s) + 14O 2 (g) + 4H 2 O(l) 4Fe SO H + pyrite Acidophilic bacteria (2) 4Fe 2+ + O 2 (g) + 4H > 4Fe H2O(l) (3) 4Fe H 2 O(l) 4Fe(OH) 3 (s) + 12H + yellow boy (4) 4FeS 2 (s) + 15O 2 (g) + 14H 2 O(l) 4Fe(OH) 3 (s) + 8SO H + Coal Creek Watershed Gunnison County, CO N N Slate River Slate River Scarp Ridge Lake Irwin Standard Mine Standard Mine Mt. Emmons Keystone Mine Mine Iron Iron Fen Forest Forest Queen Queen Mine Mine Kebler Pass Kebler Pass Elk Creek Splain s Gulch s Coal Creek Coal Creek Wildcat Creek Crested Butte Crested Butte :

4 Benthic Macroinvertebrates Stoneflies, Order Plecoptera: sensitive Caddisflies, Order Trichoptera: moderately tolerant Mayflies, Order Ephemeroptera: sensitive Past Research Will Clements, CSU: mayflies. Susan Bautts, 25 and Drew Bryenton, REU 24: Lefthand Creek. Brianna Shanklin, 25: Coal Creek.

5 Hypotheses Elevated metal concentrations and reduced diversity and abundance of macroinvertebrates after Elk Creek Tributary,, and Mt. Emmons Effluent. Correlations between sediments and benthic macroinvertebrate metal content. Differences between water and macroinvertebrate metal concentrations. Sample Sites along Coal Creek

6 Methods: Sampling June 14 & simultaneously with sediments. 13 sampling sites along 9.5km, starting point: 25/Shanklin Injection Site. In Stream: kick and overturn rocks while dragging mess net behind. Emptied nets into buckets and trays and sorted stoneflies Stored in 6 ml bottles on ice until reached the lab Frrrannnnnieeeee, give that back! Methods: Digestion Rinsed with Milli-Q water Dried in oven Measured dry weight Added Digestion solution: 1:1 soln. of 15.8M HNO 3 and 3% H 2 O 2 + H 2 O Shook in hot water bath Allowed to settle and supernatant removed and filtered with.45µm nylon filters.

7 Methods: ICP-OES Diluted 9:1 solution Measured Metal Content with ICP-OES (ARD, Model 341+) in the LEGS Lab, CU Boulder Measured Al, Cd, Cu, Fe, Mn, Pb, Zn concentrations in ppm. Results

8 Results Sample Site Description Distance D/S relative to 9/5 Injection (km) Approx count of stoneflies Mass of Stoneflies (g) Approx count of others Above Injection Site medium worms, 2 mayflies CC large, 1 small worms, 1 mayfly U/S of Elk med., 5 small worms, 2 mayflies D/S of Elk med, 2 small mayflies, other small stuff CC large, 1 med worms, 2 mayflys, 4 caddis flys CC large, 6 med., 15 small caddisflies, 2 worms, 1 mayfly and others med, 6 small worms, 4 mayflies, 5 caddisflies, and others CC med., 1 small mayflies, 3 worms, 1 caddisfly and others U/S of Mt. Emmon's affluent large, 1 med caddisflies, and others D/S of Mt. Emmon's affluent med., 4 small mayflies, 4 caddisflys CC large, 5 med., 5 small worms, 1 mayfly, and others D/S of drinking H2O resevoir inflow large, 3 med., 15 small worms, 4 mayflies, 5 caddis, and other stuff D/S of Crested Butte large, 2 med., 8 small mayflies, 4 worms Zinc concentrations µg/g dry weight U/S of Elk D/S of Elk U/S Mt. Emmons Effluent D/S Mt E Effluent Distance (km)

9 Iron Concentrations µg/g dry wt U/S of Elk D/S of Elk U/S Mt. E. Effluent D/S Mt. E. Effluent Distance (km) Iron Concentrations Fe Concentrations (modified) (modified) µg/g dry weight Distance (km) U/S of Elk D/S of Elk U/S Mt. E. Effluent D/S Mt. E. Effluent

10 Copper Cu Concentrations Cu Loading µg/g dry weight U/S of Elk D/S of Elk U/S Mt. E. Effluent D/S Mt. E. Effluent Distance (km) 9 (1375) 8 7 Zn Metal Concentrations (compiled) µg/g dry weight Cu Fe Distance (km) U/S of Elk Creek D/S of Elk Creek U/S Mt. Emmons Effluent D/S Mt E Effluent

11 Conclusions: Macroinvertebrates Elevated metal concentrations occur after Elk Creek, Mt. Emmons treatment plant effluent Benthic Macroinvertebrate populations not that affected. High concentrations of iron in background site of stream. Comparison of Synoptic Tracer, Sediment, and Macroinvertebrate Results : Zinc Coal Creek, dissolv ed Streambed Sediments Coal Creek, total Macroinv ertebrates ppb µg/g U/S of Elk Creek D/S of Elk Creek U/S Mt. Emmons Effluent D/S Mt E Effluent

12 Comparison of Synoptic Tracer, Sediment, and Macroinvertebrate Results: Iron ppb (water) U/S of Elk Creek D/S of Elk Creek Coal Creek, dissolved Coal Creek, total Streambed Sediments Macroinvertebrates U/S Mt. Emmons Effluent D/S Mt E Effluent µg/g (sediments and macroinvertebrates) ppb (water) 2 1 Comparison of Synoptic Tracer, Sediment and Macroinvertebrate Results: Copper U/S of Elk Creek D/S of Elk Creek Coal Creek, dissolv ed Streambed Sediments Coal Creek, total Macroinvertebrates U/S Mt. Emmons Effluent D/S Mt E Effluent µg/g (sediments and macroinvertebrates)

13 Further Study Data: metal speciation trends Do some practice runs of the macroinvertebrate sampling before actually starting. Investigate fish populations Use ICP-MS for other metals found below detection limit. Acknowledgements Advisor, Joe Ryan Funding provided by NSF REU, CU, CCWV Field and Lab Partner: Frannie Bui Tim Dittrich, Brianna Shanklin, Hallie Bevan Angela Bielefeldt, REU Coordinator Fred Luiszer, LEGS Lab REU Friends

14 Scarlett Graham Allegheny College Questions