James Ranville Colorado School of Mines Department of Chemistry - - PowerPoint PPT Presentation

Ch Chemical l and d Bi Biological l Re Responses s in n the e North h Fork k

• f
• f C

Clea ear C Creek F eek Fol

• llowing

g Re Remediation n of f Acid d Mine e Dr Drainage e Inputs s James Ranville Colorado School of Mines Department of Chemistry NIEHS Superfund Research Program (SRP) Progress in Research Webinar May 13th, 2019

Acknowledgements

Investigating Biogeochemical Controls

• n Metal Mixture Toxicity Using

Stable Isotopes and Gene Expression

• Grant 5RO1 1ES024358

Co-PIs & Students Colorado School of Mines

• J. Ranville, J. Meyer, E. Lloyd, J

Murphy Colorado State University

• W. Clements & Chris Kotalik

University of Florida

• C. Vulpe and Dani Cucchiara

Overall Study Objectives/Approaches

We wish to better understand how metal mixtures affect aquatic toxicology and metal bioavailability and how the presence of metal mixtures influence the remediation effectiveness for mining impacted waters We are using a laboratory and field based-approach. Laboratory studies of mixture toxicity utilize D. magna, with mortality, metal uptake (measured and computed by BLM), and gene expression as endpoints. Bioavailability of metals from sediments utilize 65Cu isotope labeling with snails as the test organism. We are directly measuring the biological and chemical responses to remediation of the mining effluents (todays presentation).

Talk Outline

• Background
• Site Description/hydrology
• Water Chemistry Response
• Biological Recovery
• Outreach
• Summary

Introduction

• North Fork of Clear Creek

(NFCC) located 50 km west of Denver, Colorado USA

• Mining activity 1850s – 1950s
• Acid mine drainage (AMD) and

mining solid wastes (sulfide weathering)

• Mixtures of toxic metals (Cu,

Zn) enter stream effecting water column and sediment chemistry

• Stream life highly impacted

(absent)

Black Hawk, CO 1987

Welcome to the North Fork Clear Creek-2016

Armoring Flocculant bed and suspended sediments Dissolved metals Aquatic Life ?

Treatment Plant

• High Density Sludge
• Operational March 2017
• Capture and treatment of

two point sources of AMD entering stream

• Gregory Incline and

National Tunnel

• Initial cost of $19.66 million

Photo Credit: Heather Henry

Flow Flow

Gauge

Research Goals (Chemistry)

• Monitor water chemistry and biology pre- and post-remediation
• Understand effectiveness of treatment plant in decreasing total metal

loading in stream

• Understand geochemistry of changes in water chemistry (dissolved)

since implementation of remediation

• Evaluate potential aquatic toxicity of dissolved metals

Discharge

500 1000 1500 2000 2500 M a r

• 1

7 M a y

• 1

7 J u l

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7 S e p

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7 N

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• 1

7 J a n

• 1

8 M a r

• 1

8 M a y

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8 J u l

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8 S e p

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8 N

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8 J a n

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9 M a r

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9

Discharge (L/sec)

Sampling Dates

Scouring Scouring Base Flow Base Flow

2017 2018 2018 2019

March 23 May 1 May 16 August 29 October 27

Visual Improvement in Stream Appearance March- October 2017 @ Downstream Site

March 28: treatment of one source begins, periodic shutdowns occur, second source treatment begins in July September 15: 24/7 treatment begins

Decrease in Total Metal Loading

0.01 0.1 1 10 100 1000 Aug-16 Mar-17 Sep-17 Apr-18 Oct-18 May-19

Load (Kg/day)

Iron

0.01 0.1 1 10 100 1000 Aug-16 Mar-17 Sep-17 Apr-18 Oct-18 May-19

Zinc

0.01 0.1 1 10 100 1000 Aug-16 Mar-17 Sep-17 Apr-18 Oct-18 May-19

Copper Decrease by factor of 1600 Decrease by factor of 50 Decrease by factor of 150

Spring Scouring Event

Pre- Treatment Pre- Treatment Pre- Treatment Post-Treatment Post-Treatment Post-Treatment

Multiple Remaining Sources with Differing Metal Compositions

REF 1 REF 2 ANT RAP TP Flow

20 40 60 80 100

REF 1 to REF 2 REF 2 to ANT ANT to RAP

Percent Increase Between Sites Cu Zn BDL

Multiple Remaining Sources with Differing Metal Compositions

REF 1 REF 2 ANT RAP TP Flow RBP ARG USGS

5 10 15 20 25

Aug-16 Nov-16 Mar-17 Jun-17 Sep-17 Dec-17 Apr-18 Jul-18 Oct-18 Feb-19 May-19

Total Iron (mg/L) Post-Treatment Pre-Treatment

Total Iron Concentration: Near Complete Removal

Matchs Visual Improvement

Only Partial Lowering of Dissolved Copper

5 10 15 20 25 30 35 40 45

Aug-16 Nov-16 Mar-17 Jun-17 Sep-17 Dec-17 Apr-18 Jul-18 Oct-18 Feb-19 May-19

Dissolved Copper (ug/L)

Pre-Treatment Post-Treatment

Particulate Iron is Your Friend For Copper

10 20 30 40 50 60 70 80 90 100 0.01 0.1 1 10 100

Percent Dissolved Copper Particulate Iron (mg/L)

Stumm 1992 Pre-remediation

Predicted Toxicity of Instream Cu + Zn to Daphnia magna

• Based on measured dissolved Cu

and Zn in stream

• Cu and Zn EC50s taken from

previous 48-h lethality tests with D. magna neonates (EC50 = 50% mortality conc.)

• Toxic units
• TUCu = [Cu]/EC50Cu
• TUZn = [Zn]/EC50Zn
• ΣTU = TUCu + TUZn
• Predicted mortality = f(ΣTU)

Predicted Toxicity of Instream Dissolved Copper and Zinc (considering effects of multiple metals)

20 40 60 80 100 M a r

• 1

7 M a r

• 1

7 M a y

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7 J u n

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7 A u g

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7 S e p

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7 O c t

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7 N

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7 J a n

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8 A p r

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8 M a y

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8 J u l

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8 A u g

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8 S e p

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8 O c t

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8 N

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8

Mortality (%)

Dilution Dilution Base Flow Base Flow

Chemistry Conclusions

• Total Copper, Iron, and Zinc loads have decreased to different degrees

since treatment began

• Multiple and variable sources of uncaptured metals continue to enter

NFCC in variable ratios

• Particulate Iron is your friend for Copper but not Zinc
• Predicted toxicity of Zinc and Copper to Daphnia magna remains

elevated post remediation

• Cannot treat what we do not capture

Field Biomonitoring Hypotheses for AMD Remediation

• H(1): Algal biomass will increase
• H(2): Benthic macroinvertebrates

will increase in abundance and taxa richness

• H(3): Benthic and emerging adult

biomass will increase

• But how quickly?

Treatment Plant

Flow direction

Sampling Locations

Golden 30 km

CSM/CSU Study Objectives

• Measure chemical and biological

stream parameters

• Identify chemical and biological

processes that drive post- remediation stream conditions

• Determine remediation

effectiveness for stream ecological health

”Recovery” Sites ”Impact” Sites

North Fork Clear Creek, Colorado Algal Colonization

North Fork Clear Creek, Colorado Larval Colonization

North Fork Clear Creek, Colorado Benthic vs Emergence Biomass

Field Biomonitoring Results and Conclusions to date--

• Discrepancies in algal colonization at AMD

remediation sites, likely due to top-down control by grazer aquatic insects

• Increased abundance and taxa richness at

downstream sites, but richness is still far below Reference site observations

• Benthic and adult emergence biomass

improved at downstream sites from Year 1 to Year 2. This suggests increased benthic production and increased subsidy export to terrestrial environments following remediation

Outreach to Local STEM K-12 Schools CSM Summer programs engineering Treatment Sources Impacts on Aquatic Life

CSM Environmental Chemistry Field Session Site investigations for local stakeholders

Questions