use of pore water in conjunction with other biotic and abiotic datasets to evaluate remedial success...
TRANSCRIPT
USE OF PORE WATER IN CONJUNCTION WITH OTHER BIOTIC AND
ABIOTIC DATASETS TO EVALUATE REMEDIAL SUCCESS IN A
FRESHWATER RIVER ENVIRONMENT
Hudson – Delaware SETAC Fall 2015 Meeting
October 7, 2015
2
•Utility of Pore Water Data in a Changing Environment
•Project Background– Operational History– Conceptual Site Model
•Pilot Bank Stabilization Project– Design– Baseline and Post-Implementation Monitoring
•Data Summary
•Lessons Learned and Implications for Future Monitoring
Overview
2016: Construction begins
2014: South River enters into regulatory process
The South River Story
1930 200019601940 1950 1970 1980 1990 2010
1950: Mercuric sulfate use stops
1982: Studies predict fish improvement in
20 years
1999: Fish tissue levels are not decreasing as predicted
2001: DuPont and VDEQ launch collaborative effort – South River Science Team
1929: Mercuric sulfate use in acetate rayon fiber production begins
1976: Mercury discovered on-site and in fish; fish consumption ban
1984: DuPont funds 100-year monitoring program
2020
2015: Baseline monitoring begins
2005 - 2012: Extensive field investigations
Site Location
N
Waynesboro, VA Fibers PlantDuPont 1929 - 2004INVISTA 2004 - present
5
Conceptual Site Model
6
Pilot Bank Stabilization Project
• Elevated THg Concentrations in
Biotic and Abiotic Media
• Erosion Documented Using Side-
Scan LiDAR
• Approximately 500’ Stabilized
7
Pilot Bank Stabilization ProjectPre-Stabilization Conditions
8
Pilot Bank Stabilization Project
9
Performance Monitoring Program
Physical Elements• Channel Morphology• EPA Rapid
Bioassessment Protocol
Chemical Elements• Surface Water• Bank Soil• Sediment• Pore Water• Asiatic Clam
Baseline Data Review
10
11
Baseline Mercury Characterization: Highest THg Concentrations in Sediment Co-located with Soil
1260
1265
1270
1275
1280
1285
-100-50050100150200250300350400
Distance (ft)
Ele
va
tio
n (
ft)
Water Surface
5060
403020100
LOI (%)
THg (ug/g)
THg and Loss on Ignition (LOI) in Near Bank Sediment
Maximum THg Concentrations in Bank Soils
T1
T2 T5 T3T4
T6
Direction of Flow
Figure adapted from Pizzuto, 2008
584 ug/g
194 ug/g
406 ug/g44.6 ug/g
431 ug/g
ug/g
or
%
Confluence with Rockfish Run
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Pore Water Hg Concentrations are Highest Near Pilot Bank
Post Stabilization Data Review
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Sediment
• Decreased THg Concentrations on Average Compared to Pre-stabilization Data
• Maximum THg Concentrations Have Decreased Since 2012
• Sediment THg Concentrations Similar to Those Observed on Particles in the Water Column
Bank Stabilization
Pore Water
• Extensive Variability in Baseline Dataset Prevents Detecting Statistically Significant Reductions
• Continued Decreasing Trend in IHg and MeHg Concentrations Over Time
Bank Stabilization
Pore Water
Sampling DateMean FIHg
(ng/L)
FIHG Range(ng/L)
SDMean
FMeHg (ng/L)
FMeHG Range(ng/L)
SD
June 2009 53 2.26 - 131 42 10 1.04 - 40.5 11
July 2009 51 5.23 - 292 83 3.9 0.36 - 14.4 4.0
August 2009 82 2.73 - 510 153 2.3 0.04 - 6.83 2.0
June 2010 27 2.94 - 176 48 4.4 0.14 - 20.9 6.6
June 2011 27 14.1 - 47.8 13 3.3 0.13 - 13.7 4.5
June 2012 25 5.37 - 32.7 9 3.4 1.1 - 7.18 2.0
June 2013 8.7 4.48 - 21.1 4 2.1 0.26 - 4.49 1.4
June 2014 8.5 5.43 - 13.5 2 2.0 0.35 - 3.69 1.0
June 2015 3.3 1.1 - 5.4 1 1.9 0.36 - 3.57 1.0
Notes:
Bank stabilization activities occurred after the August 2009 sampling event
Samples were collected at transects A-C"
FIHg: Filtered inorganic mercury
FMeHg: Filtered methylmercury
SD: Standard deviation
Asiatic Clam Tissue
• IHg Concentrations Similar Between Near-bank and Mid-channel Samples
• Typically Higher MeHg Concentrations in Near-bank Samples
Bank Stabilization
Asiatic Clam - Comparison to Baseline
Corbicula IHg
Corbicula MeHg
Sediment and Pore Water – Comparison to Baseline
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Lessons Learned - Monitoring Implications
Bank Stabilization
• Pore Water Data Most Strongest Line of Evidence Documenting Remedy Success
• Other Lines Of Evidence Provide Useful Information in a Changing Environment
• Phase 1 Interim Measures Expected to Begin in 2016
South River Science Team (SRST)www.southriverscienceteam.org
DuPont
City
City of Waynesboro
College of William and MaryJames Madison University
Virginia TechUniversity of DelawareUniversity of Waterloo
Colorado State UniversityWestern Washington
UniversityTexas Tech University
Will ClementsDave Hirschman
Ralph Turner
Expert PanelistsAcademia
Friends of the ShenandoahVirginia Conservation
CouncilTrout Unlimited
Shenandoah River Keeper
NGOs
Federal State
EPAUSF&WS
VDEQVDGIFVDH
Consultants
AECOMAnchor QEA
EngineersGeologists
Risk assessors