Update on the Assessment and Remediation of a Former Unofficial Dumpsite in the Columbia National Wildlife Area

Transcription

1 Update on the Assessment and Remediation of a Former Unofficial Dumpsite in the Columbia National Wildlife Area Lindsay Paterson, MSc, PAg SLR Consulting (Canada) Ltd. Darryl Roberts, PhD Environment Canada Bradley Klaver Public Works and Government Services Canada

2 Outline Site Location and History Previous Environmental Work Marsh ERA Results Trail EM Survey and 2013 Activities On-going Challenges

3 Site Location and History Wilmer Marsh is 1 of 4 units that comprise the Columbia NWA Federally protected area to conserve wildlife and its habitat Important segment of the Pacific Flyway migratory corridor

4 Site Location and History

5 Site Location and History

6 Previous Environmental Work Soil, sediment & surface water sampling Geophysical & geotechnical assessments Debris removal uplands bench area Shoreline remediation - marsh area Fencing improvements Risk assessments uplands bench, marsh

7 Uplands Debris Removal Before After

8 Shoreline Remediation

9 Marsh ERA

10 Marsh ERA Limited extent of sediment contamination following shoreline remediation, no surface water issues Primarily metals, SEM:AVS < 1 PAHs related to forest fire activity Final COPCs = Ba, Sn, PHC F4 (aromatic sub-fraction) for aquatic life only

11 Marsh ERA Surrogate ROCs included benthic invertebrates, green frog, painted turtle and muskrat Benthic invertebrates evaluation of sediment chemistry and toxicity testing results Green frog, painted turtle, muskrat estimation of exposure through diet and ingestion of sediment

12 Marsh ERA Benthic invertebrates Ba sediment concentrations < TRV (i.e HQ<1) No reliable TRVs for Sn, F4 (aromatic) Green frog ADD < TRV (HQ < 1) Painted turtle ADD < TRV (HQ < 1) Muskrat ADD < TRV (HQ < 1)

13 Marsh ERA Toxicity Testing Test organisms included midge, amphipod crustacean and oligochaete worm Acute and chronic effects evaluated 10-d survival and growth (C.tentans) 14-d survival and growth (H. azteca) 28-d survival and reproduction (T. tubifex) No correlation between sediment chemistry and toxicity test results

14 Marsh ERA Adverse effects to benthic invertebrates, green frog, painted turtle and muskrat from sediment contamination are unlikely No unacceptable risks to ecological receptors from residual contamination Large debris in marsh continues to pose physical hazard and contributes to ERA uncertainty

15 Trail Area Situated along southern portion of uplands bench, sloping down to marsh Previously identified as geotechnically unstable More debris visible along trail in recent years (?)

16 Trail Area EM Survey EM31 and EM38 conductivity survey Responses to 4 m and 1.5 m, respectively Several areas with anomalous responses identified along and downslope of trail Highly localized areas remaining in marsh

17 Trail Area 2013 Assessment View looking down along trail Grade ~ 16-20% View from top of slope above Grade 60-75%

18 Trail Area 2013 Assessment

19 Trail Area 2013 Assessment Glaciolacustrine soils at the site are prone to piping erosion and formation of voids

20 Trail Area 2013 Assessment Soil contamination less spatially extensive than debris Primarily found in areas with greatest amounts of debris Limited to metals (Cd, Pb, Ni, Sn, Zn)

21 On-Going Challenges Permitting and wildlife work windows Climate windows Geotechnical and erosion concerns Multi-stakeholder environment Conflicts with local human population Timing of above within fiscal year

22

23 Contact Information Darryl Roberts, PhD A/Director, Real Property Management Division Environment Canada Telephone Lindsay Paterson, MSc, PAg Project Manager and Soil Scientist SLR Consulting (Canada) Ltd. Telephone Bradley Klaver Environmental Specialist, Environmental Services PWGSC - Pacific Region Bradley.Klaver@pwgsc-tpsgc.gc.ca Telephone