Based on a Canada-United States Workshop Held at the University of Windsor s Great Lakes Institute June 18-19, 2002

Transcription

1 EVALUATING ECOSYSTEM RESULTS OF PCB CONTROL MEASURES WITHIN THE DETROIT RIVER WESTERN LAKE ERIE BASIN Based on a Canada-United States Workshop Held at the University of Windsor s Great Lakes Institute June 18-19, 2002

2 Workshop Partners and Co-sponsors CANADIAN WILDLIFE SERVICE DETROIT RIVER REMEDIAL ACTION PLAN

3 Workshop Purpose To assess PCB trends in ecosystem conditions To develop advice for future monitoring, modeling and management

4 Critical Issues Lack of formal system or mechanism to effectively integrate data and information Need to distinguish between monitoring of near-field vs. far field effects Need to shift the current piece-meal approach to monitoring, research, and management of contaminants to a more systematic, integrated approach (this will require increased funding and more coordination)

5 Critical Issues (continued) Monitoring programs are primarily driven by regulatory needs. Monitoring programs should be designed by use impairments (e.g., fish consumption advisories, fish tumors, chick mortality, degraded and deformed benthos). Lower PCB detection limits will be needed to calculate reliable PCB loading estimates.

6 Major Findings Long-term monitoring indicates significant declines in PCBs in the atmosphere, water, sediment and biota of the Detroit River and western basin of Lake Erie since the 1970s. There is limited evidence to suggest any further improvements in recent years.

7 Total PCB Trends in Lake Erie Western Basin Walleye ( )

8 Major Findings The herring gull monitoring program provides one of the most complete and consistent data bases for assessing ecosystem trends. PCB concentrations in herring gull eggs have exhibited a significant decline since the mid-1970s. Other data bases for fish and sediment also indicate long-term declines.

9 PCB 1:1 in Herring Gull eggs Fighting Island in the Detroit River, (Canadian Wildlife Service)

10 Major Findings Many ecosystem indicators exhibited a decline in PCB contamination in the upper river. Several of these same indicators suggest less improvement has occurred in the lower river. The Detroit River continues to be a significant source of PCBs to Lake Erie. The Trenton Channel is the most contaminated area within the river system.

11 PCB Concentrations (ng/l) in Water of the Detroit River during 1998 LSC RM GLIER TT TT GI TT FI WWTP DWWTP TC Kilometers Sum PCB Concentration (ng/l) # 1 Biomonitor Cw Direct Measure Cw Upstream PCB concentration W.Lake Erie PCB concentration LSC RM GLIER WWTP DWWTP TC GI FI TT TT DDR MSI MSI MSI DDR Striped columns indicate geometric mean PCBs in water from mussel biomonitoring studies. Grey columns indicate mean PCB concentrations in water based on traditional analytical techniques (Froese et al. 1997; Environment Canada). LSC = Lake St. Clair, RM = Riverside Marina, GLIER = Great Lakes Institute, WWTP = West Windsor Treatment Plant, DWWTP = downstream of WWTP; TC = Turkey Creek Outlet, GI = Grass Island, FI = Fighting Island, TT = Trenton Channel, DDR = Downstream of Detroit River, MSI = Middle Sister Island, Lake Erie.

12 Major Findings Current monitoring programs for PCB sources are inadequate for developing reliable loading estimates. Current funding and coordination of monitoring programs are inadequate.

13 Major Findings An integrated monitoring, modeling, research and management program is lacking. Absence of a comprehensive plan for synthesizing information has inhibited decision-making. The cost of sediment remediation and disagreement on suitable sediment disposal sites remain major obstacles to the restoration of impaired beneficial uses.

14 Major Findings During 1997 and 1998, sediment remediation occurred in Evans Ditch and Newburgh Lake along the Rouge River. Over 313,000 m 3 of sediment was removed, representing an estimated 8,800 kg of PCBs. Follow-up analyses of PCBs in fish collected during 2001 showed an order of magnitude decline. Post-project monitoring is essential to document the efficacy of sediment remediation projects.

15 Newburgh Lake fish mean PCB concentrations

16 Major Findings Between 1993 and 2001 approximately $130 million was spent on 10 contaminated sediment remediation projects within the Detroit River/Western Lake Erie Basin. Total estimated volume of contaminated sediment removed was 843,500 m 3, representing 198 tonnes of PCBs. MDEQ estimates that there remains approximately 2,293,500 m 3 of sediment that impacts beneficial use impairments in the Detroit River, Rouge River, and River Raisin combined.

17 Major Findings SUBSTANTIALLY MORE PCBs REMOVED VIA SEDIMENT REMEDIATION THAN NAVIGATIONAL DREDGING 198 tonnes of PCBs were removed between 1993 and 2001 as a result of sediment remediation. In comparison, approximately 1 tonne of PCBs was removed as a result of navigational dredging between the same time frame.

18 Important Recommendations Improved source monitoring is needed, especially loadings from the Detroit Water and Sewerage Department (DWSD). Improvements should include: increased sampling frequency, testing for different PCB congeners, and lower detection limits.

19 Important Recommendations A detection limit of 1 ηg/l is recommended for measuring total PCBs. For congener quantification, the method detection limit is recommended. Integrated Atmospheric Deposition Network (IADN) should be expanded to include a Detroit River-western Lake Erie station.

20 The Integrated Atmospheric Deposition Network

21 Important Recommendations Continued support should be provided to the Great Lakes Institute at the University of Windsor to sustain its monitoring and modeling programs focused on contaminant loadings and ecosystem changes within the Detroit River-western Lake Erie basin.

22 Important Recommendations The visibility and support of the Monitoring Upper Great Lakes Connecting Channels Committee should be increased. The committee could work with the Lake Erie Millennium Plan to coordinate monitoring, research, and management efforts directed at an improved scientific foundation for ecosystem-based management.

23 Take Home Messages Need integrated monitoring effort focused on use restoration Must sustain and build upon modeling efforts Should remediate contaminated sediment hotspots (including postproject evaluation of effectiveness)

24 Acknowledgements This workshop was funded in part by a grant from U.S. Environmental Protection Agency s Great Lakes National Program Office to Wayne State University We thank all workshop partners and cosponsors for their support and significant contributions

25 Workshop Partners and Co-sponsors CANADIAN WILDLIFE SERVICE DETROIT RIVER REMEDIAL ACTION PLAN

26 Report available online at: