Metro Vancouver Reference Panel recommends monitoring long-term cumulative impacts of multiple contaminants in liquid discharges
Metro Vancouver's Liquid Resource Management Plan
Appointed by the Metro Vancouver Regional Board in April 2008 to provide independent advice and recommendations regarding the management of liquid discharges and rainwater, the Liquid Waste Management Reference Panel presented their Final Report on A Liquid Resource Management Plan for Metro Vancouver to the Waste Management Committee on July 15, 2009.
A Recommended Policy Framework
The Reference Panel identified five themes that capture how the Metro Vancouver region can continue to transition from the current path and achieve the region's “sustainability vision”. These themes provide the basis for a policy framework that will guide actions on the ground.
Cumulative Impacts of Multiple Contaminants
“Current senior government regulations deal with one contaminant at a time and even though levels may be below some set threshold, the presence of multiple contaminants and their interaction can have impacts on organisms in the long term that 
are not being considered,” states Dr. Ken Hall, a scientist on the Reference Panel.
Dr. Hall is a Professor Emeritus at the University of British Columbia, and specializes in water quality and marine issues.
“The current Cautions, Warnings, Triggers (CWT) process as employed by Metro Vancouver focuses mainly on individual contaminants,” he notes.
“Metro Vancouver has started to look at the cumulative impacts of multiple contaminants – for example, by funding Benthic Process, Organic Carbon Cycling and Contaminants in the Strait of Georgia, a 2008 research report published by the Institute of Ocean Science; this study found that persistent contaminants could be distributed widely.”
“The Reference Panel has recommended that Metro Vancouver undertake more extensive monitoring of the long-term cumulative impacts of multiple contaminants in effluents….both from point and non-point sources. This will help us move from protect to improve the natural environment.”
Our Understanding of the Natural Environment
“The Strait of Georgia and the Fraser Estuary-Delta is a complex aquatic and terrestrial associated environment containing a diversity of organisms that must be protected from anthropogenic contaminants and habitat destruction; and over time improved,” explains Ken Hall.
“If not managed properly, our point (sewage treatment plants, combined sewer overflows, industrial discharges) and non-point discharges (rainwater runoff) contain a variety of contaminants that can affect the health of this natural environment.”
“Dilution due to the large flow of the Fraser and the mixing with the diurnal tides in the estuary are usually effective in diluting discharges below toxicity thresholds. However, the mobility and bioavailability of persistent contaminants creates problems when these materials can magnify in food chains and accumulate in organisms over time.”
Metro Vancouver's Commitment
“The Liquid Waste Management Plan approved in 2002 included a commitment by Metro Vancouver to undertake an extensive monitoring programme to characterize discharges and determine their impacts on the aquatic environment. Millions of dollars have been spent on this program and the results provide an exceptional database on discharge quality and impact in the immediate discharge area of the outfall.”
“The current Cautions, Warnings, Triggers Process evaluates these monitoring data in relation to regulations and reference stations to determine if more detailed monitoring is required or if mitigation measures are necessary.”
“Also, a cooperative program in association with the Institute of Ocean Sciences (IOS) has been conducting research to document contaminant distribution in the Strait of Georgia and develop an understanding of the processes that regulate the mobility and bioavailability of these contaminants.”
About the Institute of Ocean Science
Located west of Sidney on Vancouver Island on a 70-acre site, the Institute of Ocean Sciences is one of Canada’s largest marine institutes. An important link in Fisheries and Oceans Canada’s nationwide chain of nine major scientific facilities, the institute is 
the centre for research on coastal waters of BC, the Northeastern Pacific Ocean, the western Canadian Arctic and navigable fresh waters east to the Alberta border.
The Institute of Ocean Sciences has earned international recognition for its work in ocean sciences. IOS has become a major player in efforts to restore and manage coastal ecosystems, and produces more than 20 per cent of Canada’s nautical charts.
Research Findings
A recent publication titled “Benthic Processes, Organic Carbon Cycling and Contaminants in the Strait of Georgia, Canada” – in Marine Environmental Research 66: S1-S120 (2008) summarizes the research from this program.
Poor health of keystone species is of concern
The concern is that the Strait of Georgia ecosystem is not healthy and contaminant discharge may be an important factor in the poor health of many “keystone species”. A five year update report published as part of the Georgia Basin Action Plan (2003-2008) states that:
- “In 2001, it was declared that the southern resident killer whale population had the unwelcome distinction of being the world’s most contaminated marine mammals. Levels of contaminants in these local whales exceeded even those of the St. Lawrence River’s beluga population.” – page 26
- “marine foraging river otters near Victoria have elevated levels of polychlorinated biphenyls (PCBs),” – page 24 -25
- “increased area of commercial shellfish closure between 1989 to 2004” – figure on page 18.
“These documented impacts on predators at the top of the food chain (killer whales, otters) and shellfish (filter feeders that can concentrate trace contaminants) generate concern that persistent contaminants and their cumulative effects are a threat to the long-term health of this aquatic environment,” states Ken Hall.
Continuing Research Needed
According to Ken Hall, “Continuing research is necessary to obtain better information on these detrimental impacts and take necessary steps to manage contaminant discharge.”
Research will be moving in the right direction if…..
In commenting on the objectives and context for proposed research by IOS in the next phase of the LWMP as submitted to Metro Vancouver in their January 2009 presentation to the Environmental Monitoring Committee, he observes that this research “is moving in the right direction if they can answer questions such as these two”:
- How do outfall contaminants get stored and cycle through the benthic food chain and get transferred to the pelagic food chain?
- What are the critical levels of organic and/or contaminants loadings which will cause broad-scale damage to biota in the Georgia Strait?
“The ultimate question is can we get this information soon enough to make decisions to protect and ultimately improve the ecosystem of the Lower Fraser and Strait of Georgia,” concludes Ken Hall.
Posted August 2009