Following the November 2021 floods, a “staggering diversity” of pollutants, including cocaine and pesticides, were found in the Sumas Lake area, according to a new report.
The findings raise “fundamental questions about the health of fish and human habitats,” said the Rain Coast Conservation Foundation, which led a seven-week study of water samples collected from Dec. 15 to Feb. 2, 2021. Research, 2022.
The report, “Lake Reappearance: Contaminant Analysis of the Sema:the Xo:tsa (Sumas Lake) Region After the 2021 British Columbia Flood,” was presented Thursday (November 17) in Abbotsford Submit to Sumas First Nation.
The former Sumas Lake, located on the Sumas Prairie, is flooded beginning November 15, 2021. The lake, which measures 80 square kilometers, was drained by the Barrowton Pumping Station in 1924, but was refilled during the disaster.
The lack of pre-disaster data makes it difficult to determine the full impact of the flooding on water quality, Raincoast said in a release, “but in this study, the deteriorating health of the Sumas fish habitat became evident.”
“Levels of fecal coliform were 641 times higher than the upstream reference point, 135 times higher for pesticides, 60 times higher for pharmaceuticals, 43 times higher for nitrogen, 19 times higher for phosphorus, and 7 times higher for hydrocarbons,” Raincoast said.
The group said it found 177 “emerging contaminants” and “widely detected” cocaine, painkillers and pesticides.
The study identified excess nutrients, metals, hydrocarbons and pesticides as the main pollutants, “underscoring the impact of household and farming practices on fish habitat in the region.”
Other contaminants found included fecal coliform bacteria, pharmaceuticals, personal care products, perfluorinated compounds, sucralose and tire-related chemicals, the report said.
A total of 29 surface water samples were collected from 11 locations, 10 from the former Sumas Lake and 1 from the upper Frossst Creek near Cultus Lake. A total of 379 analytes (chemical constituents and bacteria) were examined, including 262 anthropogenic pollutants (not found in nature).
Raincoast said it detected an average of 87 analytes per sampling site, 20 of which were anthropogenic chemicals not found in nature.
“During the study period, environmental quality guidelines were exceeded 59 times in the surface water samples, indicating that fish habitats in the Semá:th X̱ó:tsa region are severely degraded by multiple pollutants,” the organization said.
The report’s lead author and director of Raincoast’s Healthy Waters Program, Peter Ross, said the flooding has drawn attention to “significant gaps” in environmental monitoring of Sumas Lake and fish habitat in general.
“Our report reveals a collective failure to protect water and fish habitats from pollution from multiple activities in British Columbia. We hope these findings will contribute to innovation, management and support for green infrastructure that protects communities and fish habitats.” collective investment,” he said.
Key findings of the study include:
• Water quality in the Sumas Lake area is poor despite flooding, agricultural and domestic activities have degraded the water quality.
• Fish are exposed to high levels of metals, pesticides and other pollutants of concern and low levels of dissolved oxygen.
• High nutrient levels, likely from agricultural and domestic sources, and slow-moving waters from barriers and flood protection structures, which may result in low dissolved oxygen levels;
• The lack of riparian buffers at the edges of streams, rivers and canals in the Fraser Valley means that nutrients, pesticides and other pollutants can easily wash into fish habitat during rainfall and flooding.
• Salmon are exposed to a variety of human activities and pollutant emissions during migration, the cumulative effects of which are unknown;
• Limited and inconsistent monitoring of water quality in British Columbia limits our ability to understand and manage risks associated with land use practices and chemical use;
• The impact of climate change on the water quality and quantity of British Columbia’s fish habitats is uncertain, and we do not have the ability to predict, understand and protect future fish habitats.and
• Sustainable land use that protects and restores fish habitats will benefit from innovative and shared approaches that invest in resilient infrastructure and nature-based solutions.
The research was led by Raincoast with support from the Lower Fraser Fisheries Alliance, S’ólh Téméxw Stewardship Alliance, Sumas First Nation, Pacific Salmon Foundation, Fisheries and Oceans Canada, and BC’s Ministry of Environment and Climate Change Strategy.
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