Painkillers, pesticides, and cocaine among the contaminants found in Fraser Valley floodwaters in late 2021

Synthesis report cover: A lake re-emerges: Analysis of contaminants in the Semá:th X̱ó:tsa (Sumas Lake) region following the BC floods of 2021.
Photo by Alex Harris / Raincoast Conservation Foundation.

Abbotsford, BC –  The widespread contamination of the waters of the Lower Fraser Valley is detailed in a new report, A lake re-emerges: Analysis of contaminants in the Semá:th X̱ó:tsa (Sumas Lake) region following the BC floods of 2021. The study, presented to Sumas First Nation on November 17th, documented an astounding diversity of contaminants including excess nutrients, metals, fecal coliform, hydrocarbons, pesticides, pharmaceuticals and personal care products, perfluorinated compounds, sucralose and tire-related chemicals in fish habitat. 

Following the catastrophic floods of late 2021 in southern British Columbia and neighbouring Washington State, Raincoast Conservation Foundation, with their partners, took samples of water in the former Semá:th X̱ó:tsa (Sumas Lake) area over a seven-week period. 29 surface water samples were collected, and 379 analytes were examined, including 262 anthropogenic contaminants. 

An average of 87 analytes were detected at each sample location, of which 20 were anthropogenic chemicals not found in nature. There were 59 exceedances of Environmental Quality Guidelines among the surface water samples during our study, suggesting that fish habitat in the Semá:th X̱ó:tsa region is heavily degraded by multiple contaminants. The study identified excessive nutrients, metals, hydrocarbons, and pesticides as being the primary pollutants of concern, underscoring the impacts of domestic and agricultural practices on the fish habitat that permeates the area.

While no Environmental Quality Guidelines are available to interpret the 177 new and emerging contaminants in this study, the widespread detection of cocaine, painkillers, and pesticides raises fundamental questions about the health of an area that is home to both fish and people.

The lack of baseline data from before the floods makes it difficult to determine the extent to which the 2021 disaster may have impacted water quality, but the degradation in the health of Sumas fish habitat became clear during this study. Levels of fecal coliform were 641 times higher than the upstream reference site, pesticides were 135 times higher, pharmaceuticals were 60 times higher, nitrogen was 43 times higher, phosphorus was 19 times higher, and hydrocarbons were 7 times higher.

“The former Semá:th X̱ó:tsa was once relied upon by our ancestors and provided many of the resources required to sustain our people. The November 2021 flood event demonstrated that the spirit of the X̱ó:tsa is alive and well and that we must learn to harmonize with Mother Nature today,” said Murray Ned, Executive Director of the Lower Fraser Fisheries Alliance (LFFA).

The floods brought attention to a notable deficiency in environmental monitoring in the Semá:th X̱ó:tsa and in BC fish habitat in general, and exposed the extent of degraded fish habitat in the Fraser Valley. 

“Our report reveals a collective failure to protect water and fish habitat from contamination arising from multiple activities in BC. It is our hope that these findings contribute to innovation, stewardship and collective investment in green infrastructure that protects both communities and fish habitat,” said toxicologist Peter Ross, the report’s lead author and Director of the Healthy Waters program at Raincoast. 

This study was led by Raincoast Conservation Foundation, and made possible by the support of the Lower Fraser Fisheries Alliance, the S’ólh Téméxw Stewardship Alliance, Sumas First Nation, Pacific Salmon Foundation, Fisheries and Oceans Canada, and the British Columbia Ministry of Environment and Climate Change Strategy.

Key findings from the study

  1. Water quality in the Sumas Lake area is poor, regardless of flooding, having been degraded by agricultural and domestic activities;
  2. Fish are exposed to high levels of metals, pesticides, and other contaminants of concern, and lower levels of life-giving dissolved oxygen;
  3. High nutrient levels, likely from agriculture and domestic sources, and slow moving waters from barriers and flood control structures, are likely contributing to low dissolved oxygen levels;
  4. The lack of riparian buffer zones along the edges of streams, rivers and canals in the Fraser Valley means that nutrients, pesticides and other contaminants wash easily into fish habitat during rainfall and flooding events;
  5. Salmon are exposed to various human activities and pollutant discharges along their migratory journey for which the cumulative effects are not well understood;
  6. Limited and inconsistent monitoring of water quality in BC constrains our ability to understand and manage risks associated with land use practices and chemical uses;
  7. The consequences of climate change on water quality and water quantity in fish habitat in BC are uncertain, and we are poorly equipped to predict, understand and protect fish habitat into the future;
  8. Sustainable land use that protects and restores fish habitat will benefit from innovative and shared approaches to investments in resilient infrastructure and nature-based solutions.