Ta’talu watershed: Water quality report for the 2024-25 wet season

Executive summary

Water is essential for life, and steps are needed to understand, protect and restore its health in fish habitat throughout British Columbia. The Raincoast Healthy Waters program was launched in 2023 to establish community-oriented water pollution monitoring in select BC watersheds. Two Healthy Waters sampling events take place every year in each watershed – the first in the dry season (summer), and the second being in the wet season (winter). This report highlights results from the first wet (winter) season sampling carried out with the support and participation of the Semiahmoo First Nation. 

Briefly, the Healthy Waters team collected water samples on November 14, 2024, from three water categories, including marine water (3 samples), river water (3 samples), road and runoff (3 samples). The samples were pooled into composite by category and then analysed for coliform, nutrients (6), physical parameters, metals (37), pesticides (62), polycyclic aromatic hydrocarbons (PAHs; 76), pharmaceuticals and personal care products (PPCPs; 141), polychlorinated biphenyls (PCBs; 209), alkylphenol ethoxylates (APEs; 4), bisphenols (BPs; 6), per- and poly-fluoroalkyl substances (PFAS; 40), and sucralose. Analysis of 6PPD-quinone is pending.

We detected 158 contaminants out of 577 measured in the stream and river category – i.e. fish habitat – in Ta’talu, excluding nutrients, fecal coliform and physical parameters. Overall, the Ta’talu watershed had relatively good water quality in the wet season, but additional sampling and analysis will provide further insight into contamination impacts from forest fires, domestic wastewater, industrial chemicals and road runoff on the health of this valued watershed.

The Ta’talu Watershed

Key findings

• This preliminary assessment of water quality in the Ta’talu watershed reflects the first of four site visits; our understanding of water quality in these watersheds will grow with additional sampling over the coming two years (2025-26).
• We collected and analysed water in the Ta’talu watershed during the wet season (November 14, 2024).
• Marine water was the most contaminated water category in the wet season; it had the highest concentrations of nitrate, metals, PCBs, APEs, and bisphenols.
• The stream and river sample was the second most contaminated and had the highest concentrations of E. coli, PPCPs, MRES pesticides, and sucralose. 
• The road runoff water sample had the highest concentrations of PAHs and PFAS.
• Overall, the Ta’talu watershed had relatively good water quality in the wet season:
  • There was one exceedance of Canadian Environmental Quality Guidelines in the aluminum concentration detected in the marine sample.
  • All three categories of water sampled exceeded the BC Water Quality Guideline for Total PCBs (100 pg/L).

Background

Raincoast’s Healthy Waters Program (www.raincoast.org/waters/) delivers high-resolution, community-oriented water quality analysis to watersheds across southern British Columbia. The goal of Healthy Waters is to empower communities with the understanding of the status of water quality in their watersheds, to allow for local stewardship regarding both point and nonpoint source pollution. 

Pacific Ocean Discovery Station (PODS) is an initiative of the Loon Foundation. The Loon Foundation is a registered charity that was founded in 2002 (as the Ruby Lake Lagoon Nature Reserve Society). Their mission is to ignite connections between people and the natural world, encourage responsible stewardship of natural resources for future generations, and to provide facilities and programs for environmental education, arts and cultural exploration, scientific research, and ecological monitoring.

A watershed based approach to sampling

We collect samples from five different categories of water in each of our partner watersheds: from source water, upstream of human impacts, down to the marine environment. 

Source water serves as an upstream reference sample, allowing us to determine which contaminants are being introduced as water traces its path down through the watershed. 

Stream and river samples allow us to investigate the quality of fish habitat directly, by collecting samples from streams, creeks, and rivers used by salmon and other fish species (either currently or historically). 

Road runoff serves as an impacted sample category of current concern, as many contaminants, including  PAHs, metals, surfactants and chemicals such as 6-PPD quinone can be washed off roadways and into fish habitat during rain events. 

We include tap water samples in our analysis as a way to bring our homes into the conversation – we borrow water from the environment in the form of municipal or well water, and generally return it to aquatic habitats in a more-degraded state in the form of storm and sewage effluent (treated or untreated).

Marine water samples provide insight into those contaminants that may degrade fish and whale habitat in the ocean, and enable an understanding of the contribution of land-based pollutants from the adjacent watershed to the marine environment.

Collectively, the lessons learned from our partnering watersheds will contribute to a greater understanding of threats to water quality across British Columbia, and ultimately what policy changes can be implemented to preserve the quality of water for the future of salmon, whales, and people.

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