q̓ʷətəms t̓ɩšosəm (Sliammon Creek) 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 dry (summer) season sampling carried out with the support and participation of the Tla’amin Nation and Pacific Salmon Foundation. 

Briefly, the Healthy Waters team collected water samples on September 19, 2024, from three water categories, including source water (3 samples), river water (3 samples), road runoff (3 samples), and marine water (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 69 contaminants out of 587 measured in the stream and river category – i.e. fish habitat – for the in q̓ʷətəms t̓ɩšosəm (Sliammon River), excluding nutrients, fecal coliform and physical parameters. Overall, the q̓ʷətəms t̓ɩšosəm (Sliammon River) watershed had relatively good water quality in the dry season, but additional sampling and analysis will provide further insight into contamination impacts from forest fires, domestic wastewater, and road runoff on the health of this valued watershed.

The q̓ʷətəms t̓ɩšosəm (Sliammon River) Watershed

Key findings

• This assessment of water quality in the q̓ʷətəms t̓ɩšosəm (Sliammon Creek) watershed reflects the second of four site visits.
• We collected and analysed water in the q̓ʷətəms t̓ɩšosəm (Sliammon Creek) watershed during the dry season (December 11, 2024).
• Marine water was the most contaminated water category in the wet season; it had the highest concentrations of bisphenols, metals, nitrate, PAHs, PPCPs and sucralose.
  • It was also the most contaminated water category during the dry season.
• The road runoff sample was the second most contaminated and had the highest concentrations of E coli, PFAS and pesticides.
  • It was also the second most contaminated water category during the dry season.
• The stream and river water sample had the highest concentration of 6PPDq and PCBs
• Source water was the least contaminated water category in the wet season as opposed to the source sample during the dry season.
• Overall, the (Sliammon Creek) watershed had relatively good water quality in the wet season:
  • There were eight exceedances of Canadian Environmental Quality Guidelines
  • Exceedances included:
    • Aluminum and total PCBs for the source water;
    • Aluminum for the stream and river;
    • Aluminum, copper and iron for the road runoff water;
    • Boron and copper for the marine water.

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. 

The Tla’amin Nation is situated just north of the city of Powell River in British Columbia, and is part of the Northern-most Coast Salish ʔayʔajuθəm speaking peoples. The Tla’amin people today inherited rich territories and teachings (ta-ow) stretching back well over 10,000 years. 

Tla’amin economic and political systems along with the spirituality of its people and is derived from the close relationship with the land.

The Tla’amin territory spans along the northern part of B.C.’s Sunshine Coast, extending down both sides of the Strait of Georgia, occupying an area over 400 square kilometers in size. This consists of numerous permanent and temporary settlements. Tla’amin people also frequently traded with their neighbours up and down the coast.Today, the community has almost 1,200 members, with the majority living in the main village site t̓išosəm (‘milky waters from herring spawn’).

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.