In 2008, Lopez based non-profit Kwiaht conducted a well-crafted survey to discover if household-use pesticides or surfactants have accumulated in surface water or sediments in measurable amounts, and whether they may already pose a threat to salmon and other aquatic organisms in San Juan County.

The Common Sense Alliance also performed a survey for pesticides, herbicides, metals and phthalates in soils and surface water in SJC. Their study sampled only four sites and may have used less sensitive tests. Many chemicals are toxic at parts per billion (ppb), some even in the parts per trillion range. Their study found all results to be well within the “background” range for all compounds, except zinc.

Kwiaht sampled 32 sites throughout the county and found that 69 percent of the sites tested positive for pyrethroid pesticides at levels of 1-2 ppb. Pyrethroids have low mammalian toxicity, but are extremely toxic to fish and organisms that form the base of the nearshore food chain. Levels of less than 2 ppb are toxic to salmon; therefore, it can be stated, with confidence, that pesticides at levels that threaten salmon are already widespread in our waters.

Surfactants are widely used as emulsifiers. They were detected in all 32 sites at an average level of 570 ppb, which just exceeds EPA drinking water standards. Nonylphenol, a breakdown product of surfactants, is toxic to humans and aquatic wildlife, including salmon. The main San Juan County sources for both surfactants and pyrethroids are outdoor use and runoff.

The Kwiaht study convincingly demonstrates that we have a chemical surface runoff problem that can kill salmon, affect their ability to avoid predation, even at very low chemical levels, and threaten their nearshore food sources.

Common Sense Alliance has asked: Where is the problem? The answer: It’s here, all around us.

San Olson

Lopez Island