Don Jenkins/EO Media Group
Farm animals, wildlife, humans and pets are presumably polluting shellfish beds with fecal matter, and a Seattle company has been hired to rank the sources of bacteria in two bays.
Herrera Environmental Consultants signed a $200,000 contract last week with the Washington State Conservation Commission. Over the next year, the company and its partners will analyze the DNA of fecal bacteria in a pair of contaminated bays in Puget Sound.
Herrera’s project manager, Rob Zisette, said Friday the results should identify the species polluting the bays and their relative contributions. It’s unlikely the tests they will produce exact percentages. “Ideally that’s what you’re going to get, but realistically, no,” he said.
Tracking the source of fecal bacteria is an experimental and expensive technology, but one whose supporters say could help clarify the land-use practices that need the most attention in a watershed. State lawmakers authorized the grant.
The conservation commission says the results should inform clean-up measures such as repairing septic tanks, cleaning up after pets or managing livestock.
Currently, the Department of Ecology does not use the technique, called microbial source tracking. The department points to its experimental nature and cost.
Ecology’s special assistant on water quality, Kelly Susewind, said people look to DNA testing to precisely sort out pollution sources. “People ask, ‘How do you know it’s me?’” he said. “It’s a legitimate desire.
“I think people are looking for a silver bullet,” Susewind said. “We aren’t quite there yet.”
Herrera’s project faces budget and scientific limits. Still, Zisette, said he hopes it will show Ecology and other agencies that it’s useful in finding problems.
Herrera has tested Washington waters before to identify the sources of fecal coliform. According to a 2007 report from Ecology, Herrera found bovine fecal material was dominant at midstream and downstream stations in the Willapa River in Pacific County.
Zisette said he presented the results to livestock owners and that they welcomed the evidence, rather than conjecture.
In its proposal, Herrera listed Rocky Bay, Vaughn Bay, Filucy Bay and Burley Lagoon as possible places to test water. The budget will allow for testing at two of them, Zisette said. The two have not been picked.
The plan is to take 11 water samples from 12 sites in two bays. Each sample will be tested for up to five species. The cost limits the sampling.
The DNA for humans and animals such as cows, pigs, horses, dogs, chickens, geese and gulls can be identified. There’s also the ruminant category, a classification that Zisette said he doesn’t like because it doesn’t distinguish between sheep, goats and deer.
The project is scheduled to be done by June 2019.