Snohomish County conducted water quality monitoring from April 2014 – February 2015 at nine sites (PDF) within the Lower Stillaguamish River Basin study area. Monitoring followed the Water Quality Monitoring Quality Assurance Project Plan (PDF). The results are shown in the map below.
While none of the nine sampling locations met water quality standards for fecal coliform bacteria, two showed such poor conditions that the county and partners began additional samplings and efforts to remove upstream sources. The highest priority area was the Larson Road tributary (see map), where greater than 75 percent of fecal coliform samples exceeded standards. As a result, state and local partners began working with upstream property owners to remove manure piles generated by a large horse breeding facility and implement better pasture management practices to reduce fecal coliform levels flowing into the Stillaguamish River.
The Sunday Lake Creek Down site was the next highest priority (see map) for upstream pollution identification. Although additional upstream sampling did not isolate sources, the county also conducted a field survey of the Sunday Lake shoreline and surrounding area to identify potential pollution sources by walking, boating, and driving around the area. The survey resulted in coordination with the county LakeWise Program, outreach to residents, and plans for additional field work in 2015.
For further information about the water quality monitoring portion of the Lower Stilly PIC Program contact Steve Britsch, Principal Water Quality Investigator at 425-388-3464, ext. 4668 (email).