Testing for Bacteria in Local Waterways For many years, Baykeeper volunteers sampled water quality before and after “First Flush,” the first major storm in the fall, to study the levels of various pollutants in stormwater. In 2010, Humboldt Baykeeper submitted five years of data to support designating six streams (Janes Creek and Campbell Creek in Arcata, Little River and Widow White Creek in McKinleyville, and Martin Slough and Elk River in Eureka) as impaired by bacteria. In 2015, these streams were added to the Clean Water Act’s Section 303(d) list of impaired waters, compelling the state to take action to restore and protect water quality. In 2012, we shifted our focus to bacteria pollution, since our results showed consistently high levels of fecal bacteria in most streams. But the sources that pollute stormwater have been difficult to identify, since traditional lab methods can’t distinguish bacteria from different host animals. In 2015, the Regional Water Board began a study of dozens of North Coast streams to identify the sources of bacteria pollution. The Humboldt and Sonoma County Public Health Labs developed methods for quantifying genetic markers for gut bacteria from human, dog, bird and ruminants such as cattle, deer, and elk. That same year, Humboldt Baykeeper began focused studies of Little River and Janes Creek to search for hotspots of bacteria pollution. Our findings point to cattle as the primary source along Little River, with one exception: a tributary from Westhaven contained human bacteria during a major rainstorm, suggesting that at least one septic system is failing in that area. Our study was folded into the Regional Water Board study, which was completed in 2019. The draft reports have yet to be finalized and released to the public.
In February 2020, we began a study focused on Jolly Giant Creek in Arcata, hoping to pinpoint the sources of human bacteria identified in the 2019 study. This research was interrupted by the COVID-19 pandemic after just one sampling event. The Regional Water Board took over that study in April 2020, and sampling is ongoing. Bacteria pollution is well-known among oyster farmers, who sample North Bay (Arcata Bay) regularly during dry weather to ensure that raw oysters are safe to eat. But during rainstorms, oysters cannot be harvested due to high bacteria levels in stormwater ending up in the bay. Studies in the 1990s pointed to stormwater runoff as the source, and yet here we are, still studying the problem all these years later.
In 1972, the Clean Water Act passed with the goal of cleaning up all of the nation’s waterways by the mid-1980s. Significant progress has been made to reduce point-source pollution, but cleaning up non-point sources that cause stormwater pollution has been more difficult. Until state agencies find the political will to implement solutions like fencing cattle out of riparian areas, bacteria pollution will continue to affect coastal streams like Little River as well as Humboldt Bay with every rainstorm. For more info, visit the Water Quality Program section of the Baykeeper website. The County’s ocean monitoring results are available HERE.