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City of SB's Creeks Pollution Brochure Incorporates Holden Lab Research

Santa Barbara, CA — Bren professor and microbiologist Patricia Holden has spent several years conducting research and developing new techniques to track and mitigate fecal bacteria in Santa Barbara's storm drains, streams and coastal waters. Her lab group's findings are now summarized in a 16-page booklet titled "Tools for Tracking Human Fecal Pollution in Urban Storm Drains, Creeks, and Beaches." It was put out in partnership with the City of Santa Barbara, Creeks Division, to serve as a guide to prevention and mitigation.


Patricia Holden collects water samples from a Santa Barbara creek.

"We want our researth in this area to make a difference to on-the-ground managers," Holden says. "Thus, although we have published journal articles from the work, it has been a goal also to broadly disseminate what we learned so that others can benefit without having to completely reinvent approaches. Of course, partnering with the City of Santa Barbara, in particular Dr. Jill Murray, who produced this guidance document out of the final project reports and from her work in the city, has made it possible for us to achieve endpoints that are both basic and applied."

The brochure brings together research from three projects undertaken during a three-year period in collaboration with the Creeks Division, with funding from the Switzer Foundation Leadership Program supplementing that from the State of California Clean Beaches Program and Measure B, which raises money through the Santa Barbara hotel bed tax for local creek cleanup and restoration. 

Some of the work involved capacity building to conduct the research and disseminate new information.

"Methods for addressing human pollution in the urban environment keep improving," Holden says, "and through successive projects we have been recruiting scientists, applying our findings, and communicating continuously what we learn."

She explains that the main public health concern, particularly to those who are swimming or fishing in affected waters, is fecal indicator bacteria (FIB) from human waste. But FIB can also come from animals, which do not constitute a health threat to humans, so tools are needed to determine if human waste is responsible for high FIB counts so that managers can effectively direct their remediation investments.

A technological breakthrough occurred when others developed DNA-based markers of human waste, which can be quantified in water samples through laboratory analysis. Holden's team is using some state-of-the-art DNA-based markers that are specific to human waste. They have also found that canine-scent tracking is useful in surveying for the presence of sewage in drains and, potentially, creeks in large areas. If the dogs indicate the presence of FIB, followup testing with the more expensive DNA-based markers, and also sewage chemicals, is used to confirm and quantify FIB pollution.