The Blue Water Task Force (BWTF) provides essential water quality information to protect public health at beaches. This volunteer-based water testing program, run by Surfrider chapters, raises awareness of local pollution issues and fosters community-driven solutions. BWTF labs measure fecal indicator bacteria levels in recreational waters and compare them to water quality standards designed to protect public health. These chapter-run programs supplement and extend the coverage of agency-run beach monitoring programs by sampling ocean and bay beaches, as well as potential freshwater sources of pollution such as stormwater outlets, rivers, and creeks that discharge onto beaches. While the enterococcus test results that both the BWTF and local health departments perform provide a measure of recreational water safety and indicate how much fecal pollution may or may not be in a waterbody, they do not provide information on what the source of that pollution might be - bird, humans, dogs, or other warm-blooded animals. Further testing and investigation is required to hone in on the sources of pollution so those problems can be resolved in coastal watersheds.
The Ventura County BWTF focuses on filling the gaps left by Ventura County’s Ocean Water Quality Monitoring Program, particularly during winter when they scale back testing and surfers flock to the water for the west swells that light up the local points and beach breaks. Surfers’ Point undergoes weekly water testing by Ventura County BWTF from November through March. During the 2022-2023 sampling season, a concerning 30% of the samples from Surfers’ Point failed to meet state water quality standards for enterococcus in recreational waters. In response, a pollution source tracking project was initiated at Surfers’ Point in March 2023 by Ventura County BWTF to identify the primary sources of pollution. Initial findings suggest cows, humans, swine, and dogs as the most consistent contributors to the bacteria counts. Continued monitoring by the Ventura County BWTF has revealed ongoing high bacteria levels at Surfers’ Point, as evidenced by the 28% of water samples collected in the 2023-2024 sampling season failing to meet health standards.
This year, the Ventura County BWTF performed source tracking DNA testing to investigate the source of pollution that has been affecting another popular surf spot - Rincon Point. Located just 20 miles up the coast from Surfers’ Point on the Santa Barbara County border, the County of Ventura Resource Management Agency reported elevated bacteria counts exceeding state standards at this beach in May 2023, during dry weather, warning that the water was unsafe for entry. In the late 90s, Surfrider and Heal the Ocean addressed septic tank leaks from homes in the Rincon Point watershed; however, not all homeowners participated and there is concern that fecal contamination is ongoing.
STUDY DESIGN
To address this concern, the Ventura County BWTF collected water samples in February and April, 2024 at Rincon Point and in Rincon Creek that discharges into the Pacific Ocean near Rincon Point. Samples from both sites were analyzed for enterococcus bacteria at the Ventura County Chapter’s BWTF lab, and samples collected at Rincon Point were also sent for DNA testing to Jonah Ventures, a company specializing in tests that screen for specific animal DNA. This type of testing can identify species contributing to bacteria counts, including human, dog, bovine, poultry, and horse.
The upland watershed of these two sites contains residential homes, fruit orchards, and a commercial medical manufacturing area. While out collecting samples, the BWTF volunteers reported that Rincon Creek was turbid and smelled strongly like sulfur.
RESULTS
The bacteria testing conducted by the chapter revealed that all samples, except one sample collected at Rincon Point on 4/30/24, exceeded the enterococcus-based state health standards for recreational waters. Levels that exceed 104 Most Probable Number (MPN) of colony forming units (cfu) per 100 ml seawater are considered unsafe for human health/recreational exposure.The data is summarized in Table 1. below.
Table 1. Enterococcus test results from samples collected from Rincon Point and Rincon Creek.
Table 2. Source tracking test results from Rincon Point. Results presented in average number of DNA copies per 100 ml water.
The Jonah Ventures source tracking test results from three sampling events at Rincon Point (Table 2) provide insights into potential sources of contamination. Light levels of human DNA were detected during every sampling event, indicating ongoing human presence and potential contamination sources in the area. Additionally, on 2/21/24, light levels of swine DNA were also detected.
Nearly all of the samples collected by the chapter from both Rincon Creek and Rincon Point measured high levels of enterococcus that exceeded the health standard (Table 1). These bacteria results indicate a public health risk from fecal contamination but do not provide information on the source of pollution on their own. The consistent light signal of human DNA in the source tracking testing (Table 2) suggests the need for further investigation into the sources of human-related contamination, such as sewage leaks or runoff. However, it is worth noting that the human marker DNA gave a much stronger signal in the previous study performed at Surfer’s Point in 2023. This might indicate that, in addition to humans contributing to the high enterococcus results at Rincon Point, other warm-blooded animals not covered by Jonah Ventures DNA testing could also be influencing the enterococcus fecal indicator bacteria levels. The low level of PPMoV found on 2/21/24 suggests that there may be some presence of human waste, but not substantial enough to provide a conclusive indication of significant human impact.
This study sheds light on the complex nature of contamination sources in coastal environments. While there is evidence of human-related contamination, the possible influence of other animal sources on bacteria levels underscores the need for comprehensive monitoring and investigation efforts. This highlights the ongoing importance of BWTF programs in ensuring the preservation of water quality and public health for coastal communities.
Visit the Blue Water Task Force website for updates on water quality in your area, and don’t forget to check out the 2023 Clean Water Report!