Improving water quality through California’s Clean Beach Initiative: an assessment of 17 projects

Abstract

California's Clean Beach Initiative (CBI) funds projects to reduce loads of fecal indicator bacteria (FIB) impacting beaches, thus providing an opportunity to judge the effectiveness of various CBI water pollution control strategies. Seventeen initial projects were selected for assessment to determine their effectiveness on reducing FIB in the receiving waters along beaches nearest to the projects. Control strategies included low-flow diversions, sterilization facilities, sewer improvements, pier best management practices (BMPs), vegetative swales, and enclosed beach BMPs. Assessments were based on statistical changes in pre- and postproject mean densities of FIB at shoreline monitoring stations targeted by the projects. Most low-flow diversions and the wetland swale project were effective in removing all contaminated runoff from beaches. UV sterilization was effective when coupled with pretreatment filtration and where effluent was released within a few hundred meters of the beach to avoid FIB regrowth. Other BMPs were less effective because they treated only a portion of contaminant sources impacting their target beach. These findings should be useful to other coastal states and agencies faced with similar pollution control problems.

Evaluation of the dry and wet weather recreational health risks in a semi-enclosed marine embayment in Southern California

“…During dry weather condition, which is defined as no rain event occurring within the 72 hours prior to the sampling date, two scenarios were considered: Scenario 1) storm drain runoff is diverted to a sanitary sewer with close-to-zero discharge from storm drain to the beach water (April 1 st to October 31 st , n=117), and Scenario 2) storm drain runoff is not diverted, but filtered by media filter vault and discharged to the Baby Beach recreational shoreline (November 1 st to March 31 st , n=71). Scenario 1 represents that of the dry season in California, defined as the period from April 1 to October 31 annually following the definition adopted by the California AB411 legislation (Dorsey 2010). During this season, rainfall events are rare; the beach water is warmer and attracts the highest number of beachgoers.…”

“…During this season, rainfall events are rare; the beach water is warmer and attracts the highest number of beachgoers. Due to the small size of the Baby Beach watershed, virtually all dry weather runoff (max=1.14 m 3 /day) generated in the watershed and received by the stormwater drains has been effectively diverted to the neighboring wastewater treatment plant since 2005 (Dorsey 2010). The dry weather runoff from storm drains to the beach is nonexistent or insignificant.…”

“…In principle, the SA-QMRA framework can also account for how runoff from separate storm sewer systems is locally managed. For example, at many coastal sites in Southern California, dry weather runoff is diverted to wastewater treatment plants with documented benefits for coastal water quality (Dorsey 2010). In addition to providing a more tailored approach for assessing RWI risk and public water quality notifications, the SA-QMRA approach can enable scenario testing, for example to assess how health risks might change under different mixes of human and non-human fecal sources, different FIB-to-pathogen ratios, or a changing climate.…”

Comparison of stormwater biofiltration systems in Southeast Australia and Southern California

“…Under the 2009‐0009‐DWQ Construction General Permit, stormwater runoff originating in new developments in California was recognized as point source pollution and regulated under the Clean Water Act. The Clean Beach Initiative, a fund under California's SWRCB, provided funding to projects aimed at reducing fecal indicator bacteria (FIB) loads to California's beaches from urban runoff . Stormwater biofilters were suggested as a best management practice (BMP) to preserve drainage in urban areas and prevent FIB from reaching beaches.…”

Comparison of methods for the detection of coliphages in recreational water at two California, United States beaches

“…Doheny Beach and Avalon Beach each have a history of beach closures due to high concentration of FIB. At Doheny Beach, the primary source of water quality impairment is non-point source fecal contamination (Dorsey, 2010). Four sampling stations were located linearly along Doheny Beach where marine water samples were collected.…”