Areas of Special Biological Significance (ASBS) are areas designated by the California State Water Board that include marine life refuges, ecological reserves, and designated areas where the preservation and enhancement of natural resources requires special protection. These protections prevent discharges of waste, including stormwater. In 2012, revisions to the California Ocean Plan required stormwater dischargers in ASBS to fulfill new monitoring requirements.

After participating in statewide ASBS public scoping meetings in 2006, AMS worked closely with ASBS stormwater dischargers in Central California to negotiate monitoring requirements with State Water Board staff, within the limits of the State regulations. Participants in the Central California regional program included County of Monterey, Pebble Beach Company, City of Carmel-by-the-Sea, City of Pacific Grove, City of Monterey, County of San Mateo, County of Marin, and Caltrans. AMS field teams collected 164 samples across 33 stormwater outfalls and 11 reference sites between 2013 and 2016. Field teams included AMS personnel and subcontractors with all personnel receiving training to ensure that samples were not contaminated by improper handling in the field.

Data from storm ocean samples that exceeded the pre-storm concentrations were compared to the 85th percentile of reference values and the California Ocean Plan to determine whether the storm discharge adversely affected ocean water quality. A final report was produced that provided a complete analysis and interpretation of results with an emphasis on statistical procedures that could more precisely establish cause-and-effect relationships between stormwater discharges and changes in ocean water quality during storms.

Across all program participants, 33 stormwater outfalls were sampled. Stormwater discharges from 23 smaller outfalls (18–36 inches) were sampled only during storms for oil and grease, total suspended solids, fecal coliforms, Enterococcus, E. coli. At 10 larger outfalls (>36 inches) ocean samples were collected pre-storm, followed by samples of ocean and stormwater discharge were collected during storms. Stormwater discharges from these larger outfalls were analyzed for the same constituents as the smaller outfalls, with addition of trace metals, urea, urchin fertilization, polynuclear aromatic hydrocarbons, organophosphate pesticides, pyrethroid pesticides, and urchin fertilization toxicity. Ocean samples from the larger outfalls were analyzed for all the discharge constituents, as well as kelp germination, kelp growth, mussel embryo development and survival.

Data were analyzed to answer five questions:

  1. Are there north-to-south differences in reference conditions?
  2. Are there north-to-south differences in pre-storm water quality at ASBS sites?
  3. Do storm discharges alter receiving water quality?
  4. Are alterations of receiving water quality due to anthropogenic waste?
  5. Are marine biological resources being affected by ASBS storm discharges?
    • In rocky intertidal communities?
    • In contaminant bioaccumulation in resident mussels?
    • In toxicity to kelp and invertebrates?
    • In nutrient effects on algal blooms?

AMS handled all regulatory negotiations regarding project design and scope, as well as program management. University researchers and State of California laboratories were subcontracted to provide specialized expertise in environmental effects on rocky intertidal communities and analysis of organic contaminants in water samples. AMS also produced a Quality Assurance Program Plan that was approved by the State of California.

As the regulation of stormwater discharges into Areas of Biological Significance was a new initiative by the State of California, AMS focused data analysis and interpretation in the final report to highlight aspects of the program and questions that needed further consideration before enforcement actions were taken on potential stormwater impacts to ocean waters. When the monitoring program ended, AMS provided each participant with their data and data from reference sites so they could report data directly to the State Water Board. AMS continues under contract to two program participants to conduct studies needed to identify sources of contaminants for which their stormwater discharges exceeded water quality objectives.

Dane Hardin

AMS Contact:
Dane Hardin is a water quality expert with a strong quantitative emphasis. He currently serves as the Executive Director of the Central Coast Long-term Environmental Assessment Network (CCLEAN).