Coordinated Stakeholder Implementation of Multiple TMDLs in Ventura County, California
Located in Ventura County California, the Calleguas Creek Watershed (CCW) includes a diverse landscape of urban, agricultural and open space environments. Though relatively small in area, the watershed includes some 334,000 individuals living in five major incorporated communities (Cities
of Thousand Oaks, Simi Valley, Camarillo, Oxnard, and Moorpark). Human activities have degraded numerous waterbodies within the Calleguas watershed, ultimately resulting in more 303(d) listed impaired waters than most California watersheds. Local stakeholders, including the cities, County,
United States Navy, wastewater treatment facilities, agriculture interests, and environmental groups along with the Los Angeles Regional Water Quality Control Board (LARWQCB), began a watershed planning process over eight years ago to develop a better understanding of the watershed and a strategy
to address impairments. This process has lead to the development of seven USEPA approved Total Maximum Daily Loads (TMDLs) addressing the following constituent groups: nitrogen and related effects, organochlorine pesticides and PCBs, toxicity and orthophosphorus pesticides, metals, sediment,
salts and trash.
The TMDLs were not prepared by a state or federal agency, rather the stakeholders themselves directed and provided the primary sources of funding for the TMDLs. This “Stakeholder Driven” approach provides many advantages, including sufficient funding to support
the TMDL development process. Stakeholders chose to take direct responsibility due to the potential implications of TMDLs, and believed that substantial funding was necessary for a thorough technical analysis. The authors will explain the process of stakeholder involvement, and the iterative
interaction process with State agency and USEPA staff.
In addition to TMDL development, the local stakeholders drafted the Implementation Plans, a requirement of the TMDL process in California. The Implementation Plans include requirements for monitoring, special studies, and implementation
measures, which include a wide variety of source control and structural best management practices (BMPs). The Implementation Plans were designed as a stepwise process, which included conducting additional studies believed necessary to properly identify the effectiveness and costs of particular
BMPs or strategies before prescribing BMPs.
Key aspects of the implementation plan include:
Monitoring – A watershed based monitoring program was developed to coordinate sampling for all TMDLs complementing current monitoring efforts
that include NPDES stormwater and wastewater monitoring. A compliance monitoring program was also developed to adequately measure environmental conditions during the implementation phases.
Special Studies – Studies included evaluating agricultural
BMPs, pesticide alternatives, and development of site specific objectives.
Source Control and Structural BMPs – Early actions have included management plans for agriculture identifying BMPs, nitrification and denitrification at all wastewater treatment
plants, and steps to reduce copper content in brake pads.
Stakeholder Coordination – Stakeholders have established a responsible parties group to fund implementation and coordinate actions.
In summary, the development
of the majority of TMDLs in the CCW through a stakeholder process has allowed integrated implementation of all TMDLs with each other and with the existing regulatory programs in the watershed. The focus of the implementation to date has been on source control, monitoring, and studies, though
some capital projects have been completed. Although only a few years into implementation, the watershed group is successfully working together to implement TMDLs and ensure permit requirements meet the vision of the TMDLs that they developed in partnership with the regulatory agencies.
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