Pollutant Concerns
Protecting waterways through science-based strategies that identify and reduce pollutant sources. We work with public agencies and regional partnerships to develop and implement targeted control programs addressing legacy, current, and emerging contaminants that threaten water quality and public health.
Core Services
Pollutant source identification and assessment
Watershed pollutant load evaluations
Trash, bacteria, legacy contaminant, and pesticide control programs
PFAS and emerging contaminant assessments
TMDL implementation planning and reporting
Source investigation and tracking studies
Best management practice evaluation
Regulatory compliance strategy
Regional collaboration and program coordination
Protecting water quality requires understanding pollutant sources and implementing targeted, science-based control strategies that address both existing and emerging water quality challenges. EOA partners with public agencies, regional programs, and stakeholders to identify pollutant sources, evaluate management options, and develop effective control programs that protect waterways and public health. Our collaborative approach combines technical expertise, regulatory knowledge, and applied science to support practical, cost-effective implementation.
Highlighted Projects
SF Bay Mercury and PCBs Total Maximum Daily Load (TMDL)
Bay Area Stormwater Management Agencies Association
Newport Bay Fecal Coliform TMDL and Source Management Plan
County of Orange
Highlighted Project
SF Bay Mercury and PCBs Total Maximum Daily Load (TMDL)
Bay Area Stormwater Management Agencies Association
- Total Maximum Daily Load (TMDL) projects have recently and are currently being developed for the San Francisco Bay and local water bodies (i.e., urban creeks). EOA provided technical support to the Bay Area Stormwater Management Agencies Association (BASMAA) during the development and adoption of the Mercury and PCBs TMDLs for San Francisco Bay. Technical support has included tracking the TMDL development process, coordinating and updating BASMAA managers, drafting comment letters on behalf of BASMAA, and negotiating stormwater-related language within the TMDL implementation plan. EOA has developed sampling and analysis plans to help meet TMDL goals for Mercury and PCBs for stormwater in Santa Clara and San Mateo Counties. In addition, EOA has also provided assistance on the recently adopted TMDL for Pesticide-Related Toxicity in Urban Creeks.
Highlighted Project
Newport Bay Fecal Coliform TMDL and Source Management Plan
County of Orange
- EOA assisted the County of Orange, Irvine Ranch Water District and the Santa Ana Regional Water Quality Control Board to develop a proposed scope for conducting a Fecal Coliform TMDL for Newport Bay. EOA developed a Work Plan to conduct the health risk assessment associated with elevated levels of microbial contaminants in Newport Bay and facilitated risk management decisions by integrating the health risk assessment with potential water quality program/structural costs. As a follow up to the TMDL, EOA also developed a Fecal Coliform Source Management Plan for the County of Orange. The management plan identified and quantified the contribution of fecal coliform sources to Newport Bay, and identified current and planned practical management actions that could reduce the impacts associated with pathogens in Newport Bay. Source and receiving water monitoring plans were also developed and presented to the Newport Bay Watershed Committee and submitted to the Santa Ana Regional Board in compliance with the TMDL. EOA also developed recommended revisions to the TMDL consistent with the level of public health risk related to pathogens in Newport Bay water.
