EOA provides expert technical and regulatory services to Publicly Owned Treatment Works (POTWs) for all aspects of NPDES discharge permit compliance and for developing and implementing water recycling programs. Decades of wide-ranging staff experience in the wastewater field, coupled with specialized expertise in regulatory compliance issues, allows EOA to provide exemplary cost-effective services to clients for both “one-time” and long-term ongoing projects. Our services include: 

• Technical and regulatory assistance to clients for NPDES permit reissuance and amendment 
• Design and implementation of NPDES permit special studies, compliance monitoring and reporting programs, and associated data management systems 
• Technical assistance and training for POTW industrial pretreatment, laboratory, and plant O&M programs 
• Contributing to regional initiatives to develop TMDLs and site-specific water quality objectives 
• Assisting with planning, developing, and implementing recycled and purified water programs for conventional and advanced treatment systems, including physical infrastructure, administration, monitoring, and regulatory permitting and compliance  
• Conducting Reverse Osmosis Concentrate (ROC) management studies in support of NPDES permit modifications to accommodate ROC blending with wastewater effluent and use of Nature Based Solutions such as Horizontal Levees 

EOA’s clients have included the Cities of Sunnyvale, San Jose, Benicia, and Livermore, , and special districts including East Bay Dischargers Authority (EBDA), East Bay Municipal Utility District (EBMUD), Valley Water (Santa Clara Valley Water District), Las Gallinas Valley Sanitation District, Oro Loma Sanitary District, Sewer Authority Mid-Coastside, Dublin San Ramon Services District and Sausalito Marin City Sanitary District, and other agencies. 

EOA’s clients have included the Cities of Sunnyvale, San Jose, Benicia, Livermore, and Pacifica, and special districts including East Bay Dischargers Authority (EBDA), East Bay Municipal Utility District (EBMUD), Las Gallinas Valley Sanitation District, Oro Loma Sanitary District, Sewer Authority Mid-Coastside, and Carmel Area Wastewater District, and many agencies.

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HIGHLIGHTED PROJECTS

Wastewater Treatment Plant Technical and Regulatory Services 
City of Sunnyvale Water Pollution Control Plant 

Since 1986, EOA has provided assistance to the City of Sunnyvale Water Pollution Control Plant (WPCP) on NPDES permit renewals, including Reasonable Potential Analyses, infeasibility studies, and negotiating permit requirements. EOA has also conducted special studies required by the plant’s NPDES permit, including those associated with disinfection byproducts, chronic toxicity, ammonia, cyanide, and copper & nickel. EOA provides ongoing support to the City on plant operations and permit compliance, laboratory and pretreatment staff training, annual report preparation (e.g., NPDES, , Biosolids, Pretreatment, Pollution Prevention, Recycled Water), and for the design and support of the WPCP’s data management systems. EOA developed the framework for the City’s Recycled Water Program and coordinated the design effort for most of its physical infrastructure, and prepared the Program’s Title 22 Engineering Report. EOA has also provided support for the WPCP’s master planning and capital projects, pilot projects, and participation in regional wastewater groups and programs.

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NPDES Permit Reissuance Technical Support 

East Bay Dischargers Authority (EBDA) 

EBDA has a 119 mgd permitted discharge capacity to Lower San Francisco Bay. EOA has assisted EBDA, beginning with their 2000 permit reissuance, and has helped EBDA manage and negotiate each 5-year NPDES permit application process since 2012. EOA coordinated development of the permit application packages for EBDA that included data and information on the EBDA common outfall and from its four member agencies (City of Hayward, City of San Leandro, Oro Loma Sanitary District and Union Sanitary District).

Specific tasks EOA conducted included: Developed permitting strategy; prepared draft and final application packages for all six agencies (EBDRA, City of Livermore, and Dublin San Ramon Sanitation District); provided data evaluation and supporting documentation for monitoring reduction requests; compiled, validated, and summarized eight years of monitoring data for seven agencies to support Pretreatment Program monitoring reduction request; compiled EBDA combined outfall data and prepared Reasonable Potential Analysis; calculated resultant effluent limits; negotiated permit requirements; and reviewed and prepared comments on Tentative Orders

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Reverse Osmosis Concentrate Management  

Valley Water (Santa Clara Valley Water District)

EOA provided technical support to Valley Water in Santa Clara County for management of reverse osmosis concentrate (ROC) from a proposed 10 mgd Advanced Water Treatment Facility designed to produce purified water for indirect potable reuse. The ROC management strategy included discharge of ROC blended with treated effluent from the City of Palo Alto Regional Water Quality Control Plant (RWQCP). EOA conducted a Reasonable Potential Analysis and effluent limit calculations to identify the additional initial dilution credits needed for attainable NPDES permit effluent limits. EOA coordinated a hydrodynamic study conducted by Resource Management Associates to verify the mixing zone sizes associated with the required dilution credits. EOA coordinated chronic toxicity and priority pollutant testing of ROC from a pilot Reveres Osmosis facility.  

The work demonstrated that ROC could be successfully discharged through the existing RWQCP outfall in compliance with revised NPDES permit effluent limits. Studies supported use of increased dilution ratios allowing less conservative effluent limits. EOA worked with stakeholders to obtain a Letter of Concurrence from the Regional Water Board that the proposed ROC discharge appeared feasible.