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HomeMy WebLinkAbout04.a. Receive update on Bay Area Pilot Stormwater Diversions to Sanitary Sewer Page 1 of 6 Item 4.a. CENTRAL SAN July 22, 2019 TO: REAL ESTATE, ENVIRONMENTAL AND PLANNING COMMITTEE FROM: TIM POTTER, ENVIRONMENTAL COMPLIANCE SUPERINTENDENT REVIEWED BY: LORI SCHECTEL, ENVIRONMENTALAND REGULATORY COMPLIANCE DIVISION MANAGER JEAN-MARC PETIT, DIRECTOR OF ENGINEERINGAND TECHNICAL SERVICES SUBJECT: RECEIVE UPDATE ON BAYAREA PILOT STORMWATER DIVERSIONS TO SANITARY SEWER Attached is a presentation developed to respond to a prior Committee request for information regarding Bay Area pilot stormwater diversions to the sanitary sewer. ATTACHMENTS: 1. Presentation July 22, 2019 Special REEP Committee Meeting Agenda Packet- Page 10 of 46 Page 2 of 6 BAY AREA PILOT STORMWATER DIVERSIONS TO SANITARY SEWER _= Tim Potter Environmental Compliance Superintendent REEP Committee July 22, 2019 PRESENTATION OVERVIEW Background on San Francisco (SF) Bay Municipal Regional Stormwater Permit (MRP) Two SF Bay Area Case Studies Ettie Street Diversion to East Bay Municipal Utility District (EBMUD) North Richmond Diversion to West County Wastewater District (WCWD) Applicability to Central San iz 1 July 22, 2019 Special REEP Committee Meeting Agenda Packet- Page 11 of 46 Page 3 of 6 BACKGROUND • SF Bay MRP required pilot projects to assess feasibility of dry weather/first flush stormwater diversions to publicly owned treatment works to control polychlorinated biphenyls (PCBs) and mercury (Order R2-2009-0074) • An enforcement action against EBMUD for wet weather facilities not complying with National Pollutant Discharge Elimination System (NPDES) permits resulted in a diversion pilot project in advance of MRP • Consent Decree finalized in 2014: Required EBMUD's and seven satellite collection system agencies' long-term commitment to control wet weather flows into sanitary sewers to eliminate future use of EBMUD wet weather facilities • Dry weather diversion at Ettie Street Pumping Station (PS)was included "_fth*01, 3 CENTRAL SAN r' CASE STUDY 1 ETTIE STREET DIVERSION TO EBMUD • Partnerships: • Alameda County Flood Control • EBMUD • City of Oakland (pilot project only) • Drivers • Environmental enhancement project under enforcement action against NPDES permit for EBMUD wet weather facilities for initial pilot project • Consent Decree and MRP required PCB pilot projects • Consent Decree requires Ettie Street Diversion to reduce pollutants of concern through December 2035 !.4 CENTRALSAN 2 July 22, 2019 Special REEP Committee Meeting Agenda Packet- Page 12 of 46 Page 4 of 6 'EET DIVERSION TO EBMUD Setting Ettie Street PS serves industrial and urban commercial/residential areas PS is 1 ,000 feet from connection to EBMUD interceptor (closer Oakland connection only allowed for initial pilot project) PS receives up to 0.7 million gallons per day (mgd) of dry weather flow EBMUD Diversion designed for 0.5 mgd of dry weather flow No Sewer Service Charge (SSC) for flow to EBMUD due to Consent Decree CENTRAL SAR_ STREET DIVERSION TO EBMUD Lessons Learned Diversion as a PCB control strategy would achieve reduction but at a high cost and is not adequate to meet MRP objectives Agreement for long-term diversion driven by Consent Decree Additional capital cost by EBMUD needed for long-term diversion when the City of Oakland required fees to use their collection system beyond pilot project 3 July 22, 2019 Special REEP Committee Meeting Agenda Packet- Page 13 of 46 Page 5 of 6 CASE STUDY 2 NORTH RICHMOND DIVERSION TO WCWD • Partnerships: Contra Costa County Department of Public Works Contra Costa County Flood Control and Water Conservation District Contra Costa Clean Water Program EBMUD City of Richmond WCWD Drivers: Rehabilitation of PS infrastructure MRP pilot project to control PCBs United States Environmental Protection Agency grant to fund monitoring costs Potential augmentation to support EBMUD recycled water supply ,. to Chevron Richmond Refinery NORTH RICHMOND DIVERSION TO WCWD • Setting PS serves industrial and low income residential areas PS '/4 mile from inlet to WCWD PS receives 0.4 mgd of dry weather flow WCWD did not charge SSC for pilot project only Lessons Learned Not a cost-effective PCB control strategy Inadequate dry weather volume to meet refinery recycled water without storage capacity Aw 4 July 22, 2019 Special REEP Committee Meeting Agenda Packet- Page 14 of 46 Page 6 of 6 APPLICABILITY TO CENTRAL SAN • Drivers for case studies do not apply • Lack of proximity of source to Central San system • Flood control/cities likely do not want to pay for long-term diversions • Potential impacts to Central San system and NPDES permit compliance • Potential impacts of dry weather diversions on creek habitats • Potential permitting/restrictions by resource agencies ■ 9 CENTRAL SAN r' QUESTIONS? 10 CENTRALSAN 5 July 22, 2019 Special REEP Committee Meeting Agenda Packet- Page 15 of 46