Environmental Declaration WPCP 20240409

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2. Project Description 2. PROJECT BACKGROUND AND DESCRIPTION 2.1. Project Purpose and Objectives The Proposed Project involves converting a 6.9-acre wastewater storage basin into a multi -benefit freshwater treatment wetland. The primary purpose is to reduce the loading of wastewater -borne nitrogen, phosphorus, and other contaminants, such as pharmaceutical compounds, into San Francisco Bay. Closely aligned objectives include: 1) Enhance habitat along an accessible and visible stretch of the Bay Trail to improve wildlife resources through the creation of wet meadow habitat once abundant along the shores of San Francisco Bay, yet virtually non-existent today; 2) Create ecological and engineering -based educational opportunities within a densely urban and industrialized portion of San Francisco Bay; 3) Demonstrate the effectiveness of a novel and potentially cost-effective contaminant removal process, relying in part on lessons learned from the Oro Loma Sanitation District (OLSD) horizontal levee project; and 4) Repurpose an underutilized wastewater retention basin to enhance aesthetic qualities and improve operational capacity and flexibility within San Leandro's WPCP. 2.2. Project Background In 2018, the San Francisco Bay Restoration Authority (SFBRA) awarded San Leandro a Measure AA grant to plan and design a water quality improvement, shoreline restoration, and resiliency project. This includes the conversion of an underutilized 6.9-acre wastewater storage basin adjacent to the WPCP into a multi -benefit treatment wetland to improve the operational capacity of the WPCP, anticipate future nutrient regulations, enhance habitat quality, and pilot a novel treatment wetland design. This Project builds upon and relies on lessons learned from other California -based multi -benefit treatment wetlands, including the OLSD horizontal levee project and unit -process treatment wetlands at the Discovery Bay Wastewater Treatment Plant and Prado Wetlands in Riverside County. The latter two (2) projects utilized shallow, open -water wetlands to achieve high removal of nitrate and pharmaceutical compounds. The Project incorporates elements of open water shallow wetlands and horizontal levees to maximize nitrate removal and create freshwater wetland habitat once abundant along the shores of SF Bay, yet virtually non-existent today. Existing Facilities San Leandro owns and operates its WPCP, located at 3000 Davis Street, San Leandro, CA 94577 (Figures 2.1 and 2.2, Regional Location and Project Location). San Leandro's WPCP provides secondary wastewater treatment for about 15,300 domestic, commercial, and industrial service connections throughout the northern two-thirds of San Leandro, serving a population of about 60,000. The WPCP has a design average daily dry weather design flow (ADWF) of 7.6 million gallons per day (mgd), though ADWF has averaged 4.8 mgd in recent years. San Leandro discharges secondary treated effluent through a common outfall to South SF Bay, which is managed and maintained by the East Bay Dischargers Authority (EBDA), a Joint Exercise of Power Agency with other East Bay wastewater agencies. Facilities discharging through EBDA's common outfall are regulated under NPDES Permit Order No. R2-2017-0016; CA0037869. San Leandro Treatment Wetland IS/MND