Nature Based Solutions Preliminary Design

NOTICE IS HEREBY given that the City of Hayward invites sealed proposals for 25-018 Nature Based Solutions Preliminary Design . Each proposal shall be in accordance with the general provisions for purchase of work and services on file in the office of the Utilities , 777 B Street , Hayward , CA 94541-5114 . All proposals must be submitted to the City's eProcurement Portal by 5:00 pm on Friday, January 10, 2025 and clearly identified with RFP title, number, company name and due date. It is the sole responsibility of the proposing firm to ensure that proposals are received prior to the closing time, as late bids will not be accepted and deemed nonresponsive.

The City is seeking a qualified Consultant to prepare preliminary design drawings, cost estimate, and permitting study for the Hayward Water Resource Recovery Facility (WRRF) Multi-Benefit Shoreline project that seeks to utilize a nature-based solution (NBS) to wastewater treatment. The project would consist of constructed treatment wetlands and/or a horizontal ecotone levee at the WRRF owned and operated by the City of Hayward, adjacent to the Hayward Regional Shoreline in Alameda County. According to the Federal Emergency Management Agency (FEMA) , NBS a re defined as sustainable planning, design, environmental management and engineering practices that weave natural features or processes into the built environment to promote adaptation and resilience.

The City of Hayward, California (The City), located in Alameda County, is known as the “Heart of the Bay” because of its central and convenient location to San Francisco, Oakland and San Jose. The City owns and operates its own sanitary sewer system, including the Water Resources Recovery Facility (WRRF) located in the western area of the City. The sewer system serves a population of approximately 154,000 residents, with a typical average dry weather flow between 10 and 11 million gallons per day (MGD).

The WRRF currently operates a trickling filter/solids contact secondary treatment process to remove total suspended solids (TSS) and carbonaceous biochemical oxygen demand (cBOD5). However, this process does not achieve any significant removal of nutrients. In the coming years the secondary treatment process will be upgraded as part of the City’s planned WRRF Phase II Improvements project to include nutrient removal to treat approximately 75% of dry weather flows, with the remaining 25% of flows continuing to route through the east trickling filter. The City anticipates the Phase II Improvements will achieve effluent total inorganic nitrogen concentrations of around 20 milligrams per liter during the dry season, primarily as nitrate. Further reductions may be achieved with future improvements.

Upon completion of secondary treatment, wastewater is discharged to the East Bay Dischargers Authority (EBDA) common pipeline by means of the Hayward effluent pump station. EBDA operates a common deep-water outfall that contains the wastewater effluent from Union Sanitary District, the City of Hayward, Oro Loma Sanitary District, City of San Leandro, City of Livermore, and Dublin San Ramon Services District. The City currently has no other permits to discharge treated effluent to the bay and is entirely dependent on EBDA, with a maximum allowable discharge of 15 MGD into the EBDA pipeline.

From the mid-1960s to the mid-1990s, the WRRF utilized 7 oxidation ponds at the western edge of the site. Ponds 1 and 2 have been filled in and repurposed to operate as a photovoltaic array and aging fields, while ponds 3 through 7 serve as overflow storage of secondary treated effluent for flows that exceed the 15 MGD discharge limit to EBDA. To the east of the former oxidation ponds are the effluent channel, hypochlorite station, dechlorination facility, and the Hayward Effluent Pump Station. See Attachment A-1 for a current layout of these facilities.

As part of a regional planning effort, the City is a member of the Hayward Area Shoreline Planning Agency (HASPA), which is a joint powers agency that coordinates the improvement of the Hayward Shoreline for future generations. In 2021, HASPA completed the Hayward Regional Shoreline Adaptation Master Plan (HRSAMP), which includes recommendations for the City to prepare for and mitigate the impacts of sea level rise. The HRSAMP can be accessed on HASPA’s website: Hayward Area Shoreline Planning Agency | City of Hayward - Official website (hayward-ca.gov) . Among the recommendations outlined in the Master Plan are the construction of a horizontal levee along the western boundary of the former oxidation ponds and the development of treatment wetlands in the former oxidation ponds area. These proposed facilities define the scope of this project. A basic layout of the proposed facilities can be found as Attachment A-2.

In July 2022, Environmental Science Associates (ESA) completed a feasibility study for a horizontal levee and constructed wetlands at the former oxidation ponds (Attachment B-1). Subsequently, in June 2023, Brown and Caldwell Prepared a Nature Based Solutions Feasibility Evaluation (Attachment B-2), which further investigated the potential for Nature Based Solutions (NBS) at the WRRF.

The City recently received a grant for up to $600,000 from the Environmental Protection Agency, through the San Francisco Estuary Partnership (SFEP), to move the City’s NBS project to preliminary design. Proposers should note that federal requirements are applicable to this RFP as described in Attachment C.

Through the NBS project, the City aims to achieve some, if not all, of the following:

• Sea level rise resiliency through a horizontal ecotone levee incorporated into a FEMA-certified flood protection levee as described in the HRSAMP. City intends to prepare for sea level rise of approximately 7 feet, which would result in a top of levee approximately 7 feet above the existing access road along the west side of the ponds.
• If feasible, provide appropriate wastewater treatment in the horizontal levee. City anticipates potentially treating reverse osmosis brine from a future recycled water expansion project as the likeliest treatment.
• Convert ponds 3 through 7 into constructed treatment wetlands to further reduce total inorganic nitrogen contained in treated effluent from the WRRF through denitrification
• Acquire near shore discharge permit for effluent from constructed wetlands. Potential discharge locations are shown on Attachment A-3.
• Evaluate potential impacts of groundwater emergence from sea level rise on constructed wetlands.
• If near shore discharge is not feasible, enhanced nutrient removal is desired for compliance with potential future, stricter iterations of the Regional Water Quality Control Board’s Watershed Permit.
• Comply with requirements of the Alameda County Mosquito Abatement District
• Coordination with East Bay Regional Parks District for potential enhancements of the Bay trail.

Proposers may note that Brown and Caldwell’s Nature Based Solutions Feasibility Evaluation generally seems to prefer the Free Water Surface (FWS) Wetland rather than a Unit Process Open Water (UPOW) Wetland. At this time, the City has not concluded what type of wetland is preferable and seeks further input from the consultant. Though the City acknowledges various benefits of the FWS wetland, the City remains concerned about mosquito abatement issues that appear likely to accompany this option. The selected consultant shall consider the needs of the Alameda County Mosquito Abatement District as well as City maintenance needs prior to selecting a final alternative.