San Francisco Bay Nutrient Reduction and Recycling Project
|Sponsoring Agency||Bay Area Clean Water Agencies|
|Subregions||('North Bay', 'East Bay', 'South Bay', 'West Bay')|
|Counties||Alameda, San Mateo, Solano, San Francisco, Sonoma, Contra Costa, Marin, Santa Clara, Napa|
|Public or private land?||()|
|Location (lat/lon)||37.6910, -122.3108|
|Location Description||The central focus for this Project is San Francisco Bay. The site locations for this project are shown on the image file attached in Part 1.|
This regional project will install innovative treatment facilities at multiple sites, construct new recycling facilities, and enhance monitoring (moored sensors) in the region to reduce nutrient loading into San Francisco Bay to: improve ecosystem health and water quality in San Francisco Bay; enhance water supply and flood protection; and provide other benefits including reduced greenhouse gas emissions, reduced net energy consumption, and reduced residual solids. The Project partners include the Bay Area Clean Water Agencies (BACWA), San Francisco Estuary Institute (SFEI), Re-inventing the Nation's Urban Water Infrastructure (ReNUWIt), Stanford University, Union Sanitary District, East Bay Regional Parks District and several sanitation and water districts implementing recycling or advanced wastewater treatment projects. This region-wide project will advance the Nutrient Management Strategy for San Francisco Bay. See Ref. Doc. #1.
Part 2 - Detail
Recent evidence suggests that San Francisco Bay’s resistance to its high level of nutrient loadings is weakening. Consequently, the San Francisco Water Quality Control Board has indicated interest in developing nutrient loading allocations in the next 5-10 years. See Ref. Doc. #1. Similar nutrient removal strategies in other regions of the U.S. can approach $50-100 billion to implement through capital improvements, improved monitoring/assessment, and nutrient trading. This Project will reduce nutrient inputs into the Bay through implementation of:
a. Zeolite-Anammox Total Nitrogen Removal System. Construct two full-scale or intermediate treatment systems and multiple pilot scale treatment systems at several Bay Area locations to remove nutrients and advance this technology by: i) refining pilot plant data for accurate construction cost estimates; and ii) generating enough bio-zeolite (zeolite colonized with bacteria) to seed further full scale systems. Three strengths of aquatic ammonia discharges can be de-ammonified: Side Stream (high strength), Mainstream (medium), and re-used water (low). See Ref. Document #2. Requesting $1.5M.
b. Mobile Advanced Treatment Pilot. Construct small scale and/or trailer mounted wastewater treatment units at multiple locations to test advanced wastewater treatment (Staged Anaerobic Fluidized Membrane Bioreactor System [SAF-MBR] and Coupled Aerobic-Anoxic Nitrous Decomposition Operation [CANDO]) to remove nutrients and other constituents, reduce energy use and enhance energy recovery. See Ref. Doc. #3. Requesting $1.5M.
c. Hayward Marsh Restoration. Rehabilitate a 145 acre marsh on the eastern shore of SF Bay using reclaimed wastewater to improve wildlife habitat, reduce wastewater nutrient loads to San Francisco Bay, and improve flood control through levee strengthening. Approximately 2 mgd of wastewater will be used for this project and up to 20 mgd duding wet weather. Requesting $5M.
d. Moored Sensors. Install robust water quality sensors network at strategic locations in San Francisco Bay to improve assessment and prediction of Bay conditions, and provide early warning of adverse swings. Requesting $2M.
e. Nutrient Optimization at Existing Plants. Initiate nutrient removal projects above and beyond regulatory requirements by partially funding capital improvements (pumps, aerobic digesters, etc) at some of the 37 Bay Area POTWs based on the amount of nutrient removal to be accomplished per dollar. BACWA would administer the program and the POTWs would implement the facility improvements. Requesting $2M.
f. Regional Recycling. Potential water recycling projects for this grant round are listed below. Recommendations for specific projects for grants will be as the screening process is finalized. Facilities and grant amounts will be equitably distributed among the four Bay Area sub-regions. Requesting $15M total.
1. Benicia Valero Oil Refinery Cooling Water, 2,100 AF/yr. Total $16M. Requesting $2.8M.
2. DERWA Recycled Water Project Pump St. 1, Ph. 2, 2,900 AF/yr. Total $15M. Requesting $5M.
3. South Marin Recycled Water System, 100 AF/yr. Total $3M. Requesting $2.25M.
4. Palo Alto Recycled Water Project, 900 AF/yr. Total $35M. Requesting $5M.
5. Redwood City RWP Phase 2 Central City, 274 AF/yr. Total $8.5M. Requesting $4M.
6. SFPUC Regional Recycled Water Capacity Improv, 2,336 AF/yr. Total $30M. Requesting $3M.
7. NBWRA Sub-Regional Project, 6,300-6,400 AF/yr. Total $24.5M, Requesting $6.25M.
8. Sharon Heights Satellite Treatment Plant, 197 AF/yr. Total $13.9M, Requesting $3M.
Nutrients - Studies in recent years show signs that turbidity may be decreasing, potentially breaking down the resiliency to nutrients. The adjacent Delta region has already experienced significant declines for pelagic organisms due to multiple factors, including nutrient enrichment (Interagency Ecological Program, 2008-2013). Without an aggressive approach by regulators and stakeholders to develop and implement an effective nutrient strategy there will be uncertainty about the long lasting ecosystem health of San Francisco Bay.
Increased regulation of nutrients could lead to billions of dollars for infrastructure improvements to meet more stringent requirements. Other regions of the United States have implemented strategies costing $20-$50 billion that focus on conventional treatment. A comparable approach in the Bay Area would result in new costs of up to $7.5 billion unless a more tailored approach is developed utilizing advanced treatment strategies combined with an enhanced scientific program.
Water Supply – The ongoing four year drought in California has caused extensive economic impacts, including losses in landscaping, commercial losses at water dependent businesses, and agriculture. These will continue to mount as the drought continues through the summer and fall of 2015, and potentially future years. Without additional sources of supply, including recycled water, the duration and severity of drought impacts will be more extensive.
Habitat Impacts – Marshland habitat around San Francisco Bay has greatly declined from historic levels due to multiple causes including development, dredging and filling, and sedimentation. Continuing pressure will be exerted in coming years from projected sea level rise on the order of two to five feet by 2100. Without additional restoration projects around the Bay the existing wetlands could be degraded and the special status species that depend on them could face losses. These wetlands also serve as open space and recreational-education opportunities that are highly valued by Bay Area residents that need to be protected and enhanced.
Flood Control Impacts – Numerous business, homes and infrastructure are in the floodplain immediately adjacent to San Francisco Bay. A combination of aging flood protection infrastructure and rising sea level will continue to pose risks of flooding into the future without additional flood management improvement projects.
1. Resource Stewardship. This project will reduce nutrient loading to San Francisco Bay at multiple locations and improve conditions over baseline conditions. Approximately 5.4 million pounds per year of nitrogen will be removed from SF Bay discharges (breakdown: Zeolite-anammox 2.3M lbs, Optimization 2.0M lbs, Recycling 0.8M lbs, Hayward Marsh 0.3M lbs). The proposed treatment sites and recycling facilities are shown on the Project map. Further, the proposed monitoring improvements (moored sensors) will improve knowledge/data to better characterize nutrient effects and focus ongoing projects on those providing the greatest benefit.
The Hayward Marsh restoration will enhance 145 acres of wetlands that are significant wildlife habitat migratory birds (Forster’s tern, Caspian tern, black skimmer, western snowy plover and California least tern), including three freshwater basins (85 acres) and two brackish basins (60 acres). Approximately 2 million gallons per day (mgd) of wastewater will be used for this project and up to 20 mgd during wet weather. Collectively, the project facilities and actions will meaningfully contribute to ongoing efforts to protect and restore San Francisco Bay habitat.
2. Water Supply. The proposed recycling facilities will collectively produce up to 8,800 acre feet of water per year after construction is completed. These supplies will be largely drought proof as they rely on wastewater streams as the source of supply. This will offset use of potable water to serve these same needs and lessen some of the need to import alternative sources from distant watersheds (e.g. Delta). Additionally, discharges to SF Bay, including nutrients, will be reduced. The final selections among the recommended projects will be made when the final grant solicitation is available from DWR.
3. Flood Management. The Hayward Marsh restoration effort will include improvements to flood control levees and help resist sedimentation. Dredged material will be used to restore other wetland/marsh areas that may also aid flood control efforts.
4. Infrastructure Avoided Cost. In addition to physical benefits, this Project has tremendous potential to offset billions of dollars in capital investment that would otherwise be required if a conventional approach to nutrient removal (i.e. nitrifation, de-nitrication) is mandated in the future. The cost for infrastructure upgrades to reduce total nitrogen in discharged effluent from 30 mg/L (current level) to 2 mg/L (90% reduction, Level V) is estimated at a cost of $15 per gallon per day (Falk et al, 2011). If that unit cost were applied to all Bay Area discharges, approximately 500 mgd, the resulting upgrade cost would be $7.5 billion.
If the reduction target was less restrictive than 90%, such as 3 mg/L (Level 4) then the estimate would be $3.0 billion; if 6 mg/L (Level 3) then the cost would be $2.6 billion; if 12 mg/L (Level 2) then the cost would be $1.7 billion. Evaluating the different load reduction scenarios to identify the most cost efficient and environmentally effective approach requires further advancements in innovative treatment and well calibrated models, which are both aided by the proposed Project. If this Project accounts for 5% of the justification to move from Level V treatment costing $7.5 billion to Level 4 costing $3.0 billion (e.g. it is one of several key steps for a full justification), the avoided cost benefit attributable to this Project would be 5 percent of $4.5 billion or $225 million, yielding a benefit/cost ratio for the entire Project of more than 4.0. Other scenarios (Levels 2 or 3) would also have large avoided costs and a high benefit/cost ratio. The methodology can be fully documented.
5. Emergency Preparedness. The mobile advanced treatment units have the potential to be deployed to produce recycled water during an emergency. They could be set up to produce recycled water to serve industrial or irrigation needs at facilities located near a suitable wastewater source (pipe) during an emergency if potable water is unavailable.
6. Energy Recovery, Energy Savings. The Zeolite-Anamoxx and Advanced Mobile Treatment methods both use considerably less energy or can generate energy. The SAF-MBR treatment process using anerobic digestion of dissolved organics is projected to generate 946 kWh/MG while conventional treatment consisting of enhanced primary treatment, activated sludge and anaerobic digestion consumes 340 kWh/MG. This project method is expected to result in a positive net energy change which can be quantified. When CANDO treatment method is used to remove nitrogen from side streams of anaerobic disgesters, net electrical energy consumed is expected to decrease to 300 kWh/MG, a 34% decrease compared to conventional treatment. This project method is expected to result in a positive net energy change that can be quantified. For the Zeolite-Anammox system, influent options include gravity flow that can significantly reduce energy costs. The system is designed to require minimal maintenance. See Reference Documents #2 and 3 for more detail.
7. Reduced Greenhouse Gas Emissions (GHG) emissions. The Advanced Mobile Treatment and Zeolite-Anammox systems use less energy and will result in fewer GHG emissions. Further, the reduced amount of residual bio-solids after treatment will result in less truck trips for land application or burial. The amount of GHG emissions resulting from transport of biosolids is significant and can be calculated as: Dry solids/yr x Truck trips/Dry Metric Tons x average distance/trip x GHG emissions/mile x % of Dry solids land applied = Total GHG emissions. Values for Bay Area are: 153,000 DMT/yr *29% land applied or buried* 1 truck/15 tons *30 mi ave/trip * 1.692kg CO2e/mi = 150,000 kg CO2e /yr. The reduction attributable to this Project can be quantified and the valuation calculated after DWR specifies the economic parameters to use across years.
8. Reduced Solids, Reduced Fouling, Smaller Footprint. The Advanced Mobile Treatment processes (SAF_MBR, CANDO) will produce less solids as compared to conventional treatment, (0.30 ton/MG and 0.37 ton/MG respectively, as compared to 0.48 ton/MG for conventional). Further, less space is required because hydraulic residence time is reduced. The Zeolite Anammox system is well documented for producing very low sludge volumes and results in nitrogen gas and water as end products.
Regional Impact - This project geographically spans San Francisco Bay, San Pablo Bay, and benefits the entire Estuary and Delta. The moored sensors portion of the project will significantly enhance monitoring capabilities in San Francisco Bay. The proposed facilities are distributed in each of the four sub-regions and each of the four functional areas are benefitted. Collectively, the project components will produce significant direct results and better focus future actions to address nutrient loading.
Regional Priorities addressed by the Project include:
1. Climate Change – This Project will improve shoreline sustainability near the Hayward Marsh by reusing approximately 2 million gallons per day of wastewater from Union Sanitary District as a resource for wetlands enhancement at Hayward Marsh, and by improving flood control levees.
2. Regional Water Reliability / Long-term Sustainability – Up to 8,800 acre feet per year of recycled water will result from the Project, which is a sustainable supply, not reliant on imports from distant watersheds.
3. Health of the Bay and Creeks – Reducing nutrient loading by roughy 5.4 million pounds per year and improving assessment capabilities will help restore bay processes and better focus future improvements on the most effective methods.
4. Sediment Management - Flood control improvements at Hayward Marsh will include re-use of dredged sediment at other flood control projects in the region.
Collaboration - BACWA is a regional organization representing wastewater dischargers in all nine Bay Area counties. The partners involved with implementation include the San Francisco Estuary Institute, ReNUWIt, Stanford University, Union Sanitary District and several other sanitation districts that will be making site improvements. Supporters of this project include the Interagency Ecological Program, U.S. Geological Survey, Bay Keeper, Delta Science Center, State and Federal Water Contractors, Water Science Center. The BACWA Recycled Water Committee will continue to facilitate regional meetings to help arrive at final recycling grant facility selections.
Scalability - This project is scalable and some of the facilities and actions would be reduced or reprioritized if there is a need to scale back the grant request with some reduction in benefits.