North Bay Water Reuse Authority (NBWRA) Sub-Regional Project
|Sponsoring Agency||North Bay Water Reuse Authority (NBWRA), with Sonoma County Water Agency as the administrative entity|
|Counties||Marin County, Sonoma County, Napa County|
|Public or private land?||()|
|Location Description||The NBWRP area encompasses approximately 318 square miles of land within Marin, Sonoma, and Napa Counties. This region extends some 10 to 15 miles inland of the tidal San Pablo Bay, with a total population of over 270,000 in the major urban centers of San Rafael, Novato, Petaluma, Sonoma, and Napa. A map of the NBWRA study area can be provided if requested. The specific projects included in this application are located in San Rafael (involving Las Gallinas Valley Sanitary District [LGVSD] and Marin Municipal Water District [MMWD], Novato (involving North Marin Water District [NMWD] and Novato Sanitary District [Novato SD]), Petaluma (involving the City of Petaluma), Sonoma Valley (Sonoma Valley County Sanitation District [SVCSD]), and Napa (Napa Sanitation District [Napa SD]).|
The North Bay Water Reuse Authority (NBWRA), established under a Memorandum of Understanding (MOU) between 10 local agencies, undertook cooperative, regional planning efforts to develop the North Bay Water Reuse Program (NBWRP). The purpose of the NBWRP is to provide high quality recycled water for agricultural, urban, and environmental uses and to expand the recycled water system throughout the greater North San Pablo Bay Area. Implementation of the NBWRP includes upgrades of wastewater treatment processes and construction of storage, pipelines, and pump station facilities to distribute recycled water. The NBWRP will also reduce reliance on local and imported surface water and groundwater supplies and reduce the amount of treated effluent releases to North San Pablo Bay and its tributaries.
Part 2 - Detail
The NBWRA Sub-Regional Project will provide 6,000-6,100 AFY of recycled water for municipal, environmental, and agricultural uses. The project includes 7.3 miles of distribution pipelines, rehabilitation of a 0.5-million gallon storage tank, 7.85 mgd of additional tertiary treatment capacity, relining 4,300 feet of pipe to allow for increased supply, and a significant upgrade to an existing pump station to enable service to two distinct distribution zones. The project offsets the use of potable water in Marin, Sonoma, and Napa Counties (Russian River water and groundwater), offsets surface water and groundwater used in Sonoma and Napa Counties to support landscape and agricultural irrigation, and also provides water for restoration of the Napa-Sonoma Salt Marsh. The Project components for grant funding consideration are part of the larger regional NBWRP included in the Bay Area IRWMP: http://bairwmp.org/projects/north-bay-water-reuse-program.
The specific components within this application include:
- LGVSD Recycled Water Supply Resiliency Project: LGVSD will expand its Recycled Water Facility to supply MMWD's existing recycled water system. The project increases the tertiary capacity at LGVSD by 4 mgd, to a total of 5.4 mgd. This project would allow MMWD to distribute more recycled water to its existing irrigation customers (currently using potable water, 500-600 AFY) and increase the reliability of those supplies because of fewer operational and water quality issues from the new expanded plant.
- Novato Recycled Water Central Service Area Expansion The project will increase the tertiary capacity of Novato SD's Davidson Street Water Recycling Facility from 0.85 to 1.70 mgd. This includes the installation of a third sand filter module, and expansion of NMWD's recycled water facilities to serve additional schools, parks, homeowners’ associations, and a golf course by extending approximately 5.7 miles of 8-18” pipelines and rehabilitation of an out-of-service 500,000-gallon water tank. This project will expand recycled water delivery by 300 AFY and provide 200 AFY of potable water offset.
- Expansion of Petaluma Recycled Water System: The project will increase the tertiary capacity of Petaluma’s Ellis Creek Water Recycling Facility from 4.8 to 7.8 mgd, providing 3,300 AFY for expanding urban and agricultural irrigation. This includes the installation of a second sand filter module and addition of a third channel of ultraviolet lights for disinfection. The project includes expansion of the urban recycled water distribution to serve schools, parks, and greenbelts by extending a 16” pipeline 1.6 miles in northeastern Petaluma. This project will provide an additional 51 AFY of potable water offset.
- Sonoma Valley Recycled Water Supply and Reliability Project: SVCSD will reline a 24” reinforced concrete pipeline due to operational issues that are limiting the amount of recycled water that can be beneficially used. The new cured-in-place pipe will have an operating pressure of 100 pounds per square inch (psi) and will be able to withstand spikes of 300 psi. With the relining, SVCSD will provide an additional 200 AFY, a more reliable recycled water supply to be beneficially used for agricultural uses and habitat restoration.
- Napa SD Recycled Water Pump Station North/South Split: Napa SD has worked with Napa County and LCWD to extend recycled water service into the MST area to provide up to 2,137 AFY for landscaping and irrigation purposes, and across the Napa River to provide up to 1,800 AFY for landscaping and irrigation purposes. The North/South Split is a necessary upgrade to accommodate the increased distribution of recycled water (up to 1,700 AFY), to manage the necessary water pressures, and to protect the new distribution lines from hydraulic transients.
The project does not provide benefits to a DAC.
Without implementation of the NBWRP, the North San Pablo Bay region will continue to face water supply shortages that will affect municipal and industrial customers, the agricultural industry, and environmental restoration efforts. The area’s limited surface water resources will be strained to provide sufficient local and imported supplies, and groundwater basins will be overdrafted, particularly in times of drought. Highly treated recycled water produced by the NBWRA facilities would not be put to the most beneficial use.
Napa SD’s North/South Split component is a critical missing element to the distribution of 1,700 AF of recycled water to areas that currently draw water from overdrafted groundwater aquifers in Napa and Sonoma Counties. This project will offset these overdrafts. The proposed modifications are required for recycled water deliveries in order to project infrastructure by maintaining minimum pressures in the MST and LCWD distribution systems, providing instrumentation and controls necessary to interact with the MST booster pump station to ensure the connecting pipelines and new equipment are not damaged, and protecting the LCWD distribution system from hydraulic transients.
If Petaluma’s tertiary facility is not expanded, there will be insufficient tertiary recycled water to meet peak day demands for drought-sensitive agricultural users. Without expansion of the recycled water distribution pipelines, several schools and parks will not be able to utilize recycled water and continue to impose a significant demand upon limited potable water resources.
i. Water Supply (conservation, recycled water, groundwater recharge, surface storage, etc.)
The NBWRA Sub-Regional Project will provide 6,000 – 6,100 AFY of recycled water supply to the North Bay Area (800-900 AFY in Marin County, 3,500 AFY in Sonoma County, and 1,700 AFY in Napa County). This recycled water offsets potable water from: 1) the Russian River; and 2) groundwater in Napa County. The project will also take agricultural users off of strained surface water diversions from local creeks, and limited groundwater supplies in Sonoma and Napa Counties, where overdraft and saline intrusion are issues. The project will reduce peak potable water demands, reduce reliance on imported surface water, and reduce treated wastewater discharge into San Pablo Bay by 5,500 – 5,600 AFY. Recycled water from the project would be delivered starting in March 2016, with project completion by October 2018.
Also, expansion of the recycled water production capacity would allow the project to serve agricultural users that have played a vital role in the local economy for over 150 years.
ii. Water Quality
The NBWRP includes improved levels of wastewater treatment and reduced discharges of treated wastewater into North San Pablo Bay. The project will reduce treated wastewater discharge into San Pablo Bay by 5,500 - 5,600 AFY, reducing nitrogen/nutrient loading. LGVSD’s expanded use of tertiary treated effluent will assist in meeting its new NPDES permit no discharge requirements.
iii. Flood and Stormwater Management
The additional recycled water capacity provided by LGVSD’s plant expansion may be used to irrigate future horizontal levees that will protect LGVSD facilities, including the recycled water plant, from flooding impacts and sea level rise.
iv. Resource Stewardship (watershed management, habitat protection and restoration, recreation, open space, etc.)
The project will provide 200 AFY of tertiary recycled water to facilitate restoration of several of the former salt ponds at the California Department of Fish and Wildlife Napa-Sonoma Marsh Wildlife Area.
The NBWRA Sub-Regional Project expects to have a benefit-cost ratio similar to other recycled water projects recently undertaken in the North Bay Area. The project can you provide project benefit/cost analysis information for the Prop 84 application.