Frequently Ask Questions
What are the long-term water supply challenges facing the North San Pablo Bay region, particularly Sonoma, Marin and Napa counties?
Surface and groundwater sources are limited, and some local groundwater basins are already over-pumped, which has deteriorated water levels and quality. In addition, a clean, reliable water supply is needed to continue restoration of tidal wetlands in San Pablo Bay. The effects of global warming may further stress local water supplies. Development of recycled water would augment local water supplies and thus help the region to overcome the challenges.
Currently, most water undergoes extensive treatment and is sent unused into rivers and the Bay. It must meet strict governmental regulations on the treatment, timing and quality of the treated water that is released. By increasing treatment to recycled water quality, this high quality resource can be reused productively, rather than wasting and sending it unused into rivers and the Bay.
No. Generally, the recycled water will only be sent to specific locations where it is cost-effective to install a special purple recycled water pipeline, and where the customer wants it. Generally, recycled water is sent to large users like parks, golf courses and agriculture. In the Napa MST area, there is a proposal to provide it to individual homeowners in an area where the groundwater levels are falling.
Recycled water is not used for drinking in these projects. Drinking water is distributed in a completely different set of pipes. Household use of water for drinking, personal hygiene and other uses are the smallest use of water. More than half of all water in the region is used for outdoor irrigation, which is an ideal use for recycled water.
Instead of pursuing individual recycled water projects, this coordinated, regional approach provides economies of scale for the planning, engineering and environmental studies. It also maximizes the ability of the Authority partners to obtain local, state and federal funding assistance for their projects. The North San Pablo Bay Restoration and Reuse Project has been developed specifically to meet the Bureau of Reclamation’s Title XVI funding requirements, as well as requirements for State funding. By matching proposed water recycling projects to the requirements for government funding, the Authority is getting the biggest bang for its buck, thus making the development of vital recycled water projects affordable to local users.
Will increasing the water supply by increasing the use of recycled water in the region facilitate growth?
The purpose of the NBWRA recycled water program is to offset current water use with recycled water and provide a sustainable supply of water for urban and agricultural irrigation and the environment, even in times of drought. The NBWRA does not have any jurisdiction over land use decisions. The level of growth within the region is decided by land use planning processes by individual Cities and Counties. The recycled water program is proposed to offset the use of current supplies for urban and agricultural irrigation, assist in managing peak summer-time demands on potable supplies, and provide a sustainable “drought-proof” supply for the region.
Yes. In a study of recycled water use by the Napa Sanitation District for vineyard irrigation, carried out by the University of California, it was concluded that the water “is suitable for vineyard irrigation” and that “there were no salinity or toxicity issues that would limit the use of this water.” Another study by the Monterey Regional Water Pollution Control Agency concluded that “the use of filtered secondary municipal water for irrigation of food crops consumed unprocessed is safe.” No viruses were found in samples of crops grown with recycled water and levels of naturally occurring bacteria were equivalent to those found in well water-irrigated crops. Additionally, the study showed that marketability, quality and yield of recycled water-irrigated crops were comparable to crops grown with other sources of water.
No. Currently water is treated to a high level and then sent to rivers, and the Bay. Regulatory requirements are designed to ensure that discharges from water treatment are safe for the environment. Recycled water is treated to an even higher level.
Water recycling, long past the experimental stage, is widely practiced throughout the nation and around the world to irrigate crops as well as golf courses, parks, school grounds and other open spaces without any ill effects. It is used satisfactorily in Calistoga, St Helena, Yountville, Napa, Santa Rosa, San Rafael, Novato, San Francisco, San Jose, Sunnyvale, Santa Clara, Daly City and other Bay Area communities. These uses have been shown to be safe and to not cause adverse impact to rivers, creeks, streams or groundwater.
No. The recycled water from the proposed NBWRA projects would be treated at a level and certified for safe use by people including children.
In over 70 years of use of recycled water in California, there have been no documented cases of contact-related ill effects from recycled water. School grounds and parks have been irrigated safely with recycled water. The treatment process used for recycled water, which utilizes a disinfectant, protects against infection. Moreover, public health is protected by the California Department of Public Health’s water quality standards and treatment reliability criteria for recycled water.
Among the many benefits of a coordinated, well-planned approach to the use of recycled water are:
- Reliable irrigation water for parks, golf courses, school grounds, other public landscaping, vineyards and other agricultural uses, as well as industrial applications.
- Increased water for wetland habitat restoration and stream flows for riparian habitat and fisheries recovery, and groundwater supplies.
- Less discharge of treated water into San Pablo Bay and its tributaries.