A need for more water
The Water Department’s mission is to meet the City of San Diego's current and future water supply needs. Currently, approximately 90 percent of the City’s water supply is imported, with the remaining sources coming from stored local runoff and recycled water. Since 1990, the City’s conservation program has helped reduce the City’s dependence on imported water. Today, the program saves approximately 20,000 acre feet of potable (drinking) water a year, which is enough to meet the water needs of 40,000 typical families for a year. Even with continued conservation measures, by 2030, San Diego could need 25 percent more water than it uses now. The City must diversify its sources of water and increase the use of locally-produced water to assure an adequate and reliable supply for the future.
Water Reuse Study
As part of this diversification effort, at the direction of the City Council on January 13, 2004, the Water Department began undertaking a Study to evaluate all opportunities for increasing the production and use of recycled water. The Water Reuse Study is the response to this direction and includes a master plan component. Recycled water is municipal wastewater that has been treated to a high level so that it can be reused for a variety of beneficial purposes. Water that is recycled and reused locally helps reduce the demand for imported water, and is an available water supply even during water shortages.
Current recycled water system
The City currently operates two water recycling plants. The North City Water Reclamation Plant, which opened in 1997, is distributing recycled water for irrigation and industrial use. The second plant is the South Bay Water Reclamation Plant that began operations in 2002, and has received certification to produce and sell recycled water. Agreements are in place to deliver recycled water from the South Bay Plant to customers once construction of the distribution system is completed. Both plants are able to increase the production of recycled water which could be beneficially reused in the community.
A majority of the City’s current customers use recycled water for irrigation, which has fluctuating demands according to the weather patterns. Due to these varying demands, about half of the water reclamation facility’s potential treatment capacity (on average) may be unused for part of the year. The Study is addressing the seasonal demands for recycled water to optimize the production and use of recycled water in San Diego.
The Study is a comprehensive, impartial, balanced, and science-based review of all recycled water use opportunities for the City. The following water reuse options are being thoroughly analyzed using a variety of evaluation criteria:
- expand the existing distribution system for irrigation and industrial use
- create recycled water storage reservoirs
- develop wetlands
- discharge into streams
- recharge or improve groundwater storage basins not used as drinking water sources
- after additional advanced treatment, blend with water stored in reservoirs or groundwater storage basins used as drinking water sources
- graywater use
Health and safety
The study is focusing on the health and safety aspects of the recycled water opportunities. An Independent Advisory Panel from the fields of science, economics, medicine and education is analyzing the information and make recommendations to the Study team. The team is compiling research and studies on the health impacts of various constituents that may be in wastewater. The Study is also looking at other important factors including an assessment of the costs and benefits of the various options, public acceptance, health and safety concerns, and environmental considerations.
Rev. May 2008
* Photos in text are landscaping at an apartment complex in San Diego (City irrigation customer) and a flower vase filled with fully treated recycled water from the North City Water Reclamation Plant, shown at the facility.