about your drinking water

What is Sweetwater Authority?
Sweetwater Authority is a publicly owned water agency with policies and procedures established by a seven-member Board of Directors. Five of the Directors are elected by the citizens of the South Bay Irrigation District. Two Directors are appointed by the Mayor of National City, subject to City Council Confirmation.

Sweetwater Authority provides safe, reliable water service to approximately 176,000 people in National City, Bonita and the western and central portions of Chula Vista. Its customers include residential, business, government, industrial and agricultural water users in an area covering more than 21,000 acres in the South Bay region of San Diego County.

From Left to Right, top row; J.S. "Ski" Wolniewicz, Cary Wright, Margaret Cook Welsh and Mitch Beauchamp; bottom row; Nick Inzunza, James Doud, Sr. and Bud Pocklington

What is safe drinking water?
The United States Environmental Protection Agency (EPA) and the California Department of Health Services (DHS) regulate California's tap and bottled water. These agencies establish standards that define our current understanding of safe drinking water. Last year, as in previous years, the water delivered by Sweetwater Authority met those standards. This report provides detailed information about the ways that Sweetwater Authority safeguards and treats your drinking water supplies. In accordance with State and Federal laws, it also provides a detailed listing of elements found in your drinking water and compares those levels to the maximum levels considered safe for the general public by the EPA and DHS. If you have questions about Sweetwater Authority operations or the contents of this report, please visit www.sweetwater.org or call chemists Pete Baranov or Mark Hatcher at (619) 409-6820.

Where your water comes from
Water delivered to Sweetwater Authority consumers is obtained from a variety of sources. On average, our customers receive 70 percent of their water from local water supplies, including the Sweetwater River and the San Diego Groundwater Formation. The remainder, about 30 percent, is obtained from imported water sources, transported by massive aqueduct systems from the Colorado River or the State Water Project, which carries water from the Sierra-Nevada Mountains through the Sacramento-San Joaquin Bay Delta.

About water contaminants
Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate a health risk. More information about contaminants and potential health risks can be obtained by calling EPA’s Safe Drinking Water Hotline (800) 426-4791. How is your water protected from contamination?

The local water used by Sweetwater Authority can be affected by activities within its watershed, a 200-square mile area leading into the streams that feed the Sweetwater River (see illustration, left). Sweetwater Authority uses a multiple barrier approach to protect water quality. Education, stakeholder involvement, and comments to local planners are part of the Authority’s protection efforts, in addition to the "hardware" solutions described here.
-- An innovative diversion system captures urban runoff before it enters Sweetwater Reservoir and transports the runoff below Sweetwater Dam, reducing the buildup of mineral salts in the reservoir (see photo, page 8). The diversion system can also capture and hold runoff from a chemical spill or sewage failure, allowing the contaminants to be removed and trucked away for proper disposal.
-- Well sites are closely monitored to assure that contaminants have not entered the well fields.
-- Surface water is treated and disinfected at the Perdue Plant (see diagram, right). Ground water is disinfected at the well site. Brackish groundwater is treated with reverse osmosis, then disinfected at the Reynolds Facility. (To learn more about water treatment, visit www.sweetwater.org. Click our water.)

How do contaminants get into water?
The sources of drinking water (both tap and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and it can pick up substances resulting from the presence of animals or from human activity.
Contaminants that may be present in source water include:
-- Microbial contaminants, such as viruses and bacteria, that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
-- Inorganic contaminants, such as salts and metals, that can be naturally occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming.
-- Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
-- Organic chemical contaminants, including synthetic and volatile organic chemicals that are byproducts of industrial processes and petroleum production and can also come from gas stations, urban stormwater runoff, and septic systems.
-- Radioactive contaminants, which can be naturally occurring or the result of oil and gas production and mining activities.

Treatment process at the Perdue Treatment Plant

To learn more about contaminants and health effects, call EPA's Safe Drinking Water Hotline at (800) 426-4791. Further information is also available at www.sweetwater.org and www.mwdh2o.com.