Water Department reports annual test results

Water supplied to Stanford by the SFPUC comes from two major sources: Hetch Hetchy Reservoir in the Sierra Nevada Mountains, and local watersheds.

Hetch Hetchy Reservoir

Hetch Hetchy Reservoir, which is the largest reservoir in the SFPUC system, is located in Yosemite National Park. It provides approximately 85 percent of the total water supply. Spring snowmelt flows down the Tuolumne River and fills the reservoir. The high quality Hetch Hetchy water supply meets all federal and state criteria for watershed protection, disinfection treatment, bacteriological quality and operational standards. As a result, the U.S. EPA and DOHS granted the Hetch Hetchy water source a filtration exemption. This exemption is contingent upon the Hetch Hetchy water quality continuing to meet all filtration avoidance criteria.

Alameda Watershed

The Alameda watershed, locate in Alameda and Santa Clara Counties, contributes to surface water supplies by storing rainfall and runoff in two reservoirs (Calaveras and San Antonio). This surface water source is supplemented by groundwater from Sunol Filter Galleries near the Town of Sunol. The SFPUC treats and filters these local water sources prior to delivery to its consumers.

Water System Management

The Stanford Utilities Division manages the storage, distribution, maintenance, and monitoring programs for Stanford's drinking water supply.

Stanford fluoridates the domestic drinking water and collects daily samples to monitor that fluoride concentrations are within the optimum range between 0.8 and 1.4 mg/L. Stanford also routinely collects water quality samples from various locations within the campus distribution system. Most frequently collected samples are analyzed for coliform bacteria, chlorine residual, and general physical parameters.

Supplementary water quality samples are collected to monitor for additional constituents in compliance with DOHS requirements. A certified laboratory analyzes all samples. Stanford submits monthly reports that include all monitoring results to the DOHS.

The SFPUC collects daily water quality samples from various locations within their transmission system. The samples are routinely analyzed for primary standards that apply to the protection of public health and secondary standards that refer to the aesthetic qualities of water such as taste and odor.

The Stanford Utilities Division also maintains flushing, cross-connections, and backflow prevention programs to ensure a consistent high quality drinking water supply.

Lead and Copper

Stanford University completed three consecutive six-month monitoring periods for lead and copper in 1994 and follow-up monitoring in 1995, 1998 and 2001. Stanford has not exceed the lead and copper action levels established by the U.S. EPA and DOHS. Because Stanford met all compliance standards for lead and copper, the DOHS specifies a reduced sampling program to once every three years. The next sampling will take place June 2004.

"Infants and young children are typically more vulnerable to lead in drinking water than the general population. It is possible that lead levels at your home may be higher than at other homes in the community as a result of materials used in your home's plumbing. If you are concerned about elevated lead levels in your home's water you can flush your cold water tap for 30 seconds to 2 minutes before use, and always use cold water for cooking. You may also wish to have your water tested. Additional information is available from the Safe Drinking Water Hotline (800) 426-4791)." (DOHS)

SFPUC's and Stanford's 2003 Sampling

The enclosed data tables summarize the 2003 sampling results from laboratory analyses of parameters detected in SFPUC's supply and Stanford's distribution systems. An extensive water sample collection and testing protocol is used at the various water sources throughout the SFPUC transmission system and in the campus distribution system. Both the SFPUC and Stanford monitor for many additional parameters, which were not detected.

SFPUC's source water supply results are presented in Table 1. Stanford's water quality results for the campus distribution system are presented in Table 2. Tables 1 and 2 contain the name of each substance, the highest level allowed by regulation (MCL), the ideal goals for public health (PHG), the average and range, the typical sources of such contamination. Footnotes explaining the data and a key to units of measurement are included.

Successful Implementation of Chloramine

Beginning February 2, 2004, the San Francisco Pubic Utilities Commission (SFPUC) successfully implemented a system-wide change to chloramine as drinking water residual disinfectant

The change to chloramine will help the SFPUC and Stanford Utilities consistently meet current and future water quality regulations and enhance water quality. Chloramine, a combination of chlorine and ammonia, is a more stable, longer-lasting disinfectant that produces lower levels of disinfection byproducts such as trihalomethane, a possible carcinogen. The majority of Bay Area residents outside the SFPUC service area have received chloraminated water for many years.
The SFPUC and Stanford Utilities have conducted extensive public awareness campaigns prior to the conversion to notify sensitive users of the change in disinfection, such as people with fish or amphibian tanks, kidney dialysis patients, and industrial/biotechnology businesses that use highly processed water. Chloramine must be removed from water for these sensitive uses.

Additional information is provided at the Stanford University-Water Group web site: http://facilities.stanford.edu/environment.