printable versionWater Quality Data and Water Quality Report for 2005
The following is an excerpt from the 2005 Water Quality Report provided by Stanford in compliance with the requirements of the U.S. Environmental Protection Agency (US EPA) and the California Department of Health Services (CDHS). It is the policy of the Stanford Facilities Operations - Utilities Division to fully inform its consumers about the water quality standards and typical concentrations of constituents found in the water. Stanford University is in compliance with state and federal drinking water requirements.
Drinking Water Sources
Water supplied to Stanford by the San Francisco Public Utilities Commission (SFPUC) comes from three major sources: Hetch Hetchy Reservoir in the Sierra Nevada Mountains, and local watersheds in Alameda and San Mateo Counties.
Hetch Hetchy Reservoir
Hetch Hetchy Reservoir, which is the largest reservoir in the SFPUC system, is located in Yosemite National Park. It provides approximately 91 percent of the total water supply in 2005. Spring snowmelt flows down the Tuolumne River and fills the Hetch Hetchy 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 US EPA and CDHS 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, located 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 ground water from Sunol Filter Galleries near the Town of Sunol. The SFPUC treats and filters these local water sources prior to delivery to its consumers.
San Mateo Watershed
Surface water from rainfall and runoff captured in the 23,000-acre Peninsula Watershed, which is located in San Mateo County, is stored in four reservoirs: Crystal Springs (Lower and Upper), San Andreas, Pilarcitos and Stone Dam. This water source is treated at the Harry Tracy Water Treatment Plant prior to delivery to customers.
Water System Management
The Utilities Division manages the storage, distribution, maintenance, and monitoring programs for Stanford’s drinking water supply.
Stanford routinely collects water quality samples from various locations within the campus distribution system. The 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 CDHS requirements. A certified laboratory analyzes all samples. Stanford submits monthly reports that include all monitoring results to the CDHS.
SFPUC also collects daily water quality samples from various locations within their transmission system. The samples are 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.
SFPUC & Stanford’s 2005 Sampling
The adjoining data table summarizes the 2005 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.
The table contains 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 also included.
Please review the 2005 Annual Water Quality Report in its entirety at: facilities.stanford.edu/environment.