Dublin San Ramon Services District

Contaminants that may be present in source water include:

• Microbial contaminants, such as viruses and bacteria, which may originate from upstream sewage facilities, septic systems, agricultural operations, and wildlife
• Inorganic contaminants, including salts and metals, which can occur naturally or result from urban runoff, industrial discharges, oil and gas production, or farming activities
• Pesticides and herbicides from various sources like agriculture, urban stormwater runoff, and residential usage
• Organic chemical contaminants, including synthetic and volatile compounds, which are byproducts of industrial processes, petroleum production, gas stations, and septic systems
• Radioactive substances that may occur naturally or result from oil/gas production and mining operations

Primary drinking water standards establish maximum contaminant levels (MCL) and maximum residual disinfectant levels (MRDL) for substances affecting health, along with monitoring requirements. Secondary standards protect odor, taste, and appearance but don't have public health goals as they aren't health-based.

How We Monitor Water Quality
DSRSD staff collect representative samples throughout the distribution system. These samples are analyzed in the District's certified laboratory under the State Board Division of Drinking Water's Environmental Laboratory Certification Program. Zone 7 conducts continuous online monitoring plus instantaneous "grab" sampling. In total, DSRSD and Zone 7 test for more than 100 water quality parameters.

Treatment and Disinfection
Zone 7 uses a multi-barrier approach to disinfect and remove contaminants from surface water, while groundwater is chlorinated to maintain disinfectant residual in the distribution system. After receiving treated water from Zone 7, DSRSD maintains consistent disinfectant levels and flushes water mains to prevent bacterial growth.

Source Water Assessment
Zone 7's drinking water sources include local and imported surface water and groundwater. Source water protection is crucial for public safety. Groundwater sources may be vulnerable to contamination from chemical/petroleum pipelines, leaking tanks, contamination plumes, septic systems, and wastewater collection systems. Surface water is especially vulnerable as it travels through the Sacramento and San Joaquin watersheds and Delta.

A comprehensive Watershed Sanitary Survey for the State Water Project was completed in 1990 and is updated every five years, with the 2016 survey completed in June 2017. The Department of Water Resources Municipal Water Quality Investigations Program continues comprehensive water quality monitoring of the Delta and SWP facilities.

1. How often is municipal water tested in Dublin?
   Water is tested continuously through online monitoring systems and regular sampling throughout the distribution network.
2. What causes water hardness in the Dublin area?
   Water hardness primarily comes from naturally occurring calcium and magnesium minerals in the source water.
3. How can I reduce exposure to potential contaminants?
   Consider using a certified home water filtration system designed to address specific contaminants found in your area.
4. Does boiling water remove all contaminants?
   Boiling water kills most microorganisms but does not remove chemicals, metals, or increase hardness.
5. Where can I find my annual water quality report?
   Your Consumer Confidence Report is available through the Dublin San Ramon Services District website or by contacting customer service directly.