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The risk of lead in drinking water


The city of Flint, Michigan is experiencing dangerous levels of lead in its drinking water. Naturally, this crisis is causing concern throughout the country. Could the same thing happen here? 

As has been reported, the city of Flint changed its water source without implementing appropriate corrosion control measures. As a result, the acidity (pH balance) of the water caused corrosion of the iron water mains, turning water brown, and caused lead to leach from pipes into tap water. Unfortunately, this problem was not reported because of inadequate testing. Overexposure of lead has serious long-term health consequences.

Lead levels are controlled for and monitored closely, both by Santa Clara Valley Water District and the water retailers that deliver the water we provide. The Flint crisis is highly unlikely to occur in Santa Clara Valley Water District’s service area for the following reasons:

  • Lead in drinking water rarely comes from a water treatment plant or from water mains. Lead comes from faucets, plumbing fixtures and lead solder within the home and from lead service lines, if they are present. 

  • Elevated lead is seldom found in natural sources of drinking water. Lead and other metals are naturally present at low levels in groundwater due to the erosion of natural deposits. 

  •  For the treated surface water provided by the district, regular testing of the finished water leaving our three drinking water treatment plants indicates non-detectable levels of lead. 

  • We have a corrosion control program that has been working effectively for decades. We add a corrosion inhibitor and adjust pH at our three drinking water treatment plants to prevent pipes and plumbing systems from corroding and leaching lead (or copper) into the drinking water. 

  • Our corrosion control program is approved by the California State Water Resources Control Board’s Division of Drinking Water, and we are not content with simply complying with regulations; we set internal goals that go above and beyond the letter of the law. 

  • We regularly monitor our distribution system to ensure we maintain compliance with strict state rules regarding our corrosion control program. The results show we have always complied with the lead and copper regulation. 

  • Our water treatment plants continuously monitor the corrosion inhibitor dosing and the pH balance of water as well as other important parameters 24/7. 

  • The water district’s state-of-the art, ISO certified laboratory is nationally recognized as a leader in water quality analysis and holds one of the highest levels of certification available from the State Water Resources Control Board – Division of Drinking Water. The laboratory tests and quantifies the quality of Santa Clara County’s drinking water treated by the water district, testing approximately 170,000 samples per year for over 353 regulated and unregulated contaminants including lead. 

  • Our pipelines bring water treated from our three drinking water treatment plants to distribution systems operated by several different water retailers. The water provided to residents and businesses by water retailers may be treated surface water, groundwater, or a blend. Some county residents also pump groundwater directly from private wells. Groundwater is generally not corrosive by nature. 

  • Local water providers are required to monitor and report the effectiveness of our corrosion control program in their distribution systems by analyzing samples taken from customers’ water taps. Water providers are required to provide their customers an annual Consumer Confidence Report - generally referred to as the annual Water Quality Report - that details water quality testing results for the prior year. Contact your local water retailer for water quality sampling results.

Despite the fact that California requires new household plumbing and fixtures to be lead-free, lead is still present in some plumbing fixtures, especially in houses built before 1986. Corrosion-control chemicals help to prevent lead from leaching into your tap water. Nevertheless, if you are concerned about the possibility of lead in your drinking water, you may wish to have your water tested for lead by a qualified laboratory. 

  • Local laboratories that are state-certified to perform drinking water analyses, and can test for lead in your water:

    Alpha Analytical Laboratories, Inc.
    6398 Dougherty Road, Suite 35
    Dublin, CA 94568
    (925) 828-6226

    Torrent Laboratory, Inc.
    483 Sinclair Frontage Road
    Milpitas, CA 95035
    (408) 263-5258

If you are concerned about environmental lead exposure, please contact:

Helpful resources on lead:

For more information from the Santa Clara Valley Water District, you can contact
Water Quality Unit Manager Peter Zhou at: