Water Quality Testing Program

Lead and Copper Testing

We test every three years for lead and copper in more than 50 pre-selected homes throughout the treated water service area. These tests are done on homes with older plumbing. Results are published in the Annual Water Quality Report. Between 2000 and 2005, out of the 324 homes that were tested, only two homes were found to have lead levels that exceeded the EPA minimums.

We completed the latest round of Lead and Copper Rule monitoring in June 2016. Results are in full compliance with federal and state standards and are well below the EPA’s action level. Our corrosion control efforts are effective and are demonstrated by the results below.

Lead and Copper Testing Results

Criteria Lead (mg/L) Copper (mg/L)
Sample Event June 2016 June 2016
Range <0.0005 – 0.008 0.011 – 0.34
90th Percentile* <0.005 0.17
Detection Limit for Reporting** 0.005 0.05
EPA Action Level 0.015 1.3
Number of Samples Collected 64 64
Number Sites Above Method Reporting Limit 43 64
Number Sites Above DLR 1 44
Number Sites Above Action Level 0 0

* 90th Percentile: 90 percent of the samples are less than or equal to the value presented. This value is used to measure compliance with the US Environmental Protection Agency (EPA) Action Level.

** Detection Limits for Purposes of Reporting (DLRs) are set by the California State Water Resources Control Board – Division of Drinking Water (DDW). When a contaminant is found below the DLR, it is considered non-detect (ND) for the purposes of reporting.

In the event that you are concerned about any amount of lead in water, we are providing water quality tips on how to reduce lead exposure (PDF).

For more information on lead in drinking water please send us an email or call our Water Quality Hotline at 925-688-8156.