National Drinking Water Database
California
2,655 systems serving 54,146,711 people
This drinking water quality report shows results of tests conducted by water utilities in California, provided to the Environmental Working Group (EWG) by the California Department of Public Health. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results from 45 states and the District of Columbia. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources in protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes drinking water quality for this state.
Chemicals |
Water Utilities |
Population Served |
|
|---|---|---|---|
| Detected Chemicals | 182 |
2,655 |
52,625,466 |
Exceed health guidelines* | 81 |
2,471 |
51,995,714 |
Exceed Legal Limits* | 47 |
1,228 |
40,631,638 |
Unregulated chemicals detected | 94 |
925 |
46,183,188 |
| * Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance. | |||
81 Contaminants Exceeding Health Based Limits
Contaminants detected in California drinking water above health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities
| Contaminant | Population |
Number of Systems |
||
|---|---|---|---|---|
| At Any Level | Above Health Limits | At Any Level | Above Health Limits | |
| Alpha particle activity | 43,647,432 | 43,647,432 | 1,900 | 1,900 |
| Arsenic (total) | 41,950,094 | 41,950,094 | 1,237 | 1,237 |
| Bromodichloromethane | 41,004,984 | 41,004,984 | 642 | 642 |
| Total trihalomethanes (TTHMs) | 46,123,082 | 38,126,578 | 936 | 486 |
| Dibromochloromethane | 39,466,395 | 37,579,251 | 603 | 557 |
| Radium-228 | 37,456,970 | 37,456,970 | 1,367 | 1,367 |
| Bromoform | 36,309,656 | 36,309,656 | 565 | 565 |
| Chloroform | 43,130,356 | 36,048,313 | 758 | 402 |
| Total haloacetic acids (HAAs) | 34,007,091 | 33,966,183 | 422 | 418 |
| Radium-226 | 32,437,688 | 32,437,688 | 441 | 441 |
Water Utilities in California Reporting Chemicals Exceeding Health Guidelines
Water utilities in California reporting chemicals exceeding health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities, include:
| System | Population |
Chemicals tested |
Chemicals found |
Chemicals exceeding health guidelines |
|---|---|---|---|---|
| Cwsc Salinas | 98,730 | 176 | 44 | 24 |
| Pomona - City, Water Dept. | 156,500 | 196 | 48 | 24 |
| Redlands City Mud-Water Div | 69,300 | 167 | 34 | 23 |
| City of Corona | 150,253 | 168 | 37 | 23 |
| San Gabriel Valley Water Co.-El Monte | 153,657 | 229 | 48 | 23 |
| City of Modesto | 190,106 | 176 | 37 | 21 |
| Crescenta Valley Cwd | 31,000 | 143 | 37 | 21 |
| Cws - Bakersfield | 193,914 | 186 | 42 | 21 |
| West Valley Water District | 44,768 | 160 | 32 | 20 |
| Suburban Water Systems-San Jose | 110,602 | 108 | 32 | 20 |
| City of Bakersfield | 105,600 | 178 | 38 | 19 |
| City of Fresno Water Division | 390,350 | 145 | 34 | 19 |
| City of Daly City | 92,311 | 218 | 39 | 18 |
| San Gabriel Valley WC - Fontana | 102,599 | 185 | 43 | 18 |
| California Water Service Co-Leona Valley | 1,445 | 168 | 30 | 18 |
| Glendale-City, Water Dept. | 200,000 | 198 | 42 | 18 |
| Valley County Water Dist. | 55,000 | 138 | 38 | 18 |
| California Water Service-S San Francisco | 54,060 | 157 | 35 | 17 |
| California Water Service - Stockton | 155,670 | 156 | 34 | 17 |
| Camp Pendleton (South) | 39,915 | 214 | 32 | 17 |
Sources of California Drinking Water Contaminants
The contaminants identified in California drinking water come from a wide variety of sources, including agriculture, industry, water treatment plants, and polluted storm runoff from urban areas.
Testing Summary for California
The federal government has set standards for some of the pollutants found in tap water supplies.
| Contaminants reported as tested by water suppliers in California | 389 | |
| Contaminants tested due to federal law: | 100 | |
| Contaminants tested in addition to those required by federal law: | 289 | |
Violation Summary for California
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in California since 2004
| Violation Type | Number of Violations |
|---|---|
| Failure to monitor, Routine Major (Coliform bacteria) | 1,061 |
| Maximum contaminant level, Monthly (Coliform bacteria) | 1,021 |
| Failure to monitor regularly | 859 |
| Over maximum contaminant level, Average | 809 |
| Monitoring and Reporting Disinfection Byproduct Rule | 410 |
| Failure to report information to the public or state agency in the Consumer Confidence Report | 333 |
| Failure to monitor, Routine Minor (Coliform bacteria) | 218 |
| Over maximum contaminant level, Single Sample | 178 |
| Failure to monitor, Repeat Major (Coliform bacteria) | 127 |
| Failure to monitor, Repeat Minor (Coliform bacteria) | 125 |
| Treatment Technique (Surface Water Treatment Rule) | 88 |
| Follow-up and Routine Tap Sampling | 73 |
| Maximum contaminant level, Acute (Coliform bacteria) | 66 |
| Failure to monitor: Check/Repeat/Confirmation sampling | 25 |
| Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) | 23 |
| Excess Turbidity at 0.3 NTU | 21 |
| Initial Tap Sampling for Lead and Copper | 18 |
| Failure to notify state agency | 11 |
| Operations Report | 10 |
| Variance/Exemption/Other Compliance | 8 |
| Failure to notify public of violation | 6 |
| Treatment Technique No Certif. Operator | 6 |
| Inadequate reporting of information to the public | 5 |
| Optimal Corrosion Control Treatment Installation/Demonstration | 5 |
| Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) | 3 |
| Excess Turbidity at 1 NTU | 2 |
| Failure to Filter (Surface Water Treatment Rule) | 1 |
| Initial, Follow-up, or Routine Source Water Treatment Monitoring and Reporting | 1 |
| Public Education | 1 |
