Drinking Water Quality Report
Washington
2,182 systems serving 5,288,422 people
This drinking water quality report shows results of tests conducted by water utilities in Washington, provided to the Environmental Working Group (EWG) by the Washington State Department of 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 | 91 |
2,182 |
4,980,486 |
Exceed health guidelines* | 34 |
1,826 |
4,906,613 |
Exceed Legal Limits* | 20 |
496 |
1,620,039 |
Unregulated chemicals detected | 35 |
256 |
2,788,233 |
| * 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. | |||
34 Contaminants Exceeding Health Based Limits
Contaminants detected in Washington 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 | |
| Lead (total) | 4,381,685 | 4,381,685 | 1,384 | 1,384 |
| Bromodichloromethane | 4,272,871 | 4,272,871 | 651 | 651 |
| Total haloacetic acids (HAAs) | 3,887,901 | 3,822,524 | 502 | 471 |
| Dichloroacetic acid | 3,681,299 | 3,681,299 | 350 | 350 |
| Total trihalomethanes (TTHMs) | 4,387,619 | 3,417,957 | 839 | 354 |
| Chloroform | 4,295,075 | 3,350,927 | 700 | 271 |
| Dibromochloromethane | 3,777,615 | 2,831,234 | 564 | 516 |
| Bromoform | 2,395,147 | 2,395,147 | 374 | 374 |
| Arsenic (total) | 2,222,066 | 2,222,066 | 522 | 522 |
| Copper | 3,922,960 | 2,169,030 | 1,571 | 465 |
Water Utilities in Washington Reporting Chemicals Exceeding Health Guidelines
Water utilities in Washington 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 |
|---|---|---|---|---|
| City of Tacoma Water Division | 305,000 | 177 | 28 | 17 |
| Long Beach Water Department | 2,865 | 171 | 29 | 13 |
| Lakehaven Utility District | 112,000 | 174 | 16 | 13 |
| Sammamish Plateau Water & Sewer | 60,735 | 176 | 18 | 13 |
| Eastsound Water Users Association | 1,922 | 169 | 19 | 13 |
| City of Kennewick | 64,680 | 180 | 24 | 12 |
| Lewis River Golf Course | 35 | 170 | 17 | 12 |
| Eatonville Water Dept | 2,012 | 182 | 15 | 12 |
| Southwood Water System | 18,643 | 172 | 14 | 11 |
| Snoqualmie Water | 7,800 | 147 | 13 | 11 |
| Roche Harbor Water System Inc | 329 | 85 | 22 | 11 |
| City of Renton | 55,000 | 29 | 15 | 11 |
| City of Moses Lake | 20,650 | 171 | 23 | 11 |
| Water District 19 | 2,637 | 171 | 14 | 11 |
| Heights Water | 1,735 | 85 | 13 | 11 |
| Fife Dept of Public Works | 6,135 | 88 | 15 | 11 |
| Camano Water Association | 2,492 | 29 | 15 | 11 |
| Bonney Lake Water Department, City | 30,920 | 163 | 15 | 11 |
| City of Yakima Water Division | 65,038 | 168 | 16 | 10 |
| Vinland | 2,372 | 100 | 12 | 10 |
Sources of Washington Drinking Water Contaminants
The contaminants identified in Washington 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 Washington
The federal government has set standards for some of the pollutants found in tap water supplies.
| Contaminants reported as tested by water suppliers in Washington | 194 | |
| Contaminants tested due to federal law: | 90 | |
| Contaminants tested in addition to those required by federal law: | 104 | |
Violation Summary for Washington
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Washington since 2004
| Violation Type | Number of Violations |
|---|---|
| Failure to monitor regularly | 42,917 |
| Maximum contaminant level, Monthly (Coliform bacteria) | 1,235 |
| Failure to monitor, Routine Major (Coliform bacteria) | 999 |
| Failure to report information to the public or state agency in the Consumer Confidence Report | 553 |
| Follow-up and Routine Tap Sampling | 502 |
| Over maximum contaminant level, Single Sample | 284 |
| Maximum contaminant level, Acute (Coliform bacteria) | 93 |
| Failure to monitor, Repeat Major (Coliform bacteria) | 86 |
| Initial Tap Sampling for Lead and Copper | 59 |
| Treatment Technique (Surface Water Treatment Rule) | 57 |
| Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) | 8 |
| Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) | 6 |
