The Power of Information

National Drinking Water Database


City of Tacoma Water Division Utilities - Tacoma, WA


Serves 305,000 people

Copper

Copper is a naturally occuring metal and drinking water contaminant that enters tap water by corrosion of household plumbing systems and erosion of natural deposits.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
4 days
Test Days Exceeding Legal LimitsNumber of days in which the samples taken in that day exceed the Maximum Contaminant Level (Depending on the contaminant and its MCL, that may or may not trigger an MCL violation. Some MCLs are based on averages spanning several months to a year)
0 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
32 days
Tests ConductedNumber of individual tests done for this contaminant
121 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
CopperCopper is a naturally occuring metal and drinking water contaminant that enters tap water by corrosion of household plumbing systems and erosion of natural deposits.56.17 ppb
416.94 ppb
Yes
300 ppb
No
1000 ppb
NOTE: Each dot in the above graph represents one month.
* 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.

Health Based and Legal Limits for Copper

Health Based Limits for Copper

StandardDescriptionLevel
California Public Health GoalsDefined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.300 ppb
National Secondary Drinking Water RegulationsA National Secondary Drinking Water Regulation is a non-enforceable guideline regarding contaminants that may cause cosmetic effects (such as taste, odor, or color). Some states choose to adopt them as enforceable standards. Source: U.S. Environmental Protection Agency. 1000 ppb
Maximum Contaminant Limit Goal (MCLG)A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.1300 ppb
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.1300 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2006-09-260 ppb110 ppb
2006-09-220 ppb110 ppb
2006-07-260 ppb110 ppb
2006-07-240 ppb330 ppb
2006-07-120 ppb220 ppb
2006-07-050 ppb220 ppb
2006-05-0121 ppb1021 ppb
2005-11-160 ppb110 ppb
2005-10-260 ppb110 ppb
2005-10-190 ppb110 ppb
2005-08-110 ppb110 ppb
2005-07-2830 ppb1030 ppb
2005-06-280 ppb220 ppb
2005-06-210 ppb220 ppb
2005-06-200 ppb110 ppb
2005-06-150 ppb110 ppb
2005-06-090 ppb220 ppb
2005-06-070 ppb220 ppb
2005-05-250 ppb110 ppb
2005-05-060 ppb110 ppb
2004-12-150 ppb110 ppb
2004-11-180 ppb330 ppb
2004-11-170 ppb220 ppb
2004-10-190 ppb110 ppb
2004-09-070 ppb440 ppb
2004-08-10336 ppb210 to 672 ppb
2004-07-29407 ppb3030 to 810 ppb
2004-07-28416.94 ppb1610 to 1050 ppb
2004-07-2767 ppb1067 ppb
2004-07-26371.42 ppb57026 to 1490 ppb
2004-07-17148 ppb10148 ppb
2004-06-280 ppb220 ppb