The Power of Information

National Drinking Water Database

Southwood Water System Utilities - Tacoma, WA

Serves 18,643 people


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
21 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
43 days
Tests ConductedNumber of individual tests done for this contaminant
188 tests

Testing Summary

Health Limit
Legal Limit

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.309.91 ppb
890 ppb
300 ppb
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

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
Samples taken that dayNumber of Non-DetectsRange of Results
2006-12-19345.45 ppb11020 to 710 ppb
2006-12-18430 ppb20190 to 670 ppb
2006-10-27380 ppb5060 to 740 ppb
2006-10-26252 ppb510 to 550 ppb
2006-10-2533 ppb1060 to 120 ppb
2006-10-2411 ppb1070 to 60 ppb
2006-10-230 ppb550 ppb
2006-10-17468.33 ppb6020 to 980 ppb
2006-09-19603.33 ppb6060 to 1200 ppb
2006-08-22386 ppb5060 to 790 ppb
2006-08-2140 ppb1040 ppb
2006-06-20558 ppb10050 to 1000 ppb
2006-06-19640 ppb20380 to 900 ppb
2006-04-18527.5 ppb4040 to 1240 ppb
2006-04-17720 ppb10720 ppb
2006-03-280 ppb550 ppb
2006-03-2742.22 ppb970 to 190 ppb
2006-03-21661.67 ppb6060 to 1130 ppb
2006-02-2350 ppb1050 ppb
2006-02-22222.5 ppb40120 to 410 ppb
2006-02-21221.11 ppb920 to 840 ppb
2006-01-17538.33 ppb6060 to 940 ppb
2005-12-20645 ppb4040 to 880 ppb
2005-12-19626.67 ppb3050 to 1000 ppb
2005-10-21480 ppb10480 ppb
2005-09-280 ppb110 ppb
2005-09-26440 ppb310 to 1260 ppb
2005-09-200 ppb110 ppb
2005-09-190 ppb110 ppb
2005-09-160 ppb110 ppb
2005-07-19890 ppb1630 to 3670 ppb
2005-04-260 ppb110 ppb
2005-03-240 ppb110 ppb
2005-02-150 ppb110 ppb
2004-12-230 ppb110 ppb
2004-10-19750 ppb50420 to 1260 ppb
2004-08-260 ppb220 ppb
2004-08-19230 ppb10230 ppb
2004-08-17750 ppb10750 ppb
2004-05-260 ppb110 ppb
2004-04-21100 ppb10100 ppb
2004-04-20542.5 ppb1210 to 1730 ppb
2004-02-17741.43 ppb70500 to 980 ppb