The Power of Information

National Drinking Water Database

Metropolitan District Commission Utilities - Hartford, CT

Serves 388,700 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
0 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
31 days
Tests ConductedNumber of individual tests done for this contaminant
101 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.46.53 ppb
300 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
2007-07-307.85 ppb401.93 to 16 ppb
2006-06-097.5 ppb401 to 24 ppb
2006-03-151.5 ppb430 to 6 ppb
2005-11-214.33 ppb320 to 13 ppb
2005-09-1580 ppb1080 ppb
2005-08-12300 ppb10300 ppb
2005-07-18161.5 ppb2041 to 282 ppb
2005-07-1747.8 ppb5028 to 74 ppb
2005-07-1328 ppb4024 to 36 ppb
2005-07-0130 ppb1030 ppb
2005-06-3019 ppb1019 ppb
2005-06-2824.09 ppb1107 to 65 ppb
2005-06-2728.43 ppb7020 to 46 ppb
2005-06-2616 ppb1016 ppb
2005-06-2436 ppb1036 ppb
2005-06-2387 ppb1087 ppb
2005-06-2254 ppb6026 to 96 ppb
2005-06-21276.67 ppb3046 to 736 ppb
2005-06-2065 ppb1065 ppb
2005-06-1963 ppb1063 ppb
2005-06-1423 ppb5014 to 29 ppb
2005-06-1311 ppb1011 ppb
2005-06-120 ppb110 ppb
2005-06-1136.67 ppb3012 to 71 ppb
2005-06-016.67 ppb304 to 11 ppb
2005-02-242 ppb320 to 6 ppb
2004-11-180 ppb440 ppb
2004-11-170 ppb330 ppb
2004-07-1511.29 ppb706 to 21 ppb
2004-06-090 ppb440 ppb
2004-02-1714.2 ppb509 to 22 ppb