The Power of Information

National Drinking Water Database


South Norwalk Electric and Water Utilities - Stamford, CT


Serves 42,000 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
2 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
21 days
Tests ConductedNumber of individual tests done for this contaminant
65 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.170.92 ppb
740 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
2007-08-09130 ppb10130 ppb
2007-08-0870 ppb1070 ppb
2007-07-19186.94 ppb18020 to 1360 ppb
2007-07-18135.71 ppb7050 to 310 ppb
2007-07-17180 ppb20120 to 240 ppb
2007-07-10100 ppb10100 ppb
2007-05-010 ppb110 ppb
2006-05-030 ppb110 ppb
2005-05-020 ppb110 ppb
2004-09-24510 ppb10510 ppb
2004-09-23180 ppb2050 to 310 ppb
2004-09-10110 ppb10110 ppb
2004-09-0170 ppb1070 ppb
2004-08-23130 ppb10130 ppb
2004-08-04250 ppb10250 ppb
2004-08-03740 ppb10740 ppb
2004-07-19255 ppb20220 to 290 ppb
2004-07-15174.62 ppb13060 to 390 ppb
2004-07-14227.14 ppb7060 to 470 ppb
2004-07-13140 ppb10140 ppb
2004-05-030 ppb110 ppb