The Power of Information

National Drinking Water Database

Roche Harbor Water System Inc Utilities - Shaw Island, WA

Serves 329 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
12 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)
2 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
27 days
Tests ConductedNumber of individual tests done for this contaminant
90 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.363.71 ppb
1315 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
2006-10-17493.5 ppb20118 to 869 ppb
2006-10-16115 ppb10115 ppb
2006-10-13394.5 ppb2069 to 720 ppb
2006-09-1932 ppb1032 ppb
2006-09-14278.25 ppb4035 to 620 ppb
2006-09-131315 ppb20780 to 1850 ppb
2006-09-08178.5 ppb20171 to 186 ppb
2006-09-07245 ppb710 to 820 ppb
2006-09-06370 ppb10370 ppb
2006-09-05165 ppb310 to 450 ppb
2006-08-3162 ppb1062 ppb
2006-05-11100 ppb10100 ppb
2006-05-10467.8 ppb5064 to 1180 ppb
2006-05-09273 ppb1150 to 1190 ppb
2005-08-2357.5 ppb2033 to 82 ppb
2005-06-03268 ppb10268 ppb
2005-06-0188 ppb310 to 135 ppb
2005-05-29140 ppb10140 ppb
2005-05-28222 ppb10222 ppb
2005-05-27525.8 ppb5022 to 1440 ppb
2005-05-26303 ppb6039 to 727 ppb
2005-05-25715 ppb20340 to 1090 ppb
2005-05-211110 ppb101110 ppb
2004-12-08705.25 ppb1210 to 3350 ppb
2004-08-300 ppb220 ppb
2004-06-25442 ppb10442 ppb
2004-06-23754 ppb1010 to 2630 ppb