The Power of Information

National Drinking Water Database

Baltimore City Department of Public Works Utilities - Baltimore, MD

Serves 1,600,000 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
1 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
24 days
Tests ConductedNumber of individual tests done for this contaminant
53 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.135.01 ppb
740 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
2007-07-1186 ppb1086 ppb
2006-10-1067 ppb1067 ppb
2006-08-27288 ppb10288 ppb
2006-08-2375 ppb1075 ppb
2006-08-22111.5 ppb4074 to 209 ppb
2006-08-1766.6 ppb5030 to 95 ppb
2006-08-1534 ppb1034 ppb
2006-08-10127 ppb3059 to 216 ppb
2006-08-0881 ppb1081 ppb
2006-08-03195.33 ppb3068 to 301 ppb
2006-08-0137.5 ppb2024 to 51 ppb
2006-07-28740 ppb10740 ppb
2006-07-27157 ppb3084 to 208 ppb
2006-07-2656.5 ppb2042 to 71 ppb
2006-07-25158 ppb10158 ppb
2006-07-20233 ppb2051 to 415 ppb
2006-07-1972.5 ppb2060 to 85 ppb
2006-07-12142.5 ppb20130 to 155 ppb
2006-07-0324 ppb1024 ppb
2006-06-27119 ppb6024 to 176 ppb
2006-06-2135 ppb2030 to 40 ppb
2006-06-2096.67 ppb3059 to 129 ppb
2006-06-1378.25 ppb4047 to 98 ppb
2006-06-12159 ppb10159 ppb