ContaminantIn Water AsMaximum Contaminant Level
Copper (Cu)Cu2+USEPA Action Level* = 1.3 mg/L
MCLG** = 1.3 mg/L
WHO† Guideline = 2.0 mg/L

*Action Level requires water utilities to sample specific number of samples in specific locations and verify that 90% of samples are below this level. If that is not met, an appropriate Action is required to be taken to remedy the situation.
**Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
†WHO – World Health Organization

Sources of ContaminantIndustrial discharges
Copper salts used for algae control in reservoirs
Copper plumbing materials due to corrosion
Potential Health EffectsAcute copper poisoning: nausea, vomiting, diarrhea, gastrointestinal illness, abdominal and muscle pain.
Severe cases of copper poisoning have led to anemia, liver poisoning, and kidney failure.
Treatment Methods
Reverse Osmosis
Cation Exchange


In the United States the EPA, under the authority of the Safe Drinking Water Act (SDWA), has set the Maximum Contaminant Level Goal (MCLG) for copper at 1.3 mg/L (or ppm). This is the health-based goal at which no known or anticipated adverse effects on human health occur and for which an adequate margin of safety exists. The USEPA has set an action level for copper in drinking water at 1.3 mg/L. This means that utilities must ensure that water from the customer’s tap does not exceed this level in at least 90 percent of the homes sampled. The utility must take certain steps to correct the problem if the tap water exceeds the limit and they must notify citizens of all violations of the standard.

Copper is also regulated by the USEPA as an aesthetic contaminant (metallic taste) under the National Secondary Drinking Water Regulations5 (NSDWRs) at a Secondary Maximum Contaminant Level (SMCL) of 1.0 mg/L. Copper at this concentration is rare in public drinking waters and is not considered to be a health concern.

This information is sourced from the Water Quality Association (WQA) of which WCC is a proud member. Complete reports are available via the links below. This material is shared with the objective of offering comprehensive, professional insights into relevant water quality standards and guidelines.

Copper Fact Sheet – Downloadable PDF