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Copper in drinking water

Also called Cu.

Action level
1.3 ppm
Health goal
1.3 ppm

Values in parts per million (ppm). Comes from pipes, often your own.

Contaminant referenceLimits checked Oct. 4, 2026

Where the rules stand

There is no MCL for copper. EPA uses a treatment technique with an action level of 1.3 ppm (1.3 mg/L) and a health goal of 1.3 ppm. EPA's table shows no change to the copper action level from the 2024 Lead and Copper Rule Improvements. EPA's separate, non-enforceable secondary standard for copper is 1.0 ppm.

The scale every TapBuff report uses for this contaminant: the legal line at the middle, twice it at the right.

Is it in your water?

Matched to your utility using EPA records

What EPA says about health

EPA lists stomach and intestinal distress from short-term exposure above the action level, and liver or kidney damage from long-term exposure. EPA says people with Wilson's disease should talk to their doctor if copper in their water is above the action level.

Where it comes from

EPA lists corrosion of household plumbing and erosion of natural deposits.

What handles it

  • NSF/ANSI 53

    Claim to look for: Copper Reduction

    NSF listing wording. WQA lists it as "Copper."

  • NSF/ANSI 58

    Claim to look for: Copper Reduction

    Reverse osmosis systems. WQA lists it as "Copper."

Filters with that claim on a certifier’s listing

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Sources

  1. National Primary Drinking Water Regulations, U.S. EPA. Checked Oct. 4, 2026.
  2. Secondary Drinking Water Standards: Guidance for Nuisance Chemicals, U.S. EPA. Checked Oct. 4, 2026.
  3. National Primary Drinking Water Regulations for Lead and Copper: Improvements (LCRI) (final rule, October 30, 2024), Federal Register. Checked Oct. 4, 2026.
  4. Search for NSF Certified Drinking Water Treatment Units (standards and reduction claims lists), NSF. Checked Oct. 4, 2026.
  5. Find WQA Certified Products (Gold Seal listings by standard and claim), Water Quality Association. Checked Oct. 4, 2026.
  6. SDWA Dataset Download Summary (codes from SDWA_REF_CODE_VALUES.csv, 2026 Q2 extract), U.S. EPA ECHO. Checked Oct. 4, 2026.