How to read your water quality report (CCR)

To read your water quality report, go straight to the table of detected contaminants and compare each row's highest level with its legal limit, the MCL. Then check the violation column, and read the lead, PFAS and disinfectant rows with the notes below.

The report's official name is the Consumer Confidence Report (CCR), and EPA requires community water systems to send it by July 1 each year.

Get the report

Your utility mails the report or posts it online (CDC). If a landlord or management company pays the water bill, you may not get it directly, so CDC suggests checking online or asking the landlord (same source). EPA's CCR search tool has many reports, but not every system's. Households on a private well get no report at all (CDC). If that is you, see well water testing.

The terms reports define

Reports must define MCL and MCLG. They must define the other terms below when the report uses them (40 CFR 141.153):

• MCL (Maximum Contaminant Level): the highest level of a contaminant allowed in drinking water. This is the enforceable limit.
• MCLG (Maximum Contaminant Level Goal): the level below which there is no known or expected risk to health. It is a goal, not a limit. For lead it is zero (EPA).
• Action Level (AL): the level that, if exceeded, triggers treatment or other steps the utility must take. Lead and copper use an action level instead of an MCL.
• Treatment Technique (TT): a required process meant to reduce a contaminant, used instead of a number.
• MRDL (Maximum Residual Disinfectant Level): the highest level of a disinfectant, such as chlorine or chloramine, allowed in drinking water.

Units

Results must be shown in the same unit as the limit (40 CFR 141.153). In EPA's key, ppm means milligrams per liter, ppb means micrograms per liter and ppt means nanograms per liter. One ppm is 1,000 ppb, and one ppb is 1,000 ppt. Check the unit before you compare numbers: 3 ppb of lead is 0.003 ppm.

Read one row at a time

For each regulated contaminant it detects, the report must show the highest level used to judge compliance, the range of detected levels and the likely source (40 CFR 141.153).

1. Find the contaminant and note its unit.
2. Compare the highest level (or highest average, for contaminants judged on an average) with the MCL.
3. Look at the range to see how much results varied during the year.
4. Read the violation column. If the utility broke a rule, the report must say what the violation was, how long it lasted, whether it was a health risk and how the utility is fixing it (CDC).

A detection below the MCL is not a violation. CDC defines a violation as a time the utility did not meet drinking water standards or follow EPA's rules (same source).

Lead and copper rows look different

Lead and copper rows show the 90th percentile of home tap samples, the number of sampling sites above the action level and the range (40 CFR 141.153). A 90th percentile of 5 ppb means 90% of the homes sampled were at or below 5 ppb.

The lead action level is 15 ppb under the current rule. EPA's 2024 lead rule lowers it to 10 ppb once systems must comply on November 1, 2027 (40 CFR 141.80). These results come from sampled homes, so they cannot tell you what your own pipes add. See lead pipes and lead filters.

PFAS, lithium and other unregulated contaminants

If your utility found contaminants during EPA's unregulated contaminant monitoring, the report must list their average and range (EPA). The latest round, UCMR 5, tested for 29 PFAS and lithium between 2023 and 2025 (same source). Under EPA's 2024 PFAS rule, utilities must also start telling customers their levels of the regulated PFAS in 2027 (EPA). In May 2026 EPA proposed keeping the PFOA and PFOS limits, letting systems ask for until 2031 to meet them, and dropping four other PFAS limits; those proposals were not final as of October 2026 (Federal Register 2026-10085, 2026-10086). See PFOA and PFOS limits explained and lithium in tap water.

Disinfectant rows

Chlorine and chloramine both have an MRDL of 4 ppm (EPA). CDC says to check your report to see which disinfectant your utility uses (CDC). That matters if you keep fish or do dialysis at home (same source). See chloramine in tap water.

Changes from 2027

Under EPA's 2024 revisions, reports must be easier to read starting in 2027, and systems serving 10,000 or more people must send them twice a year (40 CFR 141.155).

Next steps

• If your utility is one of the 50 largest in the US, its page on this site shows EPA's UCMR 5 results and its recent health-based violations. Example: City of Fort Worth.
• If your report lists hardness, enter it in the softener size calculator.
• For questions about your report, call your utility or EPA's Safe Drinking Water Hotline at 1-800-426-4791 (EPA).