How to read your water quality report (CCR)

What the report is

EPA requires every community water system to deliver a Consumer Confidence Report, also called an annual drinking water quality report, to its customers by July 1 each year. If you did not get yours, call your water supplier or use EPA’s CCR search tool linked from EPA’s CCR page. State reports can add state-specific information, but they must include the federal basics.

What is in it

According to EPA, a CCR includes:

• the lake, river, aquifer or other source of your water;
• a short summary of the risk of contamination of that source;
• the regulated contaminants found in your water;
• potential health effects of any contaminant detected in violation of a health standard;
• the system’s actions to restore safe drinking water;
• an educational statement for vulnerable populations about Cryptosporidium;
• information on nitrate, arsenic or lead where those may be a concern;
• phone numbers for more information, including EPA’s Safe Drinking Water Hotline, 1-800-426-4791.

Reading the table of detected contaminants

Look at five columns, in this order:

1. Contaminant, for example arsenic, nitrate, haloacetic acids or lead.
2. MCL, the maximum contaminant level: the legal limit allowed in drinking water.
3. MCLG, the maximum contaminant level goal: a non-enforceable health goal. EPA sets it at zero for lead because lead can be harmful at low exposure levels.
4. Level detected, usually a highest value or a range, and sometimes an annual average. The unit matters: ppm is parts per million, ppb is parts per billion and ppt is parts per trillion.
5. Violation: Yes or No, with a note on the typical source.

If the level detected is below the MCL and the violation column says “No”, the utility met that standard for the reporting year. If a violation is shown, the report must explain the possible health effects and what the utility is doing about it (what an MCL violation means).

What a CCR does not tell you

• Your tap. A CCR describes water leaving the utility and in its distribution system. Lead usually comes from service lines and plumbing in older homes, so the CCR’s lead line (a 90th-percentile figure from sampled homes) is not your result. See lead in tap water.
• Every contaminant. CCRs focus on regulated contaminants. Per EPA, community water systems must also report UCMR 5 results in their CCR when a contaminant is found at or above its minimum reporting level, as average and range for the prior year’s monitoring, if timing allows (UCMR 5 explained). The full UCMR 5 results are in EPA’s data, which is what our pages summarize.
• Today’s water. It covers the previous calendar year.

If something looks off

Call the number on the report. EPA’s Public Notification Rule requires systems to alert you if there is a problem with your drinking water, and those notices are separate from the annual CCR. For health concerns, talk to a clinician or your state health department.