Reading your water system's annual quality report

Every community water system, the kind that serves the same people year-round, sends its customers a drinking water quality report each year. It's also called a Consumer Confidence Report, or CCR. It says where your water comes from, what was found in it over the past year, the health risks of anything found at unsafe levels, and what the system did about any violations.

You won't get one if you have a private well. You also won't get one for water from a place that runs its own small system, such as a school, a hospital, a campground or a gas station.

Getting a copy

If you didn't get yours, call your water supplier, or look it up with EPA's online search tool for local reports.

What's in it

• The source. The lake, river, aquifer or other source, by name, and a summary of how at risk it is of contamination.
• The definitions. The terms you need to read the table.
• The table of detected contaminants. Everything the system found in its required testing during the previous calendar year.
• Health effects. What any contaminant found above an EPA health standard could do.
• Violations. What the system did to fix them.
• Required statements. Information on lead for every system, on nitrate or arsenic where they may be a concern, and on Cryptosporidium for people at higher risk.
• Who to call. A phone number at the water system, and EPA's Safe Drinking Water Hotline, 800-426-4791.

A contaminant is anything in the water besides water. Some are harmless or even useful at the right level, such as the chlorine that disinfects it.

The terms in the table

• MCLG, maximum contaminant level goal. The level below which there's no known or expected risk to health. Goals allow a margin of safety.
• MCL, maximum contaminant level. The highest level allowed in drinking water. It's set as close to the goal as treatment technology can get.
• Action level, AL. The level that, if exceeded, sets off treatment or other steps the system has to take. Lead and copper are reported this way, with the 90th percentile of sampled homes and the number of sites above the action level.
• Treatment technique, TT. A required process to reduce a contaminant.
• ppm and ppb. Parts per million and parts per billion. The table lists the detected level in the same units as the MCL, so you can compare them directly.

The table shows the highest level detected and the range of results, and it marks anything over a limit with bold type or an asterisk. Contaminants tested less than once a year show the latest result and its date.

Reading it

Start with the violations or "meets standard" column. For each violation, look at what happened, how long it lasted, whether it posed a health risk and how the system is fixing it. Compare it with past years' reports to see whether problems come back.

Read the health information for who's at higher risk. A mention of a germ or chemical in that section doesn't mean your water has it.

An annotated example

What to do next

Find this year's report from your water system, and read the violations column first. If something concerns you, call the number in the report, your local health department, or EPA's Safe Drinking Water Hotline at 800-426-4791. You can also have your tap water tested. Lead in drinking water, flushing and testing covers lead, and Private well annual testing and upkeep covers a well.