How to Read Your Water Quality Report (Consumer Confidence Report Explained)

The Consumer Confidence Report requirement comes from the 1996 amendments to the Safe Drinking Water Act. Congress decided that water utilities had been collecting all this monitoring data for years but never sharing it with the people actually drinking the water. The CCR requirement changed that.

Every community water system in the United States — meaning any public water system that serves the same customers year-round — must produce a CCR annually and deliver it to customers by July 1. If you're a homeowner, it may come as a mailing, as an insert in your water bill, or as an email if you've opted in. If you rent, your landlord is legally required to provide it to you — though enforcement of this is weak, and many renters never see it.

The CCR must include: the source of your water (lake, river, groundwater aquifer, etc.), a list of all regulated contaminants detected during the testing period and their measured levels, the EPA Maximum Contaminant Level for each detected contaminant, a notice of any violations that occurred and what health effects are associated with them, and information about how the utility is addressing any issues found.

If you can't find your CCR, there are two easy ways to get it. First, search your utility's name plus "Consumer Confidence Report" or "Water Quality Report" on Google — most utilities post them on their websites. Second, use the EPA's online CCR search tool at epa.gov/ccr. If you're still stuck, call your utility directly and ask for a copy. They're required to provide one.

Most CCRs include a table that lists every regulated contaminant that was tested for. Here's what each column means and which ones to focus on.

Contaminant name. This is the substance being measured. Don't be alarmed by a long list — a long contaminant list means the utility is doing thorough testing, not that your water is contaminated. Federal law requires testing for over 90 different substances.

MCLG (Maximum Contaminant Level Goal). This is the level at which the EPA believes there is truly no health risk — the ideal target. For carcinogens like arsenic, benzene, and several other substances, the MCLG is listed as zero, meaning there's no truly safe level. For other contaminants, it's a specific number. The MCLG is not legally enforceable — it's the goal.

MCL or TT (Maximum Contaminant Level or Treatment Technique). This is the legally enforceable limit. This is the number that matters for compliance. If the measured level exceeds the MCL, that's a violation and the utility is required to notify you and take corrective action. Some contaminants are regulated by treatment technique (TT) rather than a specific numerical limit.

Level Detected (or Range of Detections). This is the most important number in the table for your personal health assessment. It's the actual measured amount of the contaminant in your water during the reporting year. Some CCRs show a single number; others show a range from the lowest sample to the highest.

In Violation? (Yes/No). If any contaminant's detected level exceeded the MCL, this column will say yes. The report is required to explain what the violation means for your health and what the utility is doing about it.

Focus your attention on: contaminants with a detected level above zero (especially if close to the MCL), any "yes" in the violation column, and anything with an MCLG of zero (these are the ones with no truly safe level).

Lead and Copper. These are reported as "90th percentile results" — the level at or below which 90% of sampled homes tested. If the 90th percentile lead level is above 15 ppb (the EPA action level), the utility must take corrective action. If it's below 15 ppb, the system is in compliance — but remember, the public health goal for lead is zero.

Total Trihalomethanes (TTHMs) and Haloacetic Acids (HAA5s). These are the two main categories of disinfection byproducts — compounds formed when chlorine or other disinfectants react with naturally occurring organic matter in source water. The EPA limits TTHMs to 80 parts per billion and HAA5s to 60 ppb. These violations are among the most common in the EPA database, particularly for surface water systems. Long-term exposure above these levels is associated with increased cancer risk.

Nitrates. The EPA limit for nitrates is 10 milligrams per liter (mg/L), measured as nitrogen. Nitrates at levels above this are dangerous for infants under 6 months, causing a condition called methemoglobinemia (sometimes called "blue baby syndrome"). Nitrate contamination is most common in agricultural areas with heavy fertilizer use or near septic systems. If your CCR shows nitrate levels even approaching 10 mg/L and you have an infant, use a certified reverse osmosis filter for formula preparation.

Arsenic. The EPA limit is 0.010 mg/L (10 parts per billion). Arsenic is naturally present in many groundwater sources, particularly in the western United States, New England, and parts of the Midwest. Long-term exposure above the MCL increases the risk of bladder, lung, and skin cancers. Note that the MCLG for arsenic is zero — meaning even at the legal limit, there is some residual risk.

Fluoride. The EPA primary limit is 4 mg/L. Fluoride is intentionally added to many water systems at around 0.7 mg/L to promote dental health — this is a standard, safe practice. At levels above 2 mg/L (the secondary standard), dental fluorosis (tooth discoloration in children) can occur. At levels above 4 mg/L, skeletal fluorosis becomes a concern.

Finding a violation in your CCR can be alarming, but context matters. Not all violations are equal.

Health-based violations are the serious ones. These occur when a contaminant exceeded the Maximum Contaminant Level or when a required treatment technique wasn't properly implemented. These violations mean the water actually exceeded a federal safety standard at some point during the year.

Reporting and monitoring violations are less serious in terms of immediate health risk. These happen when a utility fails to test for a required contaminant on schedule, or fails to submit results to the state on time. They indicate management problems but don't necessarily mean the water was unsafe.

The important question when you see a violation is: what happened afterward? A utility that detected an MCL exceedance, notified customers promptly, identified the source, and corrected the problem is very different from a utility with the same violation that took no action. The CCR should explain what corrective actions were taken. If it's vague, contact your utility and ask directly.

One more thing worth knowing: the CCR reflects the previous calendar year's data. A violation you're reading about in July might have been identified and corrected eight months ago. That's why it's worth contacting your utility if you have concerns — ask for the most current data, not just what's in last year's report.

Most CCRs are straightforward good-news documents — the water met all federal standards. But here are the things that should prompt a closer look or a call to your utility.

Any "yes" in the violation column for a health-based contaminant. Even if it says the issue was corrected, ask your utility when it was fixed and what testing has been done since.

Lead levels above 5 ppb at the 90th percentile. Technically compliant (below the 15 ppb action level), but worth taking the extra step of getting your own tap tested if you have young children.

TTHMs or HAA5s at or above 60–70 ppb. These are approaching the MCL. If your water consistently shows high disinfection byproduct levels, a carbon block filter or reverse osmosis system for drinking water is a reasonable precaution.

Nitrate levels above 5 mg/L. If you have a formula-fed infant or are pregnant, this warrants using filtered or bottled water.

Language like "we are aware of this issue and working to address it." This vague language sometimes appears in CCRs when utilities are trying to minimize concern. Follow up and ask for specifics.

A very short report that lists almost nothing. Some utilities — particularly small ones — produce bare-minimum CCRs that technically comply with the law but tell you very little. If your report seems unusually sparse, ask for more information.

Renters are in a particularly difficult position when it comes to water quality information. The CCR comes addressed to the "water customer" — usually the person paying the water bill, which in many rental situations is the landlord.

Legally, landlords who receive a CCR are required to give a copy to their tenants. In practice, this almost never happens. If you're renting and have never seen a CCR, you're in the majority — but you still have options.

First, you can search for your water utility's CCR online or via the EPA search tool using your address. The CCR covers the entire utility service area, not individual properties, so you can find it regardless of who pays the bill.

Second, if you have specific concerns about lead — particularly if you live in an older building with original plumbing — you can request that your landlord arrange for tap water testing, or do it yourself. A certified lead test kit costs around $20 to $30 online.

Third, if you're in a building built before 1978, check for the landlord's lead paint disclosure. Homes with lead paint sometimes also have older plumbing — the two risk factors often go together.