Know Your Water

How to Read Your Water Quality Report (CCR)

Your utility sends this report every year — here's how to actually read it

Data sources: EPA, SDWA Last updated: March 2026

What Is a CCR?

A Consumer Confidence Report (CCR) — also called a Water Quality Report or Annual Drinking Water Quality Report — is a document your water utility must publish every year. It summarizes where your water comes from, what was detected in testing, and whether any EPA standards were exceeded.

The CCR is required under the Safe Drinking Water Act (SDWA) for all community water systems serving 15 or more connections. This covers about 148,000 public water systems serving approximately 300 million Americans (EPA SDWIS data).

The problem: most people glance at the CCR and toss it. The data is genuinely useful — but only if you know what the abbreviations mean and which numbers actually matter.

Finding Your Report

Your utility publishes the CCR online and may also mail a paper copy. To find it:

  1. Search "[your utility name] water quality report" — most publish PDF versions on their website
  2. Check the EPA's CCR searchepa.gov/ccr links to reports by state
  3. Call your water utility — the number is on your water bill
  4. Check your ZIP codelook up your ZIP on ZipCheckup to see violations and lead data pulled directly from EPA databases

If you are on a private well, you will not receive a CCR — your water is not tested or reported by any agency. See our well water safety guide for testing recommendations.

Key Terms Explained

The CCR is full of abbreviations. Here are the ones that matter:

Regulatory Standards

Term Full Name What It Means
MCL Maximum Contaminant Level The highest legally allowed level of a contaminant in drinking water. Enforceable
MCLG Maximum Contaminant Level Goal The level at which no known health risk exists. Not enforceable — it's a target. Often lower than the MCL
AL Action Level Used for lead and copper. If more than 10% of sampled taps exceed the AL, the system must take corrective action
TT Treatment Technique Instead of a numerical limit, the utility must use a specific treatment method (e.g., surface water filtration)
MRDL Maximum Residual Disinfectant Level Maximum allowed level of chlorine or other disinfectant

Measurement Units

Unit What It Means Context
ppm Parts per million (= mg/L) Used for most contaminants: nitrates, fluoride, TDS
ppb Parts per billion (= µg/L) Used for lead, arsenic, chromium-6. 1,000 ppb = 1 ppm
ppt Parts per trillion (= ng/L) Used for PFAS. 1,000 ppt = 1 ppb
pCi/L Picocuries per liter Used for radioactive contaminants: radium, uranium, radon
NTU Nephelometric Turbidity Units Measures water cloudiness. >1 NTU may indicate inadequate filtration

Statistical Terms

Term What It Means
Range The lowest and highest values detected across all sampling locations
Average The arithmetic mean of all samples
90th percentile Used for lead and copper. The value below which 90% of sample results fall. If this exceeds the AL, the system is in violation
ND Not Detected — the contaminant was below the lab's detection limit
N/A Not Applicable — the system was not required to test for this contaminant

Reading the Data Table

Every CCR contains a table that looks something like this:

Contaminant Unit MCL MCLG Your System Violation? Source
Lead ppb AL = 15 0 90th%: 8 No Corrosion of household plumbing
Nitrate ppm 10 10 3.2 No Runoff from fertilizer use
Total Trihalomethanes ppb 80 45 (range: 12–78) No Byproduct of drinking water disinfection
PFOA ppt 4 0 2.1 No Industrial discharge

How to interpret each row:

  1. Compare "Your System" to the MCL — if the detected level is below the MCL, the system is in compliance
  2. Compare to the MCLG — this is the actual safety target. If the MCL is 15 ppb but the MCLG is 0, that means ANY detection carries some risk
  3. Look at the range — a system-wide average of 5 ppb lead means some locations are higher. The range tells you the spread
  4. Check "Violation?" — a violation means the system exceeded the MCL or failed to test properly. This triggers EPA enforcement
  5. Read "Source" — this tells you where the contaminant comes from. "Corrosion of household plumbing" means it's a local pipe issue, not the source water

What to Look For

Priority 1: Lead

  • The MCLG for lead is zero. No amount is safe
  • The 90th percentile value is what matters — if it's above 15 ppb, the system is in violation
  • Even if below 15 ppb, any detection means some homes have elevated lead
  • The CCR doesn't test YOUR tap — it tests a sample of high-risk homes in the system. Your home may be higher or lower
  • See the lead guide and lead risk tool for more context. The CCR doesn't test at your tap — to verify, use Best Water Testing Kits

Priority 2: PFAS

  • PFOA and PFOS have a new MCL of 4 ppt (effective 2024, compliance deadline 2029)
  • Many CCRs don't yet include PFAS data — systems are still implementing monitoring
  • If your CCR doesn't list PFAS, it doesn't mean they're absent — it may mean the system hasn't tested yet
  • PFAS guide

Priority 3: Disinfection Byproducts (DBPs)

  • Total Trihalomethanes (TTHMs): MCL 80 ppb. Formed when chlorine reacts with organic matter
  • Haloacetic Acids (HAA5): MCL 60 ppb
  • DBPs are carcinogenic at elevated levels. If levels are close to the MCL (within 75%), the system is under pressure
  • Seasonal variation matters — DBP levels peak in summer when water temperatures are higher

Priority 4: Nitrates

  • MCL is 10 mg/L — this standard was set specifically to protect infants from blue baby syndrome (methemoglobinemia)
  • Levels above 5 mg/L indicate agricultural or septic influence and may trend upward over time
  • If you have an infant, any detectable nitrates above 3–5 mg/L warrant caution

Priority 5: Radioactive Contaminants

  • Radium-226/228: MCL 5 pCi/L combined
  • Uranium: MCL 30 µg/L
  • Gross alpha: MCL 15 pCi/L
  • These are naturally occurring in certain geological formations. If detected, they tend to be persistent — they won't go away without treatment

What the CCR Doesn't Tell You

The CCR has significant blind spots:

  1. Your household plumbing — Lead enters water AFTER it leaves the treatment plant, through your home's pipes, solder, and fixtures. The CCR samples a handful of homes; yours may not be one of them

  2. Private well water — If you're on a well, no government agency tests your water. You must test it yourself. Well water guide

  3. All contaminants — EPA regulates about 90 contaminants. There are thousands of unregulated chemicals (pharmaceuticals, microplastics, many pesticides) that the CCR doesn't address

  4. Real-time conditions — The CCR reports data from the PREVIOUS calendar year. Water conditions can change due to construction, pipe breaks, source water changes, or treatment failures

  5. Distribution system decay — Water quality at the treatment plant may differ from water quality at your tap. Aging distribution mains can introduce lead, manganese, and disinfection byproducts

  6. Contaminant interactions — The CCR reports each contaminant independently. It doesn't assess the cumulative health effect of multiple contaminants at low levels — a topic of ongoing research

What to Do Next

After reading your CCR:

  1. Check your ZIP code report — ZipCheckup aggregates violation data, lead levels, radon risk, and flood data into a single view with historical context

  2. If lead is detected (any level) — test YOUR tap. A first-draw sample from a state-certified lab costs $25–$50 and tells you what the CCR can't: your specific home's lead level

  3. If PFAS isn't listed — contact your utility and ask whether they've completed initial PFAS monitoring under the 2024 rule. If not, consider getting an independent test ($200–$350)

  4. If any contaminant is close to the MCL — it may occasionally exceed the MCL between reporting periods. Consider a point-of-use filter certified for that contaminant. Our filter guide matches contaminants to filter technologies

  5. If violations are listed — check whether the violation is health-based or monitoring/reporting. Health-based violations (MCL exceeded) are more serious than monitoring violations (missed a test deadline), but both indicate management issues

FAQ

Frequently Asked Questions

Is the CCR required by law?

Yes. Under the Safe Drinking Water Act, every community water system serving more than 15 connections must deliver a Consumer Confidence Report to customers by July 1 each year. The report covers testing data from the previous calendar year. Non-community systems (schools, campgrounds) are exempt.

My CCR says 'no violations.' Does that mean my water is safe?

It means your water system complied with EPA standards during the reporting period. However, EPA standards don't cover all contaminants (PFAS wasn't regulated until 2024), and they don't account for your household plumbing. Lead from pipes, for example, wouldn't appear in the CCR because it enters water after it leaves the treatment plant.

Why don't I receive a CCR in the mail?

Many utilities have switched to online-only delivery, which EPA now allows if the system serves a population that can reasonably be expected to access the internet. The utility must still notify you that the report is available. Check your water bill insert, utility website, or call them directly.

Does the CCR cover lead in my home's plumbing?

No. CCR lead data comes from the Lead and Copper Rule sampling program, which tests a subset of high-risk homes in the system. The reported value is the 90th percentile — meaning 10% of sampled homes had higher levels. Your home may be higher or lower depending on your specific plumbing. To know your home's lead level, test at your tap.

Related Guides

HomeGuides → How to Read Your Water Quality Report (CCR)

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