Your annual drinking water quality report can tell you where your water comes from, which regulated contaminants were detected, and whether the water system violated a drinking water requirement.
It cannot tell you exactly what is present at every faucet in your home.
That distinction matters. The report describes the public water system. Conditions can change after water enters a service line, apartment building, or household plumbing.
Start with three questions:
- Did the water system report a violation?
- Which contaminants were detected, and how did the results compare with the applicable limits?
- Is there a reason to investigate your individual building or tap?
This guide explains how to answer those questions without treating every detected substance as an emergency.
What is a Consumer Confidence Report?
A Consumer Confidence Report, or CCR, is an annual drinking water quality report from a community water system.
The U.S. Environmental Protection Agency requires community water systems to provide these reports to their customers. Reports are generally due by July 1 each year.
The report may be called:
- Consumer Confidence Report
- annual water quality report
- drinking water quality report
- water quality report
It normally describes water quality during the previous calendar year. It is not a real-time statement about conditions on the day you read it.
The report should include information about:
- the source of the drinking water
- contaminants detected in required monitoring
- applicable drinking water standards
- violations and associated health information
- actions taken to correct reported problems
- contact information for the water system
EPA finalized revisions to the CCR rule in 2024. Starting in 2027, reports are intended to become easier to read and more accessible. Systems serving more than 10,000 people will also be required to distribute reports twice each year. Until those provisions apply, report layouts and delivery methods may vary.
How to find your water quality report
First, identify the utility or community water system that supplies your address.
The name may appear on your water bill. Renters whose water is included in the rent may need to ask the landlord, property manager, or local utility.
You can then:
- Search the utility's official website.
- Contact the water supplier and request the latest report.
- Use EPA's Consumer Confidence Report search tool.
- Contact your state drinking water program if you cannot identify the correct system.
Make sure the report matches both your water system and reporting year. Nearby communities can use different sources or treatment systems.
If your water comes from a private well, you will not receive a CCR for that well. Private-well owners are responsible for arranging appropriate testing. Our planned guide to private well water testing will address that process separately.
Read the report in this order
A long contaminant table can make the report look more complicated than it is. Read it in a deliberate order.
1. Confirm the water system and year
Look for:
- the water system's name
- the reporting year
- the area or population served
- a public water system identification number, if listed
Confirm that the report applies to the water delivered to your address. A utility may operate more than one supply or distribution area.
2. Find the source of the water
The report should identify whether the water comes from sources such as:
- rivers
- lakes or reservoirs
- groundwater wells
- purchased water from another system
- a combination of sources
Source information provides context. It does not, by itself, tell you whether the finished water is safe.
Utilities treat and monitor water according to the source and applicable regulations. A river may require extensive treatment. Groundwater may have different naturally occurring minerals or local contamination concerns.
3. Locate the compliance or violation statement
Look for headings such as:
- violations
- compliance information
- monitoring and reporting violations
- health effects information
- important information about your drinking water
If the system reported a violation, read the complete explanation. Identify:
- the rule or contaminant involved
- when the violation occurred
- whether it was a health-based, treatment, monitoring, or reporting violation
- what customers were advised to do
- what the system did to correct the problem
- whether the system has returned to compliance
Do not assume that every violation means the water contained a contaminant above a health-based limit. A system can also violate requirements by missing a test, reporting late, or failing to complete required monitoring.
Those failures still matter because missing information reduces confidence in compliance. However, a monitoring violation and a confirmed contaminant exceedance are not the same event.
4. Read the detected-contaminant table
The table is usually the main part of the report. It may contain columns for:
- contaminant name
- date sampled
- level detected
- range of results
- MCLG
- MCL or treatment technique
- violation status
- likely source
Read across one row at a time. Do not compare numbers until you have checked that they use the same unit.
What MCL, MCLG, TT, and MRDL mean
These abbreviations appear in many reports.
Term | Meaning | How to use it |
|---|---|---|
MCLG | Maximum Contaminant Level Goal | A non-enforceable public-health goal below which no known or expected health risk is identified, with a margin of safety. |
MCL | Maximum Contaminant Level | The enforceable maximum level allowed for a regulated contaminant. It is set as close to the MCLG as feasible, considering available treatment technology and cost. |
TT | Treatment Technique | A required process used when regulation through a simple concentration limit is not suitable. |
MRDLG | Maximum Residual Disinfectant Level Goal | A non-enforceable health goal for a drinking-water disinfectant. |
MRDL | Maximum Residual Disinfectant Level | The highest residual disinfectant level allowed, while recognizing that disinfectants are needed to control microorganisms. |
These definitions come from EPA's National Primary Drinking Water Regulations.
The MCL and MCLG may be different. That does not automatically mean water below the MCL but above the MCLG violates federal requirements.
The MCL is the enforceable standard. The MCLG is a health goal used in developing the regulation.
Does “detected” mean the water is unsafe?
No. Detection alone does not establish that the water is unsafe.
Modern analytical methods can measure very small quantities. A report may list a contaminant because it was detected, even when the result remained below its enforceable limit.
Interpret the row by asking:
- What concentration was found?
- What unit was used?
- What comparison value applies?
- Was a violation marked?
- Does the report include special health information or instructions?
A result above zero is not automatically a violation. Likewise, a statement that the system met federal standards does not mean every measured substance was absent.
The useful question is not simply, “Was it detected?” The useful question is, “How does the reported result compare with the applicable standard, and what does the report say about compliance?”
Understand the units before comparing numbers
Drinking-water reports commonly use very small units.
Unit | Abbreviation | Approximate equivalent |
|---|---|---|
Milligrams per liter | mg/L | Parts per million, or ppm, in water |
Micrograms per liter | µg/L | Parts per billion, or ppb, in water |
Nanograms per liter | ng/L | Parts per trillion, or ppt, in water |
One milligram per liter equals 1,000 micrograms per liter.
One microgram per liter equals 1,000 nanograms per liter.
For example, 0.010 mg/L equals 10 µg/L. Comparing 0.010 with 10 without converting the units would produce the wrong conclusion.
Microbial results, disinfectant levels, turbidity, and radioactivity may use other units. Use the definitions provided in that report rather than assuming every row is expressed in ppm or ppb.
What “range,” “average,” and “highest level” may represent
A water system usually collects multiple samples at different times or locations.
The report may therefore show:
- an average
- a highest result
- a lowest-to-highest range
- a percentage of positive samples
- a percentile value
- a running annual average
These measures are not interchangeable.
The number used for compliance depends on the contaminant and the rule. For example, some contaminants are evaluated using averages, while lead and copper use a sampling framework and percentile-based results rather than a conventional system-wide MCL.
Read the table heading and its footnotes. If the calculation is unclear, contact the utility and ask what the reported value represents.
Why a result may be from an earlier year
Not every regulated contaminant is tested every year at every system.
Monitoring frequency depends on the contaminant, source, system history, and regulatory requirements. A report may therefore show the most recent result from an earlier monitoring period.
Check the “date sampled” column before assuming the value was measured during the reporting year.
An older date does not necessarily mean the system ignored testing. It may reflect an approved monitoring schedule. The water system or state drinking water program can explain the required frequency.
Primary standards and secondary standards are different
EPA's National Primary Drinking Water Regulations are enforceable health-based requirements for public water systems.
EPA also has secondary drinking water standards. These are generally non-enforceable federal guidelines for characteristics such as taste, odor, color, staining, or scaling.
This distinction helps explain why water can meet primary health standards but still have an unpleasant taste, mineral deposits, or temporary discoloration.
It also works in the other direction. Water can look and taste normal while containing a contaminant that cannot be detected by the senses.
Appearance, taste, and odor are therefore not reliable substitutes for a water-quality assessment.
What the report says about lead
Lead deserves special attention because much of the exposure risk can arise from service lines, building plumbing, solder, and fixtures.
The report should provide information about the water system's lead monitoring. It may include a 90th percentile result, an action level, the number of sampled sites above that level, or information about service lines.
That result does not equal the lead concentration at every home.
EPA explains that lead cannot be seen, tasted, or smelled in drinking water. Testing is the only way to determine the concentration at a particular tap. If your home has a lead service line, older plumbing, or another reason for concern, use the report as a starting point rather than proof about your individual faucet.
Our planned article on lead in drinking water will explain sampling, service lines, certified filters, and practical next steps in detail.
What a water quality report cannot tell you
A CCR is useful, but it has limits.
It generally cannot tell you:
- the exact water quality at every household faucet
- whether your internal plumbing is releasing lead or copper
- whether a building's storage tank or plumbing is poorly maintained
- what happened after the reporting period ended
- whether an unregulated contaminant was absent if it was not tested
- whether a private well is safe
- whether a home water filter is working correctly
The report also should not be used to diagnose illness. If a household member is sick or has a possible exposure, contact an appropriate healthcare professional and local public-health authority.
When the report should prompt further action
Contact the water utility if:
- the report lists a violation you do not understand
- you cannot determine whether the problem has been corrected
- you need the results for your specific distribution area
- a result, unit, date, or footnote is unclear
- you want information about lead service lines or recent lead sampling
- your water recently changed in color, taste, or odor
Contact the state drinking water program or local health department if you need independent clarification or cannot get an adequate response from the utility.
Consider household testing when there is a specific reason, such as:
- concern about lead from a service line or building plumbing
- a private well or another unregulated supply
- flooding, a plumbing repair, or a contamination incident
- an official recommendation to test
- a local contaminant concern not answered by the report
Use a state-certified drinking-water laboratory when reliable results are needed. EPA does not test residential water on request but provides state laboratory certification contacts.
Do not order the broadest available test panel without first identifying the question. The appropriate contaminants, sample location, container, preservation method, and collection procedure depend on what you are investigating.
What to do if the report lists a violation
Read the report's instructions before choosing a response.
Different problems require different actions. Boiling can reduce risks from many microorganisms, but it does not remove lead, salts, or most chemical contaminants. In some chemical incidents, boiling may be specifically inappropriate.
If a current drinking-water advisory is in effect, follow the specific instructions from local officials. CDC distinguishes among boil water, do not drink, and do not use advisories:
- Follow the utility or health department instructions.
- Check whether the advisory is for boiling, avoiding consumption, or avoiding all use.
- Pay attention to instructions for infant formula, cooking, ice, pets, and medical devices.
- Do not assume a household filter makes the water safe unless officials specifically say it is suitable for that contaminant.
- Confirm that the advisory has been lifted before returning to normal use.
An annual report may describe a problem that has already been corrected. A current advisory, however, requires timely attention. Check the dates carefully.
A five-minute reading checklist
If you do not want to analyze every row immediately, use this shorter process:
- Confirm the correct water system and reporting year.
- Identify the source of your water.
- Find the violation or compliance section.
- Note every row marked “yes” under violation.
- Compare detected values only after checking their units.
- Read footnotes for ranges, averages, percentiles, and older sample dates.
- Review the lead information separately.
- Write down questions for the utility.
- Check for any current advisory that may have been issued after the report period.
Bottom line
Your drinking water quality report is the best starting point for understanding a community water supply.
First, look for violations. Then compare detected contaminants with the correct enforceable limits, using the same units. Read the dates and footnotes before drawing conclusions.
Remember that the report describes the water system, not the exact condition of every household tap. Building plumbing, service lines, private wells, and events after the reporting period may require separate investigation.
Use the report to ask better questions. Do not use it to assume that every detection is dangerous or that every individual faucet has been tested.
References
- U.S. Environmental Protection Agency. CCR Information for Consumers. Updated November 21, 2025. Accessed September 23, 2026.
- U.S. Environmental Protection Agency. Consumer Confidence Report Rule Revisions. Updated November 21, 2025. Accessed September 23, 2026.
- U.S. Environmental Protection Agency. National Primary Drinking Water Regulations. Updated August 31, 2026. Accessed September 23, 2026.
- Centers for Disease Control and Prevention. How to Read Drinking Water Quality Reports. Accessed September 23, 2026.
- U.S. Environmental Protection Agency. Basic Information About Lead in Drinking Water. Updated June 18, 2026. Accessed September 23, 2026.
- U.S. Environmental Protection Agency. Contact Information for Certification Programs and Certified Laboratories for Drinking Water. Updated August 18, 2025. Accessed September 23, 2026.
- U.S. Environmental Protection Agency. Secondary Drinking Water Standards: Guidance for Nuisance Chemicals. Updated May 26, 2026. Accessed September 23, 2026.
- Centers for Disease Control and Prevention. Drinking Water Advisories: An Overview. Updated March 4, 2024. Accessed September 23, 2026.