How to Read Your Water Quality Report: A Step-by-Step Guide

Written by: Scott Steveson, Specialist, Wellness Quality Institute

Key Takeaways

• Every community water system must issue an annual Consumer Confidence Report (CCR) that lists only contaminants the EPA requires it to monitor.
• Four regulatory terms, MCL, MCLG, AL, and TT, help you read the main contaminants table and spot any violations quickly.
• Even when a CCR shows full compliance, it does not test for microplastics, nanoplastics, or hundreds of unregulated compounds that may still be present.
• Brands that make water-quality or plastic-reduction claims need independent verification of existing lab data because a CCR alone cannot substantiate those claims.
• The Wellness Quality Institute offers Plastic-Free Pathway Verification to review companies’ laboratory data and turn it into defensible, publicly registered claims; explore how WQI turns lab data into verified plastic-related claims.

How to Read Your Water Quality Report

A Consumer Confidence Report is a legal compliance document, not a full health assessment. Federal regulations under 40 CFR Parts 141 and 142 dictate what must appear and how it must be presented. The detected-contaminants table sits at the center of every CCR, and four terms unlock that table.

Term	Plain-language meaning	Enforceable?	What it means if your water exceeds it
MCL (Maximum Contaminant Level	The highest level of a contaminant the law allows in delivered drinking water, set by the EPA as close to the health goal as treatment technology makes feasible	Yes	A violation, and the utility must notify customers and take corrective action
MCLG (Maximum Contaminant Level Goal)	The level below which no known or expected health risk exists, set by the EPA as a non-binding target; for some contaminants such as lead the MCLG is zero	No	No legal violation, but health considerations may still apply, so water can be legally compliant while above the health goal
AL (Action Level)	Used for lead and copper instead of an MCL; if more than 10% of sampled homes exceed the AL, the utility must act, for example by adding corrosion control or replacing service lines	Triggers required action	The utility must implement additional treatment or infrastructure steps under EPA §141.80
TT (Treatment Technique)	A required process the utility must follow for contaminants that do not have a set MCL, for example filtering surface water to control pathogens	Yes (process, not a number)	Failure to follow the required process is a violation even if no specific concentration limit was exceeded

These four terms appear in every compliant CCR. Standard CCR column headings include contaminant name, unit of measurement, MCLG, MCL (or AL or TT), amount detected, violation status, and likely source of contamination. When you see “ND” in the amount-detected column, it means “not detected above the laboratory reporting limit,” not that the substance is absent at every concentration. Detection floors vary by method and contaminant.

Step 1: Locate Your Drinking Water Quality Report

Start by finding your current CCR. The EPA maintains a CCR search tool where you can look up your utility by zip code or system name. Most utilities also post the current-year report on their website, usually under a heading like “Water Quality” or “Annual Report.” If you receive water from a private well, your home is not served by a community water system and no CCR is required, so independent testing is the only way to assess your water quality.

Once you have the report, go first to the water-source section. Federal rules require every CCR to identify the type of source, either surface water such as a river or reservoir, or groundwater from an aquifer, and to name the specific source or wholesale supplier. If a source-water assessment has been completed, the CCR must either summarize it or direct you to where it can be read. Source type matters because surface water and groundwater carry different contamination patterns and face different treatment requirements.

Step 2: Read the Contaminant Table Column by Column

Begin with the contaminant name and its unit. Most values appear in ppm, which means parts per million and equals milligrams per liter, or mg/L. Others appear in ppb, which means parts per billion and equals micrograms per liter, or µg/L, or in ppt, which means parts per trillion.

Next, compare the “Amount Detected” column to the MCL column. If the detected level is below the MCL, the utility is in legal compliance for that contaminant. If it is above the MCL, the Violation column will read “Yes.”

A sample row might read: Nitrate | 5.2 mg/L detected | MCL 10 mg/L | MCLG 10 mg/L | No violation | Source: runoff from fertilizer use. That row tells you the utility is well within the legal limit. A row showing a detected level between the MCLG and the MCL, which is legally compliant but above the health goal, deserves attention even though no violation occurred.

Step 3: Check Violations and Health-Effect Language

EPA provides mandatory health-effects statements for each regulated contaminant in Appendix A to Subpart O of 40 CFR 141, and these statements must be copied verbatim in the CCR. If a violation occurred during the reporting year, the CCR must explain the dates, the potential health effects using EPA-prescribed wording, the corrective actions taken, and the current status. Look for this language in a section separate from the main table so you can see how the utility responded.

Step 4: Read Lead and Copper Action Levels Carefully

Lead and copper do not use an MCL. Instead, the action level for lead is 0.015 mg/L and for copper is 1.3 mg/L. If more than 10% of tap samples exceed the action level, the utility must take additional steps.

The CCR reports lead and copper as the 90th-percentile value across sampled homes, which means 90% of sampled taps were at or below that number. Because lead enters water mainly through household plumbing rather than the treatment plant, a utility-level result does not tell you exactly what comes out of your specific tap. Homes built before 1986 face higher risk from lead service lines and solder, so residents in those homes should pay particular attention.

Step 5: Know What Your Report Does Not Cover

A CCR only covers what federal law requires utilities to monitor. Substances outside that required list do not appear, even if they are present in the water you drink.

Microplastics provide the clearest example. EPA researchers define microplastics as plastic particles ranging in size from 5 millimeters down to 1 nanometer, with nanoplastics as a subset smaller than 1 micrometer. Despite widespread detection in drinking water, including a peer-reviewed 2018 study by Kosuth, Mason, and Wattenberg in PLOS ONE that found anthropogenic particles in 81% of 159 tap water samples across five continents, microplastics have no federal MCL and are not required CCR analytes.

The regulatory picture is changing slowly. The EPA’s draft sixth Contaminant Candidate List (CCL 6), published April 6, 2026, includes microplastics as a contaminant category under evaluation for possible future regulation. Inclusion on the CCL does not require water utilities to test for or disclose microplastics in annual CCRs under current federal Safe Drinking Water Act rules. Placement on the list only signals that the EPA is considering the contaminant for potential future rulemaking.

PFAS, which stands for per- and polyfluoroalkyl substances, form a large family of synthetic chemicals used in nonstick coatings, firefighting foam, and food packaging. They are a partial exception. In April 2024, the EPA finalized the first federal National Primary Drinking Water Regulation for PFAS, establishing enforceable MCLs for six PFAS compounds, including PFOA and PFOS. However, a May 2026 EPA proposal would rescind the MCLs for four of those six compounds and allow qualifying systems a two-year extension on PFOA and PFOS compliance until April 2031. Hundreds of other PFAS compounds remain unregulated at the federal level.

The World Health Organization’s 2019 assessment, Microplastics in Drinking-Water, remains a clear summary of current evidence: low concern on limited data, with more research urgently needed. That conclusion rests on incomplete information, which is why a CCR’s silence on microplastics cannot be read as proof that they are absent.

Learn how WQI verification addresses microplastics in drinking water

Step 6: Decide When to Seek More Verification

Use your CCR results as a starting point for a simple decision framework. Start by checking whether your CCR shows full compliance, because most reports do. EPA’s 2023 National Public Water Systems Compliance Report found that some public water systems had a health-based violation, while many failed at least one monitoring or reporting requirement. A monitoring or reporting violation means the utility did not test on schedule or did not file results on time. That situation does not always mean a contaminant exceeded a limit, but it does mean the data has gaps.

Use the following situations as prompts for further action:

• Any row in the contaminant table shows a detected level above the MCL, with Violation = Yes
• Lead or copper results sit at or near the action level, especially in an older home
• The CCR notes a monitoring or reporting violation, which leaves gaps in the data
• Your household includes infants, pregnant individuals, or immunocompromised people
• Your water source is surface water in an agricultural or industrial area
• You are a brand making water-quality or plastic-reduction claims and need to substantiate them beyond what a CCR can show

Step 7: For Brands, Turn Lab Data into Verified Claims

A CCR tells you what the utility tested and where it met legal limits. It cannot confirm the absence of microplastics or the hundreds of unregulated compounds that fall outside required federal monitoring. For brands making water-quality or plastic-reduction claims, this gap creates a verification problem. Even when brands commission independent laboratory testing, and many already do, a lab report alone does not become a defensible market claim because self-reported results are read as marketing.

The Wellness Quality Institute (WQI) is an independent verification body that reviews companies’ existing third-party laboratory data on plastic and microplastic content against a defined standard. This review helps brands substantiate real progress toward plastic-free standards instead of making impossible zero-plastic claims. WQI’s core program, Plastic-Free Pathway Verification (PFPV), governed by the standard WQI-CS-01, independently reviews a company’s existing laboratory dataset, testing methodology, product scope, and supporting controls against defined criteria focused on particle size and polymer type. WQI does not run laboratory tests, and it does not certify that any product is free of plastic, because no laboratory today can confirm the complete absence of plastic across every particle size, polymer type, and production lot.

WQI’s review criteria align with a drinking-water microplastics reference framework, which is the most stringent credible public reference currently available for this type of testing. Verification is available to US companies nationally, not only in California. California has not created, approved, authorized, or endorsed WQI or its standard.

Every WQI review produces one of two outcomes. A Standard Met outcome carries a verification decision, a scope-locked license to use the WQI logo, a public registry listing, and approved claim language. A Standard Not Met outcome remains private, is never described as a failed product, and can be resubmitted with updated information. A single assessment fee covers review, verification decision, and registry listing, while independent laboratory testing is arranged and billed separately by a qualified independent laboratory.

One-Page Checklist for Reviewing Your CCR

Use the checklist below when reviewing any CCR. Print it and work through each row as you read your report.

1. Source identified? Confirm the report names the specific river, reservoir, aquifer, or wholesale supplier and the source type, either surface or ground water.
2. Contaminant table present? Every detected regulated contaminant must appear with MCL, MCLG, amount detected, violation status, and likely source.
3. Any Violation = Yes rows? Note the contaminant, the detected level, and the health-effects language the utility is required to include.
4. Lead and copper 90th-percentile values? Compare to the action levels described in Step 4 and note whether the utility triggered any required actions.
5. Any monitoring or reporting violations? Look for these separately from the contaminant table, because they indicate gaps in the data record.
6. PFAS results present? As of 2024, utilities must begin monitoring for six PFAS compounds, so check whether results appear and whether any approach the new MCLs.
7. Microplastics listed? Expect that they will not be listed, then note this gap and consider independent testing or verification if it relates to your product or brand claims.
8. Source-water assessment referenced? If completed, the CCR must summarize it or direct you to it.

Turn your CCR findings into verified claims with WQI

Frequently Asked Questions

How often is my Consumer Confidence Report updated, and where can I find past reports?

Under the 1998 CCR Rule, which remains in effect through 2026, community water systems must produce one annual CCR by July 1 covering the prior calendar year’s monitoring data. Beginning with 2026 data, systems serving 10,000 or more people must deliver the report twice per year. Most utilities post current and recent past reports on their website, and the EPA’s online CCR search tool lets you look up your system by zip code or system name. If a contaminant was sampled in a prior year instead of the current reporting year, the CCR must note the sample date, because federal rules allow results from prior years for most contaminants as long as the sample year is clearly stated in the table.

What does “ND” or “not detected” mean in a water quality report, and does it mean the water is clean?

“ND” means the contaminant was not found above the laboratory’s reporting limit for that specific test. It does not mean the substance is absent at every concentration. Every analytical method has a detection floor, which is the minimum level below which it cannot reliably identify a substance. A result of “not detected” is always limited by that floor.

For microplastics specifically, the best validated methods begin at 20 or 50 micrometers, so particles smaller than that are invisible to the method regardless of how many are present. “Not detected” describes what the instrument found, not a guarantee that the substance is completely absent.

Are PFAS now required to appear in my water quality report?

For six specific PFAS compounds, PFOA, PFOS, PFHxS, PFNA, HFPO-DA (also called GenX chemicals), and a hazard-index mixture, the EPA finalized enforceable limits in April 2024. Under the original 2024 PFAS NPDWR, public water systems must complete initial monitoring by April 26, 2027, with full compliance with the PFAS MCLs by April 26, 2029. A May 2026 EPA proposal would rescind the MCLs for four of those six compounds and allow qualifying systems a two-year extension on PFOA and PFOS compliance. Until monitoring is complete and results are reported, many CCRs will not yet show PFAS data. Hundreds of other PFAS compounds remain unregulated at the federal level and will not appear in any CCR.

My CCR shows my water meets all federal limits. Does that mean it is safe from microplastics?

A CCR that shows full compliance confirms only that the utility met the standards it is legally required to meet. Microplastics are not among those required standards. As of mid-2026, microplastics appear on the EPA’s draft sixth Contaminant Candidate List, which means the agency is evaluating them for possible future regulation, but no enforceable limit exists and no CCR must test for or disclose them.

A compliant CCR and the absence of microplastics data are two separate things. For brands making water-quality or plastic-reduction claims, the gap between what a CCR covers and what consumers increasingly want to know is where independent verification of existing laboratory data becomes relevant.

What is WQI’s Plastic-Free Pathway Verification, and how is it different from a standard certification?

The Wellness Quality Institute’s Plastic-Free Pathway Verification is an independent review of a company’s existing third-party laboratory data on plastic and microplastic content, not a certification that a product is free of plastic. WQI reviews existing lab data rather than running new tests and verifies progress toward plastic-free standards rather than certifying zero plastic. This approach reflects current scientific limits and focuses on what the data can reliably show.

During review, WQI evaluates whether the laboratory method fits the product matrix, whether contamination controls were run, whether the tested particle-size range and polymer panel meet defined criteria, and what claim the data can support. Products whose datasets meet all requirements receive a Standard Met outcome, a scope-locked logo license, a public registry listing, and approved claim language. Products that do not meet requirements receive a private Standard Not Met outcome that is never described as a failed product and can be resubmitted. The program name, Plastic-Free Pathway Verified, describes a verified direction of travel, not an achieved state, because the science does not yet support an absolute claim.

Conclusion: Turn Existing Lab Data into a Defensible Claim

A Consumer Confidence Report is a useful starting point because it tells you what your utility tested, whether those results met federal limits, and where the water came from. It cannot tell you whether microplastics are present, how many unregulated compounds were not tested, or whether a brand’s plastic-reduction claims are supported by independently reviewed evidence. Those gaps reflect the legal boundaries of what the document must do.

For homeowners and renters, the practical takeaway is to read the report column by column using the framework above, flag any violations or near-limit results, and treat “not detected” as a bounded statement rather than a guarantee. For brands, the takeaway is that a CCR’s silence on microplastics does not replace independent verification of the laboratory data you already hold.

The Wellness Quality Institute exists to close the gap between real laboratory data and a claim a company can stand behind. In a category with no gold standard, a reviewed, scope-locked, publicly registered verification offers one of the most defensible positions available and is more likely to withstand retailer diligence, regulatory scrutiny, and consumer skepticism.

WQI Plastic-Free Pathway Verification does not certify that a product contains zero plastic, microplastics, or nanoplastics. It shows that the company is on a verified pathway toward plastic-free standards. Verification applies only to the reviewed products, submitted datasets, tested ranges, polymer panels, production or sampling periods, and supporting controls. WQI verification is not a California approval, government certification, or health or safety certification.

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