Every year, your water utility sends you a Consumer Confidence Report (CCR)—a detailed breakdown of what's in your tap water. But unless you have a chemistry degree, these reports can feel like alphabet soup: MCL, MCLG, ppb, ppm, action levels... What does it all mean? This guide will help you decode your water quality report and understand what the numbers actually tell you about your water's safety.
The Easy Alternative
Don't want to wade through a 10-page government report? We've already done the work for you. Our free water quality tool translates your city's water data into a simple score with clear explanations of what each contaminant means.
Check your water quality nowWhat Is a Consumer Confidence Report?
A Consumer Confidence Report (CCR), also called a Water Quality Report, is a document that public water systems must provide to customers every year by July 1st. It's required by the EPA under the Safe Drinking Water Act, and it tells you:
- Where your water comes from (surface water, groundwater, or both)
- What contaminants were detected in your water
- How those levels compare to federal and state limits
- Whether your water system had any violations
- Health information about contaminants of concern
Your utility might mail you a paper copy, send an email with a link, or include a notice in your water bill telling you where to find it online. If you've never seen yours, search for "[your city] consumer confidence report" or call your water utility.
Understanding the Key Terms
Before diving into specific contaminants, let's decode the terminology you'll encounter in any water quality report:
Maximum Contaminant Level
The highest level of a contaminant allowed in drinking water. This is the legal limit—if exceeded, the water system is in violation.
Maximum Contaminant Level Goal
The ideal level with no known health risk. MCLGs are non-enforceable health goals—they represent what we'd want in a perfect world.
Action Level
The concentration that triggers required treatment or other actions. Used for contaminants like lead and copper that enter water from plumbing.
Parts Per Billion
A concentration unit. 1 ppb is like 1 drop in 500 barrels of water. Used for contaminants measured in very small amounts, like lead.
Parts Per Million
A concentration unit. 1 ppm = 1,000 ppb. Used for contaminants present at higher levels, like nitrate.
Parts Per Trillion
An even smaller unit. 1 ppt = 0.001 ppb. Used for PFAS and other contaminants measured at extremely low levels.
Not Detected
The contaminant was below the detection limit of the testing equipment. This is generally good news.
The Contaminants That Matter Most
Your CCR lists many contaminants, but in Minnesota, there are three you should pay closest attention to:
Lead
Action Level
15 ppb
Health Goal (MCLG)
0 ppb
There's no safe level of lead exposure. The 15 ppb "action level" doesn't mean 14 ppb is safe—it's just the threshold that triggers required action. Any detectable lead is a concern, especially for children and pregnant women.
Lead typically enters water from household plumbing, not the water source itself. Your CCR reports the 90th percentile of lead samples—meaning 90% of tested homes had lead levels at or below that number. If your home has older plumbing, your levels could be higher than the reported average. Learn more on our lead contaminant page.
Nitrate
MCL
10 ppm
Health Goal (MCLG)
10 ppm
Nitrate is particularly dangerous for infants under 6 months, potentially causing "blue baby syndrome." The MCL and MCLG are the same, meaning the legal limit is set at the health goal—unlike lead, there's no gap between the two.
Nitrate typically comes from agricultural runoff and is more common in rural areas. If your CCR shows nitrate above 5 ppm, you might want to monitor it more closely, especially if you have infants. Learn more on our nitrate contaminant page.
PFAS
MCL (PFOA/PFOS)
4 ppt each
Health Goal (MCLG)
0 ppt
PFAS are newer to water quality reports. The EPA just established limits in 2024, so your CCR may or may not include PFAS data yet. If it does, any detection warrants attention given the health concerns associated with these "forever chemicals."
Note that PFAS limits are measured in parts per trillion—an extremely small concentration. The EPA has determined there's effectively no safe level, which is why the MCLG is zero. Learn more on our PFAS contaminant page.
How to Read the Data Table
Most CCRs include a data table showing detected contaminants. Here's how to interpret a typical entry:
| Contaminant | Level Found | Range | MCL/AL | MCLG | Violation |
|---|---|---|---|---|---|
| Lead (ppb) | 5.1 | ND - 12 | 15 | 0 | No |
Here's what each column means:
- Level Found: The average or 90th percentile of all samples (depends on contaminant)
- Range: The lowest and highest values found across all samples
- MCL/AL: The legal limit or action level
- MCLG: The health goal (what we'd ideally want)
- Violation: Whether the level exceeds the limit
Watch the Gap
Pay attention to contaminants where the detected level is below the MCL but above the MCLG. For example, lead at 5 ppb is "legal" (below the 15 ppb action level) but still above the health goal of 0. Just because there's no violation doesn't mean there's no concern.
What About Violations?
If your CCR shows any violations, it will include an explanation of what happened and what the water system is doing about it. Violations fall into several categories:
Health-Based Violations
A contaminant exceeded its MCL. This is the most serious type of violation.
Treatment Technique Violations
Required treatment wasn't performed properly.
Monitoring Violations
Required testing wasn't completed on time.
Reporting Violations
Reports weren't submitted to regulators on time.
Health-based violations are the most concerning and require immediate action by the water system. If your water has an active health-based violation, your utility should have already notified you and may have recommended using alternative water sources.
Questions to Ask After Reading Your CCR
After reviewing your water quality report, consider these questions:
- 1. Is lead close to the action level? Even below 15 ppb, lead levels above 5 ppb may warrant filtering.
- 2. Were PFAS tested? Many systems are still adding PFAS to their testing—if not listed, call your utility.
- 3. What's the trend? Compare to previous years' reports to see if contamination is improving or worsening.
- 4. Are there any violations? Even past violations that have been resolved indicate potential system issues.
- 5. What's my home's situation? CCR data reflects water at the treatment plant—your home's plumbing could add contaminants.
A Simpler Approach
We built our Water Quality Check tool because we know most people don't have time to decode 10-page government reports. Our tool takes the same underlying data and translates it into:
- A simple 0-100 score for easy comparison
- Letter grades (A through F) based on overall water quality
- Plain-English explanations of each contaminant
- Comparison to state averages and EPA limits
- Actionable recommendations based on your city's specific issues
It's free, instant, and designed to give you the information you need without the technical jargon.
Frequently Asked Questions
What is a Consumer Confidence Report (CCR)?
A CCR is an annual water quality report that all public water systems must provide to their customers by July 1st each year. It contains information about your water source, detected contaminants, compliance status, and educational information about drinking water.
What does MCL mean in a water quality report?
MCL stands for Maximum Contaminant Level—the highest level of a contaminant allowed in drinking water. MCLs are set by the EPA based on health effects, technical feasibility, and cost. If a contaminant exceeds its MCL, the water system is in violation.
What is the difference between MCL and MCLG?
MCL is the enforceable legal limit, while MCLG (Maximum Contaminant Level Goal) is the ideal level with no known health risk. MCLGs are non-enforceable health goals. For some contaminants like lead, the MCLG is zero because there's no safe level of exposure.
Where can I find my city's water quality report?
Your water utility must mail or email your CCR by July 1st each year, or notify you where to find it online. You can also search for "[your city] water quality report" or use our water quality tool for a simplified summary of your city's data.
What should I do if my water exceeds contaminant limits?
If your water exceeds any limits, your water utility is required to notify you and explain what they're doing to fix it. In the meantime, you may want to use bottled water or install a certified water filter, especially for sensitive populations like infants or pregnant women.
Skip the Technical Jargon
Get a simple, easy-to-understand summary of your city's water quality
Check Your Water Quality