Understanding Your Water Quality Report

Every year, your water utility is required by the Environmental Protection Agency (EPA) to provide you with a Consumer Confidence Report (CCR), also known as an Annual Water Quality Report. This document details what's in your drinking water, how it compares to federal standards, and where your water comes from.

However, these reports are often dense, technical, and confusing—filled with acronyms, scientific notation, and jargon. Most people receive them, glance at them, and set them aside without understanding what the numbers actually mean for their health.

This guide will teach you how to decode your CCR, understand what the numbers mean, identify potential concerns, and know when you should take action to protect your family's health.

Before diving into your report, you need to understand these key regulatory terms and what they mean for your health:

Section 1: Water Source Information

Your report will identify where your water comes from. This matters because different sources have different contamination risks:

• Surface water (rivers, lakes, reservoirs): More vulnerable to agricultural runoff, industrial pollution, and microbial contamination. Easier to treat but more variable in quality.
• Groundwater (wells, aquifers): Better protected from surface contamination but can contain naturally occurring minerals like arsenic. Harder to treat once contaminated.
• Mixed sources: Some systems use both, switching seasonally or as needed.

Why it matters: If your water comes from agricultural areas (surface water), watch for nitrates and pesticides. If from groundwater in certain regions (Southwest), watch for arsenic.

Section 2: Detected Contaminants Table

This is the most important section. It's typically a table showing every contaminant detected during the reporting year.

Typical columns include:

• Contaminant name
• Level detected (actual amount found)
• Range of detections (low to high)
• MCL (legal limit)
• MCLG (health goal)
• Likely source (where it comes from)
• Violation (yes/no)

How to Analyze This Table:

What to look for:

1. Check for violations: If "Yes," your water exceeded legal limits. The report must explain what happened and what's being done.
2. Compare detected level to MCL: Even without violation, levels close to MCLs (> 75%) warrant attention.
3. Check the range: Wide ranges indicate inconsistent quality. In the lead example above, some samples were 45 ppb—triple the action level—even though the system didn't violate.
4. Compare MCL to MCLG: Large gaps (like lead: MCLG of 0, AL of 15) indicate the legal limit isn't as protective as health experts recommend.
5. Look at ALL detected contaminants: Multiple contaminants at moderate levels may be more concerning than one contaminant at slightly elevated levels.

Section 3: Violations and Health Effects

If your water system violated any standards, this section must:

• Clearly state what was violated
• When it occurred
• Potential health effects
• What the utility is doing to fix it
• When it will be resolved

Important: Some violations are administrative (late reporting) rather than health-based (actual contamination). Read carefully to understand which type you're dealing with.

Section 4: Special Statements for Vulnerable Populations

This section provides information for people who may be especially vulnerable to contaminants:

• Infants and children (lead, nitrates)
• Pregnant women (lead, PFAS)
• Elderly individuals
• People with compromised immune systems (Cryptosporidium, other pathogens)

If you or household members fall into these categories, pay special attention to these sections and consider additional protective measures.

Section 5: Water Treatment Information

This explains how your water is treated. Common processes include:

• Coagulation/Filtration: Removes particles and some contaminants
• Disinfection: Chlorine, chloramine, or ozone to kill pathogens
• Advanced treatment: Activated carbon, UV, ozone, reverse osmosis (less common)

Understanding treatment helps you know what your utility is doing—and what they're NOT doing—to protect your water.

When reviewing your CCR, pay special attention to these contaminants that pose the greatest health risks:

Your water can meet EPA standards and still benefit from additional treatment. Here's when to consider action:

What Actions to Take:

1. Test your tap water: CCRs show water leaving the plant, not what comes out of YOUR tap. Home plumbing can add contaminants (lead) or remove others (chlorine dissipates).
   See our Home Water Testing Guide
2. Install appropriate filtration: Match your filter to your specific contaminants.
   See our Water Filter Buying Guide
3. Flush your pipes: For lead concerns, run cold water for 30-60 seconds before using for drinking/cooking.
4. Contact your utility: Ask questions about specific contaminants, treatment plans, or areas of concern.
5. Stay informed: Review your CCR annually and watch for changes in detected levels or new contaminants.

CCRs only report what utilities are required to test for. Many emerging contaminants aren't monitored:

Unregulated Contaminants:

• Most PFAS compounds: Only recently regulated, many systems haven't started comprehensive testing
• Pharmaceuticals: Not routinely tested despite widespread presence
• Microplastics: No testing requirements or standards exist
• Many pesticides: Only a fraction of pesticides used are monitored
• Personal care products: Sunscreen chemicals, fragrances, etc.
• PFAS beyond PFOA/PFOS: Thousands of PFAS compounds exist; most aren't tested

Testing Frequency Issues:

Small systems may test infrequently. Your report might show data from months or years ago. Some contaminants are only tested every 3-9 years depending on system size and previous results.

Your Home's Plumbing:

CCRs test water at the treatment plant or in the distribution system—not at your tap. Lead, copper, and bacteria can leach from your home's plumbing after water enters your property.

Watch for these warning signs when reviewing your CCR:

1. Repeated violations: Multiple violations in the same year or across multiple years indicate systemic problems, not just isolated incidents.
2. Increasing trends: If contaminant levels are rising year-over-year, even if below MCLs, it suggests worsening source water or treatment issues.
3. Vague explanations: If the report doesn't clearly explain violations or just says "naturally occurring" without detail, dig deeper.
4. Many contaminants near limits: Multiple contaminants at 50-90% of MCLs indicate stressed water quality, even without violations.
5. Missing information: Required data missing or "not tested" for contaminants that should be monitored.
6. Seasonal spikes: Large variations between minimum and maximum detections suggest inconsistent treatment or source water quality.
7. Generic health effects language: If health effects aren't specifically described for detected contaminants, the utility might be downplaying risks.
8. No improvement plan: For issues identified, there should be clear timelines and steps for resolution.

My report says my water meets all EPA standards. Does that mean it's safe?

"Meets standards" doesn't mean contaminant-free. It means contaminants don't exceed legal limits, which are set considering cost and technical feasibility, not just health. For vulnerable populations or for contaminants where MCLG is much lower than MCL, additional precautions may be warranted.

I see "ND" (non-detect) for lead. Does that mean there's no lead?

Not necessarily. ND means below the detection limit of the test used. Also, lead testing for CCRs is done in distribution systems, not necessarily at your tap. If you have a pre-1986 home, test your tap water specifically for lead.

Why does my water taste/smell bad if the report says everything is fine?

Taste and odor issues can come from chlorine (regulated for disinfection but not taste), minerals (not health hazards), or your home's plumbing. Also, CCRs test for regulated contaminants but not everything that affects taste/odor. A carbon filter usually solves aesthetic issues.

How can my neighbor's CCR show different numbers than mine if we're on the same system?

If you're in different parts of the distribution system, you might get water from different sources or treatment plants. Large water systems often have multiple sources and may produce different CCRs for different zones.

What should I do if my CCR shows a violation?

Read the explanation carefully. Some violations are administrative (late reporting) rather than health-based. For health-based violations, follow utility guidance (boil water, avoid consumption), consider bottled water or filtration, and monitor the situation until resolved.

My report is from 2024 but it's now 2026. Why is it old?

CCRs report data from the previous calendar year and must be distributed by July 1st. If you're reading in early 2026, the 2025 report might not be available yet. Some contaminants are only tested every few years, so data may be older.

Should I worry about contaminants listed at very low levels?

It depends on the contaminant and your situation. For contaminants with zero MCLG (like lead), any detection is worth addressing, especially with children. For others, levels well below the MCL (less than 25%) are generally not concerning for the general population.

Your Consumer Confidence Report is an important tool, but it's just the starting point. Understanding what the numbers mean empowers you to make informed decisions about protecting your family's health.

Key Takeaways:

1. Read your CCR every year and compare to previous years
2. "Meets standards" doesn't mean contaminant-free or risk-free
3. Pay attention to gaps between MCLs and MCLGs
4. Test your tap water—CCRs don't show what comes out of YOUR faucet
5. Consider filtration for vulnerable populations or detected contaminants of concern
6. Stay informed about emerging contaminants not yet regulated

Your water quality is too important to trust blindly. Take the time to understand your CCR, ask questions, test when appropriate, and protect your family with the right filtration for your specific situation.