June 01, 2026
What's Actually in Your Tap Water? How to Read a Water Quality Report
Most Americans drink tap water every day without knowing what’s in it. Federal law requires every municipal water supplier to tell you exactly what contaminants they found — and how they compare to safety limits. Here’s how to find your report and what to do when the numbers concern you.
What Is a Water Quality Report?
Under the Safe Drinking Water Act, every community water system in the United States must deliver an annual Consumer Confidence Report (CCR) to customers by July 1 each year. This report lists every contaminant detected in your water supply, the level found, the EPA’s maximum contaminant level (MCL), and the associated health effects.
Find your local report at EPA.gov/ccr, or search your city name plus “water quality report 2025” to find the most recent version directly from your utility.
Well water is not regulated by the EPA or tested by any municipality. You are responsible for testing it yourself through a state-certified lab. The EPA recommends annual testing for bacteria and nitrates — and additional testing if you notice changes in taste, color, or odor.
The Most Common Tap Water Contaminants
Chlorine and Chloramines
Used to kill bacteria and viruses during treatment, chlorine and chloramines are present in virtually all municipal water. They’re legal up to 4 mg/L but detectable through taste and smell at much lower levels. Most homeowners install a whole house carbon filter to remove chlorine from every tap and shower.
Lead
Lead enters water from service lines and home plumbing — not from treatment plants. Solder, fixtures, and pipes installed before 1986 are the primary sources. The EPA action level is 15 ppb, but the CDC states there is no safe level of lead exposure for children. A point-of-use reverse osmosis system is the most effective protection at the drinking tap.
Nitrates
Common in agricultural areas and near septic systems, nitrates have an MCL of 10 mg/L. They’re particularly dangerous for infants and are not removed by standard carbon filters. Reverse osmosis removes 85–95% of nitrates.
PFAS (Forever Chemicals)
These synthetic compounds have contaminated water near military bases, airports, and industrial facilities. The EPA established enforceable limits on six PFAS compounds in 2024. Certified PFAS filters using granular activated carbon or reverse osmosis are the recommended treatment.
Arsenic
Naturally occurring in rock across the Southwest, New England, and Midwest, arsenic leaches into groundwater silently — no color, taste, or odor. The EPA MCL is 10 ppb. The IARC classifies arsenic as a Group 1 human carcinogen. Under-sink RO is highly effective at removing it.
Hardness
Hard water isn’t a health risk, but it shortens appliance life, scales fixtures, and causes dry skin. Anything above 7 grains per gallon warrants treatment. Salt-free water conditioners like Nuvo H2O address hardness without adding sodium.
How to Read the Numbers in Your CCR
| CCR Column | What It Means | What to Watch For |
|---|---|---|
| Contaminant | The substance detected | Lead, nitrates, PFAS, arsenic |
| MCLG | Non-enforceable ideal level | Lead MCLG = 0. Any detection is a concern. |
| MCL / AL | Enforceable legal limit | Being below MCL is legal — not necessarily risk-free |
| Level Found | Actual concentration detected | Compare to both MCL and MCLG |
| Typical Source | Where the contaminant originates | Determines if risk is from treatment, pipes, or geography |
Your CCR reflects water quality at the treatment plant — not at your tap. Contaminants can enter through aging distribution pipes, lead service lines, or corroded household plumbing. Point-of-use filters address this gap.
Frequently Asked Questions
Is tap water safe to drink?
For most Americans on municipal systems, tap water meets all federal standards. However, “meets federal standards” and “no health risk” are not identical — some MCLs are set based on economic feasibility, not zero-risk thresholds. Households with older plumbing, well water, or contaminated source water face higher risks.
What does a standard pitcher filter actually remove?
Standard pitcher carbon filters remove chlorine and improve taste and odor. They do not remove lead, nitrates, PFAS, arsenic, fluoride, or dissolved minerals. For comprehensive contaminant removal, a certified under-sink or whole house system is required.
What is the best filter for tap water?
For drinking water, a reverse osmosis system removes 90–99% of virtually all dissolved contaminants. For whole-home chlorine treatment, a whole house carbon filter is the standard starting point. The best system depends on your specific contaminants.
Know What’s in Your Water — Then Filter It Right
Start with your CCR, identify your contaminants, and choose an NSF-certified system built for them.
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