What a water quality report is
Every community water system in the United States publishes a yearly water quality report, called a Consumer Confidence Report. EPA describes it as the annual report a utility provides to its customers. It summarizes what the system measured in the water it delivered during the previous calendar year and compares those results with federal limits.
The report also names where your water comes from, such as groundwater wells or a river or lake, states which disinfectant residual the system measured, and explains any violations during the year.
How to find yours
- Your water bill. The name on the bill is your water system. It may be a city or a municipal utility district (MUD).
- Your water system's website. Most post the latest report online, often under "water quality" or "annual report."
- EPA's search tool. EPA's Find Your Local CCR tool lists reports by state and system.
MUDs are separate water systems with their own reports. A ZIP code or a city name can include several of them, so confirm your system from your bill before you read a report.
When reports come out. Reports are due to customers by July 1 each year and cover the previous calendar year. Systems serving fewer than 50,000 people are not required to post them online under the federal rule; they provide them on request.
How wholesale works. Many MUDs buy water from a larger system or an authority, for example the North Fort Bend Water Authority. The wholesaler's results appear in the buyer's report, and when the source changes, say from wells to surface water, the disinfectant at your tap can change with it.
How to read it
- Measured value and legal limit. Each row usually shows what was measured next to the legal limit, called the Maximum Contaminant Level (MCL). The goal for the same substance, the MCLG, is a health-based target and is not enforceable.
- Units. Results are often in milligrams per liter (mg/L, the same as parts per million) or micrograms per liter (µg/L, the same as parts per billion). Compare like with like.
- "ND" or "not detected." The substance was not found at the level the test can measure. That is different from "not tested."
- Sampling period. Some substances are tested every year and others less often, so a row may show an earlier sampling date.
- Range and average. A range shows the lowest and highest results across samples. An average describes the whole set, and a single home may differ from it.
- Secondary standards. Some rows relate to taste, odor, or appearance. These are guidelines rather than enforceable limits.
What a report does not tell you
- Your own plumbing. The report describes water the system delivered. Pipes, fixtures, and water heaters inside a home can change what comes out of your tap.
- Your tap specifically. A water quality report is not a test of your tap.
- Private wells. Private wells are not covered by these reports. EPA recommends that well owners test their water with a state-certified laboratory.
- Hardness, often. Many reports do not list hardness, because it is not a federally regulated contaminant. State sample results and some systems' own pages publish it instead.
When a home test helps
A test of your own water helps when you are on a private well, when you notice a change that the report does not explain, or when a specific question needs an answer for your home. Use a state-certified laboratory for drinking water testing. EPA's home drinking water testing page links to guidance and resources.
How we use your report
We use your water system's report as context for the conversation, never as a diagnosis. It tells us, for example, which disinfectant your system measured and what it reported over the year. We then ask about what you notice at home, your plumbing, and your existing equipment before suggesting anything.
For more background, see EPA's page on Consumer Confidence Reports and the EPA WaterSense guide to selecting water treatment systems (PDF).
