How to Read Your Annual Water Quality Report
Every public water utility has to send you one each year. Here's what the numbers actually mean.
If you get water from a public utility, whether that's WSSC, Fairfax Water, DC Water, or Loudoun Water, you're legally entitled to an annual water quality report, officially called a Consumer Confidence Report (CCR). Most people never open it.
What's actually in it
Under the Safe Drinking Water Act, every CCR has to disclose the source of your water, a list of contaminants that were tested for, how much of each was detected, and how that compares to the EPA's legal limit (the Maximum Contaminant Level, or MCL).
The parts worth actually reading
Two columns matter most: the level detected, and the MCL or MCLG listed next to it. A contaminant showing up below the MCL means the utility is in compliance. It doesn't necessarily mean zero is present, since utilities are required to report even trace, legal amounts.
As of the EPA's 2024 PFAS rule, utilities now have to begin including PFAS monitoring results in these reports as testing comes online through 2027, and disclose it publicly if any of the six regulated PFAS compounds exceed the new limits.
What it won't tell you
A CCR reports what's true for the utility's system as a whole, not what's coming out of your specific tap. Anything that happens after the water leaves the main, like an old service line, aging household plumbing, or a slow hot water heater, doesn't show up in that report at all. That's the gap an in-home water test is designed to close.
