How Do I Read My Water Quality Report?
Your annual water report tells you where your water comes from, how it’s treated and what your utility found. Here’s how to read it in five minutes and what to do next.
Also asked: What Doesn’t My Water Report Tell Me? · Why Is Central Florida Water So Hard?
Read the table in five minutes
In this guide
The short answer
Find the report from the utility on your water bill, then check three things: where the water comes from, any violations or notices, and the results for anything you care about, compared with its limit in the same unit. A detection below the limit isn’t a violation. Hardness and many newer contaminants often aren’t in the main table at all.
Find the right report
Utilities must publish their annual report, also called a Consumer Confidence Report or CCR, by July 1. Search your utility’s name plus water quality report, or use EPA’s search tool. Make sure it’s the right provider. An Orlando mailing address can be served by OUC, Orange County Utilities or another system. Starting in 2027, updated federal rules are meant to make reports easier to read, and systems serving more than 10,000 customers will send them twice a year.
Start with the source
Look for where the water comes from and which disinfectant is used. A limestone groundwater source explains hard water even when the utility meets every standard. The disinfectant explains the taste and smell. Read about chlorine and chloramine.
The terms in the table
| Term | What it means |
|---|---|
| MCL | Maximum Contaminant Level: the enforceable limit |
| MCLG | The health goal. Often lower than the MCL, sometimes zero |
| Level detected | The reported result, often an average |
| Range | The lowest and highest results that year |
| MRDL | The limit for disinfectants such as chlorine |
Watch the units: mg/L equals parts per million, µg/L equals parts per billion and ng/L equals parts per trillion. Each step is 1,000 times smaller, so compare numbers only in the same unit.
Detected isn’t the same as violated
Labs can measure many substances below their limits. Compare the result with the MCL, check whether it’s one sample, an average or a range, and look for the violation column. Then notice the gap between the MCL and the MCLG. For some contaminants the health goal is zero.
Disinfectants and by-products
The report lists the disinfectant level, allowed up to 4 mg/L, and by-products: TTHM (limit 80 ppb) and HAA5 (limit 60 ppb). Read what those mean.
Where’s hardness?
Often not in the main table, because it’s a scale issue rather than a health limit. Look in the utility’s FAQ or data sheet. Divide mg/L by 17.1 to get grains per gallon, the number softeners are set by. OUC, for example, reports 129 ppm, about 7 grains per gallon.
Your five-minute review
- Confirm the utility and report year.
- Note the source, disinfectant and hardness.
- Check for violations and notices.
- Compare the results you care about with their limits.
- Write down what you notice at home: scale, taste, smell.
Then see what the report leaves out.
How Sunstorm treats the whole home
We use the highest-performing multi-stage media we can buy, size it to your water and household, and add reverse osmosis where you drink.
HydroOne or HydroDuo
Catalytic carbon, KDF and 10% cross-linked softening resin treat the water where it enters your home, so every shower, sink and appliance gets filtered, soft water.
See HydroOne →HydroSip RO
Four-stage reverse osmosis under the sink with its own faucet, for drinking water, coffee, cooking and ice.
See HydroSip →Want RO at every tap? We install Hydro360 whole-home reverse osmosis too. For most homes, filtration and softening plus kitchen RO is the better value: the same drinking water at the sink, without paying to purify the water you shower, flush and wash with. See Hydro360
Questions homeowners ask
Does a compliant report mean I don’t need treatment?
It means the utility met the rules. You can still want no scale, no chlorine taste and an extra barrier for drinking water.
Why is a contaminant listed if the utility is compliant?
Because it was detected below the limit. Detected and in violation are different statements.
Should I test my own tap?
For hardness and disinfectant, our free assessment does it at your sink. For PFAS, lead or bacteria, use a certified lab.
Sources
- EPA: water quality reports for consumers
- EPA: understanding your annual report
- EPA: report rule revisions
- Orange County Utilities: water quality reports
- OUC: water services and quality FAQs
About this guide: We check our guides against current EPA, CDC, state and utility sources and update them as rules and equipment change.
