Reading Your Yearly Water Report, Line by Line

Every public water system here puts out a yearly drinking water report, and most of us never open it. That's a shame, because it answers the questions people usually ask a salesperson: where the water comes from, how it's treated, what disinfectant is in it and what turned up in testing.

Which report covers your address?

The one from whoever sends your water bill, with a wrinkle in the county. Seminole County Utilities' 2024 report is divided into a service area map and 11 separate service area reports, and several of those areas buy their water from a neighbor. Apple Valley and Druid Hills get Altamonte Springs water, Black Hammock gets Oviedo water, Chase Groves gets Sanford water, Lake Brantley and Meredith Manor get water from Sunshine Water Services (Sanlando), and Sun Shadows gets Casselberry water.

So a Longwood mailing address doesn't settle it: some homes there are on the City of Longwood's own wells and some are in the county's Lake Brantley area. Check the name on your bill, then use the map in the county report or our find your town page.

How current is each report?

Most cities have posted reports covering calendar 2025. Seminole County's newest copy we could reach covers 2024, and so does Oviedo's. Casselberry's report could not be read when we checked, so the only confirmed description of its treatment comes from the county's Sun Shadows section, which buys Casselberry water.

How do you read the results tables?

Each row names a substance, the date it was sampled, whether there was a violation, the level found, a range, and the legal limit. Take Sanford's 2026 report, covering 2025: chlorine averaged 1.4 ppm, ranging from 0.2 to 2.3 ppm, against a maximum residual disinfectant level (MRDL) of 4 ppm. The same report shows bromate, which forms during ozone treatment, at 2.0 ppb against a maximum contaminant level (MCL) of 10 ppb, with a range from not detected (ND) to 6.7.

The level column is usually an average; the range shows the lowest and highest results. A "Y" in the violation column is the line to look for first. Units matter too: ppm means parts per million, roughly the same as mg/L, and ppb is a thousand times smaller.

Sodium is a good row to check if anyone in the house watches salt. Sanford reported 38.3 ppm (sampled in 2023) against a state limit of 160 ppm; Longwood reported 15.0 ppm, Altamonte Springs 14.6 ppm and Lake Mary 10.3 ppm. A home softener adds more on top, as the water softeners story explains.

Why don't most reports list hardness?

They simply leave it out. Of the suppliers here, only OUC and Winter Springs have published a hardness figure, and Winter Springs' came from a city web page rather than the yearly report. If you want your number, phone the utility or test at home; our hard water story has the details and the two published figures.

What changed with fluoride?

Two local suppliers have stopped adding it. Altamonte Springs' 2025 report says fluoride was removed from the drinking water system under a directive issued under Florida statute. OUC stopped adding fluoride on July 1, 2025, and says naturally occurring fluoride in Florida groundwater averages 0.14 mg/L. Oviedo's 2024 report, the newest it has posted, still lists fluoridation in its treatment steps, so look for the next edition. Other suppliers' current practice is in their own reports.

What can the report tell you about smell or taste?

It tells you how your plant deals with hydrogen sulfide, which helps sort out whose problem a smell is. Lake Mary, for instance, describes an ultraviolet light advanced oxidation process with hydrogen peroxide, carbon and chlorination; Longwood's 2025 report describes aeration followed by disinfection. If the report says the plant removes sulfide and you still smell it at both taps, call the utility; if it's only the hot side, start with the rotten-egg smell story. Oviedo customers who notice the disinfectant should read about whole-house filters and chloramine.

What if you're on a well?

No utility report covers a private well. The owner is the lab customer, and Florida DOH recommends a bacteria and nitrate test every year. See our private wells story.

Readers often ask

Where do I find the Seminole County water quality report?

On Seminole County Utilities' potable water quality page. The 2024 edition was the newest reachable when we checked; find your service area on its map first.

My bill says Sunshine Water Services. Which report applies?

Seminole County's Lake Brantley and Meredith Manor areas buy water from Sunshine Water Services (Sanlando), and the county report describes that water as aerated and chlorinated. Ask Sunshine for its own report too.

What does ND mean in the results?

Not detected: testing did not find the substance at a measurable level. A range of ND to 6.7 means some samples had none and the highest had 6.7.

Does the report tell me if my water is hard?

Usually not. Only OUC and Winter Springs have published hardness; for everyone else, ask the utility or test.

Is my water report the same as a test of my tap?

No. It summarizes the utility's own sampling across the system, not your house plumbing. Private wells get no report at all.

Where this came from

1. Seminole County Utilities — 2024 Water Quality Report — 11 service areas and purchased water
2. City of Sanford — 2026 Annual Water Quality Report — chlorine, bromate and sodium rows
3. City of Lake Mary — 2025 Water Quality Report — UV oxidation treatment, sodium
4. City of Longwood — 2025 CCR — aeration, sodium
5. City of Altamonte Springs — 2025 Drinking Water Quality Report — fluoride removal, sodium
6. City of Winter Springs — Annual Drinking Water Reports — 2025 report
7. City of Oviedo — 2024 Drinking Water Quality Report — chloramine, fluoridation
8. Orlando Utilities Commission — Water quality reports — fluoride change, ozone
9. Orange County Utilities — 2025 Drinking Water Report — aeration and chlorine
10. Florida DOH — Private Well Water Testing — yearly well testing