Most of Seffner drinks from the county. Step a few miles east or north, though, and the answer changes. County maps show no water service area at any of the 36 Dover points sampled, and much of Thonotosassa’s east side has none either. Knowing which side you are on decides who fixes a pressure problem, whether a county report applies to you, and which plumber you call.
Four Ways to Tell
- Check a bill. A monthly Hillsborough County Water Resources bill means county water, and a bill from another utility means that utility. No water bill at all is a strong hint of a well.
- Look for the equipment. A well usually has a capped casing or wellhead in the yard and a large steel or blue pressure tank in the garage or pump house.
- Find the meter. A county meter box sits near the curb. If there is no meter, think well.
- Ask the county. Call (813) 307-1000 or check the county utility service-area map. A map polygon shows a service area, not proof that your lot is connected, so confirm by phone.
Where the Gaps Are
West Thonotosassa’s newer plats, such as Toulon, Grand Oak Glen, Oakmont Reserve and Williams Pointe, were built with county water and sewer. The older east side, including Stonelake Ranch, Heritage Estates, Jefferson Heights and Pemberton Creek, shows no county mains in the records, so wells and septic are the likely arrangement. Per-lot status is something only the county or your own bill can confirm.
The west side is the opposite picture. County GIS puts about 98% of the sampled Mango points inside the South-Central water area, so a well there is the exception, and the same chloramine report applies. The Seffner crossroads sits between the two, which is why a quick check beats an assumption.
Dover is the clearest case. A February 2026 county notice said residents with low or no well water were private-well users, not county customers, during a severe drought declared by the water management district. County mains inside the area serve only a farmworker-housing complex and a child-care center.
What Changes for Plumbing
| Item | County water | Private well |
|---|---|---|
| Water report | County publishes an annual report | None; you test it yourself |
| Pressure source | Utility main | Pump and pressure tank |
| Treatment | Chloramine and corrosion inhibitor | Whatever you install, if anything |
| Interior plumbing | Plumber | Plumber |
| Pump, tank and well | Not applicable | Well contractor |
Florida’s health department recommends testing private wells at least annually for bacteria and nitrate, with the Hillsborough County health department as the local contact. Because a well’s mineral content is unknown, scale can be heavy on heaters and fixtures; our chloramine and hardness article explains what to measure.
Buying, Renting or Drought Season
If you are buying or renting a home out here, ask the owner for the last water test and for the date the pressure tank and pump were last serviced. In a dry spring a shallow well can run low, which looks like sputtering faucets, a pump that cycles constantly or sediment in the water. Those are well-contractor symptoms, not drain or fixture problems, and treating them as plumbing leaks wastes a service call.
What We Handle and What We Refer
Inside the house, a well changes little: faucets, toilets, supply lines, water heater and a whole-house repipe are ordinary plumbing jobs. See plumbing repairs and water heater repair & replacement. We refer wells, well pumps and pressure tanks to a well contractor. Septic tanks, drainfields and mound systems go to a septic contractor, which matters because many east-side addresses are on septic. If a slow drain turns out to be a septic problem, we will say so rather than run a cable.
Low pressure behaves differently too. On a well, a failing pressure switch, a waterlogged tank or a tired pump can mimic a plumbing problem, so check the tank before blaming the pipes; our low pressure diagnosis order covers the rest.
For place-specific notes, see our Dover, Thonotosassa and Pemberton Creek pages, and the cost guide for what interior work costs.
Tell us whether it is a well before you book
Say so on the phone and we will plan around it: interior pipes, fixtures and the water heater are ours, while the pump and pressure tank go to a well contractor.
CALL 813-733-7188Well and County Water Questions
Look for a monthly county water bill, a meter box near the curb, and a wellhead in the yard or a pressure tank in the garage. No bill and no meter points to a well. Confirm with Hillsborough County Water Resources at (813) 307-1000.
No. The county report covers its own system. A private well is your responsibility, and Florida’s health department recommends testing at least annually for bacteria and nitrate. Contact the Hillsborough health department for sampling guidance.
Yes, for the interior: fixtures, supply lines, water heaters and repiping. We do not service wells, pumps or pressure tanks, which belong to a well contractor. Tell us when you call so we can plan the visit around it.
No. A well supplies water; a septic system treats wastewater on your lot. Many homes east and north of Seffner have both. We do not service septic tanks or drainfields, though we can look at interior drain lines.