Who is my water company?
Enter your ZIP code and find out exactly which water company serves your address — no bill or phone tree required.
Resolved from EPA's Public Water System Service Area Boundaries (SAB v3, 44,656 systems). Methodology below.
5-digit ZIP · U.S. only · your address stays in your browser
Enter your ZIP code to find the water company — the community water system — that serves it, identified from EPA's mapped service-area boundaries, with your county's measured water hardness for context. About half of U.S. ZIPs fall inside a mapped system; the rest are likely a private well or an unmapped area, and we say so.
How it works
How the lookup names your water company
A water company's territory is a mapped polygon, not a list of ZIP codes. EPA's Public Water System Service Area Boundaries dataset draws those polygons for 44,656 community systems across the country. This tool takes your ZIP's geographic center and finds which system's boundary that point falls inside — then names it.
System names come straight from EPA's Safe Drinking Water Act inventory, usually an operator abbreviation plus the service-area name — so "Phoenix, City of" or "Kennebunk, Kennebunkport & Wells Water District." Alongside the name you get the system's source water, size, and population served, all from EPA records.
City water or a well
If no company shows: city water vs a private well
Half of all U.S. ZIP centers — 49.2% of them — fall outside every mapped community water system. That is not a failure of the lookup; it is usually the real answer: private-well country. When no system covers your ZIP, the tool says so plainly and points you to your county's measured groundwater hardness and how to test a well, rather than guessing a utility that isn't there. See well water hardness and how to test your water.
Two systems
Why two water companies can serve one ZIP
About 684 ZIP codes straddle two or more systems, because service-area lines follow pipes and pressure zones, not postal geography. For those the tool shows every system whose boundary covers your ZIP's center, each as its own card, and you pick yours by city or system name.
Why us
Why service directories can't answer this
Most "find your water provider" pages are state or regional tools that only work inside their own borders, and EPA's own system search makes you already know your provider's name before it will help. There is no national front door that turns an address into a named system — which is the gap this tool fills, for all 50 states and D.C. Want the hardness first instead of the provider? Use the water-hardness-by-ZIP lookup.
Worked example
A ZIP, walked through
Take ZIP 85003 in downtown Phoenix. Its center falls inside one service area, so the tool returns a single system: "Phoenix, City of," a very large surface-water system serving about 1.6 million people. For hardness context it shows Maricopa County's measured median of 359 mg/L — very hard — from the USGS/EPA data, and a link to find the City of Phoenix water quality report.
| ZIP | Water system(s) | County | Measured hardness | Band |
|---|---|---|---|---|
| 85003 | Phoenix, City of | Maricopa County, AZ | 359 mg/L | Very hard |
| 10001 | New York City System | New York County, NY | 20 mg/L | Soft |
| 04006 | Two systems (Maine Water Co. Biddeford–Saco Div.; Kennebunk, Kennebunkport & Wells WD) | York County, ME | 53.5 mg/L | Soft |
| 02657 | No mapped system (likely well / unmapped) | Barnstable County, MA | 22 mg/L | Soft |
Enter a five-digit ZIP and the tool returns one of three answers. A single system card names your water company with its source water, size, and population served, plus a link to find its water quality report. Two or more cards mean your ZIP straddles a boundary — pick the one whose city matches. And a "no mapped system" result means your ZIP center is outside every service area: likely a private well or an unmapped system, with your county's measured hardness shown either way.
When you'd use it
When this helps
- You just moved. New address, no bill yet, and you want to set up service or read last year's report. Enter the ZIP and get the system name to search for.
- You rent. Water is included and you've never seen a bill, but you want to know who treats your water and find its quality report. The ZIP resolves the system without an account number.
- City water or a well?. Buying or renting somewhere rural and unsure whether it's on a utility or a private well. A mapped system means city water; no system means likely a well — and your county's measured hardness either way.
- Your ZIP shows two companies. You sit near a service-area boundary and two systems appear. Match the one whose city or name fits your address, and use its report.
Methodology
Coverage & accuracy
This is a ZIP-centroid method: a conservative lower bound. 50.8% of ZIP centers fall inside a mapped community system, and 70.2% of the U.S. population lives in one of those ZIPs — EPA reports that about 87% of people are served by community systems overall, so an address-level answer is more precise than this ZIP aggregate. Where your ZIP's center lands outside every polygon, that is usually real, not a data gap.
Questions
Frequently asked
- How do I find out what water company services my address?
- Enter your 5-digit ZIP above. The tool maps it to the community water system whose EPA-mapped service area covers your ZIP's center, and names that system — no account number or bill required. For an exact answer at the property line, confirm with the named system.
- Who provides water to my address?
- In most of the country a community water system does, and the tool names it from EPA's service-area boundaries. About half of U.S. ZIP centers resolve to a mapped system; where yours does, you get the system name, its source water, size, and population served.
- How do I know if I'm on city water or a private well?
- If a system's mapped service area covers your ZIP, you're on city water and the tool names the provider. If no system covers it — 49.2% of ZIP centers — you're likely on a private well or in an unmapped area, and the tool routes you to well-water hardness and testing instead of guessing a utility.
- Why do two water companies show for my ZIP?
- Service-area lines follow pipes, not ZIP codes, so about 684 ZIPs straddle two or more systems. The tool shows every system whose boundary covers your ZIP's center as its own card; pick the one whose city or name matches your address.
- Where do I get my water company's water quality report?
- Each system card links to its report: use EPA's CCR search or search the named system directly. Our water-quality-report guide explains how to find and read it, including the hardness line most reports leave out.
- Why don't you show my water company's phone number?
- EPA's service-area data carries system names, not contact details, so we don't invent a number. Find contact information through the system's water quality report or its own website — the report link on each result card is the reliable route.
Related
Next: find and read your water quality report, check your county hardness by ZIP, or see the national map.
By Marko Visic, MPharm, BSc Physics. Source: EPA Public Water System Service Area Boundaries (SAB v3) + SDWA inventory; measured hardness from USGS/EPA Water Quality Portal. Data last verified . Methodology.
Cite this page: “Who Is My Water Company? Find It by ZIP Code.” Hard Water Map. Retrieved 2026-08-19, https://hardwatermap.com/who-is-my-water-company/