EPA SDWIS: Safe Drinking Water Information System
- Source
- U.S. Environmental Protection Agency
- Update Cadence
- Federal and state reporting cycles
- Coverage
- U.S. public water systems, violations, enforcement, and system characteristics
- Official URL
- View source
What It Measures
SDWIS stores information about public water systems regulated under the Safe Drinking Water Act. It can include water system identifiers, system names, city or county served, source-water type, population served, violations, and enforcement information.
How Local Health Signal Uses It
Local Health Signal uses SDWIS as a trust anchor for the water-quality pilot. The key product rule is that SDWIS describes public water systems, not every individual faucet in a city.
What It Tells You
SDWIS is useful for checking whether a public water system has reported Safe Drinking Water Act violations or enforcement records. It also helps identify which public system is likely relevant for a city or county.
Limitations
- SDWIS is not real-time.
- A city can have more than one water system.
- One water system can serve multiple cities.
- SDWIS does not fully answer building-level plumbing, fixture, service-line, stagnant-water, or Airbnb/rental tap questions.
- Some detailed sample values may live with state agencies or utilities rather than in the federal dataset.