Water quality · ZIP 21401
Water quality in Annapolis, MD
ZIP 21401 is in Anne Arundel County, Maryland. The largest community water system EPA lists there, CITY OF ANNAPOLIS (serving about 35,000 people), reported no health-based violations in the last 3 years. This is the utility's federal record, not a test of the water at any address.
Anne Arundel County, Maryland · EPA SDWIS
CITY OF ANNAPOLIS
PWSID MD0020001 · population served 35,000 · ground water
- Health-based violations (3y)
- 0
- Total violations (3y)
- 0
No health-based violations reported in the last 3 years for this system.
This is federal SDWIS reporting data for the community water system serving this county, not an address-level test result. Private well water is never covered by SDWIS. Where a county is served by multiple systems, this shows the one serving the most people.
Next step for your own home
What this page shows
The community water system serving this ZIP's county, its EPA SDWIS record, and any health-based violations in the last 3 years — shown above.
Source & refresh
EPA SDWIS. States report water-system records to EPA every quarter. The violation counts here cover the last 3 years. Primary source →
Limitations specific to this source
Where a county has several water systems, zipradar shows the one serving the most people and says how many others are on record; yours may be a different one. Private well water is not covered.
Maryland context
Chesapeake flood, lead pipes
Maryland has dense FEMA NFHL coverage along Chesapeake Bay tributaries. Baltimore City has extensive LCRR lead-service-line obligations and flagged EPA SDWIS compliance history. Radon Zone 1-2 across most counties.
See Maryland state page for the full state-level rollup across all 12 dimensions.
Read more on water quality
Editorial deep-dives explaining the source data, its limits, and how to read it.
Flood zones explained — what AE, X, and VE actually mean
Plain-English guide to FEMA flood-zone codes (A, AE, AH, V, VE, X, X-shaded). What the 1% and 0.2% annual-chance zones mean for your property and your insurance.
EPA Radon Zones — what 1, 2, and 3 mean and when you should test
EPA classifies every US county into Zone 1 (high), Zone 2 (moderate), or Zone 3 (low) for radon. Plain-English guide to the classifications and at-home testing.
EPA AQI categories explained — what 0–50 Good through 301–500 Hazardous mean
Plain-English guide to the six EPA Air Quality Index categories: 0–50 Good, 51–100 Moderate, 101–150 Unhealthy for Sensitive Groups, 151–200 Unhealthy, 201–300 Very Unhealthy, 301–500 Hazardous — what each level means and who is at risk.
Lead and Copper Rule 2024 — the federal lead-pipe inventory mandate
The 2024 Lead and Copper Rule Revisions (LCRR) require every US community water system to inventory and report lead service lines. Plain-English guide.
The other dimensions for ZIP 21401
Water quality is one of twelve public-records dimensions zipradar indexes per address. See the ZIP 21401 index for the other eleven — each with its own regulator, source and link:
All dimensions for Annapolis, MD →Frequently asked questions
What is the water quality for ZIP 21401?
Anne Arundel County, Maryland (which covers ZIP 21401) is served by CITY OF ANNAPOLIS (EPA PWSID MD0020001), a community water system serving a reported population of 35,000. Health-based violations in the last 3 years: 0. This is federal SDWIS reporting data for the community water system serving this county, not an address-level test result. Private well water is never covered by SDWIS. Where a county is served by multiple systems, this shows the one serving the most people.
Where does the water quality data come from?
Source: EPA SDWIS. States report water-system records to EPA every quarter. The violation counts here cover the last 3 years. The original is at https://www.epa.gov/ground-water-and-drinking-water/safe-drinking-water-information-system-sdwis-federal-reporting.
What are the limitations of water quality data?
Where a county has several water systems, zipradar shows the one serving the most people and says how many others are on record; yours may be a different one. Private well water is not covered.
Is ZIP 21401 (Annapolis) data current?
zipradar last checked this page against the source on 2026-09-24. States report water-system records to EPA every quarter. The violation counts here cover the last 3 years. The ZIP 21401 overview at /zip/21401/ lists the other topics zipradar covers for this ZIP.