Your county health department
Maryland doesn't run a statewide free testing program that we know of. Some county health departments still test wells or sell kits, so call yours first.
Maryland Department of the Environment: private well testingGetting your well water tested in Maryland
Use a lab Maryland certifies, or a mail-in kit. Across the state, the ones worth testing for are manganese, radon, nitrate and arsenic, plus bacteria every year.
About 1,199,000 people in Maryland get their water from a private well, about 2 in 10 residents.
Three ways to get tested, cheapest first.
A lab Maryland certifies
The state's list of labs certified for drinking water. Many sell bottles you pick up or get by mail, and their results count for a home sale or loan.
Labs certified by MarylandA mail-in kit
Order online, fill the bottles at your kitchen tap and get results by email in about a week. Full well tests run about $210 to $220.
Compare kits for Maryland
Buying a house or drilling a new well in Maryland?
Since October 1, 2024, Md. Code, Real Property 10-713 requires a contract for sale of property with a private well to make well water quality testing a condition of sale, with both parties certifying they reviewed the results.
What turns up in Maryland wells.
Share of tested wells over the limit, from lab tests the USGS, EPA and state agencies collected since 2000. Your own well needs its own test.
Manganese16%111 of 712Radon10%29 of 293Nitrate10%71 of 734Arsenic8%33 of 411Leadunder 1%1 of 439Fluorideunder 1%1 of 617Uranium0%0 of 327
GermsTest every year, whatever the chart says
Coliform bacteria43%15 of 35StainsNot a health risk
Iron stains37%299 of 804
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Where it shows up most
- Nitrate shows up most in Queen Anne's County (about 4 in 10 wells), Caroline County (about 1 in 9 wells), Dorchester County (about 1 in 14 wells).
- Arsenic shows up most in St. Mary's County (about 1 in 8 wells), Garrett County (about 1 in 9 wells), Queen Anne's County (about 1 in 9 wells).
Find your county.
13 counties have a full report with local test results and well depths.
Anne ArundelBaltimoreCalvertCarrollCecilCharlesFrederickHarfordMontgomeryQueen Anne'sSt. Mary'sWashingtonWicomico
No full report for that county yet. The statewide results above still apply, and so do the three ways to get tested.
Every county in Maryland: people on wells and typical depth
| County | People on private wells | Share of residents | Typical well depth |
|---|---|---|---|
| Anne Arundel County | 178,479 | 30% | 110 ft |
| Baltimore County | 98,261 | 11% | 200 ft |
| Carroll County | 89,105 | 52% | 150 ft |
| Harford County | 85,317 | 33% | 160 ft |
| Frederick County | 77,756 | 29% | 200 ft |
| St. Mary's County | 67,718 | 60% | 370 ft |
| Montgomery County | 65,389 | 6% | 150 ft |
| Calvert County | 62,337 | 67% | 320 ft |
| Cecil County | 58,187 | 56% | 148 ft |
| Charles County | 57,568 | 35% | 440 ft |
| Wicomico County | 55,610 | 54% | 80 ft |
| Howard County | 48,320 | 15% | 200 ft |
| Washington County | 47,710 | 31% | 200 ft |
| Prince George's County | 36,305 | 4% | 320 ft |
| Queen Anne's County | 36,046 | 72% | 240 ft |
| Caroline County | 21,704 | 65% | 270 ft |
| Garrett County | 20,178 | 70% | 172 ft |
| Worcester County | 19,748 | 38% | 99 ft |
| Talbot County | 17,921 | 48% | 400 ft |
| Allegany County | 17,209 | 25% | 122 ft |
| Dorchester County | 15,156 | 47% | 400 ft |
| Somerset County | 12,093 | 49% | 160 ft |
| Kent County | 10,941 | 57% | 115 ft |
| Baltimore city | 80 | under 1% | 148 ft |
Questions people ask about well water in Maryland
Does Maryland require private wells to be tested?
Since October 1, 2024, Md. Code, Real Property 10-713 requires a contract for sale of property with a private well to make well water quality testing a condition of sale, with both parties certifying they reviewed the results.
Where can I get my well water tested in Maryland?
Otherwise, use a lab certified by Maryland for drinking water. The state's list is linked on this page.
Where these numbers come from
- How many people use wells: EPA estimates from the 2020 Census.
- Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000.
- State programs and links: Maryland Department of the Environment.