ZIP 20659 falls in St. Mary's County, Maryland, where we hold 24 septic-related documents. We have not classified septic-versus-sewer status for this county, and we do not have a per-ZIP parcel count -- see the county page for what we hold and where the records are kept.
ZCTA 20659 is not entirely inside one county. Land-area share is from the 2020 Census ZCTA-to-county relationship file.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| St. Mary's County, Maryland | 96% | 24 | — | — |
| Charles County, Maryland | 4% | 11 | — | — |
1 businesses on record with an address in this ZIP: pumping, installation, design, inspection and repair. Not an endorsement, and we take no fee.
| Company | City | Phone | Rating |
|---|---|---|---|
| AAA Copsey's Septic Tank Service | Mechanicsville | (301) 884-4408 | 4.3 (6) |
Land-area overlap is from the 2020 Census Bureau ZCTA5-to-county relationship file, not an estimate of ours. Parcel and document counts are rows we hold, not a survey of every property in the ZIP. Last verified 2026-09-01.
We have not measured septic-versus-sewer status for this county yet.
ZIP 20659 spans 2 counties: St. Mary's County, Maryland, Charles County, Maryland.