Updated
Does Maryland require a septic license?
Yes. Maryland requires septic installers to hold a state credential issued by the Maryland Department of the Environment. Maryland certifies installers of nitrogen-reducing BAT septic units; installers also need the unit maker's certification, and some counties require a local license.
Who licenses septic contractors in Maryland?
Maryland Department of the Environment.
Maryland's septic credentials:
- BAT (Best Available Technology) certified installer
- County septic installer licenses in some counties
How to check a septic contractor's license in Maryland
- Open the Maryland Department of the Environment lookup.
- Search by the contractor's name, the license holder's name or the license number.
- Check the license type covers your job (installation, pumping or inspection) and that the status is active.
- If the contractor's business name doesn't come up, ask which person on staff holds the license: several states license individuals, not companies.
Septic permits in Maryland
A contractor license says who may do septic work; a permit authorizes a specific system. In Maryland, permits for new systems, replacements and most repairs come from the local health department or the state agency office that covers the property. Ask your installer to pull the permit and include the fee in the quote.
Licensed septic companies in Maryland
The Septic Guide lists 1,029 septic companies and licensed professionals in Maryland, 1,012 matched to the state's published list. Source list: MDE BAT certified installer list. This is what we could match as of October 2026, not an official count.
- Carroll County (72)
- St. Mary's County (71)
- Anne Arundel County (68)
- Calvert County (59)
- Frederick County (59)
- Charles County (47)
- Harford County (45)
- Baltimore County (43)
All septic companies in Maryland →
Maryland septic licensing: common questions
Do you need a license to install septic systems in Maryland?
Yes. Maryland requires septic installers to hold a state credential issued by the Maryland Department of the Environment. Maryland certifies installers of nitrogen-reducing BAT septic units; installers also need the unit maker's certification, and some counties require a local license.
Who issues septic licenses in Maryland?
The Maryland Department of the Environment issues Maryland's septic credentials: BAT (Best Available Technology) certified installer; County septic installer licenses in some counties.
How do I check a septic contractor's license in Maryland?
Open the Maryland Department of the Environment lookup. Search by the contractor's name, the license holder's name or the license number. Check the license type covers your job (installation, pumping or inspection) and that the status is active. If the contractor's business name doesn't come up, ask which person on staff holds the license: several states license individuals, not companies.
How many licensed septic contractors are in Maryland?
The Septic Guide lists 1,029 septic companies and licensed septic professionals in Maryland, 1,012 of them matched to the Maryland Department of the Environment list (data as of October 2026). This counts what we could match; it is not an official total.
Do you need a permit for a septic system in Maryland?
New septic systems, replacements and most repairs need a permit before work starts. The permit comes from the local health department or the state agency office that covers your property, and the permit, not the contractor license, is what authorizes a specific job.
Sources: Maryland Department of the Environment; state license lists loaded into The Septic Guide. See how we verify licenses.