Septic system requirements in Maryland
What landplan.io applies when it designs a septic system in Maryland: the system types allowed, tank sizes, setbacks and soil loading rates, with what septic products cost there.
Updated
Design a septic system for an address in Maryland
Reviewed landplan.io designs by Maryland's own rules, which our staff reviewed against the state's regulations. Last published 5 October 2026.
Septic systems allowed in Maryland
The system types landplan.io permits in Maryland:
- Sand Mound System
- At Grade Systems
- Subsurface Pressure Trench System
- Standard and Deep Trench System
- Infiltrator Advanced Treatment Leachfield
- Infiltrator Advanced Enviro-Septic® (AES)
- Discharging System
Septic tank size in Maryland
The daily design flow of a home: 150 gal/day per bedroom, at least 300 gal/day. The septic tank is sized from that flow:
| Daily design flow | Minimum tank |
|---|---|
| up to 240 gal/day | 1,000 gallons |
| 240 to 360 gal/day | 1,500 gallons |
| 360 to 600 gal/day | 2,000 gallons |
| 600 to 720 gal/day | 2,500 gallons |
| 720 to 840 gal/day | 2,750 gallons |
| 840 to 920 gal/day | 3,000 gallons |
| 920 to 1,040 gal/day | 3,250 gallons |
Septic setbacks in Maryland
| From | To | Distance |
|---|---|---|
| LineString | Drainage ways and gullies | 25 Ft |
| LineString | Elevation of spillway crest water level in a water supply reservoir | 300 Ft |
| LineString | Intermittent or Perennial Stream | 100 Ft |
| Point | Lake | 100 Ft |
| Point | Springs | 100 Ft |
| Point | Water well system in confined aquifers | 50 Ft |
| Point | Water well system in unconfined aquifers | 100 Ft |
| Polygon | Existing Septic Component to be Abandoned | 5 ft |
| Polygon | Flood plain soils | 25 Ft |
| Polygon | Lake | 100 Ft |
These are the values the landplan.io design engine applies in Maryland. Confirm a design with the Maryland health department or your county's before you build.
Parcel data in Maryland
landplan.io has parcel boundaries for 24 of Maryland's 24 counties: the counties where 100% of the state's people live. Type an address there and the design starts from the parcel.
Septic companies, designers and jobs in Maryland
- Septic companies and distributors in Maryland (11)
- Septic designers in Maryland
- Septic design jobs in Maryland
Where the rules come from
The regulations and documents landplan.io's Maryland rules are read from:
Septic rules by county in Maryland
- Allegany County
- Anne Arundel County
- Baltimore County
- Calvert County
- Caroline County
- Carroll County
- Cecil County
- Charles County
- Dorchester County
- Frederick County
- Garrett County
- Harford County
- Howard County
- Kent County
- Montgomery County
- Prince George's County
- Queen Anne's County
- Somerset County
- St. Mary's County
- Talbot County
- Washington County
- Wicomico County
- Worcester County
Questions
What septic systems are allowed in Maryland?
landplan.io permits these system types in Maryland: Sand Mound System, At Grade Systems, Subsurface Pressure Trench System, Standard and Deep Trench System, Infiltrator Advanced Treatment Leachfield, Infiltrator Advanced Enviro-Septic® (AES) and Discharging System.
What size septic tank do I need in Maryland?
landplan.io sizes the septic tank in Maryland from the daily design flow: up to 240 gal/day: 1,000 gallons; 240 to 360 gal/day: 1,500 gallons; 360 to 600 gal/day: 2,000 gallons; larger flows need larger tanks. A home's design flow is 150 gal/day per bedroom, at least 300 gal/day.
How far must a septic system be from a well in Maryland?
landplan.io keeps these distances in Maryland: Point to water well system in unconfined aquifers: 100 Ft; Point to water well system in confined aquifers: 50 Ft.
Does landplan.io have parcel data in Maryland?
Yes, for 24 of Maryland's 24 counties.