Greywater in Maryland: What Homeowners Need to Know
Maryland requires local approval for greywater systems through county health departments. The process varies by county — Montgomery, Prince George's, and Baltimore County each have different requirements. This guide summarizes the current regulatory situation and practical considerations for Maryland homeowners considering a residential greywater system.
For most homeowners, the most practical starting point is a laundry-to-landscape (L2L) system — redirecting washing machine water to mulched landscape basins. This type of system avoids any modification to existing plumbing and is the most likely to qualify for simplified treatment under any state's rules.
Before contacting any permit office, use the Greywater System Sizing Calculator to determine your daily greywater volume and whether your planned system falls within common permit thresholds. This also gives you the basin dimensions and materials list you'll need for any permit application.
What Systems Are Generally Allowed
Regardless of permit status, virtually all states that allow greywater reuse restrict it to these uses:
- Subsurface irrigation of ornamental plants, lawn, and trees (not vegetables)
- Application under mulch or via drip/bubbler methods (not sprinklers)
- Water that stays on the homeowner's property
- Systems with a sewer or septic overflow connection
If Maryland's rules require a permit, that permit covers the siting and installation of a system that meets these standards — not permission to do something unusual. The permit is the paperwork step; the system itself is the same as in no-permit states.
Next Steps for Maryland Homeowners
To move forward with a greywater system in Maryland:
- Use the sizing calculator to estimate your system specifications
- Contact your local building or health department to confirm current Maryland requirements
- Read the complete L2L installation guide for step-by-step instructions
- Check the rebate finder for any programs in your water district