You need a percolation test first. The permit costs $496. For an innovative or alternative system, it costs $750.
What the county charges
| Work | Permit fee |
|---|---|
| New system, upgrade, or Bay Restoration Fund installation | $496 |
| Innovative or alternative system | $750 |
| Shared system, centralised treatment and drain field | $331 per lot |
An innovative or alternative permit costs $254 more than a conventional one. Keep that in mind before you choose a system.
For commercial systems, the fee depends on the design flow. It costs $496 up to 1,000 gallons a day. It costs $703 for 1,000 to 5,000. Above that, it costs $925.
(Fee schedule revision 07-2024, read 21 September 2026.)
Percolation testing comes first
| Test | Fee |
|---|---|
| Failing system | $265 |
| Retest, existing lot of record | $551 |
| New subdivision lot | $595 |
| Plan review, 1–10 conventional lots | $46 per lot |
| Plan review, 11+ conventional lots | $54 per lot |
| Plan review, sand mound | $144 per lot |
A perc test is not a formality. It decides whether your lot supports a conventional system, a sand mound, or nothing. The answer sets the cost of everything that follows.
Nitrogen removal, and who pays for it
Maryland sets prices for BAT — Best Available Technology nitrogen-removal units. The price covers buying and installing the unit. It also covers two years of operation and maintenance. A Bay Restoration Fund installation needs the same $496 permit as a conventional one.
Here's why: Howard County's streams are recorded as impaired for excess nutrients and faecal bacteria. The county uses the BRF to pay for nitrogen removal. Whether your system needs it depends on where your lot drains. It is not a matter of preference.
What the lot has to have
Under COMAR 26.04.02.04, a lot approved after 18 November 1985 needs room for the initial sewage disposal system plus two replacements. That area must be at least 10,000 square feet per dwelling unit.
In the Rural West, the county's general plan says soils "generally" support drain fields. New private community sewerage systems are no longer allowed there. Only publicly owned shared systems are allowed. Howard County's Department of Public Works already runs 25 shared septic systems for named communities outside the metropolitan district.
Design and licensing
Your design must meet COMAR 26.04.02 and Howard County Code Title 3, Subtitle 8. Designers and installers need a licence from the Maryland State Board of Onsite Wastewater Professionals under Environment Article Title 9, Subtitle 11A. Check their licences before anybody breaks ground.
We recorded a source and the date we read it for every figure.