An inspection costs $500 to $600. In Maryland, whoever inspects the system for a property transfer must be on the state register.
What it costs
A contractor serving Howard County charges $500 to $600 for a septic inspection. The price depends on where your tank is. Its size matters too. So does what needs moving to reach it.
(Published range, read 21 September 2026.)
Buying or selling a house
This is the inspection you are most likely to come across. Since 31 December 2022, Maryland has required registration for any work associated with on-site wastewater disposal. The register is held by the Maryland State Board of Onsite Wastewater Professionals. The rule specifically names property transfer inspection.
Do not just ask your inspector about their experience. Ask whether they are on the register. If they are not, the other side may not have to accept their inspection.
What an inspection will not tell you
An inspection tells you what condition the existing system is in. It cannot tell you whether the lot has room to replace a failed system. That is the more expensive question.
Under COMAR 26.04.02.04, a lot approved after 18 November 1985 had to have room for the initial system plus two replacements. The minimum was 10,000 square feet per dwelling unit. An older lot may have no room for a replacement. A failing system with nowhere to put a new one is the worst outcome you could face.
If you are buying, ask what the lot was approved for. Ask when it was approved too. Neither question is about how the tank looks.
What a failure costs
Septic repairs in the county can cost upwards of $50,000, depending on what needs doing. An inspection aims to uncover that risk before you own the property.
Howard County's streams are recorded as impaired by excess nutrients and faecal bacteria. That is why the county requires inspections. It also explains the Bay Restoration Fund charges for new and upgraded systems.
We recorded a source for every figure. We also noted when we read it.