Does Washington County, Missouri require a septic inspection to sell a home?
No. Washington County's on-site wastewater ordinance lets the Health Department charge a fee to inspect a system on request from an individual, Realtor, or lending institution, an option built for the situation a home sale creates. Nothing in it requires that inspection before a sale can close. What usually drives a septic and well inspection here is your buyer's mortgage.
Source: Washington County's 1999 on-site wastewater ordinance and the Health Department's current permit application packet. Reviewed 2026-09-16.
Who and what this applies to
- This applies if your home in Washington County is on a private septic system and/or private well.
- The trigger is your buyer's loan and inspection contingency: FHA, VA, USDA — and any Realtor or lender involved can also directly request the county's own fee-based inspection.
- A variance may be granted for a repair to a system that existed before January 1, 1996, or for property platted before that date — in each case only where a real site limitation is the reason, and the county may require a higher level of pretreatment in exchange.
What a seller should do
- Find the records and confirm the system type — the pre-listing checklist.
- Book the septic inspection and the water test early, with a DHSS-licensed inspector and a certified lab.
- If a problem turns up, get a written bid from a registered Washington County installer and pull the county permit timeline. See your options if it fails.
Costs and deadlines
| Item | Detail |
|---|---|
| Water-test age limit at closing | FHA 180 days · USDA 180 days · VA 90 days |
| Septic inspection | $300–$700 in Missouri |
| County construction permit | $125.00, per the Health Department’s current application packet |
| County inspection on request (Realtor/lender/individual) | Set at, but not to exceed, the Health Department’s own cost to perform it |
Scope of this page
- The fee for a request-based county inspection is set at the Health Department’s cost and can change. Ask the Health Department for the current amount.
- The county registers installers. Ask the Health Department for the current roster.
- Whether the county expects a private well water test at a sale is a question for the Health Department; lender rules apply regardless.
For questions about a specific property, call the Washington County Health Department in Potosi at (573) 438-2164.
Official authorities
- Washington County Health Department — 520 Purcell Drive, Potosi, MO 63664 · (573) 438-2164 · the county ordinance, permits, request-based inspections, installer registration.
- Missouri DHSS — On-site Wastewater Treatment Program — (573) 751-6095 · the statewide baseline and the licensed-inspector / suspended lists.
Choosing an inspector
Use a Missouri DHSS-licensed inspector, checked against the suspended list; for a repair, Washington County requires its own contractor registration (renewed annually, with 4 hours of continuing education required each year), not just the state DHSS credential. See choosing a septic inspector and a repair contractor.
Sources & last verified
- . Reviewed in full 2026-09-16. The ordinance contains no provision requiring an inspection at the sale of a home.
- . Confirms the current $125.00 construction permit fee and office address. Reviewed 2026-09-16.
- . Reviewed 2026-09-16.
- ; ; . Reviewed 2026-09-16.
Corrections: corrections@homecleared.com.
Common questions
- Can a Realtor or lender ask Washington County to inspect a septic system?
- Yes — the county ordinance specifically lets the Health Department charge a fee to inspect a system on request from an individual, Realtor, or lending institution. It is a named option, not a requirement triggered automatically by a sale.
- Does a pre-1996 septic system get any exceptions in Washington County?
- Only in a specific case: the Health Department may grant a variance for a repair to a system that existed before January 1, 1996, or for property platted before that date, but only where a real site limitation is the reason — and it may require a higher level of pretreatment in exchange.
- What does a Washington County septic construction permit cost?
- $125.00, per the Health Department’s current application packet — separate from the cost of hiring an inspector or a request-based county inspection.
- Who administers septic permits in Washington County?
- The Washington County Health Department in Potosi, (573) 438-2164.