Septic rules in St. Clair County
St. Clair County's health department says about 30,000 homes in the county have septic systems, and its Environmental Health Division in Port Huron permits them. Clay soil shapes the process: the application says a backhoe is usually needed for soil borings and power augers are not acceptable, with two borings 50 feet apart and 4 feet deep otherwise. Installation between December 1 and March 1 is prohibited without prior health department approval.
A new residential system or a full replacement is $325, a tank-only replacement is $175, and work done without a permit costs double. A septic-only evaluation is $225. The county offers evaluations as a consultative function, not a sale requirement, and its site says a home sale needs the system in good working order, which reads as general advice without a code citation. Evaluations are observation-based, undocumented systems need the owner to partly excavate, and snow or frozen ground can prevent an evaluation, so allow at least two weeks.
The septic page gives two pumping figures, every three to five years in one place and every three years in another, as a recommendation. The county runs a 24-hour anonymous line for reporting failing systems, 877-504-7946, and we have no sanitary code title for it. Port Huron, at 79.2 percent of homes built before 1980, is the one city here. The winter care guide covers the calendar.
The county's rules, line by line
- Who permits septic systems
- St. Clair County Health Department, Environmental Health Division, 220 Fort Street, Port Huron
- Governing code
- Not found
- Inspection at sale
- No rule found in the county's published code. No mandatory time-of-sale rule found. The county offers evaluations at the request of an agency or individual as a consultative function.
- Permit steps
- Sewage permit before installing or repairing; application with plot plan, tax ID, legal description and fee; then the area sanitarian does soil borings (backhoe usually needed because of clay).
- Installers and evaluators
- No county installer license found.
- Winter limits
- Installation between Dec 1 and Mar 1 is prohibited without prior health department approval.
- Records
- Ask the health department how to request the permit file for your address.
Septic fees in St. Clair County
| Item | Amount | Note |
|---|---|---|
| New residential system | $325 | As of Oct 1, 2026 |
| Full replacement | $325 | Same schedule |
| Tank-only replacement | $175 | Same schedule |
| Septic evaluation only | $225 | Same schedule |
Rules and fees change every year. Confirm with the health department before you rely on a line. "No rule found" means the pages and code we have say nothing on that line; it is not the county saying there is no rule. Use the county rules lookup to compare counties.
What septic work costs
These are the Michigan-wide estimates from our model, not St. Clair County prices. The county's own permit and evaluation fees are in the table above.
| Job | Estimated range | Unit |
|---|---|---|
| Septic pumping | $255 to $810 | per visit |
| Septic inspection | $130 to $520 | per inspection |
| Drain field | $890 to $6,025 | per repair |
Estimates, not quotes. How we estimate costs.
All septic services
Cities in St. Clair County
These cities, each with 10,000 or more residents, follow St. Clair County rules for septic. Each city page points back here.