Septic rules and requirements in Oakland County, Michigan

Septic permits in Oakland County are issued by the Oakland County Health Division, Environmental Health Services. A new system permit costs $325. USDA rates most of the soil in the county Very limited for septic absorption fields — 89.4% of the rated acres. Oakland County — Onsite Sewage Disposal System (Septic) · checked 2026-09-23

Oakland County Health Division, Environmental Health Services

Issues the permit

checked 2026-09-23

$325

Septic system permit

checked 2026-09-23

Very limited

USDA rating, 89.4% of rated acres

checked 2026-09-16

Who issues septic permits in Oakland County?

Oakland County Health Division, Environmental Health Services, at 1200 N Telegraph Rd, Bldg 34 East, Pontiac, MI 48341, 248-858-1312. It is part of county government. The state writes the rules it applies.

The Health Division issues the septic permit and inspects the system. Michigan sets no statewide septic code. Each local health department writes its own rules under the state's Public Health Code.

Oakland County — Onsite Sewage Disposal System (Septic) · checked 2026-09-23

What does a septic permit cost in Oakland County?

$325 for a septic system permit, on the county's own schedule.

Applies to a new septic permit for vacant land, the lower of two residential fees.

In effect from October 1, 2025.

The county's fee table for this permit
New Residential Septic Permit (Vacant Land) shown above	$325	a home with a system the source lists as Vacant Land
Public/Commercial (1–1,999 gallons/day)	$468	a business with a system of 1 to 1,999 gallons a day
Public/Commercial (2,000–10,000 gallons/day)	$936	a business with a system of 2,000 to 10,000 gallons a day

A repair or replacement permit costs less. A public or commercial system costs more, priced by daily flow. Michigan sets no statewide fee.

Oakland County Health Division — Environmental Health Fee Schedule, effective 10/01/2025 · checked 2026-09-23

Is the soil in Oakland County suitable for a septic system?

USDA rates most of the county Very limited for septic absorption fields — 89.4% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.

Very limited — 437,562 acres — 89.4% of 489,440 rated acres.
Somewhat limited — 43,904 acres — 9.0% of 489,440 rated acres.
Not limited — 7,974 acres — 1.6% of 489,440 rated acres.
Not rated — 91,283 acres, excluded from the denominator — mostly urban land and water.

USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-16

What Oakland County sets itself

The state writes the code. Oakland County adds the rules below. They are what makes this page differ from the Michigan requirements.

$325

Applies to a new septic permit for vacant land, the lower of two residential fees.

A repair or replacement permit costs less. A public or commercial system costs more, priced by daily flow. Michigan sets no statewide fee.

Oakland County Health Division — Environmental Health Fee Schedule, effective 10/01/2025 · checked 2026-09-23
1,500 gallons

Applies to a home of 1 to 4 bedrooms, with a two-compartment tank.

A bigger tank applies at five bedrooms. Each bedroom past that adds more room. Michigan sets no statewide septic tank size. This is the county's own rule.

Oakland County Health Division Sanitary Code (January 2026), Article III § 7.5.1 · checked 2026-09-23
A new home site on a septic system needs at least one acre for three bedrooms. A bigger home needs more land.

Applies to a new home site set up after January 22, 1995.

Michigan's Public Health Code lets a local health department set a rule stricter than the state's. The state itself sets no minimum lot size for a septic system.

Oakland County Health Division Sanitary Code (January 2026), Article II § 2.2 · checked 2026-09-23

Sources

Each figure above has a government source and a checked-on date. USDA's Soil Data Access service supplies the soil records. A script writes them, and nobody types them.

Oakland County — Onsite Sewage Disposal System (Septic) · checked 2026-09-23
Oakland County Health Division — Contact Us · checked 2026-09-23
Oakland County Health Division Sanitary Code (January 2026), Article II § 2.2 · checked 2026-09-23
Oakland County Health Division — Environmental Health Fee Schedule, effective 10/01/2025 · checked 2026-09-23
USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-16

Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Oakland County Health Division, Environmental Health Services, on 248-858-1312.