How much does a perc test cost in Michigan?

Your county sets the fee. In 2026 the Macomb County Health Department charges $243 for a soil evaluation. St. Clair County charges $225 per parcel for its site evaluation. Both counties want a backhoe on site for the borings, and the applicant arranges it.

Why would my lot need a mound system?

The EPA lists mounds as an option where soil is shallow, groundwater is high or bedrock is shallow. Effluent flows to a pump chamber and is pumped into a sand mound in set doses. National cost guides list mounds at $10,000 to $20,000, and one traces that to the pump and the mound itself. St. Clair County's site evaluation form lists a raised mound as one possible result.

What happens before a new septic system goes in?

MISS DIG 811 needs at least three business days' notice before any digging, including the soil evaluation. Macomb County will not book that evaluation until MISS DIG has cleared the site. Under normal circumstances it books one within three to seven business days. The permit follows an acceptable evaluation, and the install follows the permit.

Does replacing a septic system need a permit?

Yes. St. Clair County requires a sewage permit before anyone installs or repairs a system. Oakland County's code says the same outside minor repairs, and Macomb County lists a repair permit on its fee schedule. Oakland and St. Clair counties inspect before backfill, and we backfill only after the system passes.

How often does a septic tank need pumping?

The EPA says household tanks are typically pumped every three to five years. Septic tank pumping is a separate trade, and a pumping company does it. St. Clair County calls regular pumping "a bargain compared to the cost of replacing an entire system."

Can a failed septic evaluation stop a home sale in Macomb County?

No, says the county. Macomb County requires a septic evaluation before closing, and the Health Department's own evaluation costs $384, pumping not included. If the system fails, a corrective action plan can be filed and money put into escrow. Repairs are due within 180 days after the county approves the plan.

Is this what Delpres Services charges?

No. The figures above are market numbers from national cost guides and public fee schedules, not our price list. Every lot and every county permit is different, so we look at the site and put the quote in writing. Call (877) 633-5773 for a free estimate.

How Much Does a Septic System Cost in Michigan?

Michigan’s environmental agency, EGLE, puts a replacement septic system at $8,000 to $30,000. National cost guides put a typical new system at about $3,600 to $12,500. Their national averages land between about $6,100 and $8,000. Mound and engineered systems run higher, often $10,000 to $20,000.

These are market numbers, not our price list. Your own number depends on your lot and on what the county finds in its soil. Our page on septic system installation in Macomb County shows how we build new and replacement systems across Metro Detroit.

What does each type of septic system cost?

Your soil decides the system type, and the type sets most of the price. The county health department makes that call from its soil evaluation. Here is what national cost guides list, next to the state’s own replacement figure.

System or item	Market range	Source
Conventional gravity system	$3,000 to $10,000	National cost guides
Pressure distribution system	$7,000 to $10,000	National cost guide
Mound system	$10,000 to $20,000	National cost guides
Engineered system	$12,000 to $15,000	National cost guides
Aerobic treatment unit	$10,000 to $20,000	National cost guides
New drain field	$5,000 to $12,000	National cost guide
Septic tank replacement only	$3,000 to $10,000	National cost guide
Full system replacement in Michigan	$8,000 to $30,000	EGLE, the state environmental agency

A conventional system lets wastewater flow by gravity from the tank to a stone trench field. A pressure distribution system adds a pump that spreads the flow evenly across the field. “Mound systems are an option in areas of shallow soil depth, high groundwater, or shallow bedrock,” the EPA says. An aerobic unit injects oxygen into the tank for extra treatment.

The guide figures are national. Local labor and material prices can put your number above or below them.

What do the county permit and soil evaluation cost?

Michigan has no statewide septic code. Your county health department sets the rules for your lot. It also runs the soil evaluation and issues the permit. Here are the 2026 fee schedules in three counties we serve:

Macomb County Health Department: soil evaluation $243, new septic permit $489, repair permit $150, engineered plan review $710.
Oakland County Health Division (from October 1, 2026): new permit $325, repair or replace permit $221, engineered plan review $100.
St. Clair County Health Department: new system or full replacement permit $325, tank-only permit $175, site evaluation $225 per parcel.

The fees are the small part. The soil evaluation needs a machine on site. Macomb County requires a backhoe at the evaluation, hired at your cost. St. Clair County says heavy clay soils mean most borings need a backhoe too. That dig is excavation and site work, and in Macomb County an acceptable evaluation must come before the permit.

What drives the price of a septic system?

Soil and the water table. Clay and high groundwater push a lot toward a mound or an engineered design. Federal soil data shows how common hard ground is here. In ten towns we serve, NRCS rates 87 to 100 percent of the land “very limited” for a conventional field. That is its worst rating. In the clay towns, the reasons are a shallow saturated zone and slow water movement. In sandy Shelby Township, the main issue is soil that drains too fast to filter the effluent. Oakland County’s code keeps the bottom of a drain field at least 4 feet above the seasonal high water table. It also rules out clay and clay loam for a conventional field below grade.

Tank size. Tanks are sized by bedrooms. Oakland County requires at least a 1,500-gallon, two-compartment tank for one to four bedrooms. Five bedrooms take 2,000 gallons.

Drain field size. The field grows with the bedroom count and with tighter soil. Oakland County designs for 150 gallons per bedroom per day. Its loading table lets sandy soil take more water per square foot than loam.

A reserve area. A Macomb County permit needs a site plan that shows a reserve area for a future field. The plan must be professionally prepared, with existing and proposed elevations.

Access and distance. A tight side yard or a long run from the house adds hours and pipe. We use mini-excavators for tight residential access and full-size machines for deep work.

A sewer nearby. State law lets a city or township require a hookup to a public sewer within 200 feet of the house. In that case the job becomes a new sewer connection instead of a septic system.

The old system. A replacement also retires the old tank. Oakland County’s code has an old tank emptied, then crushed or backfilled with earth and compacted.

Restoration. The dig crosses lawn and sometimes a drive or a walk. We restore what the dig disturbs, and that work is part of the price. Macomb County’s homeowner guide says to keep driveways and patios off the system. Oakland County’s code bans paved surfaces over it.

The season. St. Clair County bars installs from December 1 to March 1 without its prior approval. Oakland County’s code bans frozen soil as backfill. Plan a replacement for the warmer months when you can.

Does a septic repair cost less than a full replacement?

Often, when the tank and the field are still sound. National cost guides list a baffle replacement at $300 to $500. They put a drain field replacement at around $7,000. A whole new system costs more.

The county may see your system differently. “Often times failing systems are impossible to repair and must be replaced,” the Macomb County Health Department warns. Our septic system repair page covers tank and drain field fixes, and when a repair still makes sense.

Can a loan help pay for a septic replacement?

Yes, if your system is failing or close to it. Michigan’s Septic Replacement Loan Program finances replacements for those systems. EGLE created it, and a nonprofit lender manages it. Your local health department must document the problem first.

Income-qualified owners can borrow $1,000 to $30,000 at no more than 1% interest. Terms run up to ten years. Market-rate loans are open to everyone else, with rates that vary by lender. The program keeps its own list of contractors, so check that list before you sign.

How do you get a written quote for a new septic system?

The soil evaluation sets the design, so it shapes every quote. We visit the site and look at the access and the soil findings. Then we put the quote in writing. A good quote names the system type and the tank size. It also says what gets restored after the dig.

We install new and replacement septic systems in Macomb County, Oakland County, St. Clair County and Wayne County. Call (877) 633-5773 for a free estimate.