Soil and perc tests in Kent County, Michigan

USDA rates most of the soil in Kent County Very limited for septic absorption fields — 98.1% of the rated acres. The county evaluates the soil and the site before it issues a permit. A percolation test is one accepted method. The county may instead use soil borings, direct observation, or a review of USDA soil maps. USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-16

Very limited

USDA rating, 98.1% of rated acres

checked 2026-09-16

Slow water movement

Most common limiting reason

checked 2026-09-16

Yes

Site evaluation required

checked 2026-09-23

What is a perc test and does Kent County require one?

Yes. The county evaluates the soil and the site before it issues a permit. A percolation test is one accepted method. The county may instead use soil borings, direct observation, or a review of USDA soil maps.

Kent County Health Department — Sewage Disposal Regulations for Kent County, Michigan, § 601.8.3 · checked 2026-09-23

How USDA rates the ground in Kent County

Very limited across most of the county — 98.1% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.

Very limited — 503,269 acres — 98.1% of 513,231 rated acres.
Somewhat limited — 9,962 acres — 1.9% of 513,231 rated acres.
Not rated — 45,278 acres, excluded from the denominator — mostly urban land and water.

98.1% of 513,231 rated acres. 45,278 acres unrated. Survey area MI081 version 24, established 2025-09-04.

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

What limits absorption here

The reasons USDA gives for the rating, by the acres they affect. A component can carry several, so the acres overlap.

Slow water movement — 297,654 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Seepage, bottom layer — 262,506 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Depth to saturated zone — 217,548 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Slope — 153,810 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Filtering capacity — 146,748 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Ponding — 59,209 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Flooding — 38,495 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Subsidence — 27,568 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.

Ratings by soil map unit

The largest map units in the county, each with its rating. A soil survey names the ground. The county's evaluation of your lot is what a permit turns on.

36C — Filer loam, 6 to 12 percent slopes — 22,460 acres in this county — rated Very limited. Dominant component: Filer (90% of the map unit).
81B — Urban land-Spinks complex, 0 to 8 percent slopes — 20,127 acres in this county — rated Not rated. Dominant component: Urban land (60% of the map unit).
36B — Filer loam, 2 to 6 percent slopes — 20,092 acres in this county — rated Very limited. Dominant component: Filer (90% of the map unit).
17B — Chelsea loamy fine sand, 0 to 6 percent slopes — 16,474 acres in this county — rated Very limited. Dominant component: Chelsea (87% of the map unit).
37B — Capac loam, Lake Michigan lobe, 0 to 4 percent slopes — 15,633 acres in this county — rated Very limited. Dominant component: Capac (90% of the map unit).
HgtahA — Houghton muck, 0 to 1 percent slopes — 14,038 acres in this county — rated Very limited. Dominant component: Houghton (90% of the map unit).
19B — Blount loam, 2 to 6 percent slopes — 13,525 acres in this county — rated Very limited. Dominant component: Blount (91% of the map unit).
30B — Spinks loamy sand, 0 to 6 percent slopes — 13,257 acres in this county — rated Very limited. Dominant component: Spinks (90% of the map unit).

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

Sources

Each figure on this page has a government source and a checked-on date.

Kent County, MI — Staff Directory, Environmental Health Division · checked 2026-09-23
Kent County, MI — Septic & Well · checked 2026-09-23
Kent County Health Department — Application for Residential Septic/Well Project · checked 2026-09-23
Kent County Health Department — Sewage Disposal Regulations for Kent County, Michigan, § 601.8.3 · checked 2026-09-23
USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-16
Kent County Health Department — Application for Sanitary Facility/Real Estate Evaluation · checked 2026-09-23

Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the county environmental health office, on 616-632-6900.