Washington County, Illinois
Pilot Knob Township is a township in Washington County, Illinois. Septic permits inside Pilot Knob Township come from Washington County. 9 rules below are quoted from official sources and independently re-checked, most recently on October 30, 2026. Rules for unincorporated land are on the Washington County page.
Pilot Knob Township does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.
All construction on land inside Pilot Knob township that is under Washington County's zoning authority, including agricultural buildings.
“all construction in washington county requires a building permit including agricultural buildings!”
Unincorporated land inside Pilot Knob township, Washington County, IL, under the county's zoning ordinance. This is a county-administered ordinance, not an ordinance adopted by Pilot Knob township.
“before beginning any construction, a certificate of zoning compliance must be obtained from the zoning administrator.”
Zoning districts that apply to unincorporated land inside Pilot Knob township
“the three most common districts and their minimum lot sizes are: ag-40 acres, r-1 (rural residential) 2 acres, and r-2 (urban residential) 1 acre.”
Parcels in the county's AG (agricultural) zoning district inside Pilot Knob township's unincorporated land
minimum lot size (AG district): >= 40 acres (Existing 1980 homesite exception; agricultural-exemption buyer exception; pre-1980 grandfathered lots)
“the three most common districts and their minimum lot sizes are: ag-40 acres, r-1 (rural residential) 2 acres, and r-2 (urban residential) 1 acre.”
“the three most common districts and their minimum lot sizes are: ag-40 acres, r-1 (rural residential) 2 acres, and r-2 (urban residential) 1 acre.”
Private sewage disposal systems on land inside Pilot Knob township, served by the Washington County Health Department (which covers the whole county, including this township)
“inspection and regulation of food service facilities, private sewage disposal systems, and private water supplies”
Parcels in agricultural use inside Pilot Knob township's unincorporated area, for a buyer who is building on a divided parcel
“another exception to this process is if the buyer, the one building on the property is agriculturally exempt (actively engaged in agriculture and owns at least 40 acres).”
Building permits for construction inside Pilot Knob township's unincorporated area
building permit fee: 100 USD (Charged if structure is over 150 square feet)
“zoning office issues building permits for any construction. a fee of $100 is charged if over 150 square feet.”
Obtaining a zoning certificate and building permit for construction inside Pilot Knob township's unincorporated area
“if the proposed construction meets the zoning requirements, a permit will be issued within a few days.”
We looked and could not find an official answer yet. Silence is not permission; ask Pilot Knob Township or Washington County directly.
Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.
Unanswered questions are usually a sign that Pilot Knob Township publishes no rule on the point, not that none exists. Washington County’s page lists the county offices to call.
Off-grid gear
Going off-grid in Pilot Knob Township means bringing your own water and power. The kit we’d start with:
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