Septic Systems in Henry County, IL

Regulations, costs, soil data & local providers

Pop. 49,284 ~14.4% on septic ~2,839 septic homes Well drained soil

Septic pumping in Henry County, Illinois costs $300-$550 (avg $400). A new septic system installation costs $5,800-$11,600. USDA soil data rates 0% of county soils as suitable for septic absorption fields. Approximately 2,839 homes in this county use septic systems.

Septic System Costs in Henry County

ServiceLowAverageHigh
Pumping / Cleaning$300$400$550
Routine Inspection$200$300$400
Real Estate Inspection$400$550$750
Minor Repair$750$1,050$5,100
Conventional Installation$5,800$8,300$11,600
Aerobic System Installation$10,900$15,600$21,850
Drainfield Replacement$5,800$8,300$11,600
Perc Test$900$1,250$1,750

Cost estimates based on regional market data for Henry County, Illinois. Actual costs depend on system type, site conditions, and provider.

Soil & Septic Suitability in Henry County

Drainage Class
Well drained
Hydrologic Group
B
Unique Soil Types
110
Avg Bedrock Depth
3.3 ft

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Hickory 666 Well drained B
Marseilles 547 Well drained D
Oakville 498 Excessively drained A
Tell 437 Well drained B
Seaton 382 Well drained B

Septic Tank Absorption Field Suitability

USDA NRCS rates soil suitability for septic absorption fields across this county:

Not Limited (Good)0%
Somewhat Limited22%
Very Limited78%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

Groundwater & Water Table in Henry County

Monitoring Wells
1
Avg Depth to Water
400 ft
Median Depth
400 ft
Shallowest Recorded
399 ft

Water table depths in this county are generally favorable for conventional septic systems.

Source: USGS National Water Information System. Based on 3 measurements from monitoring wells.

Septic Regulations & Permits in Henry County

State Regulatory Body
Illinois Department of Health/Environment
Inspection Required for Home Sale
No / Varies
Nitrogen Reduction Areas
No
Advanced Treatment Required
No

Contact county health department for specific requirements.

Contact the Henry County health department for current permit requirements, fees, and approved system types.

Septic System FAQ for Henry County

How much does septic pumping cost in Henry County?
Septic pumping in Henry County, Illinois typically costs between $300 and $550, with an average of $400. Costs vary by tank size (1,000-1,500 gallons is typical), ease of access, distance from the pumping company, and how full the tank is. Most homeowners should pump their tank every 3-5 years.
How much does a new septic system cost in Henry County?
A conventional septic system installation in Henry County typically costs $5,800-$11,600. An aerobic treatment unit (ATU) costs $10,900-$21,850. Given the predominantly well drained soils in this area, some sites may require alternative system types. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Henry County?
Yes. Virtually all counties in Illinois require a permit before installing, repairing, or replacing a septic system. The permit process typically involves a soil evaluation or percolation test, system design by a licensed professional, application to the county health department, and one or more inspections during installation. Contact the Henry County health department for current requirements and fees.
What soil types are in Henry County and how do they affect septic systems?
Henry County has predominantly Hickory, Marseilles, Oakville soils. The dominant drainage class is Well drained with hydrologic group B. The USDA rates 0% of surveyed soils as "Not Limited" for septic absorption fields, 22% as "Somewhat Limited", and 78% as "Very Limited".
How often should I pump my septic tank in Henry County?
The EPA recommends pumping your septic tank every 3-5 years for a typical household. The exact frequency depends on tank size, household size, and water usage. A 1,000-gallon tank serving a family of 4 should generally be pumped every 3 years. Some counties in Illinois have mandatory pumping schedules — check with your local health department.
Can I install a conventional septic system in Henry County?
It depends on your specific site. USDA soil data shows that 78% of soils in Henry County are rated "Very Limited" for septic absorption fields, while only 0% are "Not Limited." This means many properties will require alternative systems such as mound systems, pressure distribution systems, or aerobic treatment units. A percolation test ($900-$1750) and soil evaluation are required before the county will approve a system design.
How long does a septic system last in Henry County?
A well-maintained septic system in Henry County typically lasts 25-30 years, though some components may need attention sooner. The concrete septic tank itself can last 40+ years, while the drainfield — the most critical and expensive component — usually lasts 15-25 years depending on soil conditions (Henry County has predominantly well drained soils). Regular pumping every 3-5 years and avoiding excess water usage are the two most effective ways to extend system life.

Free Quote for Henry County

Get matched with licensed septic pros in your area. Free, no obligation.

Quick Facts

Population49,284
Est. Septic Homes2,839
Avg Pumping Cost$400
Drainage ClassWell drained
Septic SuitabilityVery limited

Common Septic Services

Pumping: $300-$550
Inspection: $200-$400
Repair: $750-$5,100
Installation: $5,800-$11,600

Data last updated: 2026-04-13