Septic Systems in Montgomery County, IL

Regulations, costs, soil data & local providers

Pop. 28,288 ~14.4% on septic ~1,629 septic homes Somewhat poorly drained soil

Septic pumping in Montgomery 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 1,629 homes in this county use septic systems.

Septic System Costs in Montgomery 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 Montgomery County, Illinois. Actual costs depend on system type, site conditions, and provider.

Soil & Septic Suitability in Montgomery County

Drainage Class
Somewhat poorly drained
Hydrologic Group
C/D
Unique Soil Types
61

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Hickory 628 Well drained B
Oconee 395 Somewhat poorly drained C/D
Harrison 360 Moderately well drained C
Pike 360 Well drained B
Hoyleton 341 Somewhat poorly drained C/D

Septic Tank Absorption Field Suitability

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

Not Limited (Good)0%
Somewhat Limited12.9%
Very Limited87.1%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

Septic Regulations & Permits in Montgomery 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 Montgomery County health department for current permit requirements, fees, and approved system types.

Septic System FAQ for Montgomery County

How much does septic pumping cost in Montgomery County?
Septic pumping in Montgomery 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 Montgomery County?
A conventional septic system installation in Montgomery County typically costs $5,800-$11,600. An aerobic treatment unit (ATU) costs $10,900-$21,850. Given the predominantly somewhat poorly 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 Montgomery 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 Montgomery County health department for current requirements and fees.
What soil types are in Montgomery County and how do they affect septic systems?
Montgomery County has predominantly Hickory, Oconee, Harrison soils. The dominant drainage class is Somewhat poorly drained with hydrologic group C/D. The USDA rates 0% of surveyed soils as "Not Limited" for septic absorption fields, 12.9% as "Somewhat Limited", and 87.1% as "Very Limited".
How often should I pump my septic tank in Montgomery 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 Montgomery County?
It depends on your specific site. USDA soil data shows that 87.1% of soils in Montgomery 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 Montgomery County?
A well-maintained septic system in Montgomery 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 (Montgomery County has predominantly somewhat poorly drained soils). Regular pumping every 3-5 years and avoiding excess water usage are the two most effective ways to extend system life.

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Quick Facts

Population28,288
Est. Septic Homes1,629
Avg Pumping Cost$400
Drainage ClassSomewhat poorly 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