Septic Systems in Kendall County, IL

Regulations, costs, soil data & local providers

Pop. 131,869 ~9% on septic ~4,747 septic homes Moderately well drained soil

Septic pumping in Kendall County, Illinois costs $300-$650 (avg $450). A new septic system installation costs $6,150-$12,300. USDA soil data rates 0% of county soils as suitable for septic absorption fields. Approximately 4,747 homes in this county use septic systems.

Septic System Costs in Kendall County

ServiceLowAverageHigh
Pumping / Cleaning$300$450$650
Routine Inspection$250$350$500
Real Estate Inspection$400$600$850
Minor Repair$750$1,100$5,400
Conventional Installation$6,150$8,800$12,300
Aerobic System Installation$11,550$16,500$23,100
Drainfield Replacement$6,150$8,800$12,300
Perc Test$900$1,300$1,800

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

Soil & Septic Suitability in Kendall County

Drainage Class
Moderately well drained
Hydrologic Group
C
Unique Soil Types
85
Avg Bedrock Depth
3.5 ft

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Strawn 475 Moderately well drained C
Varna 465 Moderately well drained C
Clare 394 Moderately well drained C
Swygert 386 Somewhat poorly drained D
Graymont 379 Moderately well drained C

Septic Tank Absorption Field Suitability

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

Not Limited (Good)0%
Somewhat Limited0.9%
Very Limited99.1%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

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

Septic System FAQ for Kendall County

How much does septic pumping cost in Kendall County?
Septic pumping in Kendall County, Illinois typically costs between $300 and $650, with an average of $450. 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 Kendall County?
A conventional septic system installation in Kendall County typically costs $6,150-$12,300. An aerobic treatment unit (ATU) costs $11,550-$23,100. Given the predominantly moderately 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 Kendall 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 Kendall County health department for current requirements and fees.
What soil types are in Kendall County and how do they affect septic systems?
Kendall County has predominantly Strawn, Varna, Clare soils. The dominant drainage class is Moderately well drained with hydrologic group C. The USDA rates 0% of surveyed soils as "Not Limited" for septic absorption fields, 0.9% as "Somewhat Limited", and 99.1% as "Very Limited".
How often should I pump my septic tank in Kendall 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 Kendall County?
It depends on your specific site. USDA soil data shows that 99.1% of soils in Kendall 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-$1800) and soil evaluation are required before the county will approve a system design.
How long does a septic system last in Kendall County?
A well-maintained septic system in Kendall 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 (Kendall County has predominantly moderately well 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

Population131,869
Est. Septic Homes4,747
Avg Pumping Cost$450
Drainage ClassModerately well drained
Septic SuitabilityVery limited

Common Septic Services

Pumping: $300-$650
Inspection: $250-$500
Repair: $750-$5,400
Installation: $6,150-$12,300

Data last updated: 2026-04-13