Septic Systems in Arapahoe County, CO

Regulations, costs, soil data & local providers

Pop. 655,070 ~4.2% on septic ~11,005 septic homes Well drained soil

Septic pumping in Arapahoe County, Colorado costs $400-$750 (avg $550). A new septic system installation costs $8,000-$16,050. USDA soil data rates 5.2% of county soils as suitable for septic absorption fields. Approximately 11,005 homes in this county use septic systems.

Septic System Costs in Arapahoe County

ServiceLowAverageHigh
Pumping / Cleaning$400$550$750
Routine Inspection$300$450$650
Real Estate Inspection$550$800$1100
Minor Repair$1,000$1,450$7,000
Conventional Installation$8,000$11,450$16,050
Aerobic System Installation$15,000$21,450$30,050
Drainfield Replacement$8,000$11,450$16,050
Perc Test$1,200$1,700$2,400

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

Soil & Septic Suitability in Arapahoe County

Drainage Class
Well drained
Hydrologic Group
C
Unique Soil Types
84
Avg Bedrock Depth
1.7 ft

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Renohill 540 Well drained D
Weld 485 Well drained C
Bresser 478 Well drained B
Colby 415 Well drained B
Elyria 354 Well drained C

Septic Tank Absorption Field Suitability

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

Not Limited (Good)5.2%
Somewhat Limited26.9%
Very Limited67.9%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

Groundwater & Water Table in Arapahoe County

Monitoring Wells
6
Avg Depth to Water
7.4 ft
Median Depth
7 ft
Shallowest Recorded
-0.5 ft Shallow Risk

Moderate water table depth. Some sites may require modified systems or mound systems.

Source: USGS National Water Information System. Based on 219 measurements from monitoring wells.

Septic Regulations & Permits in Arapahoe County

State Regulatory Body
Colorado DPHE
Inspection Required for Home Sale
No / Varies
Nitrogen Reduction Areas
No
Advanced Treatment Required
In designated areas

Varies by county. Many counties have transfer-of-title inspection requirements.

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

Septic System FAQ for Arapahoe County

How much does septic pumping cost in Arapahoe County?
Septic pumping in Arapahoe County, Colorado typically costs between $400 and $750, with an average of $550. 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 Arapahoe County?
A conventional septic system installation in Arapahoe County typically costs $8,000-$16,050. An aerobic treatment unit (ATU) costs $15,000-$30,050. 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 Arapahoe County?
Yes. Virtually all counties in Colorado 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 Arapahoe County health department for current requirements and fees.
What soil types are in Arapahoe County and how do they affect septic systems?
Arapahoe County has predominantly Renohill, Weld, Bresser soils. The dominant drainage class is Well drained with hydrologic group C. The USDA rates 5.2% of surveyed soils as "Not Limited" for septic absorption fields, 26.9% as "Somewhat Limited", and 67.9% as "Very Limited".
How often should I pump my septic tank in Arapahoe 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. With approximately 11,005 septic systems in Arapahoe County, there are many local providers offering regular pumping services.
Does the water table in Arapahoe County affect septic systems?
Yes. The average groundwater depth in Arapahoe County is approximately 7.4 feet, based on USGS monitoring data from 6 wells. While this is sufficient for many conventional systems, sites with lower elevations or seasonal water table fluctuations may require alternative system designs. A site-specific evaluation is always recommended.
Can I install a conventional septic system in Arapahoe County?
It depends on your specific site. USDA soil data shows that 67.9% of soils in Arapahoe County are rated "Very Limited" for septic absorption fields, while only 5.2% 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 ($1200-$2400) and soil evaluation are required before the county will approve a system design.
How long does a septic system last in Arapahoe County?
A well-maintained septic system in Arapahoe 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 (Arapahoe 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.

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Quick Facts

Population655,070
Est. Septic Homes11,005
Avg Pumping Cost$550
Drainage ClassWell drained
Septic SuitabilityVery limited

Common Septic Services

Pumping: $400-$750
Inspection: $300-$650
Repair: $1,000-$7,000
Installation: $8,000-$16,050

Data last updated: 2026-04-13