Septic Systems in Allendale County, SC

Regulations, costs, soil data & local providers

Pop. 8,039 ~56% on septic ~1,801 septic homes Well drained soil

Septic pumping in Allendale County, South Carolina costs $250-$500 (avg $350). A new septic system installation costs $4,750-$9,500. USDA soil data rates 0.2% of county soils as suitable for septic absorption fields. Approximately 1,801 homes in this county use septic systems.

Septic System Costs in Allendale County

ServiceLowAverageHigh
Pumping / Cleaning$250$350$500
Routine Inspection$200$250$350
Real Estate Inspection$300$450$650
Minor Repair$600$850$4,200
Conventional Installation$4,750$6,800$9,500
Aerobic System Installation$8,900$12,750$17,850
Drainfield Replacement$4,750$6,800$9,500
Perc Test$700$1,000$1,400

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

Soil & Septic Suitability in Allendale County

Drainage Class
Well drained
Hydrologic Group
B
Unique Soil Types
48

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Cowarts 469 Well drained B
Emporia 400 Well drained C
Uchee 400 Well drained B
Orangeburg 284 Well drained B
Blanton 261 Moderately well drained A

Septic Tank Absorption Field Suitability

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

Not Limited (Good)0.2%
Somewhat Limited16.9%
Very Limited82.9%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

Groundwater & Water Table in Allendale County

Monitoring Wells
19
Avg Depth to Water
93 ft
Median Depth
90.9 ft
Shallowest Recorded
6.2 ft

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

Source: USGS National Water Information System. Based on 133 measurements from monitoring wells.

Septic Regulations & Permits in Allendale County

State Regulatory Body
South Carolina DHEC
Inspection Required for Home Sale
No / Varies
Nitrogen Reduction Areas
No
Advanced Treatment Required
In designated areas

DHEC issues permits statewide. Soil evaluation required for new installations.

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

Septic System FAQ for Allendale County

How much does septic pumping cost in Allendale County?
Septic pumping in Allendale County, South Carolina typically costs between $250 and $500, with an average of $350. 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 Allendale County?
A conventional septic system installation in Allendale County typically costs $4,750-$9,500. An aerobic treatment unit (ATU) costs $8,900-$17,850. 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 Allendale County?
Yes. Virtually all counties in South Carolina 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 Allendale County health department for current requirements and fees.
What soil types are in Allendale County and how do they affect septic systems?
Allendale County has predominantly Cowarts, Emporia, Uchee soils. The dominant drainage class is Well drained with hydrologic group B. The USDA rates 0.2% of surveyed soils as "Not Limited" for septic absorption fields, 16.9% as "Somewhat Limited", and 82.9% as "Very Limited".
How often should I pump my septic tank in Allendale 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 South Carolina have mandatory pumping schedules — check with your local health department.
Can I install a conventional septic system in Allendale County?
It depends on your specific site. USDA soil data shows that 82.9% of soils in Allendale County are rated "Very Limited" for septic absorption fields, while only 0.2% 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 ($700-$1400) and soil evaluation are required before the county will approve a system design.
How long does a septic system last in Allendale County?
A well-maintained septic system in Allendale 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 (Allendale 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

Population8,039
Est. Septic Homes1,801
Avg Pumping Cost$350
Drainage ClassWell drained
Septic SuitabilityVery limited

More in South Carolina

Barnwell County Hampton County Bamberg County Aiken County Jasper County Colleton County

Common Septic Services

Pumping: $250-$500
Inspection: $200-$350
Repair: $600-$4,200
Installation: $4,750-$9,500

Data last updated: 2026-04-13