Who regulates septic in South Dakota?

SD Department of Agriculture and Natural Resources (DANR) at the state level, most counties at the field-permit level. DANR was consolidated from the prior Department of Environment and Natural Resources (DENR).

How do the well-depth-based setbacks work?

Wells less than 100 feet deep are considered shallow and more vulnerable to contamination. SD requires 75 ft from septic tank (vs 50 ft for deeper wells) and 150 ft from drainfield (vs 100 ft). Shallow wells drawing from shallow aquifers face higher contamination risk.

Are polyethylene tanks accepted in South Dakota?

Yes, when meeting IAPMO/NSF listings and ARSD 74:53:01:24 construction requirements. Major OEM rotomolded polyethylene tanks from Norwesco, Snyder, and others are commonly approved. Frost depth and structural rating matter.

What about the Black Hills rocky terrain?

Shallow bedrock at many Black Hills parcels means conventional absorption fields often aren't feasible. Mound systems, evapotranspiration beds, and other alternative configurations are common. Cost and complexity higher than East River prairie installations.

Do tribal lands have different rules?

Yes. Tribal sovereignty means reservation installations have federal and tribal jurisdictional layers beyond state rules. Indian Health Service often involved. Coordinate with tribal environmental office and IHS before starting design.

South Dakota Septic Tank Regulations — ARSD 74:53:01

South Dakota Septic Tank Regulations

South Dakota's onsite wastewater under ARSD 74:53:01 — SD Department of Agriculture and Natural Resources oversight, the 1,000-gallon floor for flows up to 750 gpd with +250 gal per bedroom beyond 3, and realities from the Missouri River to the Black Hills.

The Governing Framework

South Dakota regulates onsite wastewater under:

ARSD 74:53:01 — Administrative Rules of South Dakota, on-site wastewater systems.
ARSD 74:53:01:25 — Minimum capacities for septic tanks.
ARSD 74:53:01:24 — Installation requirements for septic tanks.
SD Department of Agriculture and Natural Resources (DANR) — state-level administrator (consolidated from prior DENR).
Licensed on-site wastewater installers — required per DANR installer application and licensing process.
County-level permitting — many SD counties (Lawrence, Pennington, Minnehaha, Custer, and others) handle field permits with DANR oversight.

Source: ARSD 74:53:01 full text (SD Legislature); ARSD 74:53:01:25 Minimum capacities (Cornell LII); DANR Septic Tank Systems.

Septic Tank Capacity — ARSD 74:53:01:25

Flow / Bedroom Count	Minimum Capacity
Flows ≤ 750 gpd	1,000 gallons (minimum liquid before outlet overflow)
Homes with 4+ bedrooms	1,000 gal + 250 gal per bedroom beyond 3
4 BR home	1,250 gallons minimum
5 BR home	1,500 gallons minimum
6 BR home	1,750 gallons minimum

The 1,000-gallon floor and 250 gal/bedroom increment is one of the cleaner, more memorable capacity rules in the country. Polyethylene tanks meeting IAPMO/NSF listings and ARSD 74:53:01:24 construction requirements are accepted.

Installation — ARSD 74:53:01:24

Key installation requirements:

Install on a solid, level base
Access hole covers: 6–12 inches below finished grade
Airtight covers with hasp/lock may be shallower or above grade to prevent unauthorized access
Tank depth provides adequate gravity flow from building/facility sewer per SD plumbing code

Setback Distances

From	To	Minimum Distance
Septic tank	Lake or stream	50 feet
Septic tank	Well ≥ 100 ft deep	50 feet
Septic tank	Well < 100 ft deep	75 feet
Absorption area (drainfield)	Lake, stream, or well ≥ 100 ft deep	100 feet
Absorption area (drainfield)	Well < 100 ft deep	150 feet

The shallow-well penalty (75 ft tank, 150 ft drainfield vs 50/100 ft for deeper wells) recognizes higher contamination risk for wells drawing from shallow aquifers.

Regional Considerations

Sioux Falls / Minnehaha County: Highest population density. Mix of municipal sewer and dense-septic suburbs. Glacial till soils variable.
Rapid City / Pennington County: Black Hills region with varied terrain. Granite bedrock at shallow depth in many parcels forces alternative systems.
Black Hills (Custer, Lawrence, Meade): Rocky, mountainous terrain. Shoreland considerations near lakes and streams. Standard systems possible but alternative systems common where soil is thin.
Missouri River corridor (Pierre, Chamberlain, Yankton): River-valley alluvial soils. Floodplain considerations near the river.
Badlands / West River (Jackson, Shannon, Haakon): Sparse population, long distances to services. Standard systems where terrain allows.
Prairie Coteau (East River): Glacial plains, agricultural. Typical prairie-soil absorption characteristics.
Tribal lands: Several SD reservations have federal/tribal jurisdictional layers. IHS coordination typical for installations on tribal land.

Climate and Frost Considerations

South Dakota's plains climate brings similar deep-frost penetration as North Dakota. Typical design considerations:

Frost depth 4–5 feet typical, locally deeper in prolonged cold
Tanks, lines, and risers below frost or insulated
Construction season typically May–October
Seasonal cabin and recreational-property installations need freeze-protection considerations for low-flow periods

Permit Process

Contact your county planning/zoning or health office. SD permits are largely county-administered.
Site evaluation.
System design. Per ARSD 74:53:01.
Permit application. County level with DANR coordination.
Licensed installer construction.
Inspection before cover.

Frequently Asked Questions

Who regulates septic in South Dakota?: SD Department of Agriculture and Natural Resources (DANR) at the state level, most counties at the field-permit level. DANR was consolidated from the prior Department of Environment and Natural Resources (DENR).
How do the well-depth-based setbacks work?: Wells less than 100 feet deep are considered shallow and more vulnerable to contamination. SD requires 75 ft from septic tank (vs 50 ft for deeper wells) and 150 ft from drainfield (vs 100 ft). Shallow wells drawing from shallow aquifers face higher contamination risk.
Are polyethylene tanks accepted in South Dakota?: Yes, when meeting IAPMO/NSF listings and ARSD 74:53:01:24 construction requirements. Major OEM rotomolded polyethylene tanks from Norwesco, Snyder, and others are commonly approved. Frost depth and structural rating matter.
What about the Black Hills rocky terrain?: Shallow bedrock at many Black Hills parcels means conventional absorption fields often aren't feasible. Mound systems, evapotranspiration beds, and other alternative configurations are common. Cost and complexity higher than East River prairie installations.
Do tribal lands have different rules?: Yes. Tribal sovereignty means reservation installations have federal and tribal jurisdictional layers beyond state rules. Indian Health Service often involved. Coordinate with tribal environmental office and IHS before starting design.

Source Citations

Shop Septic Tanks for South Dakota

OneSource stocks polyethylene septic tanks meeting South Dakota construction requirements. Match capacity to your design flow per the rules summarized above. Tank + accessories + holding tank options below cover standard and alternative configurations. OneSource drop-ships from the OEM warehouse closest to your install address.

Plastic Septic Tanks

Full polyethylene septic tank catalog. Sizes from 300 to 1,500+ gallons for South Dakota installations.

Browse Plastic Septic Tanks

IAPMO Approved Models

NSF/IAPMO listed tanks. Some counties and some installation types require this listing.

Browse IAPMO Approved Models

Septic Accessories

Risers, lids, baffles, filters, alarms, pumps, and install hardware.

Browse Septic Accessories

Holding Tanks

Holding tanks for construction sites, recreational properties, and pump-and-haul installations.

Browse Holding Tanks

Need help matching tank capacity to South Dakota's design flow rules or confirming IAPMO listing with your local health department? We do the compatibility check.

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Storing chemicals in your South Dakota tank?

South Dakota's OSSF rules don't cover chemical-storage tanks — those are specified at the manufacturer level. If you need a tank rated for sulfuric acid, bleach, fertilizer solution, or any of 300+ industrial chemicals, our Chemical Compatibility Database has the full system-of-construction specifications.

Browse Chemical Compatibility Database All State Regulation Guides

Agricultural Tank Regulations — SD Department of Agriculture and Natural Resources

The South Dakota Department of Agriculture and Natural Resources (DANR) administers pesticide and fertilizer regulation under ARSD Title 12 (Department of Agriculture and Natural Resources — Agronomy Services):

ARSD Chapter 12:56 — Pesticide Control (rules for registration, applicator licensing, commercial and private pesticide use, enforcement).
ARSD Chapter 12:58 — Commercial Fertilizer and Soil Conditioner rules.
SDCL Chapter 38-20A — Pesticide Control Act (statutory backbone).
SDCL Chapter 38-19 — Commercial Fertilizer and Soil Amendment Act.
Bulk storage: South Dakota defaults to the federal Pesticide Container Containment Rule (40 CFR 165 Subpart E) for commercial repackaging. Industry best practice is 110% secondary containment of the largest tank with an impervious pad.

South Dakota agriculture is dominated by corn, soybeans, wheat, sorghum, and above all cattle — the state ranks among the top in cow-calf operations, feedlots, and sheep. Bulk liquid fertilizer and pesticide storage at ag retail is concentrated in the James River and Big Sioux corridors, with center-pivot irrigation expanding demand across east-river counties. Polyethylene vertical bulk tanks dominate the liquid fertilizer stock. For specific ARSD Chapter 12:56 and 12:58 containment citations, consult DANR directly.

Source: SD DANR Agronomy Services; SDCL 38-20A Pesticide Control Act; SDCL 38-19 Commercial Fertilizer Act.

Livestock Waste & CAFO Manure Storage — ARSD 74:52

South Dakota livestock density makes the CAFO and manure-storage rule family at least as important as the ag-chemical rules. DANR administers:

ARSD 74:52:01 through 74:52:12 — Concentrated Animal Feeding Operations rules. Require no discharge from production areas and land application areas to waters of the state except as permitted.
Animal Feeding Operation (AFO) definition: A lot or facility that stables, confines, and feeds or maintains livestock in either an open or housed lot for a total of 45 days or more in any 12-month period.
Manure management design: Producers must design, construct, operate, and maintain manure management systems to contain the 25-year, 24-hour storm event, plus all sources of process wastewater and liquid and solid manure.
Key sections: ARSD 74:52:01:05; 74:52:02:22 through 74:52:02:30; and 74:52:10:01 for CAFO specifics.
NPDES/State general permits: SDG-100000 general permit for large CAFOs.

Polyethylene storage tanks in CAFO settings (milk-house wash water, silage leachate collection, hog and dairy manure transfer) must be sized to meet both containment volume and the 25/24 storm event. Coordinate with DANR's Feedlot Permit Program early in design.

Source: SD State General Permit SDG-100000 (Draft); SD Feedlot Permit Program CAFO Rules; 2017 General Permit (PDF).

Septic System Sizing Deep Dive

South Dakota onsite wastewater falls under ARSD 74:53 (Small Onsite Wastewater Treatment Systems). Typical capacity table applied on the ground:

Bedrooms	Minimum Septic Tank Capacity
1–3 BR	1,000 gallons
4 BR	1,250 gallons
5 BR	1,500 gallons
Non-dwelling	Engineered design on peak daily flow

Black Hills granite-underlain lots (Lawrence, Pennington, Custer) frequently require engineered shallow systems and alternative treatment. West-river sandy soils generally support conventional trenches. East-river glacial till with variable percolation is the most common design challenge. Confirm current setbacks and Table values with DANR or your county environmental health office before finalizing a site plan.

Chemical Storage Secondary Containment & Spill Reporting

Federal SPCC (40 CFR 112) applies at 1,320 gallons aggregate aboveground oil. South Dakota layers on:

ARSD 74:56:09 — Regulated Substance Discharge Reporting rules.
SDCL Chapter 34A-12 — Regulated Substance Discharges, the statutory spill reporting framework.
ARSD 74:56 — Underground Storage Tank rules.
DANR 24-hour Emergency Response line for spill notifications.

Secondary containment for polyethylene chemical tanks should hold at least 110% of the largest tank capacity. Above 1,320 gallons aggregate oil, maintain a written SPCC plan with documented integrity inspections. Consult DANR for current South Dakota-specific RQ thresholds and reporting timelines.

Source: DANR Waste Management / Groundwater Quality; SDCL 34A-12 Regulated Substance Discharges.

Permit Pathways at a Glance

Residential septic: DANR or county environmental health under ARSD 74:53.
Pesticide applicator and dealer: DANR under ARSD 12:56.
Commercial fertilizer and soil conditioner: DANR under ARSD 12:58.
CAFO manure storage: DANR Feedlot Permit Program under ARSD 74:52 and state general permit SDG-100000.
Petroleum UST: DANR under ARSD 74:56.
SPCC > 1,320 gal oil aggregate: Federal SPCC plan; DANR spill reporting under ARSD 74:56:09.

More South Dakota FAQs

My 1,200-head cow-calf operation has a stock-pond collection system. Does ARSD 74:52 apply?: AFO classification depends on confinement days and animal type. 1,000 AU or more is a Large CAFO automatically; 300–999 AU is medium depending on discharge pathways. Coordinate with DANR's Feedlot Permit Program to determine your classification and containment requirements.
What does the 25-year, 24-hour storm event mean for design volume?: You must size your manure management system to contain the design storm event runoff plus process wastewater plus liquid and solid manure volumes. A South Dakota-specific precipitation atlas drives the rainfall input. Engineered design typically includes at least 12 months of manure storage plus the storm event buffer.
My Hutterite colony runs 3,000 finishing hogs. What applies?: Above typical CAFO thresholds for swine, DANR Feedlot Permit Program requirements kick in. Plan for full nutrient management plan, engineered lagoon or deep-pit storage, and ongoing reporting.
Do I need a permit for a 500-gallon diesel tank at my ranch?: Below 1,320 gallons aggregate, no federal SPCC. South Dakota has no state registration requirement for small farm motor-fuel tanks, but spill reporting still applies to any release that reaches a waterway.
Are Black Hills septic systems more complicated?: Yes. Granite bedrock, thin soils, steep slopes, and groundwater protection around Rapid City and the Hills require engineered alternative systems. Budget 2x–3x a typical east-river installation.
Is there a state-funded cleanup program?: The Petroleum Release Compensation Fund covers eligible petroleum UST releases. Non-petroleum chemical releases are owner liability.
What happens if manure overtops a storage pond during an extreme event?: Overtopping is a discharge and must be reported immediately to DANR. Operators should have a documented emergency response plan, pump-down capacity ready, and land-application capability to reduce storage levels ahead of forecast events.