The Short Version — What North Dakota Requires
North Dakota law requires that septic systems be designed, permitted, and inspected before they're covered up. You can't dig a hole, drop in a tank, and call it done. The state delegates this oversight to county health departments, and in McLean County and most of Central ND, that authority sits with the First District Health Unit (FDHU).
The process isn't complicated, but it takes time — usually several weeks from first contact to permit approval. Starting early is the most important thing most homeowners don't do. If you're planning a spring install, start the process in February or March, not May.
Key contacts for Central ND: First District Health Unit handles septic permits for McLean, Burleigh, Kidder, Logan, McIntosh, and Sheridan Counties. For other counties, contact your local county health department directly.
The Design & Approval Process
Here's what the permit process actually looks like in sequence:
- Soil EvaluationA licensed soil evaluator or county sanitarian comes to your site and digs test holes to assess the soil profile — texture, structure, depth to restrictive layers, and seasonal water table. This determines what system type is appropriate for your lot. You can't skip this step — the permit can't be issued without it.
- Percolation Test (if required)Some counties require a percolation test in addition to the soil evaluation to measure how fast water moves through the soil. Results directly affect system sizing and type.
- System DesignBased on the soil results, a system is designed — tank size, drain field layout, setbacks confirmed, and system type selected. In some cases a licensed designer or engineer prepares this; in others the county health department guides the design.
- Permit ApplicationThe design goes to the county health department (FDHU for Central ND) for review and permit approval. They verify setbacks, system sizing, and compliance with state and county rules.
- InstallationOnce the permit is in hand, installation can proceed. We coordinate the excavation, tank setting, drain field installation, and backfill.
- InspectionThe county inspector must inspect the system before it's covered. We schedule this and hold off on backfill until approval is given.
- Final Approval and CoverAfter inspection sign-off, the system is backfilled and the site restored.
Setback Requirements
Setbacks define minimum distances between the septic system and other features on and around your property. These are general minimums — some counties set stricter requirements, and your specific site may have additional constraints.
| Feature | Typical Minimum Setback | Notes |
|---|---|---|
| Private well (drilled) | 50 feet | May be 100 ft depending on system type and county |
| Public water supply well | 100 feet | Check with county for exact requirement |
| Property line | 10 feet | From tank and drain field |
| Foundation / building | 10 feet | Tank; drain field typically 20 feet |
| Water body / lake / stream | 50–100 feet | Varies by water body classification |
| Drainage ditch or swale | 10–25 feet | County-specific |
These are general minimums. Your county health department will specify exact setback requirements during the permit process. Always verify before finalizing your site layout.
System Types — What's Used in North Dakota and When
The system type your site requires is determined by soil conditions — not by preference or cost. Here are the three most common types used in Central ND:
Conventional Gravity System
Simplest and least expensive. Effluent flows by gravity from the tank to a conventional drain field. Requires soil that meets percolation standards. Not always an option in heavy clay soils common to Central ND.
Pressure / Dosed System
A pump doses effluent to the drain field in timed intervals, allowing the soil to recover between doses. Used when soil drainage is marginal or when elevation differences require pumping. Adds pump, controls, and electrical.
Mound System
The drain field is elevated above natural grade on engineered fill material. Required when native soil doesn't meet minimum standards. Common in low-lying areas and heavy clay sites throughout Central ND. Most expensive option.
If you're on heavy clay — and much of McLean County is — don't assume you'll get a gravity system. The soil evaluation result is what it is. A mound or pressure-dosed system on challenging ground is not a failure of design; it's the correct design for the conditions.
Tank Sizing Requirements
Tank size is set by bedroom count, not by number of occupants. In North Dakota, minimum requirements are:
- →1–2 bedrooms: 1,000-gallon tank minimum
- →3 bedrooms: 1,000–1,250 gallons (county-specific)
- →4 bedrooms: 1,250–1,500 gallons
- →5+ bedrooms: 1,500+ gallons, may require multiple tanks
Some counties require larger tanks regardless of bedroom count. It's worth confirming with the FDHU for your specific county before purchasing a tank.
Common Mistakes That Cost Homeowners Money
- Starting construction before the soil evaluation
Building a house and then finding out the best drain field location is under the foundation is a real problem. Get the soil evaluation and site layout confirmed before you finalize where the house sits on the lot.
- Underestimating ND soil conditions
If you're building in Central North Dakota and you're not on sandy river bottom ground, assume you might need a mound or pressure-dosed system. Budget accordingly. The gumbo clay soils common throughout McLean and Burleigh Counties fail perc tests regularly — this is not a surprise.
- Not planning for frost depth
Tanks, distribution lines, and risers all need to account for North Dakota's frost depth, which regularly reaches 4–6 feet in severe winters. Inadequate burial depth or poor insulation leads to frozen lines — an expensive and inconvenient repair.
- Waiting too long to start the permit process
The permit process takes time. Soil evaluators get busy in spring. County review has a queue. If you need a system in the ground by June, start the process in February — not in April when you've already broken ground.
- Placing the drain field in a low spot
Drain fields need to stay aerobic — oxygen in the soil is what drives the treatment process. Low spots that hold snowmelt or surface water in spring, or areas with a high seasonal water table, will saturate a drain field and cause premature failure. Site selection matters.
Working with Dakota Earthworks on Your Septic System
We've installed septic systems throughout Central North Dakota — Washburn, Garrison, Bismarck, Underwood, Wilton, Lincoln, and surrounding communities. We know what the First District Health Unit expects to see, how to read a soil evaluation, and how to build a system that passes inspection and holds up long-term.
- Familiar with FDHU permit requirements for McLean and Burleigh Counties
- Experience with conventional, mound, and chamber systems in Central ND clay soils
- Coordinate with county inspectors — we hold off backfill until approval is in hand
- Own equipment on-site — no subcontracted excavation
- Can connect you with soil evaluators and licensed designers if needed
For pricing information, see the Septic System Cost in North Dakota guide. For installation details, see the Septic System Installation service page.
Quick Answers
Can I install my own septic system in North Dakota?
North Dakota allows homeowners to install their own septic systems on their own property in some circumstances, but the system still must be permitted, designed to county standards, and inspected before cover. Practically speaking, most homeowners hire a contractor because the excavation, tank setting, and system assembly require equipment and experience that most homeowners don't have.
What happens if I install a system without a permit?
Unpermitted systems can result in stop-work orders, fines, and orders to uncover and inspect or replace the system at your expense. When you sell the property, an unpermitted septic system is a title and disclosure issue. It's not worth it.
How often does a septic system need to be pumped?
Most residential systems should be pumped every 3–5 years depending on household size. Your county health department may have specific recommendations. Pumping is not a permit-required activity — you hire a licensed pumper directly.