Septic tank size by state / West North Central
Nebraska septic tank size
In Nebraska the minimum septic tank for a three-bedroom house is 1,000 gallons, rising to 1,250 gallons at four bedrooms. The figure comes from Title 124 (Onsite Wastewater Treatment Systems, eff. June 27, 2022), General Permit GTS220000 (Septic Tank and Subsurface Leach Field), Section H Table 3 and Section B Table 1, which sizes the tank from design flow; the bedroom figures below are that rule's arithmetic. That matches the 1,000-gallon median of the 47 states listed here.
What the Nebraska rule says
The rule is Title 124 (Onsite Wastewater Treatment Systems, eff. June 27, 2022), General Permit GTS220000 (Septic Tank and Subsurface Leach Field), Section H Table 3 and Section B Table 1, administered by Nebraska Department of Water, Energy, and Environment (formerly NDEE), Title 124. In its own words:
H.1.a: "The minimum septic tank capacity for a single family or multi-family dwelling must be determined using the design flow and the tank capacity listed in Table 3." B.3: "For a single-family dwelling, the design flow shall not be less than 100 gallons per day plus 100 gallons per day per bedroom." Table 3 (no grinder): 200-400 gpd 1,000; 500 1,250; 600 1,500 ... 1,000 gpd 2,500.
Source: Title 124 (Onsite Wastewater Treatment Systems, eff. June 27, 2022), General Permit GTS220000 (Septic Tank and Subsurface Leach Field), Section H Table 3 and Section B Table 1, read 2026-10-20.
- Figures here are without a garbage grinder or large tub. With a grinder, a three-bedroom home needs 1,250 gallons.
- A single-compartment tank must be 50% larger if sewage is pumped into it.
Nebraska minimum tank size by bedrooms
| Bedrooms | Minimum tank | Versus the median state |
|---|---|---|
| 1 | 1,000 gal | same |
| 2 | 1,000 gal | — |
| 3 | 1,000 gal | same |
| 4 | 1,250 gal | +50 |
| 5 | 1,500 gal | same |
| 6 | 1,750 gal | — |
The first step up comes at 4 bedrooms, from 1,000 to 1,250 gallons, and a six-bedroom house needs 1,750 gallons. Beyond the table the rule adds 250 gallons for each extra bedroom. These are minimums: the permit can call for more, and a bigger tank needs pumping less often.
How Nebraska compares with nearby states
Iowa requires 1,250 gallons for three bedrooms; Kansas requires 1,000 gallons for three bedrooms; Minnesota requires 1,000 gallons for three bedrooms; Missouri requires 1,000 gallons for three bedrooms; North Dakota requires 1,000 gallons for three bedrooms; South Dakota requires 1,000 gallons for three bedrooms. 37 of the 47 states listed here share Nebraska's three-bedroom figure.
Before you size a tank in Nebraska
- Bedrooms, not people, set the size in most rules. Rooms that could be used as bedrooms are usually counted, so check how your permitting office counts a den or a finished basement.
- Garbage disposals, grinder or ejector pumps and large tubs change the answer in many states; the points above list Nebraska's adjustments.
- The tank is only half the system. The drainfield is sized separately from soil tests, and it is usually the bigger cost.
- A private well on the same lot has its own setbacks from the tank and field; the well pump and pressure tank calculators size the water side.
Figures are the state's minimum as written on 2026-10-20. Local health departments can require more; the permit issued for your property governs. See the methodology for how each state was read.