Septic tank size by state / Mountain
Nevada septic tank size
In Nevada the minimum septic tank for a three-bedroom house is 1,000 gallons, rising to 1,200 gallons at four bedrooms. The figure comes from NAC 444.8306 (Capacity of septic tank serving single-family dwelling). That matches the 1,000-gallon median of the 47 states listed here.
What the Nevada rule says
The rule is NAC 444.8306 (Capacity of septic tank serving single-family dwelling), administered by Nevada State Board of Health / Division of Public and Behavioral Health (ISDS program); Washoe County, Southern Nevada Health District and Carson City have their own rules. In its own words:
NAC 444.8306(1) table: 3 or fewer bedrooms 1,000 gallons; 4 bedrooms 1,200; 5 or 6 bedrooms 1,500. For more than six bedrooms, "150 gallons for each additional bedroom must be added to 1,500 gallons." History: "Added to NAC by Bd. of Health by R129-98, eff. 3-25-99."
Source: NAC 444.8306 (Capacity of septic tank serving single-family dwelling), read 2026-10-20.
- Five and six-bedroom homes share the 1,500-gallon row.
- Washoe County, the Southern Nevada Health District and Carson City run their own programs and may apply different numbers.
Nevada 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 | 1,200 gal | same |
| 5 | 1,500 gal | same |
| 6 | 1,500 gal | — |
The first step up comes at 4 bedrooms, from 1,000 to 1,200 gallons, and a six-bedroom house needs 1,500 gallons. Beyond the table the rule adds 150 gallons for each extra bedroom. These are minimums: the permit can call for more, and a bigger tank needs pumping less often.
How Nevada compares with nearby states
Arizona requires 1,000 gallons for three bedrooms; Colorado requires 1,000 gallons for three bedrooms; Idaho requires 1,000 gallons for three bedrooms; Montana requires 1,000 gallons for three bedrooms; New Mexico requires 1,000 gallons for three bedrooms; Utah requires 1,000 gallons for three bedrooms; Wyoming requires 1,000 gallons for three bedrooms. 37 of the 47 states listed here share Nevada's three-bedroom figure.
Before you size a tank in Nevada
- 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 Nevada'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.