Washoe County, NV
Septic permits in Washoe County
Updated · Prepared by the Plumb Right Now editorial team
Short answer
In Washoe County, Northern Nevada Public Health regulates septic systems, and the property owner must get an on-site sewage disposal construction permit before any construction. Lots served by septic must be at least one acre, and tanks are sized by bedrooms: 1,000 gallons for up to three, 1,200 for four and 1,500 for five or six. The application includes two copies of a scaled plot plan.
What Washoe County handles
Northern Nevada Public Health's Environmental Health Services division regulates sewage and wastewater disposal in Washoe County, and an owner must get an on-site sewage disposal construction permit before any construction. [1]
The minimum lot size for a parcel served by an on-site sewage disposal system is one acre. [2]
A single-family home needs a septic tank of at least 1,000 gallons for up to three bedrooms, 1,200 gallons for four and 1,500 gallons for five or six. [2]
Applications need two legible plot plans, 18 by 24 to 24 by 36 inches, drawn at 1 inch = 10 to 40 feet for properties under 10 acres. [2]
Who this affects
Adding a bedroom on septic
- Check the existing tank size against the bedroom count you'll have after the remodel.
- If the tank is too small, plan its replacement into the project and permit it first.
- Keep the drain field clear of new additions, decks and driveways.
- For the new bathroom itself, see bathroom remodel plumbing.
Common questions
Who regulates septic systems in Washoe County?
Northern Nevada Public Health's Environmental Health Services division.
What is the minimum lot size for septic in Washoe County?
One acre.
How big a septic tank does a four-bedroom Washoe County home need?
At least 1,200 gallons.
What scale must a Washoe County septic plot plan use?
For lots under 10 acres, 1 inch = 10 to 40 feet; larger lots 1 inch = 50 to 100 feet.
When do I need a septic permit in Washoe County?
Before any construction of an on-site sewage disposal system.
How many plot plans does a Washoe County septic application need?
Two legible copies at the required size and scale.
Does adding bedrooms affect my Washoe County septic system?
Yes. Tank size is set by bedrooms, so an addition may require a larger tank.
Are Reno and Sparks homes on septic?
Most are on city sewer; septic is mainly in rural parts of the county.
What size tank does a six-bedroom Washoe County home need?
At least 1,500 gallons.
Who issues building permits for Washoe County septic homes?
Washoe County Planning & Building, alongside the health permit.
Cities and services in Washoe County
- Plumbing services in RenoReno drinks mostly Truckee River snowmelt, which is fairly soft, blended with harder well water in summer. High-desert winters freeze exposed pipes, a…
- Plumbing services in SparksSparks is Reno's eastern neighbor, a former railroad town with older homes near Victorian Square and newer subdivisions like Spanish Springs. Truckee …
- Plumbing in NevadaStatewide code, licensing and climate for Nevada.
Other Nevada counties
Sources (2)
- Northern Nevada Public Health, Septic Systems & Liquid Waste · checked 2026-10-06
- Washoe County Planning & Building, Septic System Permit Application Requirements · checked 2026-10-06