Septic system requirements in Washakie County, Wyoming

The septic rules landplan.io applies in Washakie County, what a septic tank costs there, and the parcel data we hold.

Updated 5 October 2026

Design a septic system for an address in Washakie County

Wyoming's state rules apply in Washakie County: landplan.io has no county rules of its own here. State rules: Reviewed See Wyoming's rules

6system types permitted

1,000 gallonssmallest septic tank

Partly coveredparcel data

Septic systems allowed in Washakie County

The system types landplan.io permits in Washakie County:

Elevated Sand Mound System
Subsurface Pressure Trench System
Subsurface Trench System
Infiltrator Advanced Treatment Leachfield
Infiltrator Advanced Enviro-Septic® (AES)
Discharging System

Septic tank size in Washakie County

The daily design flow of a home: 150 gal/day per bedroom, at least 240 gal/day. The septic tank is sized from that flow:

Septic Tank: minimum size by daily design flow
Daily design flow	Minimum tank
up to 240 gal/day	1,000 gallons
240 to 360 gal/day	1,500 gallons
360 to 600 gal/day	2,000 gallons
600 to 720 gal/day	2,500 gallons
720 to 840 gal/day	2,750 gallons
840 to 920 gal/day	3,000 gallons
920 to 1,040 gal/day	3,250 gallons

Septic setbacks in Washakie County

Minimum distances
From	To	Distance
Polygon	Existing Septic Component to be Abandoned	5 ft

These are the values the landplan.io design engine applies in Washakie County. Confirm a design with the Wyoming health department or your county's before you build.

Parcel data in Washakie County

landplan.io has parcel boundaries for part of Washakie County (34.8% of its area). Elsewhere you draw the lot on the map.

Septic companies, designers and jobs in Wyoming

Where the rules come from

The regulations and documents landplan.io's Washakie County, Wyoming rules are read from:

Water Quality Rules and Regulations, Chapter 25: Septic Tanks, Soil Absorption Systems, and Other Small Wastewater Facilities (020-25 Wyo. Code R. (Water Quality Division, Chapter 25))

Near Washakie County

Questions

What septic systems are allowed in Washakie County?

landplan.io designs by Wyoming's state rules there and permits: Elevated Sand Mound System, Subsurface Pressure Trench System, Subsurface Trench System, Infiltrator Advanced Treatment Leachfield, Infiltrator Advanced Enviro-Septic® (AES) and Discharging System.

What size septic tank do I need in Washakie County?

landplan.io sizes the septic tank in Washakie County from the daily design flow: up to 240 gal/day: 1,000 gallons; 240 to 360 gal/day: 1,500 gallons; 360 to 600 gal/day: 2,000 gallons; larger flows need larger tanks. A home's design flow is 150 gal/day per bedroom, at least 240 gal/day.

Does landplan.io have parcel data for Washakie County, Wyoming?

For part of it (34.8% of its area); elsewhere you draw the lot on the aerial map.