Washington Administrative Code
Title 246 - Health, Department of
SEWER SYSTEMS
Chapter 246-274 - Greywater reuse for subsurface irrigation
Section 246-274-405 - Location

From edge of subsurface irrigation components

From tank and other system components

Building foundations

Down-gradient1:

10 ft.

N/A

Up-gradient:

2 ft.

N/A

Property or easement line

2 ft.

2 ft.

Pressurized water supply line/public water main

10 ft.

10 ft.

Interceptor/

curtain drains/drainage ditches

Down-gradient:

30 ft.

N/A

Up-gradient:

10 ft.

N/A

In-ground swimming pool

10 ft.

5 ft.

Spring or surface water measured from the ordinary high-water mark2

100 ft.

50 ft.

Well or suction line

100 ft.

50 ft.

Public drinking water well

100 ft.

100 ft.

Public drinking water spring measured from the ordinary high-water mark

200 ft.

200 ft.

Decommissioned well (decommissioned in accordance with chapter 173-160 WAC)

10 ft.

N/A

Down-gradient cuts or banks with at least 5 ft. of original, undisturbed soil above a restrictive layer due to a structural or textural change

25 ft.

N/A

Down-gradient cuts or banks with less than 5 ft. of original, undisturbed soil above a restrictive layer due to a structural or textural change

50 ft.

N/A

On-site sewage system primary and reserve areas

10 ft.

N/A

1

The item is down-gradient when liquid will flow toward it upon encountering a water table or a restrictive layer. The item is up-gradient when liquid will flow away from it upon encountering a water table or restrictive layer.

2

If surface water is used as a public drinking water supply, the greywater system must be located outside of the required source water protection area.