Wash. Admin. Code § 246-274-405

Current through Register Vol. 24-12, June 15, 2024

Section 246-274-405 - Location

Tier 1, Tier 2, and Tier 3 greywater irrigation systems shall be designed and installed to meet the minimum horizontal setback requirements specified in Table I.

Table I Minimum Horizontal Setbacks

		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.

Wash. Admin. Code § 246-274-405

Statutory Authority: RCW 90.46.015. 11-02-011, § 246-274-405, filed 12/28/10, effective 7/31/11.