Section 246-291-210 - Distribution systems(1) Storage reservoirs shall be designed to:(a) Prevent entry by birds, animals, insects, excessive dust, and other potential sources of external contamination;(b) Include: (ii) A lockable access hatch;(iii) A screened roof vent;(iv) An overflow pipe with atmospheric discharge or other suitable means to prevent a cross-connection;(vi) A drain to daylight, or an alternative design approved by the department or health officer that is adequate to protect against cross-connection;(vii) Tank isolation in order to perform maintenance procedures; and(viii) Other appurtenances appropriate for the protection of stored water from contamination;(c) Be above normal ground surface level. If the bottom elevation of a storage reservoir must be below normal ground surface: (i) The storage reservoir must be placed above the groundwater table; and(ii) The top of a partially buried storage reservoir must be at least two feet above normal ground surface.(2) A Group B system designed to supply fire hydrants must have a minimum distribution main size of six inches (150 mm) supplying each hydrant.Wash. Admin. Code § 246-291-210
Statutory Authority: RCW 43.20.050 and chapter 70.119A RCW. 12-24-070, § 246-291-210, filed 12/4/12, effective 1/1/14. Statutory Authority: RCW 43.20.050. 94-14-002, § 246-291-210, filed 6/22/94, effective 7/23/94.