(1) If the irrigation system is cross-connected to a public water system, Washington state department of health (DOH) rules (WAC 246-290-490
) apply to backflow prevention.
(2) Cross-connections of a fertigation system to any potable water system intended for human use must have either a department of health-approved reduced pressure backflow assembly or reduced pressure detector assembly installed for backflow prevention. Otherwise, a physical separation in the form of an air gap may be used to protect the water source.
[Statutory Authority: Chapters 15.54
, 15.58, 17.21, and 34.05
RCW. WSR 01-23-018, § 16-202-2020, filed 11/9/01, effective 11/9/01. Statutory Authority: Chapters 15.54
, 15.58, and 17.21
RCW. WSR 01-13-063, § 16-202-2020, filed 6/18/01, effective 11/9/01.]