(1) All source water used for chemigation including, but not limited to, open reservoirs, ponds, or sumps must be protected from contact with chlorpyrifos or diazinon during an application unless the source water is demonstrated to have no hydraulic connection with drainage ditches or culverts.
(2) For the purpose of subsection (1) of this section, "hydraulic connection" means, water can flow between one source (either ground or surface water) to another source (either ground or surface water). Connection can be natural or manmade.
(3) For the purpose of subsection (1) of this section, "protected" means:
(a) Placement of a barrier or covering system over the source water in a manner that ensures spray from the nozzles do not contact the source water; or
(b) Design, placement, operation, and maintenance of irrigation sprayheads or nozzles in a manner that ensures spray from the nozzles does not contact the source water.
(4) Hydraulic connections will be determined as needed, by the department upon review of the source water system design.
[Statutory Authority: RCW 15.58.040
. WSR 19-02-039, § 16-232-440, filed 12/26/18, effective 1/26/19. Statutory Authority: RCW 17.21.030
and chapter 34.05
RCW. WSR 13-01-034, § 16-232-440, filed 12/11/12, effective 1/1/14.]