PDFWAC 16-232-430
Restrictions in Grays Harbor and Pacific counties on the use of pesticides containing chlorpyrifos or diazinon for protection of ditches.
(1) Chlorpyrifos or diazinon shall not be applied to cranberries unless all ditches immediately adjacent to the application and all other ditches that will be contacted by the application are adequately protected to prevent entry of chlorpyrifos or diazinon at the time of application.
(2) For the purpose of subsection (1) of this section, "adequately protected" means:
(a) Ditches are cribbed and covered according to USDA NRCS Practice Standards "Drainage Water Management" CODE 554 (Nov. 2011); "SubSurface Drain" CODE 606 (Sept. 2011); "Surface Drain, Main or Lateral" CODE 608 (Nov. 2010); and "Underground Outlet" CODE 620 (Nov. 2010), or one of the functional equivalents below.
(i) A functional equivalent for ditch side walls is the installation of side walls with rigid material capable of maintaining ditch integrity for a period of no less than ten years.
(ii) A functional equivalent for ditch coverings is the installation of ditch coverings using rigid material capable of preventing entry of chlorpyrifos or diazinon either through chemigation activities or run-off from irrigation activities into ditches as described in subsection (1) of this section.
(b) Drainage culverts are installed and constructed according to USDA NRCS Practice Standard "Underground Outlet" CODE 620 (Nov. 2010).
(3) All ditches and culverts shall be maintained and kept in good repair as needed in order to achieve the requirements of subsection (1) of this section.
(4) Upon request, the department shall be provided with all available information related to the design, construction, and materials used to protect the ditch as described in subsection (2) of this section.