PDFWAC 222-38-040
Handling, storage, and application of other forest chemicals.
*(1) Waters and wetlands. Do not allow direct entry of other forest chemicals into any water or Type A or B Wetlands, except segments of Type Np and Ns Waters with no surface water present.
*(2) Storage, mixing, and loading areas.
(a) Mix other forest chemicals and clean tanks and equipment only where any accidental spills would not enter surface water or wetlands.
(b) Storage and loading areas should be located where accidental spillage of other forest chemicals will not enter surface water or wetlands. If any chemical is spilled, immediate appropriate procedures should be taken to contain it.
(c) Use devices or procedures to prevent "back siphoning" such as providing an air gap or reservoir between the water source and the mixing tank.
(d) Water protection requirements in subsection (1) of this section may be waived when emergency use of fire retardants is necessary to control wildfire.