PDFWAC 16-229-220
Operational area containment of liquid pesticides—Temporary field storage.
(1) During loading and unloading of liquid bulk pesticide at temporary field storage locations individual basins or portable storage containers shall be used to recover spillage and leakage from transfer connections and pumps.
(2) Liquid bulk pesticide storage containers used for temporary field storage shall be located at least one hundred feet from wells and surface water, except, for purposes of this section, irrigation water flowing directly to a field, or on a field, is not considered surface water unless the water could be carried beyond the field being irrigated.