PDFWAC 16-202-1010
How should rinsate or backflush water from a filtration device be handled?
(1) Water used to rinse, flush, or clean equipment or containers is considered rinsate. It must be applied at or below label rate to a target site or disposed of properly in accordance with chapter 173-303 WAC.
(2) Contaminated backflush water from a filtration device cannot contaminate groundwater or surface water, or adversely impact sensitive areas.