Abstract: A method of treating fungible produce at a wash station having a floor, comprising the steps of washing the produce, using a wash nozzle, with liquid containing a chemical treating agent. Effluent from the washing is collected in a storage tank. Liquid in the storage tank is conducted to a secondary tank, via a screen. Liquid in the secondary tank is conducted to a self-cleaning, self-backwashing filter. Back wash is conducted by gravity to a plurality of bag filters which collect particulate and discharge the filtered back wash into the secondary tank, above the screen. Liquid is conducted from the lower outlet of the self-backwashing filter to the storage tank. Liquid from the storage tank is conducted to the wash nozzle. The chemical treating agent is not filtered out by any of the filtration steps so that the chemical treating agent contained in the effluent from the washing may be reused and need not be dumped.