PRE-TREATMENT:
RO PREFILTERS

      * Typically cartridge type filters. Filters may or may not be attached to the RO unit.

      * Filters remove varying sizes of sediment and carbon fines to prevent damage to RO
         membranes.

      * RO Prefilters are checked daily by checking the Delta (Δ) pressure (prefilter in - [minus]
         prefilter out). The pressure is documented on the Daily Water Quality Monitoring Log
.
      * Pressures equal to or greater than 15 should be reported to B.E.S.T.