Specifications include, but are not limited to: Removal and legal disposal of existing support gravel, GreensandPlus and Anthracite media from three 6.5-ft diameter pressure filter vessels and furnish and install new replacement media. Removal and inspection of existing filter internal components. Furnish and install replacement filter internal components in kind. Inspection of existing interior coating system including steel thickness of each filter vessel and spot repairs as required to correct any deficiencies. Replacement of existing small diameter (<3”) carbon steel filter face piping with stainless steel piping. Replacement of existing PVC chemical feed piping with stainless steel for the existing Potassium Hydroxide system. Modifications to the existing backwash supply tank fill piping.