Specifications include, but are not limited to: Contractor will remove the existing sand and anthracite from filters 2-8 (a total of 7 filters) and will dispose of the old media on site. 2. Contractor will vacuum clean the existing underdrain in filters #2-7 and thoroughly investigate the underdrain system; observe the grout joints, look for underdrain lifting. Filter #4 is seen as a potentially compromised filter, Contractor will remove up to 10 IMS caps in filter #4 and probe filter #4 underdrain to check for media contamination. ; Contractor will replace all IMS caps that were removed in filter #4, epoxy seal all grout joints in filter #4 and furnish and install new media in filters 2-8; 12 inches of sand and 24 inches of anthracite. a. Specified Filter Media Size for Filters 2-8 b. 12" Silica Sand Effective Size: .45mm-.55mm Uniformity Coefficient: 1.40 c. 24" Anthracite Effective Size: 1.00mm-1.20mm Uniformity Coefficient: 1.40 ; After successful media installation (3 or more filters at a time) backwashing and skimming; the filters will be returned to the owner for disinfection. 5. Substantial leakage around the troughs in filters 1 – 8 has been observed. Contractor will seal off all leaks around the deteriorated trough grout and re-level all troughs.