Common use of Jackets Clause in Contracts

Jackets. Wherever the main crosses under a streambed, large structure or utility larger than 16-inch diameter constituting a potential hazard to the main or where the main location is considered inaccessible by the Manager, the main shall be jacketed with reinforced DWS 2500 concrete. Necessary measures shall be taken to protect the stream embankment from erosion at the points of crossing. For cross-country mains and mains located in inaccessible areas, as approved by the Manager, mains shall be concrete jacketed. Grouted riprap paving with adequate concrete keys shall be constructed on steeper slopes. Additional valves may be required before and after streambed or structure crossing and jacketed mains where practicable. Plastic and existing asbestos cement pipes shall not be jacketed. Ductile iron or concrete cylinder pipe and fittings shall be used for the portion to be jacketed. Whenever a water main crosses over or under a sewer line, the sewer line will be concrete jacketed as listed in Table 100-5. Standard concrete jacket details for sewer lines as specified by the Department of Public Works Standards shall be followed. Table 100-5 - CONCRETE JACKET REQUIREMENTS FOR SEWER MAINS Island Water Main Under Sewer Main Water Main Above Sewer Main a - 5 L.F. of reinforced concrete jacket on both sides of crossing b - 3 L.F. of reinforced concrete jacket on both sides of crossing (when water line is less than 18 inches above sewer line) c - 5 L.F. of reinforced concrete jacket on both sides of crossing (when water line is within 6 feet of pressurized sewer line or within 18 inches of gravity sewer line)