Specifications include, but are not limited to: 1. GENERAL: The designated sanitary sewers shall be cleaned of root intrusion, sedimentation, and foreign materials, by the Contractor using hydraulically propelled, high velocity jet, or mechanically powered equipment. The use of chemical root treatments or grease solvents by the Contractor shall not be permitted. Selection of the equipment used shall be at the option of the Contractor and shall be based on the condition of the pipe at the time work commences. The equipment and methods selected shall be approved by the Engineer. The equipment used by the Contractor shall be capable of removing roots, dirt, grease, rocks, sand, other materials, and obstructions from the sewer pipe and manholes. The Contractor shall effectively clean each sanitary sewer for the purpose intended or shall restore sewers to minimum of 95% of the internal pipe diameter. The Contractor shall also clean manhole walls, benches, and inverts of all such debris, as directed. 2. HYDRAULICALLY PROPELLED EQUIPMENT: The use of sewer cleaning balls or other hydraulically propelled equipment that cannot be collapsed will not be permitted. The flow of sewage shall be utilized by the Contractor to provide the necessary pressure to propel hydraulic cleaning devices. The use of additional water from hydrants or other public outlets to supplement the normal flow of sewage for this purpose will not be permitted. 3. HIGH‐VELOCITY JET CLEANING: High velocity jet cleaning equipment shall be constructed for ease and safety of operation. The equipment shall have a selection of high velocity nozzles as may be necessary to produce a scouring action from 15 to 45 degrees in all size pipes designated to be cleaned. The equipment shall also include a high‐velocity gun for washing and scouring manhole walls and floors. The gun shall be capable of producing flows from a fine spray to a solid stream of sufficient velocity for its intended purpose. The equipment shall carry its own water tank, auxiliary engines, pumps and hydraulically driven hose reel...