Agmt17 National Plant Services, Inc.

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Cleaning The CONTRACTOR shall perform a minimum of two (2) passes using the high -velocity hydraulic cleaning method. The contractor shall clean the line until the line is ready for closed- circuit television inspection that's acceptable to City. No additional compensation will be made to the CONTRACTOR in performing three or more passes in cleaning the sewer line. All pipe cleaning cost method and duration shall be included in the agreed cost irrespective of the type and size of the existing sewer lines. If a video and/or the capture images in the database do not clearly show the pipe conditions due to inadequate clean-up or are of such poor quality that the Engineer is unable to evaluate the condition of the sewer or locate sewer service connections, the CONTRACTOR shall re -televise that section of the pipe at CONTRACTOR'S expense. The CONTRACTOR shall protect the manholes to withstand forces generated by equipment, water, and air pressure. The CONTRACTOR shall clean the sewer pipe of any obstruction and debris including roots in accordance with the "Standard Specifications for Public Works Construction (Green book)", latest edition. CONTRACTOR shall use a jet/vacuum combination unit for cleaning all sewer lines. The combination unit shall operate at 80 gallons per minute at a pressure of 2,500 psi, and be equipped with approximately 800 linear feet of hose. CONTRACTOR' S operating technicians shall have a minimum of 3 years of experience cleaning with this piece of equipment. CONTRACTOR shall clean the lines in a downstream direction, beginning from the most upstream manhole of a particular reach or set of reaches, and begin cleaning so that the debris will continually be pulled downstream. In order to jet clean the lines, a high pressure water pump on the combination truck shall deliver water from attached tanks through a high pressure hose to a cleaning nozzle. The water pumped through the cleaning nozzle shall propel the nozzle and attached high pressure hose through the sewer. Once the cleaning nozzle has arrived at an upstream manhole, the nozzle shall be pulled back through the pipe at a velocity controlled by the operator. During the cleaning process, the cleaning nozzle will not travel faster than one foot per second in the line. While the cleaning nozzle is pulled back, the vacuum system shall be used to simultaneously remove debris flushed by the cleaning nozzle. CONTRACTOR shall use a root cutting nozzle to remove all debris. The root cutting nozzle shall revolve 360 degrees, be capable of cleaning at 4"48" lines, and operate at 80 gallons per minute at a pressure of 3,000 pounds per square inch. Dislodged roots shall be captured and removed from the line either by the vacuum or a basket. The CONTRACTOR shall remove all sludge, dirt, sand, rocks, roots, grease and other solid or semisolid material resulting from the cleaning operation at the downstream manhole of the section being cleaned. Procedure for removing roots may include the use of mechanical equipment such as rodding machines and bucket machines using root cutters and porcupines. Passing material from manhole section to manhole section which could cause line stoppages, accumulations of sand in wet wells, or damage pumping equipment, shall not be permitted. Chemical root treatment shall not be used by the CONTRACTOR. REV: 08.04-17 PR Page 7 of 14 ATTY/AGR.2017.173/National Plant Services, Inc.