(A) General.
(1) The CIPP process will renovate an existing pipeline from the inside by the installation of an interior pipe that fits tightly to the inside of the existing pipe. The process will be accomplished through the use of existing access, such as maintenance holes or other existing openings, and is to be done with minimal excavation. The new interior pipe, called a CIPP liner, is provided in sufficient thickness to address the deterioration situation of the existing pipeline. Typical thickness ranges from 4.5mm to 50mm depending on the size, condition and depth of the existing pipe. Liner thickness shall be submitted to the Engineer for review and approval based on the project-specific situation.
(2) Restoration of existing sanitary sewers by installation of a resin impregnated flexible felt tube into the existing sewer line utilizing a vertical inversion standpipe and hydrostatic head and curing by circulating hot water or steam/air mixture to produce a hard, impermeable pipe during the cure process.
(3) The finished pipe liner in place shall be fabricated from materials which, when complete, are chemically resistant to, and will withstand internal exposure to, domestic sewage having a pH range of 6 to 9 and temperatures up to 150°F.
(B) Description. CIPP rehabilitation consists of inserting CIPP liner into the existing pipe in a soft, flexible and expandable configuration containing thermosetting resin in a viscous liquid state. A resin absorbent carrier tube called a felt bag will be used to carry, properly position and uniformly distribute the liquid resin within the existing pipe. Upon final positioning and expanding of the carrier tube against the inside surface of the existing pipe, the resin will be transformed to a solid state by a thermosetting process. The thermoset process will be initiated by applying heat to the resin that was previously catalyzed before its absorption into the carrier tube. The methods used to introduce the required heat will be by internally circulating heated water or by a flow through of steam/air mixture.
(1) The process of absorbing the catalyzed resin into the carrier tube is called resin impregnation or wet-out of the carrier tube. The process of installing the resin impregnated liner tube into the existing pipe is called inversion or pull-in, depending on the specific insertion method used and type of carrier tube. The process to make the liquid resin in the carrier tube transform to a solid by the thermostatic reaction is called curing.
(2) Following the cure of the CIPP liner, the closed ends of the liner at manholes or other accesses will be removed and the pipeline made available for flow. Incoming connections, such as service laterals, will be reinstated into the pipeline by cutting corresponding openings in the cured CIPP liner. For non-human entry sized pipeline, CCTV monitored robot cutters will be used. For all other pipe, reinstatement may be done by human entry.
(3) The CIPP lining installation process will include the cleaning and preparation of the existing pipeline to a suitable state, and the provision of flow bypass when necessary. The CIPP rehabilitation is completed with CCTV inspection of the finished liner.
(C) Submittals. The following shall be submitted by the contractor to the District:
(1) The contractor shall have completed a minimum of 50,000 feet in wastewater collection systems construction within five years of the project bid. Contractor shall submit short project descriptions and references (name and phone numbers of property owners or construction inspectors) for five projects;
(2) Shop drawings, catalog data and manufacturer’s technical data showing complete information on material composition, physical properties and dimensions of new liner;
(3) Pre-installation television inspection reports and video;
(4) Detailed project plan, including drawings and written descriptions of the entire construction procedure to fabricate, wet-out, stage, install liner, bypass pumping configuration, details and equipment, inversion locations and location of all special connections;
(5) Television inspection reports, video and test results made after new liner is installed;
(6) Testing reports and results from final installation;
(7) CIPP liner installation and sequencing plan for the entire project, to the District and owner for review and approval. Plan shall show location of all insertion points, water draw locations and staging areas;
(8) Emergency response plan;
(9) Project schedule;
(10) Resin manufacturer’s heating and curing requirements;
(11) Final design calculations, liner thickness and resin design for all lined segments; and
(12) Resin and tube installation test results of field installations for system proposed.
(E) Installation. It shall be the responsibility of the contractor to coordinate with the District to locate and designate all manhole access points open and accessible for the work and provide rights-of-access to these locations. If a street must be closed to traffic because of the orientation of the sewer, the contractor shall take all actions necessary to provide access for the mutually agreed time period. The contractor must coordinate with the District for access to water hydrants for cleaning, installation and other process related work items requiring water.
(1) Cleaning of sewer lines. The contractor, when required, shall remove all internal debris out of the sewer line that will interfere with the installation of CIPP. The contractor shall dispose of all debris removed from the sewers during the cleaning operation at an acceptable facility.
(2) Bypassing sewage. The contractor, when required, shall provide for the flow of sewage around the section or sections of pipe designated for repair. Plugging the line at an existing upstream manhole and pumping the flow into a downstream manhole or adjacent system shall make the bypass. The pump(s) and bypass line(s) shall be of adequate capacity to accommodate the sewage flow. The District may require details of the bypass plan to be submitted that include, at a minimum, 24-hour backup pumping equipment/generator, emergency contact numbers, qualified personnel to provide continuous supervision of bypass pumping system, traffic control, surface pipe restrictions and the like, adequate to accomplish the bypass pumping operation.
(3) Inspection of pipelines. Inspection of pipelines shall be performed by experienced personnel trained in locating breaks, obstacles and service connections using closed circuit television (CCTV) inspection techniques. The pipeline interior shall be carefully inspected to determine the location of conditions that may prevent proper installation of CIPP. These shall be noted and corrected. A video and suitable written log for each line section shall be produced for later reference by the District.
(4) Line obstructions. It shall be the responsibility of the contractor to clear the line of obstructions, such as solids and roots, that will prevent the insertion of CIPP.
(5) Public notification.
(a) The contractor shall make every effort to maintain sewer service usage throughout the duration of the project. In the event that a connection will be out of service, the longest period of no service shall be eight hours. A public notification program shall be implemented, and shall, as a minimum, require the contractor to contact each home or business connected to the sanitary sewer, inform them of the work to be conducted and when the sewer will be off-line.
(b) The contractor shall also provide the following:
1. Written notice delivered to each home or business the day prior to the beginning of work on the section and a local telephone number of the contractor to discuss the project or any potential problems; and
2. Personal contact with any home or business that cannot be reconnected within the time stated in the written notice.
(6) Confirmation of locations. The contractor shall be responsible for confirming the locations of all branch service connections prior to installing the CIPP.
(Ord. 2019-02, passed 4-25-2019)