1. (a) The following trenchless technologies may be used for installation of new wastewater collection system pipe:

   1. (1) impact moling, which is technique that launches a percussive soil displacement hammer (mole) from an excavation to displace soil and form a bore. The new pipe is drawn behind the mole or pulled into the bore using the hammer's reverse action. A pneumatically driven mole displaces the soil by the action of a percussive piston;
   2. (2) pipe ramming, which is a simple technique using a pneumatic hammer to drive steel casings through the ground from one pit to another; or
   3. (3) microtunneling, which is a remotely controlled mechanical tunneling system where the spoil is removed from the cutting head within the new pipeline, which is advanced by pipe jacking. The cutting head must have the appropriate cutting tools and crushing devices for the range of gravels, sands, silts, and clays that may be found at the collection system site.

2. (b) The following trenchless technologies may be used for replacement of wastewater collection system pipe:

   1. (1) pipe bursting, which is a method of on-line replacement of fracturable pipe. An expanding device, either pneumatic or hydraulic, is introduced into the defective pipeline, shattering the pipe and drawing in the new pipe behind it. Insertion of short lengths may be made from pits but this involves jointing of the pipeline within the pit;
   2. (2) pipe splitting, which is similar in technique to pipe bursting but is used on non-fragmental pipes such as steel, ductile iron or polyethylene. The system uses specialized splitting heads designed to cut through the pipe wall and joints and expand the existing pipe into the surrounding ground; or
   3. (3) pipe eating, which is an on-line microtunneled replacement technique. The existing defective pipeline is crushed (or eaten), by the tunneling machine and removed through the new pipeline. It is used predominantly on concrete sewer installations. This system allows for size replacement and upsizing.

3. (c) The following trenchless technologies may be used for lining of existing wastewater collection system pipe, which reduces the inside diameter of the pipe:

   1. (1) cement mortar lining, which is the application of a cement mortar (typically about four millimeters thick) to the inside of a pipe to protect against corrosion;
   2. (2) epoxy spray lining, which is a method of lining pipes with a thin lining of resin (typically about one millimeter thick) that is sprayed onto the interior surface of a cleaned collection system pipe to isolate the pipe from the wastewater and possibly reinforce the structural capabilities of the pipe;
   3. (3) cure in place pipe, which is method of lining existing pipe with a flexible tube impregnated with a resin that produces a pipe after the resin cures. The resin may be set by the use of heat or ultraviolet light; or
   4. (4) sliplining, by which continuous or discreet pipes are inserted within existing pipes.
4. (d) Any other trenchless method of installing, replacing, or repairing collection system pipe is nonconforming technology and subject to the requirements of §217.7(b) of this title (relating to Types of Plans and Specifications Approvals).
5. (e) A wastewater collection system using a trenchless technology must be designed, installed, and constructed in accordance with American Society for Testing and Materials (ASTM) or American Water Works Association (AWWA) standards with reference to materials used and construction procedures. In the absence of ASTM or AWWA standards, executive director review may be based upon other recognized standards utilized by industry engineers.

6. (f) The report must include the following;

   1. (1) the trenchless method;
   2. (2) the type of pipe;
   3. (3) the type(s) of soil;
   4. (4) the pipe length and diameter;
   5. (5) pipe slope;
   6. (6) the method for disconnecting and reconnecting lateral and service connections;
   7. (7) the provisions for flow bypass for existing system; and
   8. (8) the pipe standard.
7. (g) The method for disconnecting and reconnecting lateral and service connections must be included in the report.
8. (h) Pipe installed by a trenchless technology is subject to the testing requirements in §217.57 of this title (relating to Testing Requirements for Installation of Gravity Collection System Pipes) and §217.68 of this title (relating to Force Main Testing).

Source Note:The provisions of this §217.56 adopted to be effective August 28, 2008, 33 TexReg 6843.