This section covers all materials and testing for replacement of existing lines shown on the drawings by the patented trenchless method of pipe reaming, to be performed only by a legally licensed contractor. The replacement procedure shall be conducted by the use of a Horizontal Directional Drill (HDD) using an appropriate reamer to grind and pulverize the existing pipe, flush the pulverized pipe material and drilling fluid through the existing pipe to a retrieval point, and a new HDPE, Fusible PVC, Restrained Joint PVC, or Restrained Joint Ductile Iron of the required size installed simultaneously.

A. Description: Pipe installation shall consist of furnishing all labor, equipment and materials for a complete installation in accordance with the Contract Documents.

B. Modifications: It is understood that requirements throughout this section may be modified in accordance with Section xxxx of the Contract Documents.

C. Reference to Standards: References to Standard Specifications shall be understood to mean the latest revision of said specification as amended prior to the date of solicitation of bids, except as otherwise noted in the Contract Documents.

D. Submittals: The contractor shall provide certifications, shop drawings and samples as specified in Section xxxx for all materials specified for use on the project.

E. Experience: The contractor shall have prior experience with this type of installation, demonstrate proof of instruction by the licensor, or provide on site services of the licensor until such time the contractor's competency to perform the work is satisfactory to the Owner and/or Engineer.

Specifications requiring tens of thousands of feet of installation (pipeline replacement) by the successful bidding contractor and several thousand by the proposed supervisor are often politically motivated or an attempt to imbue replacement process with an unnecessary degree of complexity that would require such experience. It is important that the specification writer realize that the "technology" is in the tools, not necessarily in the processes. Such onerous requirements restrict competition, are no guarantee of quality, and often detrimental to the owners purse. Quality construction is the result of a good contractor working under the watchful eye of an informed inspector.

1. Pipe - Reference to ASTM specifications and Pipe Manufacturers specifications and recommendations should be made before issuing project documents because of continuous updating of the various specifications and procedures. Certain specifications listed here have doubtless been updated. It is therefore important to obtain the latest available specifications to avoid submittal conflicts.

a. Pipe shall be solid wall high density polyethylene (HDPE) pipe meeting the requirements of ASTM F714 Polyethylene (PE) Plastic Pipe SDR (xx) based on outside diameter, ASTM D1248 and ASTM D3350.

b. The pipe shall be manufactured from high density molecular weight polyethylene resin which conforms to ASTM D1248. The pipe produced from this resin shall have a minimum cell classification of 345464C (alpha suffix is indicative of pipe color. Consult manufacturer for specifications relating to pipe color and/or striping) per ASTM D3350.

a. PVC pipe shall be a restrained joint type such as Certa-Lok^TM manufactured by CertainTeed Corporation or AQUAMINE ^®, manufactured by Aquamine LLC and conform to the requirements of ASTM D2241, "Standard Specification for Polyvinyl Chloride (PVC) Pressure Rated Pipe" (SDR Series), and manufactured from Type 1, Grade 1, 2000 psi hydrostatic design stress Polyvinyl Chloride compound and materials in accordance with ASTM D1784 Class 12454-B, or other restrained joint PVC pipe conforming to these specifications and capable of withstanding the stresses of the installation process. Pipe with the CertaLok joint is available in AWWA C900 and C905 DIPS sizes 4" through 16" in DR to 14 and the Yelomine Series in IPS sizes 2" through 16" in various DRs. (See CertainTeed literature). Aquamine is identical to Yelomine except it is blue in color with a maximum size of 12". CertainTeed Yelomine is yellow in color, C-900 and C905 pipe is white.

b. Joints shall meet the requirements of ASTM D3139, "Joints for Plastic Pressure Pipes Using Flexible Elastomeric Seals."

c. O-rings shall meet the requirements of ASTM F477, "Standard Specification for Elastomeric Seals (Gaskets) for Joining Plastic Pipes."

d. Pipe shall have a minimum SDR of xxxx.

a. Restrained Joint Ductile Iron Pipe as manufactured by American Cast Iron Pipe Co. or US Pipe. Complete data is available from www.acipco.com (American Cast Iron Pipe Co.), www.griffinpipe.com (Griffin Pipe Products Co.), and www.USPipe.com ( US Pipe Co.). While not normally the choice material for gravity sewers, coated and lined DIP RJ is a good alternate when DI properties are required. Consult manufacturers for detailed specifications.

a. Fusible PVC in AWWA C900 sizes 4" though 12" and C905 in sizes 14" through 48" marketed by Underground Solutions, Inc., Sarver, PA Fusion information and other data is avaiable on line at www.undegroundsolutions.com

a. Electrofusion saddles as manufactured by Central Plastics or Friatec AG.

b. Heat fused saddles as manufactured by, Central Plastics or CP Chem.

c. InsertaTee^TM by Inserta Fittings Company.

d. Electrofusion couplings as manufactured by Central Plastics or Friatec AG.

Inserta Tees are not made of HDPE but are for use on HDPE as well as PVC. They are also not strictly a mechanical fitting in that they are a "snap-in" type, but need to be included somewhere in the specification. Because new HDPE fittings are being developed so rapidly, Central Plastics in Shawnee, Oklahoma and/or a Friatec dealer should be consulted before specifying specific electrofusion fittings.

a. Standard PVC fittings compatible with pipe.

a. Mechanical fittings for HDPE as manufactured by JCM, Victaulic or equal.

b. Ductile Iron Mechanical Joint or Flanged fittings, various manufacturers.

c. HDPE flange or mechanical joint adapters, from various HDPE fabricators (for pressure installations).

1. Safety: The contractor shall carry out his operations in strict accordance with all OSHA, Manufacturer's Safety Requirements, and as described in Section xxxx of the Contract Documents.

2. 2. Television Inspection: The line proposed for replacement shall be televised to assure that existing conditions are conducive to pipe reaming and to locate active service connections. Although commonly inserted in specifications in this exact or nearly exact form, televising for suitability after contract award with no avenue for redress or change may be questionably legal, or at least places the owner in a defensive position if it is discovered that the procedure is not suitable, which would be true for any trenchless application.

3. Sewage By-Pass: The contractor shall provide for continuous flow around the section of line designated for replacement. The pump and by-pass lines shall be of adequate capacity and size to control the flow at all times during the installation.

4. Sags in Line: If pre-installation video inspection reveals a sag in the existing line that is greater than 1/x diameter of the existing pipe and continues for more than "y" feet, the Engineer may direct the contractor to make necessary point repairs to align the pipe within acceptable limits prior to or after replacement of the installation section. Payment for this work shall be in accordance with the applicable sections of the Contract Documents. Quantifying "x" is something some engineers do as a way to define degree of sag. There does not seem to be any general consensus in the definition. The number of sags, that in the opinion of the Engineer, are too severe to be realigned by the replacement process should be quantified and a bid item established for "Point Repairs". The rationale for this is that in practice, the replacement process realigns the pipe far better than generally expected and the project is best served if Point Repairs are addressed after reaming. If for instance 5 Point Repairs are established in the Bid Schedule and 5 are done, the owner & contractor remain whole. If only 2 are done, positions are essentially the same except the Owner has saved some money. If they are subsidiary to other items, the bid has been artificially inflated if any point repair is not done.

5. Pipe installation sections shall be scheduled to maximize installation lengths and minimize the number of insertion pits required. Insertion pits shall be located over manhole replacement locations, if possible, to minimize surface disturbance.

6. HDPE pipe shall be fused in strict accordance with the manufacturers' recommendations. Operator certification by a manufacturer is often not an option and the "certifier" will often be the pipe supplier.

7. Pipe shall immediately follow the reamer through the bore channel. The reamer overcut should not exceed the maximum diameter of the replacement product by more than 3 inches. No final cuts or connections to HDPE shall be made to the pipe less than four hours after the pipe has reached its' final position. PVC RJ shall be "bunched" after being pulled into place in accordance with the manufacturers' recommendations.

8. Slurry generated by the installation shall be disposed of in accordance with all applicable local, state and federal regulations.

9. Removal and Reconstruction of Inverts and Manholes: manholes not scheduled to be removed and through which the reamer will pass, shall have the invert removed sufficiently to allow the reamer to pass without deflection and allow for a structurally sound repair/replacement of the invert per Engineer’s /Owner’s Standard Procedure. (The Engineer may wish to consider anchoring HDPE at manholes with electrofused restraint fittings should the circumstances of facility use, i.e., a significant temperature change in sewerage, indicate the need.Using the proper reamer, an experienced contractor can satisfactorily ream through a manhole without removing the invert. This procedure is preferable but does carry a fair degree of risk to the contractor and should not be undertaken without prior success.

10. Service Connections: Existing service connections shall be located, exposed, disconnected, and/or isolated from the main before beginning replacement operations. Services shall not be reconnected until the replacement line is in its final position. All services off line during installation or at any time during the course of the project shall remain in service by pumping or by-passing as required until such time that they can be permanently reconnected to the main.

11. Reconnection of Service: Connections to the new line shall be made using fittings consistent with the type of pipe installed and as specified.

12. Testing: TV, Air, Mandrel. per Engineer's/Owner's Standard Procedure. Note: Fusion beads on small diameter HDPE may not allow a 95% ID mandrel to pass.

This sample specification is for general reference only. ASTM references are unchecked for accuracy and/or application. Refer to manufacturer's current published literature. Specific details relating to scheduling, pipe handling, fusion, manhole gaskets, concrete, testing, TV, imaging, etc., have been omitted for brevity. Individual owner/engineer requirements, designs, and/or modifications should be added to make a complete project specific specification.