Utility Contractor

MAY-JUN 2018

As the official magazine of NUCA, Utility Contractor presents the latest information affecting every aspect of the utility construction industry, including technological advancements, safety issues, legislative developments and instructional advice.

Issue link: http://digital.utilitycontractoronline.com/i/976710

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Page 33 of 51

34 Utility Contractor | May/June 2018 I n the late 1980s a good friend and competitor was awarded a large 18-in. sewer project near a lake. The soils were a silty sand with a high water table that made excavation in the quicksand conditions very difficult. In the end he was un- able to complete the project and as a result lost his business. Had my friend been able to use the latest trenchless technology available today he would have rescued his company and most likely made a decent profit on the project. An ongoing project near the same lake with similar soil con- ditions illustrates the advances that trenchless technology has made in becoming a very cost-competitive alternative to open- cut sewer installations. The project is the first phase of a large sewer system expansion by the City of Provo, Utah, to service an area of rapid development. Bids received for 15- and 18-in. sewer mains ranged from $2 million to $2.5 million with the low bidder 25% lower than the next bidder. A proposal for trenchless installation of the sewer was discussed with the low bidder, which would reduce his bid by over $200,000. Because this phase of the project was required to start and finish with very tight deadlines, the lead time required for the trenchless option made it impractical for use on this first section. Here are the original bid results and comparative bid results had the trenchless option be available to each bidder. Why is the open cut option so much more expensive? Over the last two decades the cost of open-cut sewer proj- ects has increased significantly. Factors that have caused the increases relate to more stringent design, environmental, safety and public nuisance issues: • Public nuisance issues - Work hour limitations; Increased traffic control; Increased truck traffic issues; Work hour restric- tions during high traffic volumes and special events; Night work only with noise limitations; Winter and weather shut- down requirements. • Environmental Requirements - Noise mitigation; Storm water runoff restrictions; Equipment pollution such as mud on roads; Strict dewatering, treatment and disposal requirements; Wetlands or animal disturbance issues. • Design Requirements - Off haul of all excavation; Import- ed gravel for all backfill; Increased pavement restoration to en- tire lane or road width; Existing utility damage prevention. • Increased Safety Requirements - More robust trench shor- ing requirements; Increased OSHA requirements such as dust disturbance mitigation. The cumulative effect of these more stringent requirements results in substantially increased costs and risk to the contrac- tor. Overruns on gravel backfill alone, due to sloughing soil conditions, can cause an otherwise profitable project to suffer substantial losses. Why is the trenchless option so much less expensive? With the relatively small footprint at manhole locations, the trenchless technologies eliminate 95% of the issues with the open- cut work mentioned above. The cost of compliance with these is- sues is simply not incurred. The attractive advantages of trenchless methods result in less cost, safer projects with less risk and more profit for the contractor and less cost to the project owner: • Public nuisance issues - Work around the clock is nor- mally permitted with a noise attenuated generator as the main power source; Work can proceed during inclement weather and cold winter conditions; Public inconvenience and traffic control are minimal; No truck traffic except for excavation and backfill of shafts at manhole locations. TRENCHLESS METHODS CAN REDUCE COST OF UTILITY INSTALL ATIONS By Mike Ellis Engineer Bidder 1 Bidder 2 Bidder 3 Open Cut Bid $2,482,354 $2,500,000 $2,434,286 $1,960,069 Trenchless Bid $1,875,646 $1,799,421 $1,818,246 $1,727,315 Trenchless Savings $606,708 $700,579 $616,040 $232,754 Bid Results

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