Ask the DP Pro

Q How can Contractors Mitigate Risk on Trenchless Pipeline Projects?

A BY James H. Anspach & Tom Olson

RISK ON TRENCHLESS PROJECTS comes in various forms: subgrade investigation, design, contract language, trenchless method selection, and execution. How contractors can mitigate this risk varies.

While a contractor normally will not perform the subgrade investigation, the contractor can advise the engineer on how this should be performed, and why. Insofar as unforeseen underground utilities and untimely utility relocation are the most common cause of delay on highway-heavy projects, the engineer should follow ASCE 38. This should begin with a solid records research (including the project owner’s records as well as the utility companies’ records) and visual observation of the site. The engineer should then utilize Multi-Channel Ground Penetrating Radar, combined with pipe and cable locators, and perhaps even Time Domain Electromagnetics. Synthesizing all this data enables the engineer to assign a Utility Quality Level (B, C, or D) to the utilities (x, y and z) and other obstacles, and characterize the soil conditions. If financially feasible, the investigation results should be included as part of a Geotechnical Baseline Report. With an accurate subgrade profile and input from the geotechnical engineer on how this profile could affect both design and construction, risk is significantly mitigated. The engineer and contractor can choose the proper bore bath and trenchless method, respectively.

A key component of this risk mitigation is the contractor’s evaluation of the subgrade information, as well as the contractor’s right to rely upon that information. Notably, sometimes the subgrade profile information is not actually included in the contract documents; it is only available “upon request.” The contractor must ensure that it gets the information and fully reviews it to select the proper trenchless method. If the information is based on soil borings, contractors must evaluate whether and to what extent the borings properly correspond to the horizontal and vertical location of the bore path. As a matter of law, the less subgrade information given, the less right the contractor has to rely upon it (i.e. there is greater risk). The same is true if the information presents inconsistent subgrade conditions. In addition, engineers regularly include disclaimers (e.g. “owner does not guarantee accuracy of information”) that purport to limit or sometimes preclude reliance. Insofar as disclaimers are typically set forth in the Supplemental or Special Conditions, contractors need to ensure they obtain and review these contract sections. And to further mitigate related risk, contractors should obtain legal advice on whether and to what extent disclaimers are enforceable within the states in which they are/may be working.

In addition to reviewing the subgrade information and the right to rely upon that information, the contractor should determine if the trenchless design is clear. Has the engineer defined what trenchless method to use or is it up to the contractor’s discretion? This can be tricky in that sometimes engineers use language which could be interpreted either way (e.g. “Jack and Bore”). To mitigate risk, contractors should seek written clarification before bidding.

To further mitigate risk, contractors need to review the General Conditions as well as the Special and Supplemental Conditions to determine what their rights are in the event they encounter subgrade conditions different than indicated in the contract documents or otherwise normally encountered. Is there a differing site or changed condition clause? Assuming there is such a clause, which is typical, what are the related procedural obligations? One of the biggest failures contractors make to not mitigate risk is failing to follow these obligations. This includes providing written notice and stopping work in the affected area until the engineers investigate the alleged differing site condition.

Upon entering the actual construction phase, the contractor should compare the marks on the ground placed by utility owners’ One Call operations to that of the utilities on the construction plans. If there are errors or omissions, addressing and resolving them early eliminates headaches later on.

With a proper roadmap in place, contractors can significantly mitigate risk on trenchless projects.

James H. Anspach, PG (r), Dist.M.ASCE, A.A. Professor, Civil, Construction and Environmental Engineering Department, Iowa State University. Tom Olson, Partner, Olson Construction Law.

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