About Us


Staheli Trenchless Consultants (STC) is a specialty engineering firm that focuses on the reduction of trenchless risk through trenchless engineering services including feasibility studies, geotechnical investigations, design and bid services as well as construction management and inspection services. The firm’s principal engineer Kimberlie Staheli is a recognized leader in the trenchless engineering community, and has worked closely with many of the foremost authorities in the field, including Dave Bennett with whom she co-founded Bennett-Staheli Engineers in 1995. Staheli Trenchless Consultants and Bennett Trenchless Engineers became stand-alone firms in 2007 as the result of a mutual business decision between the co-owners of Bennett-Staheli. The two firms continue to work closely on several projects in both California and Washington State.

STC provides feasibility and design services for projects which include microtunneling, horizontal directional drilling, guided boring, auger boring, pipe ramming, pipe bursting, EPB tunneling and in-place rehabilitation such as sliplining. Feasibility studies include evaluation of geotechnical data and site conditions, identification of risks and mitigation measures, and recommendation of trenchless methods and construction feasibility. Design services include providing input into the development of plans, authoring technical specifications for construction, preparing geotechnical baseline reports, performing risk assessments, developing project schedules, and providing engineer’s cost estimates for trenchless construction.

In addition to standard design services, the firm has participated in design reviews for a third party by serving on value engineering panels for a number of trenchless projects at various levels of design ranging from 30% to 90% completion. When participating in value engineering, STC focuses on modifications to trenchless project designs which will both minimize overall construction risk and cost.

STC also provides construction management services, both pre-bid and post-construction. Pre-bidding services include developing and evaluating pre-qualification packages as well as bidding contractors quality assurance (i.e. ensuring bidding contractors have an appropriate level of experience to match the complexity of the project). Post-construction services include contractor claim evaluation to determine claim validity, expert witness testimony and counseling following claims. Construction services also include full-time on-site construction management to track contractor performance, verify that projects meet specifications, and minimize risk during construction.

STC is certified as a Women’s Business Enterprise (WBE) in both Washington and Oregon.