NUCA Top Job of the Year Winner

Iowa Trenchless played a central role in the award-winning Lower Conner Creek Interceptor project—one of the most technically challenging trenchless efforts completed in the Kansas City region. The project consisted of 2,600 linear feet of new sanitary sewer, constructed through three major trenchless methods:

  • 640 LF soft-ground TBM pipe jacking using steel casing
  • 1,300 LF rock tunnel using ribs-and-board support
  • 640 LF of pilot-tube guided auger bores for additional sewer segments

The work was completed for the Unified Government of Wyandotte County/Kansas City, Kansas, with Rodriguez Mechanical Contractors as the prime and Iowa Trenchless and Midwest Mole as trenchless subcontractors.

Key Challenge: Unexpected Bedrock Knoll

The original design called for a 570-foot soft-ground tunnel. However, supplemental geotechnical exploration revealed a significant bedrock knoll between the launch and receiving shafts. To keep the project viable, the tunnel was realigned and extended to 640 feet.

Iowa Trenchless completed the tunnel using an Akkerman 480 TBM equipped with a closed-face cutterhead and Permalok steel casing, advanced by a 1,200-ton hydraulic jacking frame. Production reached rates as high as 60 feet per shift, averaging 35 feet per shift overall.

Rock Tunnel Installation

Midwest Mole delivered the 1,300-foot rock tunnel through interbedded limestone and shale using a custom-built 66-inch TBM optimized for penetration and steering control. A segmented liner system using ring beams and wood lagging reduced jacking forces and allowed the TBM to advance off its own installed liner—key to maintaining tolerances and productivity.

Additional Trenchless Work

To complete the system, additional 24-inch and 30-inch steel casings were installed beneath a highway and a Class I railroad, using:

  • Akkerman 240A GBM
  • Michael Byrne and Barbco auger boring machines

Outcome

The project succeeded due to continuous coordination between the prime contractor, Iowa Trenchless, Midwest Mole, and the engineering team. Completing multiple complex trenchless installations prevented:

  • Major schedule delays
  • Disruption to the surrounding community
  • Significant additional cost to the municipality

The project was recognized with NUCA’s prestigious Top Job of the Year Award, highlighting its technical innovation and collaborative delivery.