The area of Jerome, an old mining town on Highway 89A between Prescott and Flagstaff , was besieged by heavy rainfall in late December 2004. This led to the partial failure of the embankment and a dry-stacked rock wall, subsequently undercutting the northbound lane of Highway 89A.

The Arizona Department of Transportation (ADOT) retained NCS to develop a plan for the emergency stabilization of the surficial slide failure and the permanent remediation of the undercut roadway. As a precaution, ADOT had closed the roadway which serves as a major connection between Prescott and the Cottonwood/Camp Verde area. Hence, time was a crucial factor in the remediation effort

NCS designed a soil nail fix to stabilize the slope. ADOT opted for rebuilding the dry-stacked rock wall instead of using a carved shotcrete facing. The tight timeline of the project prevented NCS from doing an in-depth soil investigation, so available literature on previous investigations and geology had to be employed. Also, in the absence of survey data, the soil nail wall had to be designed based on and the soil nails had to be superimposed on digital photographs taken by ADOT.

NCS' scope of work included the following tasks:

• Site reconnaissance and review of pertinent literature
• Soil nail wall design based on photographs
• Field test supervision

This project has been completed and is in service.