Sinkhole Emergency!

2004 Romeo Arm Interceptor Reconstruction
(Sinkhole Series: second post of four)

The latest sinkhole in a residential neighborhood has caught the attention of Southeastern Michigan residents who are concerned about how sinkholes occur and how they can be fixed. ​Last week we posted an article about how sinkholes happen, and this week we will be posting about some of the work we have done to help with sinkhole issues in the area to show the work behind the repairs. NTH Consultants' engineers, no stranger to sinkhole investigations, have been called on for our expertise many times over the years to help with both emergency assistance as well as long term rehabilitation of sewers at sinkhole sites. An account of one such example is below.

As some may recall, in August 2004, six homes were evacuated when a 40-foot deep sinkhole developed over the Romeo Arm Interceptor in the city of Sterling Heights, Michigan. The Detroit Water and Sewerage Department immediately assembled a team of staff members, contractors, and engineers to formulate an emergency plan to stabilize the area. As prime consultant, NTH Consultants led an effort to stabilize the area, ensure wastewater service was not interrupted and to permanently repair
the damaged interceptor.

Stabilize & Repair Interceptor Collapse
Following on-site evaluations, it was determined that the following procedures would be necessary to stabilize and repair the interceptor collapse:

• Stabilize the sinkhole’s continued expansion by utilizing compaction grouting, jet grouting and steel sheet pilings
• Install multiple dewatering wells to prevent groundwater from transporting soil into the failed sewer
• Design and construct a sanitary sewer bypass system around the damaged portion of the interceptor to ensure continued wastewater flow
• Design and install two bulkheads to isolate the damaged portion of the interceptor
• Develop procedures to permanently repair the failed interceptor, including the design of a recovery shaft

Restoration of Alignment
Following the repair of the interceptor, the NTH team developed restoration plans for the entire alignment of the project. The restoration program included the following:

• Complete reconstruction of 15 Mile Road within the sinkhole region
• Pavement rehabilitation of all roads affected by the sinkhole
• Reconstruction of water mains, and sanitary and storm sewers
• Reconstruction of seven private utility systems lost in the sinkhole
• Landscape restoration along the entire project alignment

Efficiency & Speed 
When the sinkhole was first encountered, the media estimated that repairs could take several years to complete. Working with several other contractors, often on a 24/7 schedule, the team made this new pipe operational within 204 days.

Subconsultants:
Engineering

• Spalding DeDecker
• Lakeshore Engineering
• Superior Engineering
• Malcolm Pirnie
• Multi-Solutions Technologies

Construction

• L. D’Agostini & Sons
• Mersino Dewatering
• Rohrscheib Sons Caissons
• Spartan Specialties
• Thompson Pump Midwest
• O’Laughlin Construction
• Rotor Electric
• Great Lakes Diving & Salvage
• Hayward Baker
• Dubay’s Landscaping
• Will Brown Landscaping
• Six S
• Korneffel Construction
• George Brown Trucking
• Ferguson Enterprises