Sample Project 15 Mile Sink Hole - October 2004 Location: Sterling Heights, Michigan, USA Client: D.W.S.D. Start Date: October 2004 End Date: On Going

Project Scope
On August 22, 2004 a break in a 8 inch water main caused a sinkhole to form and then caused a break in the 11- foot diameter sewer interceptor below 15 mile road at Fontana Drive in Sterling Heights, Michigan. The sewer interceptor is located approximately 60 feet below ground. The sewer interceptor has a flow capacity of 30 - 60 million gallons a day.

Project Problem.
The staff of the Nautilus Marine Group International was retained by D.W.S.D. for all underwater construction work within the sewer interceptor. The first task was to determine the extent of the damage and stabilize the sewer interceptor from further damage. Then repair the damage to the sewer interceptor system and finally to perform an inspection on the remaining 5000 feet for cracks or breaks within the system.

Scope of Services
The staff of the Nautilus Marine Group International dive team was comprised of a six-man dive team utilizing two divers, a dive supervisor and two dive technicians as the tender/standby diver. The divers employed surface supplied air diving techniques to support the underwater services. The divers used a helmet mounted underwater video camera to document the current conditions of their work. All diving operations were performed from the ground at the interceptor inlets on the ground.

The first major task for the staff was the fabrication and installation of bulkheads at the upstream and down stream end of the interceptor allowing for the damaged portion to be removed. The staff then did several deep penetration dives (1800 feet) both upstream and down stream inspecting the interceptor for additional damage. When cracks or breaks in the interceptor were found an High Pressure grout injection system was used to seals the cracks or breaks. Repairs to the interceptor are currently on going and expected to be completed winter of 2006.