On Christmas eve 2016 a 250-foot-long, 100-foot-wide sinkhole opened up in Fraser, Michigan, a suburb of Detroit. Authorities believe it formed after an 11-foot-wide sewer pipe burst 55 feet below ground; however, a sinkhole this massive means that the leak was ongoing for some time and may indicate other problems. The hole continued to grow over the holiday weekend and authorities say the ground won't be safe enough for residents to return for at least two weeks. The Mayor of Fraser, Michigan has declared a state of emergency. Gas and water have been shut off and engineers and contractors work to steady the sinkhole and start filling it back in. Three homes have been destroyed, 22 families evacuated.
The sinkhole runs along 15 Mile Road, which divides the two communities of Fraser and Clinton Township. It's expected to shut down 15 Mile for several months. This isn't the first time a sinkhole has struck the area. This is at least the third time that a huge sewer pipe has failed in this immediate area. Most recently the same road caved in in 2004. Contracts for repairs on the same 11-foot-diameter pipe the cause of the 2004 sinkhole were at the center of racketeering charges against former Detroit Mayor Kwame Kilpatrick.
Macomb and Oakland counties have spent about $170 million on sewer infrastructure repairs during the past 12 years, designed specifically to prevent this type of catastrophic failure from happening again. The 2004 collapse took more than $50 million and 10 months to fix, and this sinkhole is just outside that repair zone. According to a lawsuit filed against the Detroit Water and Sewerage Department by area residents following the 2004 sinkhole, the same line collapsed in the same location in 1978, only six years after construction was completed.
Repeated catastrophic sewer line failures involving pipes within their operational life span is usually caused by one or more of the following three things: poor construction, poor engineering and design, or a lack of maintenance. Macomb public works officials will have to determine why, specifically, the latest sinkhole occurred.
The sewer lines move about 70 million gallons a day of wastewater from the suburban Macomb and Oakland counties to the Detroit wastewater treatment plant. The city of Detroit owned the sewer line system that included the 15 Mile Interceptor until 2009, when Oakland and Macomb counties each took over ownership of their respective sewer infrastructure. Inspections following the 2004 sinkhole revealed several miles of sewer lines in need of significant repair, and transferred the piping system to the counties, which had better bond ratings than Detroit. This allowed the sewer system to borrow the money at a lower rate making the work more affordable.
However, Detroit managed the work and former Detroit Mayor Kwame Kilpatrick is now serving 28 years in federal prison for multiple crimes including contract-fixing on the $54.3-million contract for the repair of the 2004 sinkhole on 15 Mile Road in Sterling Heights. In court documents, Mayor Kilpatrick has denied any wrongdoing in the sinkhole repair and has argued that the Detroit water department was “completely responsible for every administrative decision" that was made during the job.
Right now the raw sewage is being diverted to the Clinton River due to the wet weather. Officials say there should be no problems with dry weather sanitary sewer flows, as these flows are still being routed through the collapsed interceptor pipe. Rainfall or snowmelt, however, will overtax the system as occurred during recent rains and snowmelt over the holiday weekend. Temporary measures to mitigate the environmental impact from the sewage release are being investigated. The underlying cause why this particular area is experiencing multiple sinkholes when similarly old and neglected sewer pipelines have not remains unanswered.