2 March 2012
The cause of the Oak Creek landslide in Wisconsin
Posted by Dave Petley
Long term readers will remember back in November last year I featured on a number of occasions a landslide at the We Energies power station at Oak Creek in Wisconsin (see posts here and here). An anonymous commenter has highlighted a new report yesterday in the Journal Sentinel that provides more information about the cause and the aftermath. The report notes that:
The state Department of Natural Resources issued a notice of violation to the Milwaukee utility on Thursday saying the agency believes the company violated solid waste regulations when it built a pond in and above a pond built atop a coal ash landfill on the power plant site.
“We have reason to believe that the failure to install a liner in the storm water pond was a significant factor in the bluff collapse,” the DNR said.
The notice of violation indicates We Energies could face fines of up to $5,000 per day.
There are a couple of interesting resources on the WDNR website about this landslide:
- There is a good presentation available about the landslide and its aftermath.
- There is a dedicated website for the landslide and its environmental impact.
At the moment the details of the investigation to which this news report pertains does not seem to be on the DNR website (does anyone have a copy?), but this image of the site (from here) shows that there were two ponds present at the top of the slope before the failure:
Given the nature of the materials at the site (take a look at the post-failure image below), it is surprising to me that there were apparently unlined ponds at the top of this slope:
I remember this. I was one of the last cars that traveled on the old highway before they closed the road.