Oak Creek - State environment regulators gave We Energies a pass in 2008 - exempting it from certain rules so that construction work could be done atop coal ash landfills on a bluff on the Lake Michigan shoreline at the utility's Oak Creek Power Plant, officials said Tuesday.
Department of Natural Resources officials determined in 2008 that construction activities on an ash-filled ravine and other small landfills south of the utility's two plants on the property would not increase the risk of the ash or other contaminants getting into the lake, said Frank Schultz, the department's waste supervisor in Milwaukee. We Energies is building an air quality control facility for the older power plant at the site.
State environmental and utility regulators at the time decided that the construction activity would not significantly damage the environment, so no impact studies were needed.
Work progressed until Monday, when a wide section of the bluff, including part of an ash-filled ravine, collapsed, sending a destructive cascade of mud down the slope and into the lake. No one is certain of the extent of the environmental damage, DNR officials said.
The ravine was filled in the 1950s.
The Public Service Commission's 2008 decision approving the project said the agency determined the $900 million pollution control project at the original Oak Creek coal plant was not a project that required either a detailed environmental impact statement or a less exhaustive environmental assessment.
An environmental study could have explored the potential impact of building a storm-water retention pond so close to an ash-filled lake bluff, said Jennifer Feyerherm of the Sierra Club in Madison.
"The whole point of one of these assessments is to identify things that could go wrong and try to mitigate them or decide if that risk is too big," she said.
"Any large construction project poses risks to the environment, especially a large construction project that is next to a national treasure that supplies drinking water to millions," Feyerherm said.
A contractor for We Energies was to begin skimming fuel and other floating debris by early Wednesday off the surface of the lake where the mudslide ends and a plume of pollution begins.
A boom on the lake's surface forms a semicircle 1,500 feet long, extending 200 to 300 feet from the shoreline, and that is the area that will be skimmed first, We Energies spokesman Brian Manthey said at a Tuesday news conference.
A second, longer boom will be placed in a semicircle farther out in the lake Wednesday, Manthey said. The second boom will contain fuel or other floating debris that has been pushed by wind or currents a greater distance from the shore.
Beginning Wednesday or later in the week, the contractor will check the lake south of the plant to look for fuel or other debris that may have floated toward Racine County, Manthey said.
A separate contractor Tuesday was to begin building a dirt berm on top of the hill where the mudslide began. The berm will prevent storm water from washing additional coal ash, soil or other debris down the slope and into the lake, Manthey said. Rain is forecast Wednesday and Thursday.
Cause under review
We Energies is continuing to investigate the cause of the bluff collapse, Manthey said. The utility also is working with state and federal regulators to determine how to stabilize the slope so that cleanup of the mudslide can begin.
"The ash has been in that ravine for 50 years," the DNR's Schultz said. The top of the bluff had not been unstable in the past.
"Something changed on the site," he said.
Schultz said investigators are looking at several suspects that might have played a role in Monday's bluff collapse: an unlined storm-water retention pond adjacent to the ash-filled ravine; flow of water seeping out of the retention pond into soil and into the coal ash; and construction activity.
The 2008 exemption from the DNR prohibited We Energies from constructing a storm-water pond on the historic ash fill, Schultz said.
No portion of the pond was built on the ash-filled ravine, Manthey said Tuesday.
We Energies late Monday began pumping water from the hilltop storm-water retention pond as a precaution to prevent another mudslide.
Engineers were not certain of the stability of the bluff adjacent to the mudslide, so the pond was drained to remove the weight of the water from the hilltop, Manthey said. The pond is uphill of the section of bluff that collapsed.
University of Wisconsin-Milwaukee geology professor Tom Hooyer told the Journal Sentinel that water seeping out of the unlined pond might have loosened soil in the hill and destabilized the slope.
A portion of the slumping bluff encompassed coal ash and other material used to fill a ravine in the 1950s, according to We Energies. Coal ash likely was carried into the lake.
On Tuesday, representatives of the DNR and U.S. Environmental Protection Agency collected samples of coal ash and mud from the bottom of the slide area at water's edge. The samples will be tested for heavy metals and other contaminants in the ash.
"After sample analysis is completed, within the next few days, (the agencies) can evaluate the threat to the environment, specifically to Lake Michigan," said Phillippa Cannon, spokeswoman for EPA's regional office in Chicago. Additional samples will be collected Wednesday.
The mudslide destroyed a temporary storage building and pushed construction trailers and storage units down the slope, leaving behind a debris field that stretched 120 yards long and up to 80 yards wide at the bottom. A pickup truck and construction equipment ended up in the water. Fuel from the vehicles created a visible sheen on the lake's surface.
The slide area is immediately south of the air quality control system under construction at the power plant. This is the second-biggest construction project in the history of We Energies.
It's on the same 1,400 acre site as the largest and mostly costly project - the two new coal-fired boilers to the north of the original Oak Creek power plant.
The utility agreed to add the air pollution controls as part of a settlement with the EPA to resolve concerns over whether the utility had modified its plants over the years without adding modern pollution control equipment.
Together, the two projects are estimated to cost $3.25 billion - costs the utility's ratepayers have borne over the years through higher electricity rates.
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