Contaminated dirt was potentially used to fill demolition sites across Detroit and is the focus of a widening federal criminal probe of the city’s demolition program, multiple sources familiar with the investigation told the Free Press.
The Special Inspector General for the Troubled Asset Relief Program is also probing whether some companies used free dirt obtained from a variety of unverified sources— including the I-96 freeway construction project — and then passed it off as an approved residential dirt source before billing the federally-funded Detroit Land Bank Authority demolition program for materials they never actually paid for, sources said.
And in its first public acknowledgement of the probe, the Michigan Department of Environmental Quality confirmed late Thursday that it is aware of the nature of the investigation and the “potential use of I-96 soils as backfill in residential areas” in Detroit.
Construction at the Little Caesars Arena, happening as of April 2016.
“From review of the data, it appears that these soils were contaminated with chlorides (salt) from road deicing,” the MDEQ said in a statement to the Free Press. “The chloride concentrations in the soil did exceed the residential soil criteria.”
The MDEQ also confirmed it has had conversations with SIGTARP, and possibly other federal agencies, about the dirt usage.
Separately, one contractor, city officials confirmed late Wednesday to the Free Press, was recently ordered to dig up dozens of sites across the city that were filled with “unverified backfill” dirt. The city said Thursday a review of the company is “ongoing and may result in additional sites” being identified.
However, the exact number of potential sites where unverified dirt has been used overall is not yet fully known, sources said, raising questions of whether there’s a potential environmental impact.
The MDEQ said in its statement that: “This would be of concern in areas where people drink well water but because the area is served by city water, there is not a public health risk from this soil. High chlorides in the soil can be toxic to plants and plants growing in chloride contaminated soils may be affected.”
But Nick Schroeck, director of the University of Detroit Mercy’s environmental law clinic, pushed back against MDEQ’s stance.
“I would still be concerned about chloride washing off of sites during rain events and snow melt and getting into storm drains and making its way into surface waters, or that it would be captured by the combined sewer system and have to be treated at the wastewater treatment plant,” Schroeck said. “In the event of a water main break or other loss of pressure to the municipal water supply, ground water can seep into the drinking water distribution system. If the groundwater surrounding the drinking water pipes is contaminated, it can lead to potential contamination of drinking water.”
When asked for comment, the U.S. Environmental Protection Agency said the “EPA does not comment on ongoing investigations.”
However, the EPA said that in 2014 it worked with the city and the MDEQ to “enhance demolition practices,” including the program’s backfill sourcing and testing.
“The new protocol requires each contractor to identify source material location and testing evaluation of commercial soil sources in advance of backfilling so as to avoid bad fill material negatively impacting neighborhoods,” the EPA said in a statement, adding however, that Detroit is ultimately “responsible for identifying dirt sources under its protocol.”
City officials said due to testing performed by environmental consultants, dirt from the I-96 road construction project and the Little Caesars Arena site has been deemed “not suitable for residential use” and has been prohibited from being used.
It’s not immediately clear when that testing occurred.
The Michigan Department of Transportation did not respond to specific questions about the investigation and MDEQ’s assertion that the dirt wasbut spokesperson Diane Cross said in a statement that the I-96 project included the excavation of about 812,000 cubic yards of “earth” and of that, 7,000 cubic yards, was considered “non-hazardous contaminated material.”
“Those 7,000 cubic yards had slightly higher than normal readings for naturally occurring arsenic and, while not hazardous, (it) was given special consideration to where it was moved,” Cross said, adding that the soil was used in two areas within the scope of the I-96 project.