Hundreds of Detroit home demolition sites were potentially backfilled with toxic construction debris from a demolished shopping mall and other sources, creating an unfolding public health threat in the city’s neighborhoods.
Detroit, the nation’s lowest income big city, is in the US industrial heartland. It was left with tens of thousands of empty structures as industrial plants closed and people left the city in past decades – Detroit’s population dropped from nearly 2 million people around 1950 to fewer than 700,000 today. The city’s demolition program is widely considered the largest ever in the US.
Despite repeated requests from the Guardian, Mayor Mike Duggan’s administration and state regulators have so far not disclosed which toxins have been detected. Independent environmental health experts and a former regulator say lead, mercury, cadmium, PAHs, and asbestos – chemicals that are toxic at very low exposure levels – are likely in the type of slag used to backfill the neighborhood sites.
The problem could have been avoided, some demolition experts say. Duggan’s demolition program brought down tens of thousands of homes at a cost of hundreds of millions of dollars over his 12 years in office. Contaminated sites were found three times previously, and in 2018 drew federal scrutiny.
The latest round of contaminated sites – potentially 424 so far – is on pace to be the widest scale, and comes as Duggan leaves office this week to campaign full-time for governor as a pro-business independent. He has touted his blight elimination program as a top achievement.
Steve Hoin, a former state regulator who worked on previous Detroit demolition site remediations, questioned whether the administration followed advisory protocols developed in 2018 with state and federal regulators. The protocols were designed to avoid a repeat of the same problems.
The 2018 protocols also may not have been rigorous enough because they did not require the city or contractors to test all dirt. Testing is the best way to ensure dirt is safe, but it would have slowed the demolitions.
“Regardless, it’s mismanagement because clearly they had knowledge in 2017, and before that, that contaminated fill was coming in, and they haven’t fixed the problem,” said Hoin, a former geologist with the Michigan department of environment, Great Lakes and energy (EGLE). “I’m not sure if it was competence, or ‘we don’t care about the protocol because we want to get the demos done in time.’”
Duggan’s replacement, Detroit city council mayor pro tem Mary Sheffield, will inherit the problem, which Duggan estimated could cost about $18,000 per property to remedy, though some experts said it could be higher.
In a statement, Duggan administration spokesperson John Roach said contaminated backfill dirt is a problem around the country, and the suggestion that the issues in Detroit reflect bad city management “is false”.
“The only reason this has come to light is because of the City of Detroit’s investigation and testing,” Roach said. “It’s not possible to prevent all unscrupulous contractors from using bad soil, but no one has been more effective than the City of Detroit at holding them accountable when they do.” Roach said the test results will be publicly released.
A spokesperson for EGLE said the agency “will continue working with the City to determine appropriate actions, including possible remediation or enforcement if contamination is confirmed”.
The current problems came to light earlier this year when a Detroit office of inspector general investigation found a contractor hired by the city had used dirt contaminated with construction debris from the demolition of the Northland Shopping Mall. Testing reported in early November found 42 of 47 sites exceeded pollution thresholds, and much of that was “unsafe for direct human contact”.
At a 22 December press conference, Duggan announced that 424 sites had been identified as potentially contaminated, but did not name the contaminants.
Duggan said 32% of 50 sites tested so far were “above regional background levels”. The regional background levels are important because an exceedance triggers a mandatory environmental cleanup and indicates a risk to the public.
In effect, the city may now have small toxic waste dumps scattered throughout its neighborhoods, which is a “gargantuan problem”, said Allen Burton, an ecosystems management researcher with the University of Michigan.
“There might be a bag of really toxic stuff there,” Burton said.
The 2018 protocols were developed after debris from a freeway demolition was used to fill neighborhood demolition sites. The protocols increased scrutiny of dirt sources and required testing of dirt sourced from commercial land.
However, it opened an opportunity for contractors to lie and claim their dirt came from residential areas to avoid testing, said RJ Koscielniak, an Eastern Michigan University geology professor and urban decline scholar. He did his doctoral dissertation on Detroit demolitions and has reviewed hundreds of thousands of program documents.
Koscielniak said the city never “put in place legitimate controls” in part because regulations were opposed by contractors, and because the administration did not want to slow the demolition program.
“There’s an insistence that [the demolitions] get done with a velocity that compromises any regulations,” he said.
The contaminants likely in the shopping mall debris are linked to health issues like cancer and reduced cognitive ability in children. Those living around the sites face a health risk from dust that blows off the property, Hoin said. Children playing on the sites, or others who come into contact with the dirt, may face more immediate health impacts.
Hoin and Burton added that chemicals like lead are so toxic that even those below background levels can still be a danger. The background threshold for lead in Detroit is higher than in other cities, and does not necessarily convey safety, Burton said.
During his 22 December press conference, Duggan downplayed the health threat, stating that there would only be a risk “if you were to dig through the foot of topsoil and spend a lot of time digging in the dirt.”
Burton said hazardous waste sites are capped with specialized liners or several feet of clay, which Detroit has not put in place. Burton added: “I don’t buy what the mayor said.
“Anything that is near the surface is going to be a hazard to the neighborhood,” Burton said. “I think the mayor is just trying to get people off his back.”
