State regulators say they will not test the air around a BASF toxic waste site at Hennepin Point on Grosse Ille’s north end for dangerous contaminants after a new report from a company-hired consultant concluded the risk to nearby residents and wildlife was low.
But independent environmental experts questioned why the evaluation didn’t include some of the most toxic contaminants known to be in the site’s soil, and said state regulators should have tested the air to know for certain whether a health threat exists.
Planet Detroit reported in early 2024 how the 225-acre Hennepin Point site is made up of distiller blow off (DBO), a toxic substance dumped there by chemical company BASF and others. Previous testing has also found mercury, lead, and other heavy metals at the site, and some independent experts told Planet Detroit they feared residents living nearby could be harmed by long term exposure to toxic dust blown from Hennepin.
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Grosse Ile’s Hennepin Point is full of toxic waste. Is it a threat to wildlife and humans?
Regulators still aren’t sure what the risks are after decades of pressuring BASF, which owns the site and is liable for its cleanup.
BASF pollution: Environmental groups secure public health assessment for Wyandotte
State and federal authorities will assess the impacts of BASF’s ongoing pollution on air, water and soil.
BASF’s hired consultant tested Hennepin’s soil for some contaminants, checked wind data, looked for spots on the peninsula from which loose dust could blow, and factored in the levels at which dust exposure for some contaminants is harmful. It concluded the human health risk from air exposure was low.
“Based on the current site conditions and the multiple lines of evidence analysis … the probability of windblown particulate matter originating from Pt. Hennepin is low,” the report states. “Air monitoring is not necessary.”
But some independent experts who reviewed the data questioned why regulators did not require BASF to test the soil and air for mercury, xylene, and arsenic – among the most dangerous compounds previously found at Hennepin. Steve Hoin, a retired state geologist who oversaw Hennepin Point’s remediation for around 20 years and reviewed the new report, said the risk may be low, but the agency still should conduct air monitoring to be sure.
“It may be that we don’t have a risk, but I still would say that local air sampling is a necessary part of the determination,” Hoin said. “The way I would word it is ‘Confirm your modeling is correct.’” He questioned whether the report met the standards set in state law because it is largely a qualitative analysis, and should include some air monitoring.
Planet Detroit reached out to the Michigan Department of Environment, Great Lakes and Energy (EGLE) about the legality of the report for comment and did not receive a response.
Denise Trabbic-Pointer, who previously worked in the chemical industry and is now with Sierra Club Michigan, said there is no reason not to test for arsenic, xylene, and mercury, and characterized the report as “fluff”.
“It missed a lot of stuff, and that seems purposeful – they know what they have found historically in the DBO out there,” Trabbic-Pointer said.
State regulators also raised concerns about air exposure for workers on the site in the late 1990s and early 2000s. EGLE, which oversees the site’s remediation and ordered BASF to do the evaluation, has been criticized in the past for relying on consultant’s modeling or reports instead of using air quality data.
Hugh McDiarmid, a spokesperson for EGLE, said it “has reviewed [the report] and concurs with its conclusions.”
When asked specific follow up questions from Planet Detroit about why there was no air sampling or testing for among the most dangerous contaminants at the site, McDiarmid said. “Again, we’ll let the dust memo speak for itself. Particularly the conclusion.”
BASF in a statement said it found the risk to be low and said it works with EGLE “to prevent any adverse impacts on the Detroit River or the surrounding community resulting from historical activities at the Point Hennepin site.”
Toxic waste dumped for decades
The companies dumped DBO at the site for decades through 1951. BASF also stored mercury waste in lagoons and injected it into salt caverns at Hennepin Point around 50 years ago, state and federal regulatory documents show, and regulators are now trying to determine if the complex geological area beneath the island is leaking it or other contaminants. Documents also show that waste drums with unknown materials have been found at the site.
The state is also testing surface water around the site for contamination, but the full results aren’t yet available. Regardless, it’s likely not of immediate threat to humans living nearby, regulators and some independent experts say, because it is far from drinking water intakes. BASF already faces increased regulatory scrutiny and pressure over staggering levels of toxic waste leaking from its Wyandotte plant property into the Detroit River.
EGLE ordered BASF to develop a remediation plan for Hennepin in 2006, but the agency was dissatisfied with the company’s proposal and ordered a new one. That was never developed because the agency lacked the manpower and other more contaminated sites around the state took priority, officials previously said.
The new report noted that vegetation covers much of Hennepin Point, and that reduces how much dust blows from the site. It also said the prevailing winds blow from the southwest, so dust blowing from the site will largely go to the northeast, into the river and Canada.
The report states that the average wind speeds on the island are typically between about seven and eight miles per hour, a speed that won’t kick up dust. Hoin, meanwhile, said exposed DBO can essentially “crust over,” making it less likely to blow in the wind. BASF also said in a statement that the DBO has “weathered into soil.”
The report noted truck traffic in the area is light, so there’s little risk of exposure from disturbance, and the road on Hennepin has some gravel on it that also helps reduce DBO dust.
All told, the risk of air contamination is low, the report states.
“Based on the current site conditions that include vegetation coverage on the island, limited exposed soil surface areas, and no construction activities, the probability of windblown particulate matter generation is very low,” it states.
McDiarmid noted that BASF will continue to add new vegetation to the area, which will also help reduce dust.
Stuart Batterman, a University of Michigan environmental health researcher, agreed that the risk is probably low: “Based on historical weather patterns and assuming that the vegetative cover remains intact, fugitive dust generated from the area would not seem to be much of a risk.”
Given that only patches of open dust on the site remain, the wind would have to be blowing in just the right direction for air sampling to get a good reading, he added.
‘It’s a gap’ in monitoring
But some raised questions about some of the report’s assumptions. Hoin and Trabbic-Pointer noted that consultants only collected soil samples from part of Hennepin Point, and no toxicity threshold to DBO inhalation exists, so it is impossible for EGLE to know if the levels in the air are safe without developing those.
Meanwhile, the report’s wind speed estimates of around seven miles per hour seemed low to some experts.
“This sounds crazy as the winds do funnel up the river and we all know there have been many many high wind days in this area,” said Allen Burton, a University of Michigan ecosystem science researcher.
Federal data shows slightly higher wind speed averages on Grosse Ile – above 10 miles per hour for the last month with gusts that topped 35 miles per hour. Though the report states that the winds are largely coming from the south and would blow dust off the island, high winds in recent days have blown directly across Hennepin and toward nearby homes.
Batterman said dust collected from nearby homes could be tested if the state did not do air quality sampling on the site.
Hoin, the former EGLE geologist, said he was not surprised that the agency did not monitor localized air quality because the agency’s air quality division is geared toward monitoring regional or statewide air quality.
“It’s a gap,” Hoin said. “You can do all the modeling you want, but then you have to go in and collect data to prove the model – they don’t seem to understand that critical last step.”