Federal officials this year declined to pursue full cleanup of the menu of toxic chemicals still on-site at the Madison Heights factory responsible for the contaminated green slime oozing onto I-696.

The Environmental Protection Agency made that determination after receiving a report in March from Michigan’s environmental officials, who’d detailed the contaminants remaining on the property and outlined next steps for evaluation.

Among the concerns raised: the potential for a basement pit that “contained green wastewater with hazardous levels of chromium” to have leaked into soil and shallow groundwater.

The EPA already had spent nearly a year removing thousands of gallons of chemicals from the former Electro-Plating Services property, which the state closed in late 2016 after at least 20 years of environmental issues.

“The EPA, upon information in (the state report) determined it didn’t meet the criteria for continued Superfund examination,” said Hugh McDiarmid of the Michigan Department of Environment, Great Lakes and Energy (EGLE).

As a result, McDiarmid said, the property did not move onto the Superfund evaluation list. According to EPA processes, that step would have involved additional site analyses and determining whether chemicals were moving off-site.

One reason for the lack of action appears to be due to low levels of concern that the chemicals - including hexavalent chromium, cyanide and TCE - would make their way into drinking water sources. The EPA did not respond to multiple requests for comment since Dec. 23.

However, the CERCLA Preliminary Assessment prepared by EGLE and submitted to the EPA on March 28 does detail that chemicals remain on the property, located less than 100 feet from I-696 and in a heavily populated area just north of Detroit in Oakland County.

“Wastes removed and disposed off-site, but potentially released into soil or groundwater due to documented leaks and poor containment, include the following hazardous substances: ammonia, cadmium, chromium, cyanide, chromium and cyanide liquids, gasoline, lead, mercury, nickel, silver, toluene, TCE, used oil, xylenes, and zinc,” EGLE informed the EPA.

The report continued: “Based on documented investigations, numerous historical sources of hazardous substance releases were present, two present sources are known to remain, and one or more potential sources may be present.”

That includes at least 200 cubic yards of contaminated sub-surface soil and up to 100,000 pounds of releases from the main plant. Possible releases include, EGLE said, acetone, ammonia, benzene, chromium, cyanide, ethylbenzene, mercury, toluene, TCE, xylenes, and zinc.

While EGLE’s report did not indicate the potential for chemicals to seep through a retaining wall on the highway, it did note that some contaminants were moving to the north-northeast in shallow groundwater.

And threats to surface water from chemicals on the property also were noted: “Contaminants could potentially reach tributaries of the Clinton River via overland flow through storm water drains. If a release had occurred at the ground surface, contaminants could migrate over the ground surface into nearby storm sewers known to exist along East 10 Mile Road.”

While high levels of hexavalent chromium were found in a nearby storm sewer, state officials said tests of drinking water intakes showed no risk to the public. Water from the property reaches four sub-watersheds of the Clinton River and eventually empties into the northern part of Lake St. Clair.

This month’s migration of cancer-causing chemicals from the closed factory was not the first time. A release of hexavalent chromium was found on the property in 1994, according to EGLE. That’s a sign that an ongoing threat remains, it said.

“Because of the confirmed observed release to groundwater, there exists the potential for a continued release, especially since the remaining sources are not significantly contained,” staff wrote early this year.

While EPS has numerous regulatory issues dating back to the 1990s, it faced escalating enforcement after 2010. By fall 2016, state officials conducted an inspection. Findings, according to the report to the EPA:

• unstable flooring on the plating bath level;

• an estimated 5,000 containers holding liquid or solid waste and processed

chemicals with most improperly stored, some leaking, open, and corroded;

• containers of acids, bases, metal oxides, cyanide, and chlorinated solvents;

• incompatible chemicals stored together;

• a pit in the basement containing liquids from the plating baths; and

• sludge excavated from the pit and surrounded by a berm reportedly made from hazardous waste chromium from the pit.

On December 21 , 2016, the state issued an Order to Cease and Desist Operations. On December 22, 2016, the EPA was requested for an emergency clean-up, a $2 million effort that lasted through December 2017.

Meanwhile, most of the buildings used as the metal plating business remain on-site, with one demolished. The owner, Gary Sayers, was convicted in 2019 and sentenced to federal prison and restitution for the contamination.

McDiarmid said the state remains active with the EPA as both agencies determine best steps for ongoing management of the chemicals reaching the highway and the storm drain. Unclear so far is why the EPA declined to look further at the site earlier this year and whether that will change.

Internal reviews at EGLE also are starting to see if staff in their site evaluation missed any potential chemical pathways to I-696, such as a utility pipe.

“We do want to know what happened,” McDiarmid said.

According to EGLE, regulators continue to work on the site daily, including the following activities:

Daily vacuuming of nearby catch basins.

Maintenance and inspection of sump pumps collecting contaminated water from both inside the facility and on the highway embankment.

Daily monitoring of air in the building using hand-held monitors.

Preparing for the impact of rain and freezing weather.

To report environmental emergencies, contact the Pollution Emergency Alerting System hotline 1-800-292-4706.