The benzene leak from a Ford Motor Co. assembly plant that pushed some residents in Flat Rock from their homes can no longer be detected in some parts of the sewer system and there are only “trace amounts” in other pats, state officials said Tuesday.
Testing shows that the leak that happened last week has now resulted in no detectable fumes in parts of the sewer system, which is separate from Flat Rock’s drinking water system, said Jill Greenberg, a spokeswoman for the Michigan Department of Environment, Great Lakes and Energy.
But in other parts of the sewer system, there “trace amounts” of benzene that are well below the levels that are considered to be a “flammable risk,” she said Tuesday, amending an initial statement.
“Ford is conducting an investigation on-site with EPA oversight” to figure out why the line failed, Greenberg said.
Ford officials plugged the leaking line at various points and then applied firefighting foam that does not contain PFAS that suppressed the benzene vapors, environmental officials said. Sewers have been and continue to be flushed, EGLE spokesman Hugh McDiarmid said Tuesday.
The EPA is sending a mobile lab to Flat Rock to begin testing the air inside homes, which will help the state determine when to lift its voluntary evacuation recommendation, according to state and federal officials.
“Right now we’re in the middle of the environmental emergency response. This is a really significant, environmental emergency,” Greenberg said. “And it’s taken all hands on deck. We’ve got federal agencies, local agencies, HAZMAT on the street. It’s really important that we take this seriously, and we have.”
The current understating from Ford is that underground piping attached to a fuel storage tank leaked more than 1,000 gallons of gasoline, McDiarmid said. A full inspection of the area is ongoing, officials said.
The amount of time that city residents have been exposed to the fumes is still under investigation, McDiarmid said.
If exposed to high levels of benzene, symptoms include headaches, dizziness, weakness, a rapid heart rate accompanied by drowsiness or sleepiness, Michigan Chief Medical Executive Joneigh Khaldun said Sunday, and can appear within minutes of exposure. Long-term exposure, around a year, can affect blood cell count and weaken the immune system, potentially leading to blood cancer, Khaldun said.
The leak from the Ford plant, Greenberg said, went “directly into the sanitary sewer line that then went into the city” of Flat Rock. The city’s drinking water is considered safe, but “the city is taking water samples out of an abundance of caution,” she said.
Flat Rock Fire Chief James Kotona could not be reached for comment.
A timeline of what led to the emergency is beginning to unfold.
On Monday, Aug. 30, “gasoline-like” odors were reported to the city, Mayor Mark Hammond said.
Hammond notified the U.S. Environmental Protection Agency on Tuesday afternoon, and it responded, EGLE’s Greenberg said. State law requires the reporting of any oil spill into the waters of the state and a spill of at least 50 pounds or more of oil to the surface of the ground.
The state department “made calls to Ford, the three pipeline companies and the active gas station (last) Tuesday night and asked them to investigate their properties for potential chemical releases,” Greenberg said.
“EGLE conducted the on-site inspection with Ford on Wednesday,” she said. “According to Ford, they discovered the leak on Wednesday after the EGLE inspector left. EPA and EGLE were alerted to the spill on Thursday and immediately responded to the Ford Plant to do an on-site inspection.”
Wayne County Executive Warren Evans signed a state of emergency on Wednesday that wasn’t announced until Thursday, when Gov. Gretchen Whitmer followed shortly afterward with a state of emergency for Wayne and Monroe counties.
Bob Holycross, Ford’s vice president of sustainability, environment and safety engineering, said Friday night the automaker on Wednesday discovered “what originally looked to be a relatively small leak in a pipe that carries gasoline used to fuel vehicles built at the plant.” But on Friday, he said, the company “determined that the scale of the fuel leak was much larger, and that Ford is the likely source of the problem in Flat Rock, for which we apologize.”
“High” levels of the industrial chemical benzene had been detected within a 4-square-mile perimeter including the areas south of Vreeland Road, east of Cahill Road, north of Woodruff Road and west of Interstate 75, Greenberg previously said. A larger area was recommended for evacuation on Sunday by state health officials but not required.
The City Council is holding a 7:30 p.m. meeting at the city’s high school, a change from the original venue. The council meeting will be streamed live on the city’s Facebook page.
Staff Writer Melissa Nann Burke contributed.