The debate surrounding storing petroleum coke alongside the Detroit River isn't over yet.

In August last year Detroit's buildings safety engineering and environmental department (BSEED) denied Detroit Bulk Storage's request to store "petroleum coal or coke type material" in a yard across from Windsor and waive the maximum height requirement for storage of material there.

At the time the company claimed it didn't know a special permit was needed to store petroleum coke in the open air on its riverside property.

Petroleum coke, also known as pet coke, is a black, coal-like byproduct produced in the petroleum industry. It's used as inexpensive fuel.

On Tuesday Detroit's board of zoning appeals was set to hear from Detroit Bulk Storage. But the company seemingly changed tactics and pet coke did not come up.

"Our proposed use, in following with our application, is to store other materials. Not petroleum coke. Not coal. Not any by-produce dealing with petroleum on the property," said Teri Whitehead, the lawyer for Detroit Bulk Storage.

The move came as a surprise to activists watching the proceedings and to Rashida Tlaib, who represents Detroit's 6th District in the Michigan House of Representatives. She had previously fought against the pet coke piles

"It was ridiculous. It was so embarrassing," said Tlaib. "I think this was, man. They found out we're coming back. We'd better just withdraw."

Environmental groups and activists on both sides of the border, including the Sierra Club and Windsor on Watch, have protested pet coke storage alongside the river.

However, Professor Jan Ciborowski of the Great Lakes Institute for Environmental Research at the University of Windsor previously told CBC that pet coke poses no bigger threat than piles of aggregate currently stored on the Canadian side of the river on Windsor's west end.

He said pet coke "is not a hazardous substance."

Activist Jake McGraw was at the meeting on Tuesday. He still has concerns about the intentions of Detroit Bulk Storage.

"I don't give them a lot of trust," said McGraw, who added the company's application for storage was very vague.

The zoning board of appeals eventually decided to push the hearing back to April. Detroit Bulk Storage will have to give more details about what it intends to store on its riverside property at that time.