Work crews from the City of Miami and the Florida Department of Transportation teamed up on Friday to clean up a huge pile of trash along Miami’s MacArthur Causeway, just yards from Biscayne Bay.

Environmental activists, such as Clean This Beach Up founder Maria Algarra, say they spotted the mound of trash weeks ago, but tell NBC 6 that volunteer crews lacked the equipment needed to clean up such a large amount of waste.

Algarra says activists contacted FDOT and other local agencies to deal with the pileup, which she says may have been caused by a homeless encampment or an illegal dump.

“So we’ve actually been looking for places like this where homeless people are living or camping, and we’re also looking for illegal dumping sites,” Algarra said. “And it just so happened to be one of them.”

The city brought out heavy machinery on Friday to tackle the mess.

“It was so much trash that it was impossible for our teams to clean it up,” Algarra said. “So imagine, they needed machines to clean that up, it was probably 6-10,000 pounds of debris.”

She says illegal dumps, like the one found along the causeway, are not just an eyesore but a danger to marine life in Biscayne Bay.

“Waste is actually a huge problem that we have to deal with,” Algarra said. “There are a lot of beautiful endangered species here that get tangled up and eat these plastics.”

An FDOT spokesperson said Friday that crews were done for the day, but told NBC 6 that crews may have to return to the causeway next week to complete the job.