The Gowanus Canal in Brooklyn is filled with chemicals, waste, and junk. But for those interested in New York’s past, its murky depths might also contain intriguing historical debris. Over the next four weeks, The Village Voice reports, cleanup workers will dredge 36 large items from the water, including two wrecked ships and a fallen tree. Onlookers who swing by the canal’s Fourth Street Turning Basin might be able to catch a glimpse of these forgotten artifacts for themselves before the contractors finally dispose of them.

This project marks the pilot stage of a multi-year endeavor to rid the notoriously filthy Gowanus Canal of its toxins and debris. Built in the mid-19th century, the nearly 2-mile-long body of water was once used as an industrial transportation hub that emptied into New York Harbor. Over the decades, it became severely contaminated with waste from factories, chemical plants, and nearby sewer systems. Today, the Gowanus Canal is considered to be one of America’s most toxic bodies of water. To tackle the pollution head-on, the Environmental Protection Agency (EPA) designated it as a Superfund site and called for an ambitious, multi-million dollar cleanup initiative.

The EPA used sonar to locate large items, like a 63-foot sunken ship that was once used to ferry passengers to Fire Island, and a floating sculpture that sank in 2015. Over the next month, contractors will pull them out of the water, use a barge to transport them to a staging area near Smith and Huntington streets, and then dispose of them. (Ultimately, the final graveyards of these items will be determined by how toxic they are.) None of the items are expected to be historically significant, but there "might be some surprises," the EPA's community involvement coordinator Natalie Loney told DNAinfo.

Once all the debris is finally removed from the basin, cleanup crews will dredge contaminated sediment out of the basin, take steps to ensure that remaining toxins can’t leak out, and then focus their attentions on other sections of the canal. The entire project is expected to be completed by 2022.

[h/t The Village Voice]

Know of something you think we should cover? Email us at tips@mentalfloss.com.