Despite what officials called a “successful cleanup” following the April 5 fuel spill on the causeway, the town is looking at a one-month cleanup following the incident.

The contracted cleanup company — Clean Harbors — made a mess of Dias Landing with leaking, heavy dumpsters that spilled possibly contaminated liquid and sunk into the pavement. The follow up has resulted in a two-week-long back-and-forth to fix the parking lot, but it could be another two weeks before the company finishes, officials said.

“They’re taking the oil from the causeway and concentrating it on a hard surface that runs directly into the harbor,” said Harbormaster Steve Melo.

Dartmouth Week reached out to Clean Harbors, but calls were not returned before publication.

Clean Harbors used nine, 25-yard, roll-off dumpsters to contain and transport soil impacted by the April 5 diesel spill, according to emails obtained by Dartmouth Week. The original 100- to 200-gallon leak resulted from a broken valve pipe on a Petro Home Services truck, which was delivering fuel to the causeway construction crew on April 5. Officials commended the immediate response to the spill.

However, on April 10, Melo noticed that Clean Harbors had taken over much of the public landing with trucks, trailers, a boat, and the roll-offs without permission. He explained that commercial businesses cannot use the landing without prior consent from the Harbormaster’s Office, and the associated usage fee runs upwards of $300 per day.

He then noted that the dumpsters were not only leaking, but were sinking into the pavement.

“It was rusty water with rainbow coloring on top. It could’ve been worse. It didn’t run all over the parking lot,” said Melo. He also noted a fuel odor.

He immediately contacted town and state officials about the leaking dumpsters, he said.

“Anytime we have a threat to surface water in a marine environment, we’re going to make sure we respond as quickly as we can,” said the state Department of Environmental Protection’s Bob Murphy.

During an April 13 inspection of the site, Murphy noted “some dark staining” in the immediate area of the roll-offs, “an amount of expended Speedy Dry [which is an oil absorbent],” and “no visual evidence of any migration to Apponagansett Bay.”

An inspection by the town’s Conservation Officer Marc Garrett — which happened the same week as the spill — revealed that there were “as many as three separate releases from several containers, with spill stains over large patches of pavement, and only one partially used bag of Speedy Dry on location,” according to emails.

Garrett also noted via email that “the weight of the load contained within each dumpster and the dumpsters themselves, appears heavy enough to cause pavement divots under each containers’ metal rollers.”

The reports did not mention oil sheen at the landing, and Garrett had added that he double-checked the causeway and found no remnants of the spill.

However, Melo said that both his department and Clean Harbors had deployed adsorbents for the leaking diesel, and Clean Harbors’ Harry Davidson had sprayed the roll-offs with sealant.

Paul Cappelletti, from the Smithfield-based John Rocchio Corp., — the general contractor for the $8.2 million causeway rehabilitation project — said that the dumpsters could not be removed from site until the soil test data came back.

Public Works Director David Hickox said the results came back clean, and all but one dumpster has been removed off the landing as of April 19.

“[Clean Harbors] feels very good that they got the majority of the oil off the site. There’s no indication that it’s leaking into the bay,” he said.

According to an April 17 email from Clean Harbors’ Project Manager Lisa Irwin — who is responsible for remedial investigations, and not waste removal — responded via email: “Although the pavement was unsightly and iron-stained, the wet locations had no discernable petroleum sheens, did not feel greasy, and did not have petroleum odors.”

While both town and state officials urged Clean Harbors to address the staining and pavement damages, it is unclear if the company will take it on. It is unclear how much the damage will cost to repair.

“There is a rust stain that will likely fade with time. I will inspect the area again the next time I am on-site,” responded Irwin via email. “If the stain persists, we could attempt a cleaning to make the area more aesthetic.”

Irwin said via her April 17 email that she plans to leave absorbent booms in place for another couple of weeks as a precautionary measure, as more extreme tides are expected next week.

“I plan to conduct a follow-up inspection during an extreme low tide to document if sheens occur,” she wrote.

Melo explained that the landing is run in unison with the state Public Access Board. In a 1960’s agreement, it was decided that the PAB would build the ramp and improve the land, while the town would be responsible for managing its useage.