(NewsNation) — It will take about three months for the Environmental Protection Agency to complete its cleanup of the site where a train derailed in East Palestine, Ohio, on Feb. 3, EPA Administrator Michael Regan said.

This number can change, though, based on site conditions, weather and access to disposal facilities, Regan elaborated on a press call Friday.

Still, he said, the EPA is “optimistic about the current trajectory” of the cleanup process.

“This is real progress,” Regan said.

All 1,900 feet of the south train tracks have been removed from the site where 50 tanker cars, some carrying hazardous material, derailed, according to Ohio Gov. Mike DeWine’s office.

The rail cars, including 11 that were held while the National Transportation Safety Board investigates the wreck that led to the controlled release of chemicals, were taken off the derailment site.

“Test results show that some portions of sampled soil meet the clean standards determined by state and federal authorities,” a news release from the governor’s office said. “Those sections will be filled with gravel, and reconstruction of the tracks will begin. Areas that did not meet the clean standards will undergo more soil removal, and another round of testing will take place.”

About 4,600 tons of excavated soil were removed, leaving 26,700 remaining.

To date, about 6.8 million gallons of liquid waste and 5,400 tons of solid waste have been taken out of East Palestine to waste facilities, Regan said.

Some states have tried to block accepting waste from the Ohio cleanup site. Shipments to Michigan and Texas were halted, and Oklahoma recently rejected one as well.

“There are too many unanswered questions and ultimately I made the decision that this is not in the best interest of Oklahomans,” Gov. Kevin Stitt said in tweets posted on March 12.

Officials in these states have said they did not get advance notice about the shipments.

Regan told reporters Friday that some states have taken “misinformed” and “misguided” shots at the EPA as it tries to dispose of the contaminated waste.

Norfolk Southern is under an EPA order to get rid of the waste, and Regan said it expects the company to comply with this. Compliance includes insisting waste disposal companies honor their contracts with Norfolk Southern, he added.

States trying to block waste from the Ohio village is “impermissible and unacceptable,” Regan said. “It’s the people of East Palestine who have been hurt and EPA will not stand for it.”

As of Wednesday, the Ohio Department of Health and the Columbiana County Health District has received 13 additional samples from private water systems. Ten of them showed “no detectable contaminants” while three wells had trace detections, though DeWine’s Office said these were at levels “well below safe drinking water standards.”

“Water sample results from private water systems of East Palestine area homes continue to show no harmful levels of contaminants,” the news release said.

So far, test results from 126 samples have been verified.

Test results can be found on the Columbiana County Health Department site at https://www.columbiana-health.org/resources/.

This story is developing. Refresh for updates.