Public attention is drifting from the aftermath of the Norfolk Southern train derailment in East Palestine, Ohio, last month, but the cleanup of the toxic chemicals that spilled and burned is ongoing — and likely won’t stop for quite some time.

“I estimate the timeline to be years” for remediation of the area, said Kelly Pennell, a professor of civil engineering and director of the University of Kentucky’s Superfund Research Center.

After what appeared to many to be a slow start in addressing the release of toxic chemicals into the environment, Norfolk Southern — with prodding from the Environmental Protection Agency — seems to have picked up the pace of its disaster response. Millions of gallons of contaminated water and thousands of tons of contaminated soil have been carted off, drinking water sampling continues, and waterway cleanup is ongoing. But plenty of challenges remain — including gaps in monitoring soil and water and in knowledge of what chemicals the spill left behind, and pushback from the places that might receive and dispose of the toxic waste.

With misinformation and distrust still flowing freely in East Palestine, the slow process of toxic site remediation is doing too little to relieve residents’ fear and uncertainty. It’s a process that has been repeated over and over after environmental disasters, from the Exxon Valdez spill to Tennessee’s coal ash catastrophe in 2008; initial guesses of remediation timelines can undersell what’s on the horizon by years.

“Remediation is not only removal of chemical contamination, but it also includes the complexity of a community grieving of what was, accepting of what happened, envisioning what can be, and, importantly, preventing and reducing exposures to contamination through that entire process,” Pennell said. “Too often, remediation does occur on a fixed timeline, excluding renewal and regrowth.”

Exporting soil and water

On Feb. 21, the EPA officially ordered Norfolk Southern to “conduct all necessary actions associated with the cleanup” of the derailment site. As of Monday, the company reports it has recovered 3.2 million gallons of affected water and transported it off-site, and it has removed 2,366 tons of “waste soil.” It has also used clean water to flush 5,200 feet of affected nearby waterways and has sampled the drinking water from 186 private wells.

Some of these measures are themselves controversial. Norfolk Southern has reportedly planned to send shipments of contaminated soil to a toxic waste incinerator less than 20 miles from East Palestine that has previously been cited for Clean Air Act violations. The company has sent other soil and water to states including Michigan and Texas, prompting backlash from residents and authorities there.

“These are the standard methods, but they are never accepted by local residents,” said Alan Rabideau, a professor and chair of the University of Buffalo’s Department of civil, structural, and environmental engineering. “Landfills engineered for hazardous waste are certainly capable of safe disposal, but nearby residents never like the idea of hosting someone else’s waste. Incineration can be similarly effective if operated properly but can produce toxic air emissions if mishandled.”

He added that there are no cost-effective alternatives available for disposing of large quantities of affected soil.

Mysteries in the ground

It also isn’t completely clear what chemicals and toxins are present around the spill site, even more than a month after the Feb. 3 derailment. Researchers and experts from Texas A&M and Carnegie Mellon universities continue to monitor air quality, and have reported potentially concerning levels of acrolein, which can cause skin and respiratory tract irritation, among other effects.

On March 2, the EPA finally issued an order that Norfolk Southern begin testing for dioxins, highly toxic, carcinogenic chemicals likely to have been created by the intentional burning of vinyl chloride in the immediate aftermath of the crash. If they are found, that will further complicate the cleanup efforts, as they are known to persist in the environment for extended periods of time.

The vinyl chloride itself also poses a challenge. Rabideau explained that vinyl chloride is a “dense nonaqueous phase liquid” which can easily migrate downward through soil and reach the water table. If that happens, remediation that lasts “months or years” becomes much more likely.

“Vinyl chloride is extremely toxic, resistant to treatment, and likely to migrate downward because of its density,” he told Grid. “You’ve got serious problems there, regardless of what else was released.”

David Schaad, a professor of civil and environmental engineering at Duke University, agreed. “Once it gets in the groundwater, it’s another ballgame,” he said. “Vinyl chloride is a known carcinogen. It’s a nasty actor.”

An air of distrust

Pennell stressed that successfully remediating a toxic site requires building and sustaining trust across a community.

“To build trust and collectively define goals, including which chemicals in the soils, water and air need cleanup, we have found that developing partnerships across multiple stakeholders and establishing knowledge brokers is valuable,” she said. “There appears to be a lack of true partnerships and growing distrust in East Palestine.”

For example, some of the testing of air and water in East Palestine is being conducted by the environmental consulting firm CTEH, contracted by Norfolk Southern. In a Facebook post, a community group called River Valley Organizing warned that “CTEH has questionable practices to say the least” and suggested test results paid for by Norfolk Southern should not be trusted. That group and others have called for independent testing instead.

Officials have started to talk about the issue of trust and to stress that the timeline for remediation may be longer than most would hope. EPA Administrator Michael Regan has said the agency wants to “earn the trust of this community,” and that it will keep pressuring Norfolk Southern for “as long as it may take.”

“The term remediation means different things to different people,” Pennell said. “People often seek specific deadlines that can be defined as when remediation will end. I can certainly understand that desire.”

Thanks to Lillian Barkley for copy editing this article.

Article originally appeared on Grid.