Potential airborne debris and gases are covered and trapped on a portion of the West Lake Landfill near St. Louis. Radioactive waste was illegally dumped at the site decades ago. (Linda Davidson/The Washington Post)

This post has been updated.

The Environmental Protection Agency on Thursday ordered a long-awaited cleanup of a Superfund site northwest of St. Louis, saying residents living near the landfill contaminated with World War II-era nuclear waste deserve action after waiting 27 years for federal regulators to issue a decision.

EPA Administrator Scott Pruitt’s decision to partially excavate tons of radioactive material from the West Lake Landfill over five years — at an expected cost of $236 million to the liable companies — goes beyond a 2008 solution proposed by the George W. Bush administration to cover and monitor the waste.

“The people of the St. Louis region deserve clarity and answers,” Pruitt said in a statement Thursday. “I promised them an answer, and today I am making good on that commitment.” He added that he sought a remedy at the site that would “protect public health, comply with the law, and hold potentially responsible parties accountable.”

Thursday’s announcement also was intended to be Exhibit A in demonstrating Pruitt’s commitment to revitalizing the agency’s Superfund program, which includes the nation’s most polluted sites, by streamlining and accelerating cleanups. But it underscored how few Superfund sites have simple answers, though nearly all of them generate intense emotions.

“We were hoping for full, 100 percent excavation. But we know that would be difficult to accomplish,” said Dawn Chapman, a founder of Just Moms STL, an activist group that has long pushed for an extensive excavation with relocation of families near the landfill.

Chapman said her group views the outcome as a hard-fought victory but one that is far from guaranteed, given the public-comment and cleanup process likely to unfold over years. “We have to stay here and watch it and see it through,” she said. “I look ahead, and I see these other big battles coming. We’re not going to blink because you can’t. … We will continue to fight to get even more [radioactive waste] removed.”

Pruitt’s decision goes further than the action sought by Republic Services and Exelon, whose subsidiaries are responsible for the cleanup at West Lake along with the federal Department of Energy. The companies have argued that the agency’s own science shows capping the waste is the safer option and that excavating the toxic material could create serious public health risks.

While the $236 million price tag of the EPA plan is significantly higher than what the firms hoped to spend, it is well below the cost, projected at nearly $700 million, of a full excavation.

In a statement, Republic Services said it was “pleased that the EPA has finally ended decades of study and again is issuing a proposed plan for the site.” But the company cautioned that a final decision could take years.

What remains to be seen is whether the decision on West Lake represents how Pruitt is likely to approach other Superfund sites.

In recent months, Pruitt has promised aggressive Superfund cleanups and made a public show of butting heads with corporate interests — something he has rarely done on other issues during his first year at the EPA. Yet aside from creating a list of 21 targets needing “immediate and intense” attention, as well as forming a task force to recommend ways to expedite cleanups and “reduce the burden” on companies involved, Pruitt has explained very little about how he intends to deal with the hundreds of other toxic-waste sites around the country.

“What’s the plan for the other sites that aren’t on [Pruitt’s] priority list?” asked Nancy Loeb, director of the Environmental Advocacy Center at the Northwestern University Pritzker School of Law. She said Pruitt’s decision at West Lake might be “a positive step” but added, “It raises the question of whether Superfund is being used to showcase a few projects without actually doing more to clean up contamination at all 1,300 sites.”

Meanwhile, the Trump administration has proposed cutting the Superfund program’s budget by 30 percent, or about $330 million annually. And while there are responsible companies that the EPA can legally force to pay for cleanups at many of the locations Pruitt has mentioned, many others are “orphan” sites where the polluters have gone bankrupt or are no longer legally liable for remedying the problem. At those, the federal government still shoulders most of the tab — and the pot of available dollars keeps shrinking.

“I am concerned about orphan sites across the country in the Superfund portfolio,” Pruitt told lawmakers on Capitol Hill this week. “I think there are greater challenges beyond money. But money matters in that side of our responsibilities.”

Pruitt highlighted West Lake early in his tenure at the EPA.

“The past administration honestly just didn’t pay attention to [it],” he said on a local radio show in April. “We’re going to get things done at West Lake. The days of talking are over.” In May, Pruitt took to television to say a plan was coming “very soon.”

Eight months have passed since then. But families in the shadow of West Lake, which was added to the Superfund program in 1990, are no strangers to waiting. The site’s 200 acres include not just the radioactive waste illegally dumped in 1973, but also a former sanitary landfill. Decomposing trash is smoldering underground in what scientists call a “subsurface burning event.” There are concerns about the fire reaching the radioactive waste, though the companies there have taken numerous steps to prevent that.

Over the years, residents have complained of quality-of-life and health problems, including a periodic stench in the air and anecdotal tales of cancers, autoimmune disorders and miscarriages in adjacent neighborhoods. At the same time, numerous air, water and soil tests from the EPA and other government agencies have shown no link to such conditions.

Pruitt’s plan will now be open for a period of public comment before it is finalized.

Read more:

How Scott Pruitt turned the EPA into one of Trump’s most powerful tools

Scott Pruitt vows to speed the nation’s Superfund cleanups. Communities wonder how.

At Superfund sites, Scott Pruitt could flip his industry-friendly script

EPA lists 21 toxic Superfund sites that need ‘immediate and intense’ cleanup