Across the road at what appeared to be a more recently operational plant, a pair of tall white tanks had tipped over into a heap of twisted steel. It was not immediately clear what, if anything, might have been inside them when the storm hit.
EPA Administrator Scott Pruitt has called cleaning up Superfund sites a top priority, even as he has taken steps to roll back or delay rules aimed at preventing air and water pollution. Trump's proposed 2018 budget seeks to cut money for the Superfund program by 30 percent, though congressional Republicans are likely to approve a less severe reduction.
Like Trump, Pruitt has expressed skepticism about the predictions of climate scientists that warmer air and seas will produce stronger, more drenching storms.
Under the Obama administration, the EPA conducted a nationwide assessment of the increased threat to Superfund sites posed by climate change, including rising sea levels and stronger hurricanes. Of the more than 1,600 sites reviewed as part of the 2012 study, 521 were determined to be in 1-in-100 year and 1-in-500 year flood zones. Nearly 50 sites in coastal areas could also be vulnerable to rising sea levels.
The threats to human health and wildlife from rising waters that inundate Superfund sites vary widely depending on the specific contaminants and the concentrations involved. The EPA report specifically noted the risk that floodwaters might carry away and spread toxic materials over a wider area.
The report listed two dozen Superfund sites determined to be especially vulnerable to flooding and sea-level rise. The only one in Texas, the Bailey Waste Disposal site south of Beaumont, is on a marshy island along the Neches River. The National Weather Service said the Neches was expected to crest on Saturday at more than 21 feet above flood stage - 8 feet higher than the prior record.
In Crosby, across the San Jacinto River from Houston, a small working-class neighborhood sits between two Superfund sites, French LTD and the Sikes Disposal Pits.
The area was wrecked by Harvey's floods. Only a single house from among the roughly dozen lining Hickory Lane was still standing.
After the water receded on Friday, a sinkhole the size of a swimming pool had opened up and swallowed two cars. The acrid smell of creosote filled the air.
Rafael Casas' family had owned a house there for two decades, adjacent to the French LTD site. He said he was never told about the pollution risk until it came up in an informal conversation with a police officer who grew up nearby. Most of the homes had groundwater wells, but Casas said his family had switched to bottled water.
"You never know what happens with the pollution under the ground," said Casas, 32. "It filters into the water system."
The water had receded by Saturday at Brio Refining Inc. and Dixie Oil Processors, a pair of neighboring Superfund sites about 20 miles southeast of downtown Houston in Friendswood. The road was coated in a layer of silt. Mud Gully Stream, which bisects the two sites, was full and flowing with muddy water.
Both sites were capped with a liner and soil as part of EPA-supervised cleanup efforts aimed at preventing the contamination from spreading off the low-lying sites during floods. Parts of the Brio site were elevated by 8 feet.
John Danna, the manager hired by the companies to oversee the sites, said in a phone interview that he went there after the storm and saw no signs of erosion. He said he didn't know how high the flooding got in Harvey's wake and that no testing of the water still draining from the area had been conducted. EPA staff are expected to visit in the next week, he said.
A security guard at the Patrick Bayou Superfund site, just off the Houston Ship Channel in Deer Park, said Saturday that flooding came hundreds of feet inland during the storm. The water has since receded back into the bayou, where past testing has shown the sediments contain pesticides, toxic heavy metals and PCBs. The site, surrounded by active petrochemical facilities, is still awaiting a final plan for cleanup.
The San Jacinto River Waste Pits Superfund site was completely covered with floodwaters when an AP reporter saw it Thursday. According to its website, the EPA was set to make a final decision this year about a proposed $97 million cleanup effort to remove toxic waste from a paper mill that operated there in the 1960s.
The flow from the raging river washing over the toxic site was so intense it damaged an adjacent section of the Interstate 10 bridge, which has been closed to traffic due to concerns it might collapse.
There was no way to immediately assess how much contaminated soil from the site might have been washed away. According to an EPA survey from last year, soil from the former waste pits contains dioxins and other long-lasting toxins linked to birth defects and cancer.
The EPA said Saturday the San Jacinto Waste Pits site is covered by a temporary "armored cap," a fabric covering anchored with rocks designed to prevent contaminated sediment from migrating down river.
McGinnes Industrial Maintenance Corp., one of the contractors working at the project, said in a statement Saturday that its workers reported that "visible portions of the cap indicated the waste beneath remained in place following the storm." The company did not respond to questions about how much of the 34-acre site was above water at the time.
According to an EPA review last year, the cap has required extensive repairs on at least six occasions since it was installed in 2011, with large sections becoming displaced or going missing.
The EPA said its personnel planned to go to the site by boat on Monday.
Kara Cook-Schultz, who studies Superfund sites for the advocacy group TexPIRG, said environmentalists have warned for years about the potential for flooding to inundate Texas Superfund sites, particularly the San Jacinto Waste Pits.
"If floodwaters have spread the chemicals in the waste pits, then dangerous chemicals like dioxin could be spread around the wider Houston area," Cook-Schultz said. "Superfund sites are known to be the most dangerous places in the country, and they should have been properly protected against flooding."