At the Highlands Acid Pit on Thursday, August 31, 2017, the No Trespassing sign on the barbed-wire fence encircling the 3.3-acre Superfund site barely peeked above the churning flood water from the nearby San Jacinto River. Long a center of the nation’s petrochemical industry, the Houston metro area has more than a dozen such Superfund […]

HIGHLANDS, TX (AP) – Floodwaters have inundated at least five highly contaminated toxic waste sites near Houston, raising concerns that the pollution there might spread.

The Associated Press visited the sites this past week, some of them still only accessible by boat.

Long a center of the American petrochemical industry, the Houston metro area has more than a dozen such Superfund sites, designated by the Environmental Protection Agency as being among the most intensely contaminated places in the country.

EPA spokeswoman Amy Graham could not immediately provide details on when agency experts would inspect the Houston-area sites. She said Friday that staff had checked on two other Superfund sites in Corpus Christi and found no significant damage.

“We will begin to assess other sites after flood waters recede in those areas,” Graham said.

Near the Highlands Acid Pit, across the swollen San Jacinto River from Houston, Dwight Chandler sipped beer and swept out the thick muck caked inside his devastated home. He worried whether Harvey’s floodwaters had also washed in pollution from the Superfund site just a couple blocks away.

In the 1950s, the pit was filled with toxic sludge and sulfuric acid from oil and gas operations. Though 22,000 cubic yards of hazardous waste and soil were excavated in the 1980s, the site is still considered a potential threat to groundwater, and EPA maintains monitoring wells there.

When he was growing up in Highlands, Chandler, now 62, said he and his friends used to swim in the by-then abandoned pit.

“My daddy talks about having bird dogs down there and to run and the acid would eat the pads off their feet,” he recounted Thursday. “We didn’t know any better.”

EPA Administrator Scott Pruitt has said cleaning up Superfund sites are a priority, even as he has taken steps to roll back or delay rules aimed at preventing air and water pollution. President Donald Trump’s proposed 2018 budget seeks to cut money for the Superfund program by 30 percent, though congressional Republicans are likely to approve less severe reductions.

Like Trump, Pruitt has expressed skepticism about the predictions of climate scientists that warmer air and warmer 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 posed by rising waters inundating Superfund sites varies widely depending on the specific contaminants and concentrations involved. But the EPA report specifically noted the risk that floodwaters might carry away and spread toxic materials over a wider area.

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, with only a single house from among the roughly dozen lining Hickory Lane still standing.

After the flood 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.

At the Brio Refining Inc. in Friendswood, the floodwaters had receded by Saturday. There was a layer of silt on the road leading to the Superfund site. The company operated a chemical reprocessing and refining facility there until the 1980s, leaving behind polluted soil and groundwater.

The San Jacinto River Waste Pits Superfund site was completely covered by water 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 access 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.

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.”