The Environmental Protection Agency approved a plan to remove sediments laced with highly toxic dioxin from a partially submerged Superfund site near Houston damaged during Hurricane Harvey, officials announced Wednesday.
The announcement comes two weeks after the federal agency said an unknown amount of dioxins — which have been linked to birth defects and cancer — may have washed downriver from the San Jacinto Waste Pits after floodwaters jarred loose a protective cap of fabric and rock designed to keep them from spreading.
The EPA said in a statement that it planned to excavate 212,000 cubic yards of contaminated material from the site along the San Jacinto River that was a paper mill in the 1960s. It estimated the cost at $115 million.
The statement said a small, unspecified amount of material would stay on the site and that temporary barriers would be built to hold back the river during excavation and removal.
The agency did not specify a timeline and one of the companies responsible, Waste Management subsidiary McGinnis Industrial Maintenance Corp., said Wednesday that it would oppose the removal, adding that it provides less protection to affected communities than the existing cap.
"We disagree with EPA's claim that the local or downstream areas can be protected during removal," McGinnis said in an emailed statement.
On Sept. 28, EPA announced that sediment samples collected by an agency dive team from the exposed area underwater showed dioxin levels more than 2,300 times the threshold for triggering a cleanup.
Dioxins do not dissolve easily in water but can be carried away with any contaminated sediments and deposited over a wider area.
Local residents said contaminated mud might have washed into neighborhood homes that flooded during the late August storm.
At least a dozen Superfund sites in and around Houston were flooded last month in the days after Harvey's record-shattering rains stopped.
About 16 acres of the San Jacinto site were covered in 2011 with the cap — three years after it had been placed on the Superfund National Priority List.
The cap has required extensive repairs on at least six occasions in recent years, with sections becoming displaced or going missing.