U.S. Steel Corp. expected to begin phasing in operations Friday at the Portage facility that released a toxic chemical into Burns Waterway earlier this week as preliminary test results did not detect the carcinogen in the waterway or Lake Michigan.
According to an EPA statement Friday, preliminary results of water samples collected Wednesday that included the lake, the waterway, and Indiana American Water's intake did not indicate an impact from hexavalent chromium. All of the results were below the EPA's method detection limit of 1 part per billion. The agency has a national drinking water standard for total chromium of 100 parts per billion, including trivalent chromium and hexavalent chromium.
Three beaches in the Indiana Dunes National Lakeshore, as well as one in Ogden Dunes and an intake for Indiana American Water, will remain closed for the time being, officials said.
Officials at the national lakeshore closed West Beach and the Portage Lakefront and Riverwalk on Tuesday after learning of the chemical spill, caused by a pipe malfunction at the steel mill.
Ogden Dunes officials closed their beach as a precaution, and Indiana American Water shut down its intake, relying on its Gary plant instead. Park officials Wednesday closed the beach at Cowles Bog, though the trails there remain open.
Officials with the park and the U.S. Environmental Protection Agency have said the spill did not cause a fish kill, though park officials were going to continue to monitor any possible long-term effects on the park's natural resources.
U.S. Steel has done extensive testing on the repairs made at the plant and continues to monitor its environmental compliance with all of its systems, the company said Friday in a release.
"Recent sampling has indicated we are in compliance with our water permit limits. We have determined all repairs are safely working as intended. We have developed a controlled and phased approach to a facility restart with extensive input from the participating government agencies," the statement said.
Officials have yet to determine how much hexavalent chromium was released into the water.
Chronic exposure to hexavalent chromium can damage DNA and cause cancer to the lungs, skin and kidneys, an assistant professor of chemistry at Indiana University Northwest said earlier this week. While the chemical is water soluble, its dissipation rate depends on how much of it there is.
The EPA does not have a separate hexavalent chromium standard, but the agency is evaluating health effects data to determine whether a maximum level for hexavalent chromium is needed.
The federal agency planned to provide oversight as U.S. Steel restarted its operations, which have been idle since Tuesday when a malfunctioning pipe caused the discharge of hexavalent chromium into Burns Waterway within 100 yards of Lake Michigan.
"EPA recommended that the company delay its restart until the agency had sufficient data to show there were no lingering effects to the waterway or Lake Michigan," the EPA said in its statement.
The EPA and its partner agencies, including the National Park Service, reviewed U.S. Steel's operations restart plan, and the EPA will observe the startup process and closely monitor the outfall discharge.
A release from Bruce Rowe, public information officer for the Dunes National Lakeshore, said testing will continue at the national lakeshore.
"The National Park Service is working with the EPA and other agencies to develop a long-term monitoring protocol," the release said. "Lake currents and waves have the ability to move this hazardous material onto park beaches at a later date. Park staff is concerned with potential impacts to both beach users' health and long-term harm to wildlife and other park resources."
U.S. Steel said in its statement that a "controlled, phased and highly monitored" restart of the process would begin sometime Friday, allowing the company, the EPA and other agencies to conduct water and soil samples while the beaches and water intake remain closed.
"The process will begin with a line-by-line restart of operations that do not use chromium in their processes," the statement said. The steel mill is taking samples from the facility every two hours.
U.S. Steel and participating government agencies will conduct "vigorous visual inspections and water quality monitoring at the outfall and in the areas surrounding the outfall."
Operations will be shut down immediately if elevated levels of chromium are detected, U.S. Steel said.