"This week's revelations are of concern about another chemical that was released into the water supply," said Daniel Horowitz, managing director of the U.S. Chemical Safety Board.
Horowitz said the CSB would include a review of the matter in its ongoing investigation of the chemical Crude MCHM by Freedom Industries.
"We're going to look into it, along with all of the other safety issues this incident raises," Horowitz said, in an appearance on "The Diane Rehm Show" on National Public Radio.
Horowitz said that CSB investigators have found that chemical storage tanks at the Elk River site wee "very old" and "designed to a very old standard, without leak detection or secondary containment."
In a joint press release late Thursday afternoon, the state Department of Health and Human Resources and the Department of Military Affairs and Public Safety said that testing for PPH from water samples taken after the spill showed no detectable levels of the chemical.
State teams retested 30 samples drawn since Jan. 10 from the intake and outflow at West Virginia American's treatment plant, using a method that would detect down to 2 parts per million of PPH, the press release said. All 30 samples came back with "no detect" readings, the release said.
When word that PPH was also in the Freedom Industries tank was first reported, state officials said Tuesday evening that it would take them four to five hours to complete testing for that chemical.
The press release said, though, that the retesting was concluded earlier in the day Thursday. State officials offered no explanation for the delay from their initial timeframe for the results.
According to the release, the state "plans to pursue" additional testing using a detection limit of down to 1 part per million.
Also, the release said that "a review of water quality tests routinely conducted at the treatment plant show no sign of phenol, a chemical byproduct that should appear if PPH reacted with water treatment processes."
The state's news release said that the PPH results "indicate no health concerns, based on the latest guidance" from the CDC.
Asked what sort of screening level the state based that statement on, and how the state knew that any levels below the 2-part-per-million PPH detection limit were not harmful, DHHR spokeswoman Allison Adler suggested checking with the CDC.
Barbara Reynolds, a spokeswoman for the CDC, said her agency has not set a health screening level for PPH.
Also Thursday, U.S. Sen. Joe Manchin issued a statement calling for the Freedom Industries' facility to be torn down and the site "completely remediated."
Already, though, DEP officials issued an order two weeks ago, the day after the spill, that required Freedom to remove all materials from all storage tanks at the site.
U.S. Environmental Protection Agency officials, in a prepared response to questions the Gazette submitted on Jan. 15, referred questions about the site cleanup to the state DEP.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.