A consulting firm was brought in this weekend to monitor the Elk River where a spill of an estimated 7,500 gallons of 4-methylcyclohexane methanol, an organic chemical also known as Crude MCMH, left thousands of Charleston-area residents without water suitable for drinking or bathing.
"We are down below 1-part-per-million but we need to consistently be below 1-part-per-million for a 24-hour period," National Guard Col. Greg Grant said Saturday.
About 100 monitoring tests were scheduled at the American Water Company treatment plant that was affected by the leak, which was discovered last week.
The West Virginia MetroNews Network in Charleston said residents of the city and nine surrounding counties would get the word on when they could resume using their water taps once the testing showed consistently acceptable levels of MCMH.
The company that owns the leaky storage tank submitted a routine report last winter to emergency managers outlining the chemicals they were holding at the Elk River site. Documents said at least 100,000 gallons of MCMH were being stored on the site, which was originally built as a fuel terminal in the 1930s.
The Wall Street Journal said MCMH, a type of alcohol which is used to clean coal, was apparently a concern for American Water Co. "This was not a chemical we were familiar with," company spokeswoman Laura Jordan said Saturday.
American Water was not completely unaware of the potential threat MCMH posed. The Journal said the state drafted a report in 2002 that identified the storage terminal a "potential significant contaminant sources" for the Charleston area.