West Virginia chemical spill: What's 4-methylcyclohexane methanol?

A West Virginia chemical spill, which has cut off water to hundreds of thousands of citizens across nine counties in the state, is used in the coal industry. The compound involved in the chemical spill into West Virginia's Elk River – 4-methylcyclohexane methanol – is used to clean coal.

A West Virginia chemical spill into the Charleston-area Elk River Thursday has closed schools, businesses, and left up to 300,000 people without water in nine counties across the state. President Obama issued an emergency declaration for the state of West Virginia, and officials are urging West Virginians of affected areas not to use tap water, which has been contaminated with a chemical used to clean coal.

"Due to the nature of the contamination, it is not safe to use the water for any purpose," West Virginia American Water (WVAW) said in a notice posted online. "Alternative sources of water should be used for all purposes. Bottled water or water from another, safe source should be used for drinking, making ice, brushing teeth, washing dishes, bathing, food and baby formula preparation and all other purposes until further notice." 

The West Virginia chemical spill occurred when a compound called 4-methylcyclohexane methanol leaked from a hole in the bottom of a storage tank, Thomas Aluise, a WVAW spokesman told the New York Times. The liquid then filled a container designed to contain leaks before flowing into the Elk River, about a mile north of a water treatment plant. 

What is 4-methylcyclohexane methanol?

The compound involved in the West Virginia chemical spill is used to rid coal of impurities before it is burned to generate power. 

"Short version – it is used in removing some sulfur from coal," David Bayless, director of Ohio University's Ohio Coal Research Center, wrote in an e-mail to the Monitor. "That is a separation process ... usually done at the mine before the coal is shipped to the utility to burn." 

How does that work?

Coal straight from the mine brings with it various types of shale, clay, and impurities. To burn it more efficiently and with less pollution, the energy-dense coal must be separated from its associate waste.

One method is coal washing, which leverages natural differences in density to separate coal from the sulfur, ash, and rock that we'd rather not burn. The raw material is ground up into tiny chunks, sorted, and initially screened for impurities. Then a fluid (often water) is pulsed upward through a bed of crushed coal and its impurities. Lighter coal particles rise to the top of the slurry, while the heavier impurities fall and are removed from the bottom. The purified coal is then dried in a final preparation process before being shipped off to the power plant. 

Water alone is not enough to purify coal. Chemicals like 4-methylcyclohexane methanol are added to create a frothy, heavy consistency that enhances the process.       

Is it dangerous?

Officials say the West Virginia chemical is not lethally toxic. It is considered potentially harmful if swallowed or inhaled and can cause eye and skin irritation. There had been no official reports of hospitalizations or fatalities as of midday Friday. 

Does the US still burn a lot of coal?

Yes. Despite innovations in renewable technology and a boom in natural gas production that has undercut coal, the carbon-heavy fuel is still the predominant provider of electricity in the United States and globally. Coal plants generated 37 percent of US electricity in 2012, according to the US Energy Information Administration, down from 50 percent in 2007. It is estimated to have risen 3.9 percent in 2013 and projected to rise 3.3 percent in 2014, as natural gas prices rebound. New environmental regulations on power plants may slow that growth.