Two Kentucky water systems temporarily shut down their intakes early Monday as a plume of the chemical spilled last week in West Virginia passed in the Ohio River.
The cities of Ashland and Russell stopped drawing water from the Ohio after the chemical — 4-methycyclohexane methanol, or MCHM — reached Ashland at 5:30 a.m., according to the Kentucky Department for Environmental Protection.
The level of the chemical at Ashland was 0.023 parts per million, according to the state. That is well below the level of 1 ppm that the federal Centers for Disease Control and Prevention reportedly told West Virginia officials would be an acceptable level in drinking water.
Both water systems reopened their water intakes and resumed treating water later Monday, but they added carbon to the process as a precaution. The carbon absorbs organic contaminants and removes trace levels, according to Dick Brown, a spokesman for the department.
There was no indication of concerns about the quality of water from any Kentucky water system as a result of the chemical, according to a news release.
The state is helping test for the presence of the chemical in the Ohio River. The plume is expected to reach Northern Kentucky on Tuesday night.
The chemical is used to clean coal at wash plants. It is a frothing agent that separates fine fragments of coal from rock and debris, according to Bill Bissett, president of the Kentucky Coal Association.
Most of what is used in the process evaporates, but some goes out with the coal or ultimately is stored in impoundments with waste material, he said.
Bissett said only half of the coal-preparations plants in the state use the chemical.
There apparently are no large tanks of MCHM in Kentucky similar to the one that leaked in West Virginia.
The Department for Environmental Protection said the chemical was stored only in small quantities at coal-prep plants. The plants are required to have systems in place to contain the chemical if it leaks.
Little information is available about the potential toxic effects of the chemical, though it is not thought to be highly toxic, according to the state.
Data sheets from manufacturers indicate is it harmful if swallowed and can cause skin and eye irritation.
However, information is not available on issues such as whether it is a cancer-causing agent and how long it takes to break down in the environment, according to the state's news release.
Some studies have shown that long-term exposure can cause serious health problems, but the plume passing Kentucky is not expected to stay in the water long enough for that to be a concern, state officials said.
The chemical leaked from a large storage tank in Charleston, W.Va., last week. The water supply to 300,000 people was shut down Thursday after it was detected.
According to media reports, 14 people were hospitalized and more than 160 others treated.
The chemical leaked into the Elk River and made its way downstream to the Ohio River by noon Sunday.