Three former executives pleaded not guilty on Thursday to charges stemming from a chemical spill that fouled drinking water for about 300,000 West Virginians, media reported.
Prosecutors in December accused Freedom Industries Inc, its former president Gary Southern and other officers of negligence and fraud after the discharge of a chemical pollutant into the Elk River near Charleston a year ago.
The leak of a chemical foam used to wash coal breached a containment area one mile (1.6 km) upstream of a water treatment and distribution plant near Charleston, according to the charges.
Company officials were also accused of failing to maintain the containment area and failing to properly inspect the tank containing the chemical.
Southern, who was arrested in early December in Florida and released after posting a $100,000 bond, pleaded not guilty on Thursday, local broadcaster WOWK-TV reported.
Former company officers Dennis Farrell and William Tis pleaded not guilty to similar charges and have been released, each on a $10,000 bond, West Virginia MetroNews reported.
The trial is due to start on March 10.