A committal hearing into Environment Protection Authority charges against Hazelwood operators over the 2014 mine fire commenced this week in the Latrobe Valley Magistrates' Court.
Four companies including National Power Australia Investments Limited, Hazelwood Pacific Pty Ltd, Australian Power Partners B.V. and Hazelwood Churchill Ltd have each been charged with three offences.
They are each accused of polluting the atmosphere over and nearby to the township of Morwell between 9 February and 25 March 2014.
The charges include making the atmosphere noxious or poisonous or offensive to the senses of human beings as well as making it harmful or potentially harmful to the health, welfare, safety or property of human beings, and making the atmosphere detrimental to any beneficial use made of the atmosphere.
On Monday, the court heard there would be an estimated 19 witnesses called during the committal proceedings, with two of those to be called at a later date in November. Witnesses include residents of Morwell, Country Fire Authority firefighters and incident controllers plus experts who conducted EPA measuring, the court heard.