Facing 15 counts of dumping a harmful substance into the St. John River, Irving Pulp and Paper is planning a legal challenge to Canada’s environmental regulations for pulp and paper mills, CBC News reports. The company is charged under the Fisheries Act regarding effluent from its mill at Reversing Falls.

According to the CBC report, Irving’s defence will include “a direct Charter challenge against the way a water pollution test used nationwide for several decades is applied by Environment Canada in its pollution regulations.”

The procedure known as the acute lethality test involves placing live fish in a tank of pure mill effluent to see if they survive.

The trial is expected to take place in 2018.