Irving Pulp and Paper’s plan to launch a constitutional challenge to Canada’s environmental regulations is expected to shine a bright light on water pollution standards for mills across the country. The company, which has a mill at the Reversing Falls in Saint John, is charged under the Fisheries Act with 15 counts of dumping a harmful substance into the St. John River. If convicted of all charges, the company will face a minimum fine of $3 million. 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. … In its Charter challenge, Irving is asking the court to strike down sections of the Fisheries Act tied to the lethality test when it comes to pulp and paper mills.