Federal lawyers have made a last bid to stop a class-action lawsuit over contaminated water in the town of Shannon, Que., near the Valcartier military base.

The water table in Shannon, Que. was contaminated by TCE, a powerful industrial degreaser.The water table in Shannon, Que. was contaminated by TCE, a powerful industrial degreaser. (CBC)Arguments in the $2-billion groundwater contamination lawsuit ended at the Quebec City courthouse on Monday.

Lawyers for the federal government and SNC Technologies say the lawsuit should never have been certified in 2007 because its parameters are too wide.

"If your definition [of the suit] is overbroad, it has an impact on the ability for the court to resolve the recourse in an expeditious fashion," said defence lawyer David Lucas.

More than 3,000 claimants are involved in the class action against the government and SNC Technologies.

They allege the Department of National Defence dumped trychloroethylene (TCE), a local industrial-strength degreaser, into local lagoons 60 years ago, and contaminated the water sufficiently to cause high cancer rates in the military town.

The federal government had been warned that TCE was being dumped in local lagoons.

Shannon residents drank the water for 22 years before they discovered the contamination in 2000.

DND says it was following existing standards for handling TCE and discounts the class-action lawsuit because it is too inclusive.

Argues against collective action

Lucas said because every person's level of exposure to TCE was different, claimants should pursue individual legal action instead of collective action.

Allegations have not been proven in court.

There is no doubt among claimants that collective damages are due, said Claude Juneau, a physician who worked in Valcartier for 37 years.

"We know that [TCE] affected the brain," he told CBC News. "That's why we have so many cases of cancer of the brain, cancer of the liver, cancer of the kidneys."

Juneau, now a claimant in the lawsuit, blames his kidney problems on exposure to contaminated water.

Superior Court Judge Bernard Godbout will hand down his decision later this spring.