LONDON, Ont. -- Groups opposed to industrial-size wind farms are looking to intervene in a landmark appeal that begins Monday against one of Ontario's largest wind-energy projects.

The constitutional challenge before Divisional Court focuses on claims by farm families concerned about the potential health effects of living as close as 500 metres to the turbines.

Their lawyer, Julian Falconer, argues the law is rigged when it comes to official consideration of any harmful effects the turbines might pose.

"In wind, the fact that it may hurt you is not enough -- you have to actually prove it will hurt you," Falconer said in an interview. "This is not how we manage health."

At issue is the proposed $850-million K2 Wind project, which would see 140 turbines put up near Goderich. The provincial Environment Ministry has approved K2 as well as the smaller 15-turbine St. Columban project near Seaforth, Ont.

Both K2 Wind Ontario and St. Columban Energy argue their projects are safe. They say they obtained the required permits following an extensive approval process that included two years of planning and environmental studies.

In upholding the ministry approvals, the Environmental Review Tribunal decided it had no conclusive proof that turbines pose a health hazard to those living near them.

In all, four families are taking part in the fight against K2, St. Columban, and the 92-turbine Armow wind farm near Kincardine, Ont. It is the first constitutional challenge to Ontario's Green Energy Act to reach the appellate court level.

The families, who failed last month to force an immediate halt to construction of the wind farms pending outcome of their appeal, argue the impacts have not been properly studied and the legislation makes it all but impossible to raise health concerns.

Hoping to join the fight are 14 community groups from various parts of the province calling themselves the Coalition Against Industrial Wind Turbines.

The coalition wants to argue, among other things, that an issue of fundamental justice is at stake.

"A statute designed to protect health cannot be illusory," the group states in its factum.

Late last month, a judge ruled that it should be up to the Divisional Court panel hearing the appeal on Monday to decide whether to allow the coalition intervention.

Project proponents want the court to stop the coalition, saying the court process is already too far along and the intervention would cause "undue disruption."

Earlier this month, Health Canada reported that its study of 1,200 residents in Ontario and P.E.I. turned up no sign of health problems caused by wind-turbine noise.

The noise might be annoying but had no link to sleep disturbances, dizziness, tinnitus, migraines, increased blood pressure, heart disease, or diabetes, the agency said.

Critics, however, argued Health Canada had not released details of what they called a poorly designed study and said it had yet to undergo any peer review.

An unrelated court battle involving a nine-turbine wind farm development south of Picton, Ont., is set to go before the province's top court in December.