The case, brought by Ian Hanna, a resident of Prince Edward County, 200 kilometres east of Toronto, argues that regulations in Ontario's Green Energy Act, governing how far turbines must be from houses, are illegal. If the court agrees, new wind development could come to a standstill.
The case will also be an opportunity to air the views of those who feel wind turbines are unhealthy. Mr. Hanna's argument is based on the premise that the minimum setback in Ontario - 550 metres - does not take into account the possible negative impacts to human health that turbines may cause.
Essentially, he argues, there is no medical evidence that the setback is safe, and that by publishing its regulations without sufficient proof, the province has breached the "precautionary principle" in its own environmental bill of rights.
That principle says the government has to show an activity is safe before it is approved.
Indeed, Mr. Hanna's court filings say, the government knew there was literature that raises concerns about turbines, and spells out that not enough was known to settle the setback issue.
A court victory, said Mr. Hanna's lawyer Eric Gillespie, would essentially put a moratorium on building any new wind farms in Ontario. That would be a huge victory for wind farm opponents, who say there need to be far more studies done on health impacts. "If the court determines that [Ontario] has insufficient science to support its decision, then governments, the wind industry and communities will have to look very closely to determine in a more scientific way where industrial wind turbines should be located," Mr. Gillespie said.
Increasingly, opponents have been protesting the spread of wind turbines, insisting that they cause health problems and calling for more detailed studies before the devices become even more ubiquitous. Both sides have cranked up the rhetoric recently last week, one anti-wind group complained that a wind farm developer had called it a "group of terrorists."
To support his client's case in court, Mr. Gillespie will present evidence from three physicians who say turbine noise and vibration can cause high stress, sleep deprivation and headaches among people who live near them.
The government argues, in a document filed with the court, that the doctors' conclusions are suspect, and that it reviewed all the literature available on the issue, and held public consultations before creating the guidelines.
It also says that complaints about possible health effects from turbines come from a small number of people, while the government's role is to try to clean the air for all residents of Ontario by shifting to renewable power.
There is "no conclusive evidence that wind turbine noise has any impact on human health," the government filing states. Available information suggests a 550-metre setback is adequate, it adds, and that that distance is "clearly conservative," given the existing studies. It dismisses the data about health problems as "anecdotal hearsay."
The government also argues that a new environmental review tribunal set up under its Green Energy Act is the right place to air health issues, not the provincial court.
Dianne Saxe, a Toronto lawyer who specializes in environmental issues, said she would be very surprised if Mr. Hanna wins his case. She said he is stretching the precautionary principle beyond what it actually covers. And the government "should have no trouble at all proving that it considered the health concerns of the anti-wind activists, because they were very vocal," even appearing at legislative committee meetings, she said.
Ms. Saxe thinks it is likely the court will deal only with the narrow legal aspects of the case and not make any substantial ruling on the health effects of wind turbine placement.