And Catherine Rudel-Tessier is recommending the government impose fines and sanctions for those who don't follow the rules.
In a report made public Wednesday, Rudel-Tessier said public health authorities did not have the proper tools to combat the outbreak in the Quebec City area last year, which came 16 years after a 1996 outbreak prompted calls for change.
Rudel-Tessier says not enough was done to change the system.
"Despite the recommendations in 1997 and other publications that followed, no rules were in place and the (local health authority) did not benefit, at the time of the outbreak in 2012, from the necessary tools to effectively manage the situation as well as they could have," Rudel-Tessier wrote.
The outbreak originated in an office tower owned by one of the province's labour federations. Even though the outbreak was public knowledge in mid-July last year, the owners of the building didn't shut the towers because they were convinced they'd been cleaned and disinfected.
Rudel-Tessier said global warming is intensifying the demand for air conditioning. That, coupled with an aging population, is increasing the number of those susceptible to the infection.
Legionnaires' disease is contracted by breathing in small droplets of water contaminated with bacteria. Symptoms include coughs, fever, chills and respiratory problems.
The deadly bacteria grow in the stagnant water of cooling systems and spread in little droplets through air conditioning.
Heavy smokers and people with weak immune systems are most at risk of catching the disease, which is not contagious and cannot be transmitted from one person to another. It presents little or no risk to most people, although elderly people are more vulnerable.
Rudel-Tessier said many solutions were recommended following the 1996 outbreak, including an inventory of the towers.
Some of those recommendations were ignored and the inventory list is only being completed now.
She also suggested the province clarify the roles of different departments and agencies for monitoring, prevention and intervention.
The coroner heard from a dozen witnesses and experts earlier this year during a public inquiry.
A class-action lawyer representing the widow of one of the victims says the regional health agency didn't do enough and that he is considering legal action on behalf of the victims' families.
Jean-Pierre Menard says he has obtained other documents and is preparing for a possible legal case, although it's far from a sure thing.
Menard told a news conference in Quebec City that mounting a legal challenge would be difficult. But he said the documents he's obtained confirm local health authorities were in the dark three weeks after the outbreak and didn't know where the coolers were.
"The local health authority was really navigating blind," Menard said. "They were surprised and they didn't really know what to do. They went along hoping something would happen — that the epidemic would extinguish itself — and that didn't happen."
He was joined at a news conference by Solange Allen, whose spouse died in the outbreak.
"Even if we get money, it will never replace my husband, and if we don't get anything, it's even more catastrophic," Allen said. "If we get something, I'll be very, very happy."