$200m ozonation plant a first
Barry Artiste, Now Public Contributor
An ozonation plant may look good on paper, especially if waste is a severe problem. But to state the byproduct is clean air is a fallacy. Ozone Generating Machines though good at disinfection in some instances, in some studies Ozone may be a carcinogen, though it is disputed by some. What I do know is Ozone is a Toxic oxidizing gas , much different in it's chemical properties and toxicity than Oxygen. It is a safer alternative at water treatment over bromide and chlorine. Though we have Ozone in the Stratosphere, we do not breath it, for if we did respiratory problems would result. Another point is that Ozone Generators also discharge negative and positive charged Ions into the atmosphere and may not totally Environmentally friendly, though as an alternative to raw waste, perhaps it is a tradeoff. Though Ozone cannot be the end all, be all solution, it does have it's limitations in decontaminating bacteria and other contaminates, especially if these contaminates are imbedded in materials makes it difficult if not impossible to decontaminate. Something this Media story does not explain.
$200m ozonation plant a first
Montreal plans to be the first large metropolis in the world to disinfect all its waste water using ozonation, a cutting-edge technology that uses ozone to remove bacteria, viruses, harmful pharmaceutical drugs and industrial chemicals dumped into the St. Lawrence River.
"We are proposing an innovative solution that will make Montreal a leader in waste-water disinfection," said Montreal Mayor Gérald Tremblay yesterday as he announced that the city will seek help from the provincial and federal governments to add a $200-million ozonation facility to its current treatment plant.
Montreal's waste-water treatment plant in Rivière des Prairies is recognized as the third largest in the world, treating about 32 square metres of water every second.
The plant uses various physical and chemical processes to remove suspended solids and phosphorus in waste water and then pumps that water back into the river near île Ste. Thérèse, at the northeastern tip of the island.
But for the last decade, environmental groups and communities downstream from the plant, such as Sorel-Tracy, have been demanding Montreal also disinfect the waste water, as evidence mounts that some of the substances released into the river cause illness and disease or act as "endocrine disruptors."
(Endocrine disruptors are chemicals that scientists believe interfere with the body's endocrine system and produce negative effects on developmental, reproductive, neurological and immune processes in humans, fish and animals.)
In the mid-1980s, Montreal invested in equipment and infrastructure to disinfect waste water using chlorine. But in 1987, the provincial environment department banned the use of chlorine for waste-water treatment, because it harms marine and plant life.
Chlorine is still used in many cities around the world to disinfect water, but the debate about its safety and environmental impact rages on. So all eyes will be on Montreal as it pioneers what seems to be a less harmful alternative.
In the early 1990s, the Montreal waste water treatment station, along with various partners, began studying two different chlorine-free processes for disinfection: ozonation and ultraviolet radiation. In 1997, a joint committee of representatives from the plant, the provincial Environment Department and the Municipal and Regional Affairs Department was given a mandate to analyze all current research, conduct pilot projects and recommend the best disinfection method for Montreal.
That committee concluded in November that ozonation was not only more effective than ultraviolet radiation in eliminating bacteria, viruses and harmful chemicals, but was far less harmful to marine life.
Ozone kills germs and bacteria by transferring electrons with other organic substances and oxidizing them, or in effect eating them up, leaving oxygen as its only by-product.
Pilot projects conducted in the $2-million "eco-laboratory" at Montreal's treatment plant showed that ultraviolet radiation - used by many cities in North America, including Laval - killed fish and other marine life close to the outflow at a much higher rate than ozonation did.
Water-treatment experts at yesterday's press briefing stressed that study results could be applied only to Montreal's waste water, explaining that the results probably depend on the specific type of chemicals being released by industry. Montreal has a heavy concentration of pharmaceutical companies.
The mayor noted that without funding help from the province and the federal government, Montreal cannot afford to build the ozonation plant. But he said he expects the city to be on the hook for only 15 per cent of the cost, as the province generally funds about 85 per cent of municipal water-treatment projects.
"Montrealers are not the only ones who will benefit," Tremblay said. "This is a project for all of Quebec, especially all the communities along the St. Lawrence River."
The mayor also hopes communities upstream from Montreal will consider adopting the same technology.
Environmental groups reacted with relief to yesterday's announcement, although some said it has taken the city too long to make the decision.
"We've been pushing for disinfection for at least 10 years, and specifically for ozonation for at least five of those years," said Bruce Walker, of STOP.
Coralie Deny, of the Conseil régional de l'environnement de Montréal, said the announcement is great news to anyone who lives downstream from Montreal and enjoys swimming or water sports.
The Montreal water-treatment plant is responsible for treating 45 to 50 per cent of Quebec's total waste water. Only about 40 per cent of Quebec's total waste water is disinfected.
A few other cities, like Indianapolis, use ozonation to disinfect waste water, but Montreal will be the first to disinfect great volumes of water using this method. Montreal's plant is behind only Seoul's and Hong Kong's in terms of the amount of water treated.