Pipe dream? Fixing the Ottawa River's sewage problem

It's a filthy problem that could cost hundreds of millions of dollars to fix: Ottawa, Gatineau, Arnprior and other Ontario and Quebec communities along the Ottawa River flush raw sewage into the waterway whenever it rains heavily.

But experts say it's a complex problem and the obvious solution might not be the best one.

In 2007, Ottawa dumped sewage into the river about 200 times, while Gatineau did so almost 1,500 times. So far in 2008, Arnprior, Ont., has sent sewage into the river at least nine times.

A recent survey of 800 Ottawa-Gatineau residents found 92 per cent think sewage overflows are unacceptable and should be fixed.

The issue caught public attention when the City of Ottawa revealed that a raw sewage spill of more than 700 million litres occurred in the summer of 2006 and was likely responsible for bacterial contamination that closed downstream beaches for weeks. The city was subsequently fined $564,000, but sewage continues to pour into the river and most of it is dumped, not spilled.

The problem arises because Ottawa, Gatineau and other communities have a combined sanitary and storm sewage system that carries both types of wastewater to their sewage treatment plants. During heavy rains, the pipes don't have the capacity to carry all the extra rain water on top of the usual sewage. In order to prevent the water from backing up into people's houses, municipalities release some of the untreated sewage into the river.

Separated sewer solution poses problem

Dixon Weir, head of water and wastewater services at the City of Ottawa, said that in Ottawa's case, combined sewers — the source of the overflow problem — are concentrated in the downtown core, which has a piping system designed and installed in the 1960s.

Since the massive 2006 spill became public, many people have called for a system that fully separates sanitary and storm sewers. Ottawa Mayor Larry O'Brien has said fixing the sewage system for good would cost $600 million and would take years.

The recent survey commissioned by CBC/Radio-Canada found that even though a huge majority of residents say sewage overflows are unacceptable, only 55 per cent would be willing to pay a tax surcharge of $50 to $1,000 per household in order to help fix the problem.

Weir himself said he does not favour splitting storm and sanitary sewers into separate pipes downtown. He believes the environmental benefits would not justify the cost of that expensive solution, and it would pose problems of its own.

The extra storm water would have to be treated somewhere. While the treatment wouldn't have to be as rigorous and mechanical as treatment for sanitary sewage, it would still take up a lot of room. That would create a challenge, given that the problem is concentrated downtown.

"Finding the space and the capacity to provide that level of treatment is very, very difficult in these mature, grown-up communities."

So far, all three levels of government have committed $100 million towards fixing Ottawa's problem.

Weir said $30 million of the money will be used to implement a computerized monitoring and control system that he estimates will reduce the amount of overflows by 65 per cent.

University of Ottawa ecologist Frances Pick said the city also needs a strategy to reduce the amount of stormwater that ends up in its sewers in the first place by allowing it to be absorbed into the soil, which cleans it and slows its journey into the river.

"The more asphalt you've got, the more problems you've got," she said.

One of the reasons the sewers reach capacity during storms mainly in the downtown area, she added, is because new subdivisions must meet regulations that require them to manage stormwater. That could mean building stormwater retention ponds or wetlands.

Problem greater in Gatineau

Whatever problems Ottawa has are even greater in Gatineau. Municipal officials in the two cities report that while there are only 125 kilometres of combined sewers left in Ottawa, there are close to 180 kilometres in Gatineau, even though Gatineau has a population one-third the size of Ottawa's. Consequently, Gatineau had close to 1,500 sewage overflows in 2007 — almost 7.5 times the number Ottawa had.

However, unlike Ottawa, Gatineau doesn't keep track of how much raw sewage it discharges into the Ottawa River.

But it's not just the capacity of the Gatineau's pipes that poses a problem for the river.

Louise Lavoie, head of the city's environment department, said Gatineau's sewage treatment plant was last upgraded in 1982 — 26 years ago — and is now almost at full capacity. Ottawa's sewage treatment plant was last upgraded in 1992 and still has lots of capacity left.

Gatineau expects to upgrade its plant sometime in the next eight years and has set aside $35 million for the project. It is also studying which parts of the its sewage network should be changed first.

But even Gatineau's treated sewage contains more bacteria than Ottawa's. That's because Ottawa treats its waste with chlorine to kill micro-organisms such as E. coli. The process is illegal in Quebec due to scientific evidence that chlorination produces carcinogenic byproducts.

Small municipalities face funding crunch

The raw sewage problem isn't restricted to large municipalities like Ottawa and Gatineau.

Many smaller communities along the river's banks also have combined sewage systems that overflow into the river, including Arnprior, a town of 7,000 about 60 kilometres upstream from Ottawa.

Arnprior Mayor Terry Gibeau said many towns have to decide whether limited infrastructure funds should go toward pipes and treatment plants, which people don't really notice, or toward crumbling roads and bridges.

"One of the interesting things in this field is sometimes it seems you're rewarded for doing nothing," said Gibeau, adding that municipalities that have neglected their infrastructure until they are in a crisis are more likely to get funding than those that try to keep up with their maintenance and upgrades.

"So that's kind of frustrating. There has to be a more equitable way of allocating infrastructure dollars to municipalities."