Ottawa Citizen 5 July 2009
by Kate Jaimet, Copyright The Ottawa Citizen 2009
And the sewage runs through it
Between April and November last year, 895 million litres of raw sewage, mixed with rainwater or melting snow, poured into the Ottawa River. A recent city report estimates that 51.8 per cent of E. coli in the river (above naturally occurring levels) comes from sewage overflows. Why does it flow into the river at all? Kate Jaimet investigates.
Growing up on Petrie Island in the 1960s, Yves Grandmaitre saw some pretty unsavoury things floating in the Ottawa River.
'Some days, the floating scum on the water was four or five inches thick. It looked like the head on a beer. It was brown and oily,' recalls the owner of Ozile's Café, Marina and Tackle Shop on Petrie Island. 'Other days, you'd have condoms floating, you'd have tampons. You don't see any of that anymore.'
If anyone knows first-hand about the water around Petrie, it's Grandmaitre. His father owned the islands before selling them to the city about 20 years ago. And for all the public outcry about sewage in the Ottawa River, Grandmaitre said it's a lot better than it used to be.
"As far as I'm concerned, having been here for 47 years, the water quality today is way beyond what it's ever been."
But despite the apparent improvement in the water quality, beach-goers can anticipate that on days after heavy rains, Petrie and other beaches will be closed this summer due to high counts of E. coli bacteria.
E. coli is what's known as an "indicator organism." Not only is it nasty in itself, but it also indicates the presence of other, associated bacteria. That's why the city tests for E. coli every day, and shuts the beaches if the count is too high.
"If you do swallow the water (with a high E. coli count), there is a risk of getting gastro-intestinal illness," explains Jean-Guy Albert, a program manager for Ottawa's public-health department. "If you swim, you could get an ear infection or an eye infection."
Last summer, E. coli closed Petrie Island Beach for 19 days; Westboro Beach for 21 days and Britannia Beach for one day. Much of the problem, especially at Petrie Island, came from the overflow of city pipes containing a combination of rainwater and household sewage, which washed untreated into the Ottawa River.
In fact, last year between April and November, 895 million litres of raw sewage mixed with rainwater or melting snow poured into the river. A recent city report estimated that 51.8 per cent of E. coli in the Ottawa River (above naturally occurring levels) comes from sewage overflows from the City of Ottawa.
But why does raw sewage flow into the river at all? Much of the problem dates to 1949, when the sewer system was built in the old Ottawa core.
At that time, the same pipes were designed to carry both household sewage and rainwater from storm sewers. Originally, the pipes ran directly into the Ottawa River; there was no treatment whatsoever.
In 1961, the city built a sewage treatment plant called the Robert O. Pickard Environmental Centre. As well, an interceptor pipe was built, running parallel to the Ottawa River to collect water from the mixed rain-and-sewage pipes that used to drain into the river directly, and take the stuff to the treatment plant.
The area of combined sewers originally stretched from Rockcliffe to Westboro and reached as far south as the Rideau River, although separated sewer pipes have since been built in some of those neighbourhoods.
At five locations, "float-operated gates" control the flow between the combined rain-and-sewage pipes and the interceptor pipe. The gates, which are only beginning to be replaced by more modern technology, work on a counterweight system. If there is a low flow of water in the pipe (that is, when it is not raining), the gate is open, allowing the sewage water to flow into the interceptor pipe, and go to the sewage treatment plant. But if it is raining, the counterweight rises along with the water volume, causing the gate to close. At that point, the conduit to the interceptor pipe is closed, and the mixed storm and sewage water is forced to flow into the Ottawa River, just as it did in the original 1949 system.
It doesn't take much rain to cause a sewage overflow like that.
"We anticipate that rain more than 2.5 millimetres will generate an overflow," said Dixon Weir, the city's general manager of environmental services. "Over an entire (sewer) drainage area, that represents a huge amount of water by volume."
Sewage overflows have been happening for decades -- just ask Grandmaitre -- but in the summer of 2006, when a stuck gate caused nearly a billion litres of raw sewage to flow into the river over 11 days, public opinion and political will came to bear on the problem. It spurred a repair and construction spree in the city sewers that, if all the pieces are approved by city council, will cost $203.8 million over the next 14 years.
The plan involves major upgrades to the sewage system to drastically cut down sewage overflows.
But sewage overflows aren't the only problem. Westboro Beach, which is upstream of all the Ottawa sewage outlets into the river, was closed for 21 days last summer -- two days more than Petrie Island, which lies downstream. Though the source of E. coli at Westboro isn't entirely clear, much of it may come from stormwater washed into Pinecrest Creek, which empties into the Ottawa River just upstream of Westboro.
"Dog poop, you name it -- when it's raining, it gets washed into the river," Albert said.
If the city's $203.8-million cleanup project proceeds as proposed, the E. coli washing into the river should be cut by 38 per cent by next year. By 2035, if Gatineau does its part in modernizing its sewage system, E. coli should be down by 59 per cent. And that should mean fewer beach closings.
"The less we can contribute to the impact on the river, whether it's from combined sewage overflows or whether it's what we put on our lawns, everyone has a responsibility to take care of the river," Albert said.
In the meantime, Weir said, the good news is that the overall health and water quality of the river is good.
Sewage overflows don't appear to have a lasting environmental impact, he said.
"It's a short-term thing that moves through," said Weir. "We have a wide list of all sorts of species (in the river). They're healthy."© Copyright (c) The Ottawa Citizen
Fixing the Sewage Problem
July 31 to Aug. 3 -- Heavy rains force the float-gate on the Keefer regulator to close, shutting off the conduit into the interceptor pipe and forcing mixed sewage and rainwater to drain into the river.
Aug. 4 to 15 -- Although the rain has ended, the gate is jammed with silt and remains closed. Raw sewage continues to pour into the river: 960 million litres by the time the problem is discovered.
Aug. 1 to 15 -- High E. coli counts force the beach at Petrie Island to close. The public-health branch investigates, but cannot find the cause.
Aug. 15 -- A technician notices the sewage flowing into the river at the Keefer site, and notifies his manager, who dispatches a crew to inspect. The crew opens the Keefer float-gate with a crowbar and uses a high-pressure water jet to clear out the accumulated silt. The problem is fixed, but the Ontario Ministry of the Environment is not notified.
May -- A public-works engineer, examining the water-flow data from August 2006, notices the spill and notifies the Ministry of the Environment. City council and the public-health branch still are not notified.
May -- Councillor Bob Monette is touring the sewage plant with a community group when the person giving the tour mentions the spill and links it to the Petrie Island Beach closings in the summer of 2006. It is the first time the news of the spill is disclosed to a councillor.
Aug. 28 -- In a report to council, the public-works department looks at water-flow data over the past 10 years and identifies 10 major spills in that time.
Sept. 30 -- The city is charged under the provincial Water Resources Act for permitting the spill and failing to report it. A $562,500 fine is levied.
Oct. 22 -- The auditor general's report on the spill is submitted to council. The report identifies the lack of maintenance and lack of regular inspection of the regulators as problems. It also criticizes an attitude in the works department that sees sewage spills as normal.
The rusty old regulator gates are being replaced with new, computer-controlled gates, and a $204-million proposal is on the table to fix the sewage problem for good.
156 Billion Litres of Sewage a Year
The city estimates that more than 99 per cent of Ottawa's sewage is treated before being released into the Ottawa River. The city estimates it produces 156 billion litres of sewage in a year, and that less than one per cent flows into the river untreated.
Even at this rate, however, between April and November 2008 an estimated 895 million litres of combined sewage and rainwater flowed untreated from Ottawa pipes into the river.
To fix the sewage overflow problem, the plan proposes four main elements, some of which are already under way:
- Modernize and computerize the five gates that regulate the flow from combined pipes into the interceptor pipe, so that more effluent is directed toward the sewage plant rather than into the river. Sensors will monitor the volume of fluid in the interceptor pipe and gates will block off the flow of sewage from combined pipes into the river, only to be opened if the interceptor pipe has reached its maximum capacity. Construction is already under way and the project should be finished by spring 2010 at a cost of $30 million.
- Improve monitoring at a cost of $5 million
- Build underground storage tanks that can hold the sewage-and-rainwater mixture until a storm is over, and then send it to the sewage-treatment plant for processing. This project is estimated to cost $45 million, and should be completed by fall 2013, if approved by city council.
- Build separate rainwater and household sewage pipes in certain parts of the city. This project is estimated to cost $37.5 million and should be completed by fall 2011. In addition, $72 million is proposed over the next 14 years to better treat and manage stormwater that runs into the creeks that flow into the Ottawa River directly upstream of Westboro Beach and Petrie Island.