The City of Burnaby is planning to keep a closer eye on raw sewage flowing into the Burrard Inlet, as per new wastewater rules announced by the federal government in July.
There are three combined sewer outfall points in Burnaby, where raw sanitary sewage mixes with storm-drain water and is released in the Burrard Inlet during heavy rains. Metro Vancouver monitors two of the outfall points, and the city is responsible for the third. Burnaby is hoping to have a monitoring system in place by fall, in time for the wet weather.
"Obviously, our role is to improve things and protect the environment," said Barry Davis, acting director of engineering. "Burnaby has as a ton of history of supporting the environment and protecting the environment, and this is part of our mandate. It's important for us to do."
Combining sewers is an outdated practice, but some cities - like Burnaby, New Westminster and Vancouver - are stuck operating combined sewers leftover from the days when untreated sewage emptied in the Burrard Inlet and the Fraser River.
A small part of the Burnaby's sewer system is combined, and the system overflows during heavy rain, releasing raw, unfiltered sewage into the Burrard Inlet.
"The overflow, there's sewage in it, but most of that water is rainwater," Davis said. "Whatever's in the sewer would be highly diluted but if there's toilet paper, that sort of thing, it's possible."
The outfall points function like safety valves, ensuring the system doesn't overflow and back up into people's homes, flooding them with sewage.
According to the new federal rules, municipalities have to report annually on how much combined sewage is flowing into the environment.
According to Metro Vancouver's liquid waste management plan, the City of Burnaby was already supposed to be estimating and reporting on the frequency, location and volume of sewage overflows from regional combined sanitary sewers, but because of technical difficulties involving the steeply sloping landscape, that wasn't possible.
"In essence, because of the steep grades, to do accurate monitoring has been very difficult. We just haven't been able to make it work," Davis said.
The new plan is to mea-sure the depth and the frequency of overflows and the time and the length so the city can estimate the volume.
"It's basically, in essence, a level gauge that would be continuously monitored," Davis said.
According to the new federal rules, the monitoring equipment must be in place by Jan. 1, 2013.
Burnaby's combined sewers date back to the late '40s and early '50s, before the region's waste treatment plants were in place. New sewer systems built in Burnaby since the early '60s have separate pipes for storm water and sanitary wastewater. The city has until 2050 to separate the combined sections to ensure raw sewage doesn't go into surrounding waterways, and one outfall point was already separated in 2006. Davis said the city puts aside money every year to replace the combined sewer system, but the job is expensive.
"If you look at the dollars involved, you are talking many, many millions. It's not something you can do all at once," he said. "If we stay on track, we would anticipate on being substantially complete by 2050 for everything."
Burnaby's combined sewers are by Capitol Hill in North Burnaby and near Glenbrook in the south, which crosses underground to New Westminster and is released into the Fraser.
According to a 2010 Metro Vancouver report, more than one million cubic metres of combined sewage water (raw sewage, rainwater and snowmelt) were released from Burnaby's outlets into the Burrard Inlet in 2009, the most recent year on record, and that's not including the outfall point that the city hasn't started monitoring yet.
By comparison, the heaviest volume was at two outlets at Vancouver's Clark Drive, which released more than 14 million cubic metres of waste the same year. The lowest volume was at MacDonald Street in Vancouver, with 7,142 cubic metres. In all, more than 30 million cubic metres were released into local waterways from the region's combined sewer outlets in 2009, up from 20 million the previous year.
