VANCOUVER—Water advocates say Vancouver’s goal of being the world’s “greenest city” by 2020 is admirable but impossible without cleaning up its act when it comes to dumping untreated sewage into its waterways.

Some pipes in Vancouver — as in other Canadian cities — carry both raw sewage and rainwater runoff to treatment plants. But during heavy rains, these pipes end up carrying more waste water than the plant can handle.

That triggers overflow points where both sewage and rainwater pour directly into rivers, lakes, or the ocean.

More than 45 million cubic metres of untreated sewage flowed into B.C. waters in 2016, according to Environment Canada data obtained by StarMetro.

More than half of that entered waterways around the Lower Mainland — the Burrard Inlet, False Creek, and the Fraser River — according to a Metro Vancouver report.

It’s a far cry from where Vancouver needs to be if it wants to be a leader in water quality, said Lauren Hornor, a Fraser Riverkeeper board member and a regional representative for Swim Drink Fish, a water-quality advocacy group.

“We really should be a model for the entire world, but we’re just not there yet,” she said.

The City of Vancouver has announced its goal is to separate its sewer and stormwater systems by 2050. But in the meantime, untreated waste water is still pouring into its waterways.

And heavy precipitation, which causes the combined sewer pipes to overflow, will likely occur more often in the coming decades, according to Nathan Gillett, manager of Environment Canada’s centre for climate modelling and analysis.

In Vancouver, average annual rainfall is forecast to rise between 10 to 20 per cent by the end of the century; more intense rainstorms are also expected, he said.

The risks of more frequent sewer overflows were outlined in a 2008 report that examined the vulnerability of the Vancouver-area sewage system.

Vancouver has so far separated about 55 per cent of its combined pipes, said the city’s water and sewage infrastructure director Daniel Roberge.

The city separated sewage and storm pipes in the downtown area 20 years ago, he said, and it’s continuing work to separate pipes leading to the Burrard Inlet, False Creek, and the Fraser River.

But E. coli levels in some of Vancouverites’ favourite water-sport destinations do exceed Health Canada thresholds at times, especially during the summer months when people are more likely to be swimming.

Vancouver Coastal Health currently releases data on E. coli levels in busy waterways like False Creek, Trout Lake, and the city’s beaches.

Fraser Riverkeeper said it plans to supplement that data with a citizen-science program this summer, in which residents are invited to sample and test water in False Creek. That data will be available on the Swim Guide app.

But water advocates like Hornor have been calling on cities to monitor combined sewer overflows in real-time so that people know when to avoid swimming in certain areas ahead of time.

Roberge confirmed Vancouver is taking steps to install sensors inside the city’s pipes to create a sewage-monitoring system.

“This year, we’re going to be choosing some locations, some technology, and we’re going to start validating data on combined sewer overflow,” he said. “In 2019, the plan is to look at how best to provide this information to the public.”

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In the meantime, the city said it’s trying to reduce rainwater flowing into the sewer system by 90 per cent, which would help lower the number of combined sewer overflow events.

“We are trying to divert that water and prevent it from going into the pipes in the first place,” said Melina Scholefield, head of the city’s green infrastructure program.

Through that initiative, city workers install rain gardens, permeable sidewalks, and green roofs to collect and absorb as much rainwater as possible before it has a chance of flowing into storm drains. The vegetation and soil remove pollutants from the water, she explained.

City staff are also building basins underneath sidewalks – like one at Burrard and Cornwall – that collect rainwater and direct it to the roots of trees that line the sidewalk above.

The city has installed 50 such features since November, and now has a total of 240 pieces of green infrastructure. It aims to install hundreds more in the next four years, according to Scholefield.

Increasing greenery in the city would also improve biodiversity and help cool city temperatures during the summer months, she said.

What can you do to help solve the sewage overflow problem?

Experts say everyone can help limit the effect of sewage overflows, here are a few easy things you can do:

The Natural Resources Defense Council suggests using materials like gravel, wood, or other porous material whenever possible on your property to allow more water to be absorbed by the ground.

Individuals can also create green roofs, planter gardens, disconnect your downspouts, or use a rain barrels to decrease the amount of runoff from your home, suggests Canada Research Chair in source water protection Sarah Dorner.

Lauren Hornor, with Fraser Riverkeeper, says we should watch what we put down the drain. Any chemicals, cleaners, or medications dumped down household drains could end up in a local waterway when combined pipes overflow.

The same warnings apply to storm drains. The NRDC says good car maintenance can help reduce leaking fluids like oil and antifreeze, which can wind up in the storm sewers.

Finally, conserve water. The Environmental Protection Agency says using less water reduces the flow during rain storms. So fix those leaks and use taps and toilets that use less water.

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