Ottawa faces $18.5M fix to unclog frozen pipes, councillors told
Environment committee OKs extending Lemieux Island intake pipes to escape troublesome 'frazil ice'
Tiny, needle-like ice crystals known as "frazil ice" are causing big problems at one of Ottawa's two water purification plants, and could cost taxpayers millions of dollars to combat, city councillors heard Tuesday.
In a presentation to Ottawa's environment committee, staff described frazil ice as small, needle-like crystals that form on cold, clear nights in the rapids upriver from Lemieux Island.
As frazil ice forms, it sticks to metal objects. When it builds up as a mass of slush under the river's winter cover of ice, it's drawn into the plant's intake wells, clogging pipes.
Ice forces shutdowns
Since January 2013, the city has spent hundreds of thousand of dollars each winter to keep the Lemieux Island plant free of frazil ice. While the Britannia plant upstream has been largely spared because it's surrounded by deeper water, frazil ice "modestly impaired operations" there for a few weeks in 2015, according to the staff report.
Ice buildup has also forced temporary shutdowns at the Lemieux Island plant, cutting its normal daily production of 200 megalitres of drinking water by more than half.
During recent winters, the city has attached temporary extensions to the intake pipes, sending them further and deeper into the river where frazil ice isn't such a problem.
Permanent solution pegged at up to $18.5M
A permanent solution — installing pipes that will stretch to the Quebec side of the river, 225 metres from the Ottawa shoreline — is estimated to cost between $17.2 million and $18.5 million.
Staff have identified $8 million in a capital account for the project, but the remainder of the cost would have to be borne in the city's budget. The city may also seek federal infrastructure funding for the project, should it be approved.
Councillors on the environment committee heard about four other possible solutions, including a berm and a boom to divert frazil ice, but in the end backed staff's top choice to extend the intake pipes.
The committee's decision still needs the approval of city council.