The Yukon Environmental and Socio-economic Assessment Board has approved a new wastewater treatment facility in Dawson.
The deep-shaft system will be the Yukon’s first – only a handful of similar sewage facilities are operating in Canada.
The biological treatment facility will be located in downtown Dawson and will use the 20-year-old Vertreat deep-shaft technology.
In the below-ground system, sewage is treated with oxygen to break down sludge.
The assessment board raised concerns the facility could accidentally taint groundwater sources. Dawson’s drinking wells are 200 metres away from the proposed treatment plant.
“The proposed location of wastewater treatment shafts … combined with the potential for an accident or malfunction resulting from human or mechanical error during the installation and/or operation of the DWWTP pose a serious risk,” it wrote.
In addition, plant effluent could affect fish and wildlife along the Yukon River.
Wastewater effluent has been known to cause algae blooms and can affect the reproduction and DNA structure of fish in the river.
Seepage may also happen at the Quigley Landfill, where bio-solid waste from the plant will be stored. The landfill has no underground liner and relies on permafrost, which is at risk of melting, to contain leachate, according to the assessment board.
Those risks can be averted by regular groundwater monitoring and new monitoring stations at the landfill, according to the assessment board.
The plan to build a new facility in Dawson has been controversial.
After the $25-million bid was awarded to BC-based companies Corix and Noram last April, Whitehorse construction company Ketza appealed the bid on grounds of professional misconduct. That appeal was overturned this spring.
And recently, the project’s costs had risen $9 million higher than previously expected. The additional funding will go towards incorporating a district heating system into the facility and paying off lawyer fees and engineers.
Construction of the facility is slated to begin this spring. (Vivian Belik)