A project to build an outfall to discharge treated sewage water into the Yukon River will cost $3.5 million more than expected.
“We have never done a project of this scope and this type in Whitehorse before and the estimate was based on previous projects in a similar vein,” said Wayne Tuck, the city’s engineering and environmental services manager.
Oil, material, and labour costs have risen during the past few years, and availability of equipment and contractors is limited.
Luckily, the budget overrun won’t cost taxpayers extra.
All of the money is coming from the federal Gas Tax Fund.
To pay for the work, the city will likely defer the Porter Creek reservoir project, which was also funded by the Gas Tax Fund.
“Not awarding this contract could result in failure of the city’s facility and a significant environmental impact on the surrounding area,” according to the report that Tuck submitted to council on Tuesday night.
“Delaying the project could result in higher environmental costs in the future.”
The Livingston Trail Environment Control Facility, the city’s sewage lagoon, was completed in 1996.
In 1998, the city chose to defer construction of the outfall that would discharge treated water directly into the Yukon River.
Instead, it diverted the water into nearby Pot Hole Lake.
The water then percolated through the soil down to the river, which also provided additional treatment of the effluent.
However, the city has run into a number of problems that have decreased the usefulness of Pot Hole Lake.
One of these is the short time period when the city can discharge the water — 90 days from August and October.
Even though 3.4 million cubic metres of treated sewage is released into the lake each year, this isn’t enough to completely empty the city’s lagoons.
This has caused the ponds to become increasingly full with each passing year.
The wet, cloudy, cooler weather has exacerbated the problem because of decreased evaporation.
And there has also been vandalism of the current outfall and a deterioration of the aquifer that connects the lake to the Yukon River.
All of this makes the discharge line to the Yukon River an essential project for the city.
Proposals were received for the project from Skookum Asphalt and Castle Rock Enterprises.
City engineers estimated that the project would cost $2.35 million but both submissions quoted a price over twice that amount.
Skookum priced the work at $5.58 million while Castle Rock would charge $5.64 million.
Administration recommended awarding the contract to Castle Rock as Skookum’s proposal did not have water board approval.
It is an extremely complicated project.
The outfall required work on the Yukon River, which is a salmon bearing river and a highly visible tourist feature.
And construction has to be completed through steep and varying terrain.
The design and construction of the new outfall still has to go before the Yukon Environmental and Socio-economic Assessment Board.
The city hopes to have the work completed by next spring.
Council will vote on amending the budget and awarding the contract next week.