Saint John city council has given approval to the final instalment of harbour cleanup.

It has taken more than 10 years and cost almost $100-million, but Tuesday night city council awarded the final tender necessary to complete the project.

"[It's] probably the single, largest project the city has ever undertaken," said Saint John engineering manager Brian Keenan

Marsh Creek

A $4.5-million collector sewer and force main to divert sewage away from Marsh Creek in Saint John and toward a new treatment plant in Red Head was part of harbour cleanup. (CBC)

"The planning stages actually began in the early 2000s and it took seven or eight years of planning and four to five years of construction in order to complete. It's a major undertaking."

The final tender was awarded last night to Galbraith Construction for $1,118,020 to build a lift station, force main and sewer on Mill Street in west Saint John, near Reversing Falls. That was $664,000 below the budgeted cost of $1,940,000 for that piece of the project.

Twenty years ago, well over half of the city's sewage went straight into the city's harbour without being treated. When the new west side pump station begins operating next summer, 100 per cent of the city's sewage will be treated.

The cost of the project climbed over time. In 2006, it was projected the bill would be $79 million. When construction was about to begin three years later, the estimated cost was increased to $99.4 million. City engineers say the total project cost will come in at or under the $99.4 million figure.