March 26, 2010

JORDAN PRESS

Workers begin construction on Princess Street in downtown Kingston. While it will be disruptive, efforts are being made to ensure businesses stay open and customers can access the stores at the heart of the eastern Ontario city.

FEATURE | Sewer and Watermain

Kingston, Ontario’s own Indiana Jones adventure plays out

City rips out its heart to replace century-old sewers

JORDAN PRESS

correspondent

KINGSTON, ON

The City of Kingston will spend approximately $3 million this year to rip up the base of Princess Street in the heart of the downtown core to rebuild the road and replace the century-old underground infrastructure.

And for crews working on the project, it will be a little like Indiana Jones and the Lost Sewers because blueprints are guesses based on drawings made after the fact and few engineers have actually seen what’s really down there.

Specifically, workers will replace the stone box sewers that carry wastewater and storm water out of the core of Kingston’s historic downtown. The ancient infrastructure, more than 100 years old, will see the light of day for the first time in generations before being removed and replaced with modern pipes.

“It’s exciting to be able to replace some of the oldest infrastructure in the city and some of the oldest infrastructure in the province,” said engineer Mark Campbell, the city’s construction manager for the project. “When we look back at the job, people will look at the surface.” The value to the engineering world is under the street.”

Many of the sewers located in the central and oldest parts of Kingston, were originally built and installed in the 1800s and early part of the 20^th century. The pipes were combined sewers — they handled sewage along with storm water — and ran directly into the harbour and waterfront. There was no sewage treatment.

The old sewers are about four-and-a-half feet wide and three-and-a-half high and run just over one kilometre under Princess Street west of Division Street, carrying sewage downhill via gravity.

CITY OF KINGSTON

The stone box sewers under Princess Street are among the oldest pieces of infrastructure in the province. Few City of Kingston engineers have ever had a chance to work on the hand-laid pipes and even fewer chances to see inside.

The stone box sewers in the downtown are built out of the bedrock and were laid by hand. Undeniable craftsmanship created perfectly formed boxes, Campbell said. Workers cut the base of the sewers out of the limestone bedrock, then built the walls out of rock and mortar and capped the sewer with a stone archway with a keystone.

“Can you imagine the backbreaking work it would have been at the time?” Campbell said. “To me, that’s an engineering feat. Can you imagine doing that today? It’s a very effective way of managing sewage. It’s very creative.”

There are few access points to the stone box sewers, so there have been limited opportunities to send in cameras. Few city engineers have actually seen a stone box sewer, let alone worked on one.

“You can’t maintain these things, but they’re operational,” Campbell said.

Working on the sewers today will be, to say the least, interesting. Underground infrastructure drawings were done in 1950, but based on information from 1900, so blueprints may not be 100 per cent accurate. In the lead-up to construction, city engineers and archeologists used ground-penetrating radar to determine the layout of the pipes and other historic infrastructure underneath Princess Street to minimize surprises.

Work on rebuilding the bottom two-and-a-half blocks of Princess Street will take approximately four months to complete. City officials and the contractor doing the job, Len Corcoran Excavating Ltd., are coordinating work with area businesses. Walkways will remain open for pedestrians during construction to maintain access to storefronts along Princess Street.

Campbell said the job is unique from another perspective: The city and Corcoran entered into a partnership agreement for the job.

The contractor has made suggestions for the final layout of infrastructure, Campbell said, and has used a full-time public relations staffer to meet with affected businesses to determine what can be done on the construction side to keep business operating smoothly.

Work will start this spring and city hall officials have guaranteed to have the work completed by June, just in time for the height of tourist season.

“It will be done on June 30 one way or another. We will be out of there,” Campbell said.

The city has already done preliminary work to get the project jump-started.

In 2009, Utilities Kingston engineers did work on an underground electrical vault on the southwest corner of King and Princess streets — a major intersection downtown — in anticipation of this year’s work.

More significant utility work will take place this year on the underground electrical infrastructure, specifically the manholes and underground electrical vaults around the intersection of Princess and Ontario streets. (Electrical wires are all underground in the downtown core.)

When work begins, crews will start in the middle of the two-block stretch of Princess Street and move west. At the same time, work will begin on King Street, one block south of Princess Street, and move north until crews meet at the intersection of King and Princess streets.

Crews will then begin to move to the southern portion of the project.

Campbell said construction timelines and staging has been worked out so that the intersections of Princess and King streets and Princess and Ontario streets aren’t closed at the same time.

The roadway will be the same dimensions, but the sidewalks will be completely rebuilt with new planters and bicycle racks once the job is completed.

But the work is just the start. After replacing two blocks of stone box sewers, the plan is to eventually go up the rest of Princess Street, one chunk at a time, and remove history and replace it with modern pipes.

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