Sinkhole caused by rupture of 92 year old water main: de Wit

Two public works employees inspect a sinkhole on Fifth Street East on March 12, 2015. The public works manager says it was caused by a water main break which undermined part of the street. (Cornwall Newswatch/Bill Kingston)

CORNWALL – A broken water main and sinkhole on Fifth Street East should be repaired by the end of the day (Thursday).

The street next to Cornwall Collegiate and Vocational School (CCVS) has two water mains running in parallel – an 18 inch feeder line on the south side of the street and a six inch service main on the north side – as well as a sewer in the middle.

The six inch main, which was installed in 1923, ruptured sometime recently and slowly eroded the ground underneath the road, where it escaped into a storm sewer.

“The service main in front of 115 Fifth Street East has broken and the water, rather than manifesting itself up through the ground, has been undermining underneath the asphalt and escaping in a storm sewer. We have no idea how long that’s gone on of course,” Public Works Manager Bill de Wit tells Cornwall Newswatch.

He says, even though the pipe is nearly 100 years old, it has a good track record with very few instances of a rupture.

De Wit believes the 18 inch feeder main, installed in 1950, is in good condition. “There’s nothing wrong with it, it’s actually a very good pipe.” He says there are plans in the next two years to reline and add valves to allow shutoffs to a smaller area of Fifth Street.

While the water main is being repaired, there a bigger problem under the ground. “We haven’t located it, but there must be a hole in the sewer because that’s where the water’s escaping to,” de Wit said. “We believe there’s some sort of rupture in the sewer pipe as well.”

He says, once the water main and sewer are repaired, the hole will be filled in and the street will be “cold patched” with asphalt.

De Wit says the winter has been challenging for the pipes with, in some cases, nearly seven feet of frost. “Frost causes things to lift and the water is very cold, it’s just at zero, pipes become brittle. We have a little bit of movement and we have a break.”

As for how the Fifth Street East sinkhole was spotted, de Wit says a Cornwall police officer on patrol called the public works dispatch late Wednesday night about a depression in the road.

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