By Richard Leitner, News Staff

A change in plans will see the Hamilton Conservation Authority truck about 400 cubic metres of zinc-contaminated sediment dredged from the reservoir by the Crooks’ Hollow dam to the Taro dump in Stoney Creek when the structure is demolished.

Project manager Hazel Breton said the Ministry of the Environment requested the revision, which eliminates the need for a sediment management area on the west side of Spencer Creek as originally intended.

The remainder of dredged sediment, now estimated at just 1,600 cubic metres, will be used to help rebuild the creek’s flood plain into pre-dam conditions and return it to a meandering route, she said.

An April 2006 study originally estimated there were 5,000 cubic metres of  sediment  and found the presence of nine heavy metals, with two samples showing zinc at levels that could “significantly” harm small aquatic organisms.

“It’s a very small amount,” Breton said of the contaminated sediment to be shipped off site. “It’s less than 400 cubic metres.”

Authority directors shortly before Christmas awarded the contract for the $1.2-million demolition and site restoration work to R&M Construction of Acton, Ontario, the lowest of four bidders.

Breton said work has already begun on a creek channel to bypass the dam during construction, but the demolition itself is still awaiting final ministry approval.

She said the demolition must begin soon if it is to be completed by the end of March, when fish start spawning and heavier runoff and rain make conditions too wet.

If approval isn’t received shortly, work could be pushed back to July. The project’s second phase includes the creek’s reconfiguration and construction of a new bridge about 30 metres upstream from an existing one.

The area has been closed to the public since late December.

“We’re very excited to be just on the brink. We wish we had our approvals,” Breton said. “It’ll be amazing to see how the system will behave and what it will look like when it’s returned to a natural state.”

Built in 1916, the dam and its reservoir served Dundas with potable water until 1959 and provided flood control until the Christie dam took over that function in 1971.

Breton said the project will preserve a remnant portion of the dam on the side opposite Crooks Hollow Road, the cast iron pipe that conveyed water to Dundas, a stop-log hoisting system and nearby wells.

New plaques will also allow visitors to read about the area’s history and key role in Dundas’s early industrial development.

“It’s all good stuff,” she said.