Teamwork Keeps Quarry Alive

The names Lafarge Canada Inc. and Ducks Unlimited don’t look right together in the same sentence but when put in context with the expansion of Lafarge’s limestone quarry and plant near Brookfield, NS, there’s no question the two organizations belong on the same page.

In fact, long before the mining industry and wildlife organizations started bumping heads over the use and abuse of mining lands and wetlands, (especially after the recent Oil Sands disaster involving the death of more than 1500 ducks in a tailings pond near Fort McMurray) Lafarge and Ducks Unlimited were working together to help ensure that the planned expansion of the Brookfield quarry would be beneficial to the environment and its inhabitants, namely birds and other waterfowl.

The quarry and plant have been on the site in Colchester County since 1965 and have a production capacity of 500,000 tonnes of cement per year, but on average it produces about 300 kT per year.

Associated with the plant facility is the open-pit quarry mentioned earlier where calcium-rich limestone is mined. After being crushed, the limestone is conveyed to the cement plant where it is calcined in two long-dry kilns to produce an intermediate product called clinker, which is then ground with gypsum and additional limestone to produce cement. Since opening the quarry, several million tonnes of overburden have been excavated and placed in a manner that encourages wildlife habitation. By including a mix of features such as gently rolling hills and native grasses, a wildlife friendly area has been created adjacent to the active quarry.

Increasing demand for cement over the years resulted in the quarry reaching the end of its limestone deposit to the south and west of the property, forcing Lafarge to focus on stone to the east and north.

To advance, however, meant diverting a number of waterways adjacent to the property. It took many planning and working meetings with the provincial Department of the Environment as well as the Federal Department of Fisheries and Oceans before getting approvals but once in place, Lafarge immediately started working with Ducks Unlimited to design and build the diversion channels around the quarry to help develop a functional waterfowl habitat.

Knowing that the diversion channels would be part of the final site reclamation, Lafarge worked extensively to ensure they were built in a wildlife friendly manner. Also, Lafarge and Ducks Unlimited have signed a 30-year stewardship agreement to help ensure the channels and other Lafarge sponsored wetland projects remain an even better habitat than what the original brooks provided.

The building of the diversion channels involved two distinct watercourses adjacent to the quarry; Marsh Brook was diverted into a newly constructed perched channel on the west side of the quarry, and three years later Lake Brook was diverted into this perched channel. This perched channel flows into the lower end of Lake Brook which remains intact and eventually meets up with the Shubenacadie River.

The original Marsh Brook channel flowed from a pond west of the plant and was 500 m long. Its replacement, now 1.6 km long, was built by moving 2.3 million tonnes of waste material from one side of the quarry to the other. The new channel incorporates two new wetlands and two deep pools lined with river gravels to create fish habitat. The Lake Brook diversion channel is 520 m long and flows from Shortt’s Lake providing a route which is more suitable for the annual gaspereau migration to the lake than the original brook. Lafarge built two new ponds at the inlet of the channels to control potential flooding and also rebuilt an eastern dam and spillway at Shortt’s Lake. While working on the dam structure, Lafarge also installed a new fish pass for gaspereau to enter the lake, a feat that was virtually impossible until this fish pass was created.

The new Brooks were designed and built to create more fish habitat than was available previously. However the route of the new channels did not allow the inclusion of wetlands to compensate for those altered during the diversion so, they had to look beyond the Brookfield quarry to create and improve wetlands as compensation. Lafarge owned lands that were suitable for this, which were located just minutes from the nearby village centre. To maximize the value of these wetlands, Lafarge and DU worked together to incorporate walking trails enabling locals to get close to the wetlands and the wildlife that call them home. This has been a resounding success, with many people using them, including local residents and people visiting the area from afar.

As already mentioned, accessing the remaining limestone reserves on the Lafarge properties involved a great deal of quarry development planning and it’s estimated that the re-routing and new alignments of the adjacent channels will permit the extraction of additional limestone for about 30 years of continued quarrying and cement manufacturing at Brookfield.

The Lafarge quarry and cement manufacturing facilities have operated in the Brookfield area since the mid 1960s and through these recent efforts to reach its remaining limestone resources; it looks as if the company is planning to stay a while longer.