Environment Priority in Construction

ENVIRONMENT A PRIORITY IN CONSTRUCTION

Wednesday, September 05, 2007 (Napanee Beaver)

Friday, September 07, 2007 (Picton Gazette)

A few weeks ago, I was asked by a construction company to undertake a site visit along Highway 41, north of Bon Echo Provincial Park, to check for the presence of any late nesting birds in the areas where they were about to work. I have done several such site visits in the past when bird issues have been encountered, and I continue to be impressed with the regard these companies have for the environment.

A bridge project over the 401, north of Brighton last year, for example, ground to a halt, when a construction worker noted the presence of a small bird swooping around an area where they were about to start construction. As workers leaned on their jack hammers, I peered into a small conduit in the concrete supports under the bridge, and as one worker shone his flashlight inside, up popped several small heads, mouths agape, almost a metre back inside. A pair of rough-winged swallows had decided that the deep man-made cavity was as good as anything they could possibly excavate. Ready-made hole, sound construction, shelter from the sun. So why not live here? Judging by their size, it would only be about 10 days before the young would fledge, so the workers were advised to put up a temporary snow fence to keep any scheduled work a reasonable distance away from the nest site as it was clear that the birds didn’t really mind the noise of construction equipment. As workers gathered around to take their turns peering into the cavity, the feeling of compassion and concern for this single pair of nesting birds was more than what many of us might expect from burly operators of construction equipment.

During the few times each year I exchange my Tilley hat for a hard hat and don my steel toed boots and safety vest, I can’t help but be moved by the genuine concern that those involved in construction have for the flora and fauna they may encounter. At the Salmon River project a couple of years ago, the total re-building of the 401 bridge over the river involved building two access roads, each two kilometres in length on either side of the highway, leading from Wyman’s Road. Both areas, from the edge of the highway to the fences, had to be carefully surveyed for any significant species of flora or fauna. I couldn’t imagine anything tolerating the traffic noise and fumes from the 401 long enough to nest in roadside bushes, and as might be expected, we found nothing. However, we did find a large patch of side oats grama, a rare prairie plant that seems to thrive well on alvars, and this site was part of the Napanee Alvar. The access road near its entrance was thoughtfully re-routed to avoid this patch.

The big concern though were the barn swallows who have traditionally nested in loose colonies under the bridge structure. And when April rolled around that year, they showed limited interest in wanting to nest elsewhere. With portions of the bridge being dismantled to make way for new decking, and the overall structure widened, it was important that the swallows be encouraged to take their household duties elsewhere, at least until after the new structure was completed. Considerable work and expense went into modifying the underside of the bridge to make it less attractive to barn swallows wanting to nest. And that was no easy task as we found, for even the end of a tiny bolt protruding through the structure somewhere was often enough to provide the necessary support for a barn swallow’s mud nest. And they build fast we soon found out. Although I performed the regular monitoring and critiqued the modifications, if it wasn’t for the interest the construction company workers and MTO took in the presence of the barn swallows and their constant monitoring during my absence, the massive project might have ground to a halt due to contravention of the Migratory Birds Act had the birds succeeded in their nesting efforts.

With the Salmon River directly below the bridge, there were obviously other environmental concerns as well that had to be addressed, mainly with debris from the bridge falling into the water, adversely disrupting fish habitat. Considerable expense and time went into modifying the structure beneath the decking to contain the debris. Lumber was cut and allowed to rest on the bottom flanges of the steel girders, essentially creating a flush undersurface which also served to deter the swallows from nesting. On top of that, plastic was placed with the added protection of geo-textile. Below the decking, any nooks and crannies and cubby-holes were all covered with chicken wire and fastened to the concrete. The entire under surface of the structure from one and to the other, and across its entire width, was modified in this fashion.

This project was truly an eye opener for me considering all the environmental implications. A fisheries biologist was on hand almost daily to monitor efforts in preventing any silt or debris from entering the watercourse. Imagine if you will, dismantling a concrete structure, over a river, jack hammering old concrete, pouring new concrete, at the same time causing minimal disruption in traffic flow, and engineering it in such a way that not one piece of debris could fall into the water.

At a time when some many of us are quick to wince, and then worry about habitat destruction whenever we see yet another construction project in progress, engineers and constructions workers, and other contributing agencies should be applauded when neither time nor expense are spared in many of these projects that take place in sensitive areas.