York's 'Big Pipe' Problem

"The huge, gravity-fed sewer, which will stretch from the east side of Lake Simcoe to Lake Ontario, is being built to serve one of the fastest-growing regions in the country. With huge growth in York Region in recent years, the population is expected to almost double to 1.3 million by 2026. The existing system, which was built in the 1970s under Yonge St. and serves Vaughan, Markham, Richmond Hill, Aurora and Newmarket, is pretty much at capacity. A new twin sewer, under Leslie St., is needed to accommodate emerging subdivisons and industries north to Holland Landing. Rural communities like King City and Whitchurch-Stouffville will also hook in.To build the first phase of the 16th Ave. section, a tunnel had to be burrowed as deep as 50 metres into the ground to make way for the 2.7-metre-diameter concrete pipe — big enough to drive a car through. Millions of litres of groundwater had to be pumped out and discharged into streams and storm sewers so tunnelling could be done safely.Problems began surfacing early in 2002, when wells several kilometres from the site began to dry up. As work continued and millions more litres of water were sucked from aquifers — underground lakes and rivers — the area of impact spread. Within months, rural Markham residents living north of Major Mackenzie Dr. began complaining about well levels dropping dramatically and dirty water."