The recent post on the Geothermal conversion taking place on Bessborough Drive has proven to be one of the most popular in recent days. A return visit found work in full swing. Three holes have been bored 300 feet into the earth. The contractor, Four Seasons Geothermal of Mississauga, says it might have gone down 600 feet if the property had permitted a larger drill. But, three holes at the shallower depth will provide lots of heat in the winter to keep the home warm. The contractor also spoke of cost, and the time required to return one’s investment. At $15 per square foot, it may take ten years. But if the property is heated with electricity at present, the time to return the cost will be more like five or six years. Anyone can do the arithmetic to find an estimated cost of this conversion by multiplying the square footage of his house by 15.