I want to use my 30 gal/min flowing well for an open loop geothermal system but my township has an ordinance against open loop systems with no appeal. The well currently flows into a large tank and then overflows down to a creek. Would it be practical to build a heat exchanger that I could put in a tank and thereby have a closed loop for the township but still use my well? The heat exchanger would have 30 gallons of 53 deg. F. relatively low mineral content water flowing accross it per minute. I have no room for a pond or horizontal loop field. A local contractor sized the house for a 5 ton Waterfurnace NDV064A with an open loop system but that's not an option now.