At first glance WaterFurnace looked like any other geothermal HVAC fabricator-installer. Then we saw how they integrated natural lakes (per the Ontario dealer install photo above) or stormwater detention or retention ponds into the design, routing fluid exchange tubes through walkways entroute to the surface water, so averting the need to salt and sand, and we realized that there was some serious green design genius in play. Using the zoning code-mandated stormwater systems for energy storage, their cost for incremental HVAC gains are very low. Now that's piggybacking at its best. From the website: "FORT WAYNE, IN-- WaterFurnace International, Inc. one of the nation's leading manufacturers of geothermal and water source heat pumps, announced today the unveiling of its new EnvisionTM Series product line, now available through its dealer network. The new Envision product holds the distinction of having the highest heating & cooling efficiency of any product certified by the Air Conditioning & Refrigeration Institute in category 13256-1 (GLHP)".
Because WaterFurnace offers multiple configurations for several markets, understanding this fully takes some study. We suggest you try a Google Image Search to help envision the applications. Also, see explanation of stormwater terminology below.
Via: Sustainable Industries Journal (Subscription Only).
Stormwater may be held on-site in three basic configurations:
A "detention" basin fills up during the storm and lets out the water slowly thereafter, draining contents completely, via outlet structures and via infiltration, within a few hours or days. This would not be useful for WaterFurnace application.
A "retention" basin keeps the storm water in for longer periods: losses are through evapo-transpiration and groundwater infiltration. Would work for WaterFurnace where year round precipitation/runoff balances, but attracts nuisance geese, may support algae blooms, and must be fenced to keep kids out.
A hybrid Detain/Retain approach is a possible compromise. Ask the dealer.
Covered cistern type retention basins are increasingly used for on-lot residential applications. This solves the nuisance problems and might work for WaterFurnace as well. Ask the dealer.
Natural waterway use would require permits and justifiably so.
Septic systems? Maybe, depending on zoning and permitting requirements.