I'm considering replacing my air to air heat pump with a geothermal system. any advice? stray thoughts? drilling a well to tap water source (our community water well is over 280 ft deep near the bottom of the Devonian strata---just above the Silurian--- some winters, I can smell the hydrogen sulfide of the silurian ---Would I need to go this deep to assure a continuous supply of water? vs coils buried in the ground ( I have the space) federal tax credits of 30%, state of 6% What would you do ?