I'm a "newbie". I'm about two weeks away from contracting for the installation of a GSHP. I have a large lot but it is heavily treed, so vertical wells make the most sense. I've also decided that I prefer the closed loop system to an open loop "pump and dump. From the IGSHPA web site I gather that it is possible to install closed verticle loops in a column of standing water providing the rock and water levels make sense. (Based on a well I drilled five years ago, my site has 17' of overburen and a static water level of 5') . I'm thinking that a closed loop pipe in water will be less expensive to install (no grout) and will conduct heat from the pipes to the surrounding rock as well if not better than grout. My HVAC contractor is certified and has installed a dozen systems but they were all trench type systems. The rep. from the State water management department acknowledged the possibility of installing a standing column system (with 20' of grout to cap the well) but was pushing for a fully grouted well. The well driller is insisting on a fully grouted well. My question is 1. Can a system be installed in standing water and 2. is it more or less efficient than if I filled the same wells with Bentonite grout?