We bought a house from the local coal furnace installer / store owner, so it has a fairly elaborate system for radiant floor heating and domestic hot water. We added a wood stove in the living area to add redundancy and supplement the coal heat. The coal supplier is less than 1/2 mile away, so we have easy access to our supply of coal.
I am wondering about using the bottom ash. There is talk online about the components of the ash including arsenic. However, the conversations I find are typically geared to large scale use (power plants etc). I would like to find a way to productively use the ash or manage it in such a way that it won't do any harm. Currently we empty the ash as the previous owner did, which is to maintain the parking area behind the shop and I use it to create access to gates to the winter livestock fence etc.
Does anyone have a suggestion on how to handle the ash? Geoff Lawton talks about neutral soils not picking up heavy metals. Also, could a water element with a reed bed or an element with fast growth trees on the downslope side of the parking area capture any of the heavy metals that may get into the soil?