I am planning my sustainable homestead. In the planning I am incorporating humanure and grey-water recycling, as well as rain water irrigation. But I will need a source of fresh water for drinking and supplementing the recycled water supply.
What sustainability concerns should I be considering when I am planning my well?
I've answered about the impact of drilling a well on water table, which is the most important aspect.
But your question includes also an aspect of water quality. These two aspects are sometimes contradicting each other. If the water source is plentiful, one well should be enough. Otherwise, consider two wells:
The wells should be far enough from each other so that the lower one wouldn't significantly drain the one above. This can be avoided by deeper drilling.
And both wells should be used regularly to prevent 'clogging'. It can take some time until the underground water makes its path to supplement the water requirements of the well. When the well isn't used for certain time, those paths can detoriate.
If it's possible, build a tank or a retention basin to keep the rain water for irrigation. It's the most sustainable way of using the rain water.
Even if it could seem as a good idea I wouldn't join the retention pond with the well. Mixing the surface water with underground water can pollute the underground water.
There are many considerations for building a well concerning water quality. But sustainability wise refill rate seems like the most important concern. If your region is pretty dry and has a low water table then drilling a well may cause damage to the groundwater system. However, I think it is unlikely that a single well will have any negative impact, unless you plan on using a large amount of water for a swimming pool or something like that. I think checking with the municipality might be a decent place to start.
