buried wood bed / sunken hugelbed near shallow dug well

I'm at the point in my project where the filling of the big dig has begun, and one of the questions I had was about the use of animal bedding in the fill with a shallow dug well very close to the site.   We only have an acre, and with the lay of the land, the position of the house and septic, and the availability of sun exposure the only good place to dig the pit for the bed was within about 40 feet of our well. It's a dug well about 15 feet deep that refills almost instantly and is in very sandy/silty soil.  The well can't be dug deeper by easy means as the constant flow of water at that depth causes any hole sot just fill in as you dig them, and we don't have the money to bring in a professional outfit with serious equipment.  And we seem to be tapped into the same water source as the public spring people use that's not far from our house as the water level in the well never drops even after hours of heavy use in the driest weather.

The question I was curious about is the possibility of contaminating my well with what goes into the pit.  The pit is about the size of an in-ground swimming pool, about four to five feet deep, and the sides are being supported by vertical sections of fresh cut logs since the sandy soil doesn't like to stay in place with heavy rains.  Most of the fill to this point has been leaves, plant waste, part-finished compost, and lots of chunks of wood from green to very rotted and full of fungus.  I did just add a layer of the winter's bedding from a chicken and sheep pen, and I have the option of adding several truckloads of horse bedding (mixed wood chips, sawdust, hay, and horse stuff).  Originally I thought about adding the horse stuff to the pit too, but fear of contamination has me leaning toward composting that separately in piles back away from the well as I did last year.  In piles, I can turn it frequently and have finished compost by fall, while I'm afraid that in the thick pile of stuff in the pit it would take much longer to break down and be a possible source of trouble for the well.

Has anyone had any issues with well contamination along these lines or am I over-thinking again?

Maybe I missed it in your post, but is your pit on lower ground than your bottom source of your well? If not, then there might be some seepage into your well.

It might be best not to risk contamination of your well can compost your "riskyer" items as far away and downhill from your well.

With a well not very deep, I suggest that you test your water regularly either way to be sure that it is safe to drink.  

the only good place to dig the pit for the bed was within about 40 feet of our well. It's a dug well about 15 feet deep that refills almost instantly and is in very sandy/silty soil.  The well can't be dug deeper by easy means as the constant flow of water at that depth causes any hole sot just fill in as you dig them, and we don't have the money to bring in a professional outfit with serious equipment.  And we seem to be tapped into the same water source as the public spring people use that's not far from our house as the water level in the well never drops even after hours of heavy use in the driest weather.

I would like to caution you about using anything that is not biologically safe in this situation.

It is never wise to play biological roulette, with the sandy substrate there will not be enough filtering to fully capture any pathogens that might be in the materials you use to fill the "pool" bed.
I don't consider taking risks of this nature as a wise decision, since it may affect others.

Do consider your statement about the fact that others use the same water source.

In the event that some one did get sick, and it was determined to be from that water, it will be tested and if found to be the source of contaminate origin, well, you get the implication I hope.
You are inviting legal actions since you mention this water source is or may be part of a publicly used spring, any pathogens that could infect others would most likely be of the type that can be traced back to your property.

Redhawk

That's something I hadn't thought of, surprisingly since I tend to err on the side of too much caution.  I suspect that most of the reasons we have occasional positive coliform results from the well is that we are downstream and downhill from the true source that our well, and probably the spring pipe, are being fed by.  There is also a small stream not far away, maybe 50-75 yards or so, that drains past some less than pristine properties and at least one small farm.   I wonder if the spring ever gets tested for coliforms or other contamination, or if it's one of those "use at your own risk" situations.  Either way, you're absolutely right and I want nothing to do with any potential problems.  I'll stick with the basics in the pit and leave the horse stall stuff for the compost piles, which sit next to our septic field on the other side of the property and stick with fast composting that.   Thanks for the "second set of eyes", sometimes that's the best way to figure out the best path.