Building proximity to a well
Trevor_Lambert
| Posted in Green Building Techniques on
I will be adding a shed to my property, and need to get the ground prepared (levelled and top soil removed) while the landscaper is doing the final house grading. For various reasons, I’d like to put it near our well. Is there a minimum setback for this kind of thing? The shed will be something like 14×18, probably on a slab but maybe just 2″ patio stones, occasionally having a car parked on it. The well is a 30″ bore, about 50′ deep. I’m just not sure whether placing a large weight beside it will impose some kind of lateral load to the soil down below.
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Replies
A 30” diameter well is BIG. Is this an old school stone-lined well? If that’s the case, I’d be a little concerned about your building putting pressure on the surrounding ground that might collapse the well. You’d need to know soil composition and some other things and would want to contact a local engineer for that.
You local building department is probably the best source of info for any particular separation requirements. In my area, water wells are regulated at the state and county levels. I’d check with your local city/township first, county next. They should be able to get you the info you need.
Bill
Where I live, new buildings can be no closer than 50' to an existing well, and new wells can be no closer than 50' to an existing building.
I think there are two distinct issues that we shouldn't conflate.
One is whatever restrictions local authorities put on the proximity of building to wells - which vary widely. Ours places none on buildings, the only setbacks are to sewage disposal fields.
The second is whether any construction activity in close proximity to the well might do damage. That's certainly a concern, but probably one that can only be assessed on site.
I think Bill had given good suggestions to address both issues
It's a corrugated fibreglass well casing, installed 2008. According to the build record, solid from +2 to 7 feet and 49-50 feet, screened from 7-25'. That implies nothing between 25-49 feet; does that seem right?
I've got a call into the building inspector now.
I’m not familiar with that type of well construction, assuming this is a water well. In my area, well casings are either steel or PVC, usually either 4” or 5” casings. Screening is usually in the bottom part of the well since wells draw from the bottom of the casing.
Sediment reports usually are read as “we saw blabla1 soil composition STARTING AT x footage, CONTINUING until we found blabla2 composition at y footage, CONTINUING until we found blabla3 composition at z footage” etc. You read it as continuing with the prior soil/sediment composition until they give an update to something else at a new, deeper footage. They basically record what their drill brings up as they go down. This info is used by govt people to get an idea of the sedimentary layers underground.
Old records can be, shall we say, interesting. My well went in before there were addresses, so the records read something like “well drilled for bob past the turn by the pond” all handwritten. The depth reports were a little freeform. Your well records are probably going to be on more standardized forms, but it depends on the state.
I’d ask your building dept people about your well construction if you are unsure. They should be familiar with whatever the standard conventions are in your area and will be able to explain it to you.
Bill
It says brown sand to 4', grey sand to 7' and blue clay to 50'. Also says they used 2500lbs of Benseal slurry for sealant down to 10', and 50 tons of packed gravel from 10-50'. Maybe I'll try calling the drilling company, as I don't hold out much hope the building department is going to know anything beyond what their regulations say.
Benseal is probably a bentonite slurry. It’s a clay that’s commonly used as a grout for underground work.
The drilling company will probably be your best bet for good info as to what they did.
Bill