Author Topic: Sandpoint well vs pumping lake water?  (Read 994 times)

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Offline Farthig

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Sandpoint well vs pumping lake water?
« on: April 19, 2017, 07:50:08 PM »
Hello!

My wife and I will be building a new cottage on a lake, and need to determine out best option for sourcing water. This is quite probably discussed elsewhere here, however in that I know absolutely nothing about the subject, I'm probably not searching for the right terms. Hence, if someone can point me to any articles or posts that do discuss this already, please let me know.

Our initial assumption was that we would pump water from the lake (as many of the other property owners on the lake do currently). The cottage will be about 19.5m (~65') from the top of the beach; the lake is quite shallow in front of the property; there is, in fact, something of a sandbar in front of our property. This is relevant as the cottage is in rural Quebec, and we wish to make the property four-season. Hence, whatever pipe we run to the lake will need to run out far enough into to be at a point that is beneath the winter freeze depth. In other words, the hose will probably need to be very long.

Someone has more recently mentioned that we might want to consider a sandpoint/driven well. According to our neighbour, whose property is roughly the same distance from the water line, he routinely gets a few inches of water in his 4' crawlspace basement in the Spring. This, I assume, means that the water table is not very deep.

What we're trying to find is some kind of pro/con list comparing these two options. My uneducated guess is that the sandpoint would be probably considerably less expensive (no heated pipe heading way out into the lake). What I don't know is the disadvantage of the sandpoint well. The articles that I have found talk about the easy contamination due to shallowness, but if we're comparing against drawing lake water, then that argument is no longer relevant: we would probably be looking at a UV purification system (or comparable solution) either way.

Any thoughts or tips would be most welcome!

Cheers.

Offline ChugiakTinkerer

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Re: Sandpoint well vs pumping lake water?
« Reply #1 on: April 19, 2017, 08:33:38 PM »
Welcome to the forum!

I'm a newbie on the topic but I have read about it on the internet, so... I must be an expert!   ???

Sand points can be really straightforward and economical in the right environment.  If you have a lot of rocks in the upper sediments then it may make it too difficult to drive the point.  In sand and finer gravel they are reportedly a joy.

Your neighbor's water is probably the result of snow melt.  The water table may be much deeper, perhaps even lake level.

If you have some time and ~$500 to invest you can go ahead and try driving a sand point.  Just don't plan on recovering any of those costs if it doesn't work.  For my place I'm planning on hauling water from the lake in a barrel using an ATV.  I am on a hill about the same height as yours and the logistics of pumping approx 800' distance seems too much for me to consider right now.
My cabin build thread: Alaskan remote 16x28 1.5 story

Offline hpinson

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Re: Sandpoint well vs pumping lake water?
« Reply #2 on: April 19, 2017, 08:52:34 PM »
The problem I have with sandpoint wells is that don't have much capacity beyond what you can draw immediately.  Yes contamination can be a problem but a good sandy aquifer to some extent mitigates (though contaminants can also travel farther) - just keep well away from you or your neighbors outhouse or septage pit.

The recharge rate not a problem with a lake feed, or a well drilled with some capacity that has a decent recharge rate.

I think you might want to try and determine depth to water table and recharge rate.  You can make an educated guess at this by looking for other similar wells in the area. Any of you neighbors have a well?  Ask them about depth to water table and recharge rate.

What kind of material is between you and the water table? If it is completely sand it is likely that your water table is similar to lake level, and then you would want to calculate the rise between lake and your cabin and if sand your recharge at least has the potential of being good. Soil and rock complicates.

Some negatives about pulling water from a lake are potential contamination, length and rise of run, line diameter in regards to friction, line maintenance, blockage of the intake, freezing of the intake, and potential legal restrictions on such a water source down the road. Any of those may or may not be a problem depending on water quality (test), the physical characteristics of your site, design, and building/ environmental regulations. I'm guessing Quebec has some pretty specific regulations of lake water feeds.

If the distance from ground to water table is minimal (10 to 75 feet), and the material below you is sand, have you considered just bringing in a driller and setting a shallow cased well, i.e. enough below water table to give you some pumping capacity?  Pumping from 50 feet can even be done with a hand pump, keeping costs way down.

« Last Edit: April 19, 2017, 09:06:36 PM by hpinson »

Offline paul s

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Re: Sandpoint well vs pumping lake water?
« Reply #3 on: May 15, 2017, 03:00:10 PM »
have done all of the above over the years

eventually you are likely to have contamination and even a drought.

i would do the following

with a back how did as far down as you can ith about a 20 ft dia circle

15. down is nice deaper is better

lay dow n a 4 to 6 inch layer of crushed rock 3/4 in in dia and about 10 ft in dia

begin stacking 3' long cement tiles  24 inches in dia one on top of the other in the center of the stone

gently back fill with sand and gravel until you are back to the orginal grade, this fill is typically from the excavation put down 6 inches of topsoil and plant a good local grass

this is your well

install pump and line to house

if there is not enough water in the well during the summer or dry times install sprinlkes over the 20 ft diameter and pump water from the lake and water the area
 well willget narually filtered water and will have plenty of  water

 i did this on lake ontario at port bay in wollcott ny
 kept a family of 6 going all the time
  be 100 ft from any septic system ateast