my contractor started digging yesterday and at about 7' he hit sand and dig down to about 15' and it was still sand. the bottom of the hole was filling with water. i think he is oging to dig down a bit into the sand and then pack clay back on top of it. can someone give me some insite on wether this sand is good or bad and also the relavance of the water filling up the hole. contractor says not to worry but im worried.

TZ,

It depends. If your area of Louisiana is as flat as mine, it's usually not good. If you have any high ground around you, the outlook is better. Occasionally you can have a pond that self fills to a usable depth.

If you have plenty of good, tacky red clay, it's possible to set it aside and tamp it on top of the sand and make a waterproof barrier. 6" or a foot won't do it. I think 18" is bare minimum, and 24" would be better. The clay needs to have the right moisture content to pack correctly. Tamping must be done carefully and thoroughly for it to hold water reliably.


Layering clay is a lot of extra work for the contractor, and cost for you. I hope the sand area isn't too big.

the place im digging is in a low spot that held water

you might end up w/ a really great groundwater table pond. this wouldnt be bad at all unless the water table drops too much in summer, but it does provide a constant source of fresh water.

If you do wind up with a water table or ground water pond as I did, you might want to put it in the lowest spot on the property possible, don't build up the banks any more than absolutely necessary and make it perpendicular to the slope as much as possible.