What do you do if you found an underground spring when you removed your old liner preparing to install a new one in your inground pool?

Answer 1

I have a similar problem and am working with my installation engineer to find a solution. There is no good or universal answer.

The principle to the solution is straightforward: the incoming water must be captured and sent elsewhere at a rate greater than the rate of infiltration.

My builder has indicated that he has used a backhoe drill (like they use to install telephone poles) to make a hole next to the pool for a sump.

In my case, the problem is complicated by the presence of hard bedrock about 5 ft down in an 8.5 ft deep pool. Fortunately, the base under the deep end has gravel and sand that can act as a porous french drain. The trick is getting a drainage hole down there.

Plan A: What I wanted to do was drill an angled hole of about 6-10 inches diameter at an angle from outside the concrete decking. Well drilling companies won't touch the project - too busy, equipment too big, they like to drill straight down. A backhoe with a drilling attachment should work if an estension bit could be found. My rock is going to complicate Plan A and require a drill rig in the area that can go thru rock. (They exist, I just don't know if they have one in Northern Virginia.)

Plan B (The PIA plan): The backup plan is to use a backhoe to dig a 4 ft hole next to the decking. A section of concrete sewer pipe will be dropped into th hole vertically to shore up the walls while we remove the rock with a jackhammer down to about 12 ft. Then, we are going to use a handheld hammer drill to bore horizontal weep holes from the shaft into the gravel layer under the pool IF I can find extension bits to drill the 6 ft distance into the gravel.

Plan C: If all else fails, I drain the pool, take out the liner, and cut into the vermiculite bottom and side layers to install a sump well and discharge line. The trick would be to make the discharge big enough to I can change out the sump pump without draining the pool.