Water Under Foundation - Is it pool water?

Mar 5, 2018
7
0
dallas
#1
My neighbor, who also has a pool found water under her foundation last week when construction people were adding pillars to her foundation.

To the best of my knowledge I didn't and don't have a leak.

I just completed a 24hr bucket test and did not see any difference between the inside / outside water lines.

I did test the water under her foundation and the Salt reading was about 490 PPM. (Her pool is Chlorine and measure 690 PPM and my pool is salt and at the time was measuring 2900 PPM. Since then i've raised my pool to 3500 PPM).

We are trying to figure out where the leak is coming from.

Tap water from the garden hose was 70 PPM.

So we believe it is pool water due to the high salt content. Not sure if it is definitively from a Salt Pool (mine) or Chlorine Pool (hers) due to the salt reading from the water under her foundation at 490 PPM

She also did a bucket test and thought there was no leak in her pool.

But the water is coming from somewhere. It could be another neighbor's pool too but my pool is next to where the water was found under her foundation (could just be the low point, don't know

Questions

1) How can we tell if the water under her foundation is definitively pool water?
2) If it is pool water, how can we determine if it is from a salt or chlorine pool? How does one account for the water mixing with rainwater in the soil and all the dirt and minerals in the ground? The water under the foundation is a little dirty.
3) Any other ideas/suggestions on how to determine source/cause of water under neighbors foundation?

Thanks
 

Dirk

TFP Guide
Gold Supporter
Nov 13, 2017
4,375
0
Central California
#3
Turn off everything in each home. Every valve. Use the supply valves (stops), too, if they're not too old and still turn. Make sure nothing in the house is dripping. Turn off the water main, too (at the house, not at the street).

Then go out to your water meters and look for the flow indicator. It's usually an asterisks shape or a triangle. They're very sensitive. If the indicator is moving at all (watch it for a while if it's not obviously moving), you probably have an underground leak in the water main to the house.

How old are these houses? Water mains don't last forever. I just replaced a copper one that was about 30 years old. My brother's made it about 40 years. My mom's about 50.

Got gophers? A gopher tunnel can carry water from quite a distance, so theoretically the leak could be anywhere in the surrounding homes.
 

PoolGate

TFP Guide
Gold Supporter
Jun 7, 2017
2,436
0
Damascus, MD
#4
What are you using to test the salt level? The k-1766? Each drop from that is 200ppm and I believe the margin of error on any test is 400ppm.
 

riley00dog

Gold Supporter
Nov 14, 2017
2,207
0
Brisbane, Qld, Australia
#5
What I’d do... Find out who’s loosing the most pool water. Together, mark the water level in the skimmer box of both pools. Twenty four hours later, measure water loss. Since they’re in the next door to each other there shouldn’t be a huge difference in evaporation etc. Be sure to have the same conditions for each pool, such as cover off. I’d do it once with all equipment off, and again with equipment running to give better information.
 

Dirk

TFP Guide
Gold Supporter
Nov 13, 2017
4,375
0
Central California
#6
What I’d do... Find out who’s loosing the most pool water. Together, mark the water level in the skimmer box of both pools. Twenty four hours later, measure water loss. Since they’re in the next door to each other there shouldn’t be a huge difference in evaporation etc. Be sure to have the same conditions for each pool, such as cover off. I’d do it once with all equipment off, and again with equipment running to give better information.
Great idea. The pools would have to be close in temperature for that to work well, though. Different colored bottoms would affect results. No harm in trying it, though. Put a bucket in each pool while you're doing the leak/evaporation comparison, then you'll have four data points to consider. Read the directions again for the bucket test. And monitor how your neighbor does it. Not everybody does that test correctly. Time to tighten up your testing procedures to rule out testing/human error.

I think Allen's CYA test is the only meaningful chemical test. Dirt is both a filter and a contaminate. The testing you've been doing are clues, for sure, but I don't see how anything revealed beyond the presence of CYA would mean anything. And even the absence of CYA would not be 100% conclusive.

I like Allen's dye idea, if you're willing to dye your entire pool. But again, only the presence of the dye would be conclusive, not its absence.

A lot would depend on the type of soil we're talking about...

By the way, is the level of the water in the foundation area higher or lower than in either pool?

PS. Until you determine where the water is coming from, you're wearing gloves while handling it, yes? And rinsing your test gear very thoroughly? Get my drift?
 

danpik

TFP Guide
Jun 4, 2012
1,682
0
western NY
#8
What makes you/her suspect this anything other than normal ground water? (edit: Ok i see where it has salt) If I go to my brothers house and dig a 6" deep hole in his dirt floor basement, I will find water. Been like that since the house was built in 1905 (we assume). Never had problems unless we get a lot of rain then the level comes up a bit (2-3"). His neighbor actually has a hand driven well that he uses to water his garden. Bottom of the well is about 10'.