The problem with the drain tile configuration you have is that it will rely on gravity to discharge the collected water into the storm sewer system, if the pitch isn't just right towards storm drain, water accumulates in the pipe and finds it is way into the basement all over again.
I also agree with mudmixer on that the weeping tile should run all around the perimeter of the foundation, not only the 3 walls. As it turns out, water is a pretty tricky element. If not properly dealt with it will find or dig its way back into your basement.
In addition, because the tile does not drain into the day light or a sump pump in a way that you can measure its effectiveness, probably the only way to check it would be digging out a part of the discharge line.
The truth here is: the system is faulty. Period. Otherwise the water wouldn't be in your basement. And you have two options to fix it:
- Dig the whole thing out, again, and fix the pitch (or whatever it is that is wrong with it). And I sure hope that the contractor who installed this system gave you a decent warranty on it, otherwise count on spending just about the same amount you spent the first time.
- Install an interior drain tile system, along the internal perimeter of your basement walls, with a sump pump system.
I would strongly suggest you go for the second option for a number of reasons:
- It works just as well as, or better than, weeping tiles when properly installed. Interior drainage systems have been used successfully for over 20 years to control basement leakages.
- It costs 50% less than digging out your weeping tiles.
- The installation is much quicker and less disruptive. (it usually consists in jack hammering a few inches of the slab, close to the wall, laying drain tiles over a bed of gravel, link it to a sump pump, and patching the slab.
- These systems, unlike conventional weeping tiles, are serviceable throughout the years, which is why reputable companies back them up with a Transferable Lifetime Warranty.