I'm renovating my basement and adding a toilet, shower and sink. Tore up concrete and dug around cast iron stack and drain pipes to be replaced and I'm noticing a bit of water pooling up around the pipes. Wondering if I was too rough with the shovel? Or is it just groundwater? I actually sopped the water up with a towel so it was bone dry and two hours later the water is back. Any thoughts?

Also there is a second pipe I found that I have no idea what it's for maybe a stormdrain? I wasn't going to worry about it and just put my drains over it but maybe it is leaking?

You have to figure out where and what is leaking and fix it. At least you tore the floor up and found it, not found a water problem and had to tear the floor up. I know I would be replacing drains like that if I was going to be covering it with concrete INSIDE my house.

Likely ground water. Try shutting off your main tonight and don't flush any toilets. Dry he area and see if it wet tomorrow morning. How much below grade is your basement floor and do you know much about the water table in your area?

Agree with Ballenberg: most likely it is ground water.

Wow, in our area I don't see water tables like that! That's why I jumped right to the leaking pipe. If your water table is that high and you don't have a good vapor barrier under the concrete, you probably have a damp basement. Still, definitely make CERTAIN that the pipes are sound and good enough for a long time before you repour that concrete.

Water tables are pretty funky. My basement sits 6.5' down below grade and then the concrete floor and gravel take another foot. 9 months a year the table is at 8-9' so my sumps runs everyday but not long. All depends on where you live and how your land sits.

Thanks for your quick replies. In all honesty it could be either broken pipe or ground water. I know there are some people who need sump pumps who live closer to lake ontario, I'm probably at the highest point and furthest from any body of water in Toronto. Also, a little more info, some water is pooling up 8 inches higher than the rest and 4.5 feet away from the drain as depicted in picture.
Also a little concerned that if there is a leak, it may be coming from what I think is the eaves drain which runs parallel to the main drain. Wasn't going to replace that one. If it is a broken pipe, fine, I'm replacing the exposed main drain anyway, but what do I do if it's ground water?
But in the way of diagnostic, let me reiterate what I think you'd have me do: turn off the main supply, dry out the drain, dry the water pools, and see if the water returns and if it is it's groundwater?

Forgot to mention also, there's never been a problem with dampness in this basement until I started working on it, and this is the last of the 50 year old identical houses on the street to get a finished basement with dugout floor for bath. Might lend itself toward the broken pipe.

If that one pool of water is HIGHER than the pipes then it could be a high water table. It also could be that a drain OR supply (if any are below that concrete) that is broken somewhere else under the slab. Your understanding of what to do to try and isolate the problems is fine. Hope you can find it without too much aggravation.

EPM

Went to a plumbing supply store and picked up some dye to put down the drain. The eco-friendly stuff sure is expensive. No leaks though. I've settled on ground water as the reason. So, I'm diving into the abyss today. Thanks for your tips.