What can I stop a leak in my basement floor with?

It started leaking for the first time with that big flood we had back last May and has done it twice since, but only when its a really heavy rain. there are two slabs poored to make the basement floor. In the seem that goes down the middle of the floor there are 2 or 3 small spots (smaller than a pencil) that seaps water when the ground is very saturated. Is there some sort of an epoxy that would be good to seal this with?