Water Spot on Front Porch Cement
What would be the possible cause of water spots coming through in basically circles on my front porch? There is a stress crack around it, so could this be from it being wet outside or would I be unfortunate in having an underground leak? This is on my front porch only and it is usually dry and grey during non-rainy times and I don't see any reason that there would be any plumbing pipes run under my front porch for it to be a leak. I have a well so I can't tell if there is a leak from a water bill because I don't get those. Please Help!!!