Waterproofing/Sealing my Basement Walls.?

I recommend sealing the inside walls with Dryloc, especially if you're going finish your basement. Also, you have a sump pump? It will be helpful to make sure the ground is graded for water runoff away from the house.

I've used dryloc for my friend's basement that had leaks in the walls. I used hydraulic cement to patch the leaks first then painted the walls with Dryloc, (purchased from Home Depot, but available at Lowes or home centers and hardware or paint stores). It's been a year now without any leaks. Good stuff. If yours is dry now then it won't be much trouble.

She has a high water table in her area too.

The alternative for her was to reseal the outside of the walls but excavating is very costly to have a contractor to do the work.

I would bet your basement is sealed, but It never hurts to check, and you would only need to dig down a foot or so to see if it is. I think the old stuff was Black not blue. Also, it is always a good idea when finishing the basement to add an interior sealer. It just paints on, and if the walls ever do leak from the outside, the inner seal will still protect your house. Another good idea is a floor drain if one doesn't already exist.

If the only moisture is on the wall then you can likely stop the problem by applying a coat of Thompsons water sealer. You can find it at any home improvement store such as Home Depot or Lowes. The source of the moisture should be dealt with as well. Likely source would be leaking gutter or downspout. If you have moisture on the floor you will probably need to install a french drain inside the wall to carry the moisture out of the basement.

You would go with American Dry Basement Systems which has provided all types of waterproofing solutions.