CAT5 or 6 is gross overkill. Telcos use "CAT Nothing" cable for drop wires to houses every day. Your circuit goes many more miles over "CAT Nothing" cable before it reaches from the pole to the central office. I assure you that at&t is not going to run CAT5 cable of any sort, in fact I seriously doubt that they even stock it. All that is required for your service drop is "B" service wire, usually in five pair construction.

The only way that water in a conduit will cause ring trip is if the cable itself is nicked or otherwise damaged. Cable, even indoor-rated won't cause ring trip even if it is in a conduit full of water. Of course, indoor cable won't last very long in this environment.

If you wish to place the cable in PVC conduit, that's great, but not necessary. I do have to ask one question though: It's the telephone company's responsibility to deliver service to your physical address, not to the pole at the street. Why aren't you making them handle this replacement?

Ed Vaughn, MBSWWYPBX