Cap off a water line from well
Just recently had a mobile home removed and the water supply line had a shut-off valve on it and was shut off, but water came out when I opened valve. It was sticking up about 2 1/2 feet above ground. Called a plumber to cut it back and cap it off. He had a hard time with it and couldn't get it to stop leaking. It is black 3/4" pipe (marking on pipe says Hylan 100 psi 3/4").
Problem is after inserting a threaded adapter and screwing on metal cap, the clamps wouldn't tighten because the pipe was so hard, it was hard as a bone. He tried heating up the pipe to get get some flexibility into it so clamps would tighten, but no success. He was going to try to find something that would work better, but haven't heard from him yet, he was supposed to come today, but guess he got busy with other calls. Leak is not bad, maybe 15 drips per minute, which is probably 2-3 gallons a day, but it is tied into a well. Line from well runs to house and line to mobile home tied into it somewhere next to house.
Any idea what kind of pipe it is, plumber said it wasn't used anymore and it's next to impossible to find fittings for it. I would like to dig it back toward house and cap it off. Any ideas/suggestions are greatly appreciated.