My supply line comes into our house into the finished room in the basement, Goes into the meter. Then it goes up vertically and then splits, one goes to an outside spigot, and the other goes to a house water filter and then to the house plumbing.
If noticied lately that then is water dripping from the pipe and water filter, I tightened the filter, and wiped down the pipes. It seems to be related to how much laundry (washing) we are doing. At least that is when I noticied it first, was X-mas, when the kids got a lot of clothes. We did about 15 loads of laundry for two days. Could it be from the constant running of water into the washer, and the room being heated???
I use to have insulated pipe wrap on most of that section, but that got all wet so I took some of the wet part down.