As has been posted already, the surface of the pipe is colder than the
dew point of the air in the basement. You can:

1) lower the dew point of the basement by either running a dehumidifier
in the basement or stopping moisture from getting into the air from
whatever souce of moisture there is in the basement.

2) Raise the surface temperature of the pipe.

3) Heat the basement, which will raise the temperature of the pipe
indirectly.

4) Insulate the pipe.

Hope this helps.

Stretch