Perhaps the plumber then went to lunch and forgot to come back and cap the drain pipe. In any case, someone should install a cap now, before a backup causes sewage to flood the crawlspace.

A Sirius problem?

A few things are wrong here. The most obvious is the plumbing vent pipe that supports a satellite dish. Our plumbing code calls this “flagpoling” and prohibits it outright. Plumbing vents shouldn’t support any other objects, including television aerials, satellite dishes, and, of course, flagpoles. Flagpoling can cause the horizontal portion of the vent (in the attic) to sag and hold water. It could also cause the vent to break and admit sewer gas, or even water, into the attic.

At the right side of the photo, trying to hide near the edge of the frame, the B-vent is very badly rusted. This vent carries exhaust from a furnace and/or water heater through the roof. When they get this badly rusted, B-vents can develop holes and leak. It’s time to replace this one.