|This is a picture of a garbage disposal
under a kitchen sink, whoever hooked this drain
line up used two traps instead of just tying
into to the trap that was already there.
Every plumbing fixture
requires a trap
Hooking up two traps like this could cause a siphon that will cause the water to be sucked out of both traps, allowing sewer gases to go into the home. A real plumbing contractor would have never hooked the garbage disposal this way.