TOPIC: Disposal Trap

I know the S-Trap is wrong. And none of the plumbing in the brand new house is vented. Does anyone know if the disposal can be trapped? It seems I remember seeing/hearing you cannot trap a disposal?

I would note the pictured plumbing as the following:

improper double trap(s) noted. Fixtures must not be double-trapped because of the unnecessary additional restriction of flow and the increased potential for stoppages.  Double-trapping can cause air to be trapped between the two trap seals, and the ?air-bound? drain will block flow.

improper trap noted. The S - trap is an unvented trap. They can lose their water seals, permitting sewer gases to escape into the home. Recommend is replacing with a vented P - trap.

Here is an illustration. You can crop it to make it look better.

No vents either you say?, new house? May be able to use an air admittance valve.

You are right seems all wrong.

Thank you Dave. I do have pre-loaded comments about S-Traps in my Report Software, but I think I like yours better. I inspected one Monday that did use the AAV, but I still don't think it's proper to use it on a main 3" sewer pipe in the crawlspace? I would imagine a kitchen/bar island would be one place it would be acceptable.

Here in San Diego County, there are some subdivisions that use nothing but AAV. I have found them in walls with a grill cover under the sink for access. I am guessing that some one figured out that it causes less trouble then leaking vent jacks on a tile roof.  The s traps though are a red flag.