During a recent home inspection in Sacramento, a mystery was identified. For two years, the homeowners thought that they smelled sewer gas.

When the wind blew, there was no smell as the air circulation under the house dissipated the strong odor.  On calm days, the odor was strongest under the hall bathroom... like from a giant litter box.

The photo shows a crack in a Wye fitting (whitish area), not the waste line pipe. The material is ABS pipe a black rigid, non-pressurized plastic pipe used to drain sinks, bathtubs, showers, and toilets.  It’s a tough material that will last a long time if properly installed.