Is my washer drain unsafe?

[Joecoolaug]

Hi, I've been reading up on drainage systems, and I'm beginning to worry our washer drain is vented to our basement.
The washer drains directly to a large utility sink, which has a p-trap then drains to the house's main out line. However, just downstream of the p-trap (connecting to the drain in a wye) is what appears to be a standpipe open to air. There is no trap below it - it appears to vent directly from the sewer line.

I'm not especially familiar with plumbing, so I googled everything I could on the subject. I couldn't find anything that would explain this. Is my basement open to sewer fumes?

Thanks for the help.

 

[Geofd]

yes you are probably smelling sewer gas... it should be connected to the vent system in that are if that's not possible there is a fitting a mechanical vent fitting you can install but the best way is connecting to the plumbing vent system