Water softener standpipe- no trap? No gasses?

[Kvn27]

The question- how to determine if there is a trap buried in the concrete? The situation- I am adding utility sink dwv to an area next to my whole home Water Softener. The DWV will tie into an existing 2 inch standpipe capped with a WS drain line at the top. There is an allowable air gap in the pipe itself for the WS line but I am puzzled by one thing. The WS line doesn't have the safety air hole incase there was a backup. I can add one no problem. But the curious thing is that the line was connected to the standpipe by a hole just big enough for the line to fit in. Now I don't smell any sewer gasses, but before I reconnect everything I want to figure out what the new vent situation should be once I connect the new sink Drain pipe. Should i add an AAV just incase?

 

[wwhitney]

The question- how to determine if there is a trap buried in the concrete?

Pour in a gallon of water, then peer down to see if you can see a reflection from standing water. And/or check for standing water with a rag well secured to a fairly rigid stick (so it doesn't follow any elbows, just goes straight down).

Should i add an AAV just incase?

That's not the question, the question is whether you need to add a trap and a vent (which could be an AAV).

If there is a trap, then there should be a vent, so you can also look at your piping configuration to see if there's a vent pipe. Posting a picture would provide more info.

Cheers, Wayne

 

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[Jeff H Young]

yes you gotta know what you have befor you decide what you need. I belive you have a crossconnection on the w/s.
That pipe might just go to a drywell or out to a canal ?