Trapped by My House Trap

rpgnyc

I'm trying to connect a washing machine and utility sink into a drain in my basement and was hoping to get a little guidance from the brilliant minds here. I'm an avid DIY'er renovating a home my partner and I just purchased in New Haven, CT. So far in the plumbing arena I've been able to tackle burst pipes, replumbing the kitchen sink, adjusting shut off valves and replacing some worn copper pipes with PEX. I owe a lot of that to the insightful discussions here (and finishing a basement with my papi when I was 9 years old). That said, I find myself a little kerflummoxed by our house trap.
I read @KC_Jones thread with @Jamie Hall's wonderful comment (https://forum.heatinghelp.com/discussion/150900/trap-on-4-sewer-main-in-basement) and gained a little insight, and the biggest thing I gleaned was that if the house trap appears intact there's no need to replace it. I'm attaching some pictures below. The thing that confuses me the most is it appears to have two cleanouts, though I'm not entirely sure. Can this trap in fact be used if I figure out how to properly vent it, or must it be bypassed or replaced? Any insight would be appreciated, and thanks in advance!

Jamie Hall

Leave it be. The two horizontal cleanouts allow you to get into either leg of the trap (the thing is a capital "U" under there) to get whatever needs to be gotten, while the sloping one will go to a Y connection on the house lateral and allow you to ream out the house lateral if that gets plugged up. There should be no need to vent it. The house side of the trap should be vented through the house main vent. The street side is inherently vented through the sewer, which (we hope) never runs full and thus can never pull the trap.

That's a better installation than some I've seen...

rpgnyc

Thank you so much, @Jamie Hall. Do you know if it would it be possible to plumb a drain for a washing machine into the sloping Y connection or either of the horizontal cleanouts? Anyone have any thoughts on this?

JUGHNE

IIWM, I would put a 4 x 2 wye into the sloping connection.
Turn it so the 2" branch points straight up and install a fitting 4" adaptor with plug to retain the clean out function as it was.

You need a trap for the washer and a stand pipe as high almost as the washer. The height helps disperse the suds keeping the standpipe from overflowing.

You may need a vent for that P-trap as the house venting is loop sealed by the house trap. IMO

Shalom

My parents' house in brooklyn has four cleanout caps. How come? well there are two parallel sewer systems in Brooklyn, one (vented) that takes the runoff from storm sewers and discharges straight into the bay, and the other (sealed) that takes stuff from house drains etc. and goes to the sewage plant on Knapp Street (and then discharges into the bay). You can see two manhole covers side by side, one labeled "STORM" and the other "SANITARY". The Storm ones have a hole in the center, the others don't.

The rain gutters on the roof discharge into the storm system, and the sinks, toilets etc. into the sanitary system. You aren't supposed to let the two of them mix up, but some homeowners if the sewer backs up, just take off all the covers and let it go down wherever it wants... this may be why they sometimes find E.coli in the bay...

(edit, it sometimes goes the other way too,. I remember one time when there was a storm surge, and the pressure in the storm system went up. It popped the cap off and filled the basement with gray water from the street corner catch basins. My mother took off the other cap and let Knapp Street deal with it. Oh, and the insurance company refused to pay off on flood damage because there weren't any broken pipes. They advised us to sue the city for the damages, but that went nowhere, because our city councilman state senator for our district had just quit for a sex scandal (married man, got involved with another man, wife found out) and the office was vacant. Good times in Brooklyn.)