Sewage backflow through open pipe under kitchen sink

[nitsirk817]

Disclaimer: not a pro! But I'd sure love some opinions/advice on this freak accident that happened to our condo.

The main line in our four-story condo building clogged with roof debris after a wind storm last week. Category 3 water backed up into the kitchen of our unit on the third floor...while we were on vacation of course. The sewage spewed out from under the kitchen sink via what I assume is a dishwasher trap or vent pipe of sorts. It's an open pipe slanting upward (see photos). The plastic dishwasher tube is placed into the opening of this tube. The sewage poured from this open pipe for several days before we came home to discover the mess. A remediation company is in the process of ripping out floors, cabinets, and baseboards.

Has anyone heard of or seen this type of piping and is it legal or code to leave it uncovered like this? Obviously, the worst case scenario has happened and now we want to ensure it never happens again. The plumber who snaked the main line said this open pipe is code but "freaks him out." Did the builder cut corners? Is there something missing (backflow prevention valve of some sort)? To all you plumbers out there with consciouses— what would you do or recommend in this situation?

The condo building was built in 2006 but let unfinished until 2012. Developer rented units as apartments until resold as condos in 2017. We purchased the unit in early 2018, and this was not mentioned during the inspection. Location is in Boulder, Colorado.

 

[Cacher_Chick]

If not for that drain, it would have backed up through the sink drain and overflowed the sink. The flood often comes from the lowest drain, which in many places is the shower.

 

[Sponsor]

 

[MACPLUMB]

What you are posting makes no sense,
1st. storm water does not connect to the sanitary sewer,
2nd. what you have is a back up of the kitchen waste pipe between the second and third floors, so when people on the upper floors run their kitchen sinks and dishwashers it comes out of your drain,
3rd. why you have that open pipe I cannot tell you it is not to code I have plumbed in 5 states over 35 years and never seen anything like
that ! suggest you contact a local plumber or the city code enforcement,
Note if it was blocked on first floor level it would run over on the second floor,
and when you say main line then you are talking sewage which would have overflowed the showers, and toilets, and bathtubs as these are lower then your kitchen pipes

 

[Reach4]

I see it as a standpipe. There is a p-trap. Pretty normal. I am not a plumber.

What is not so normal is that the sewer system became full and overflowed.

If not for that drain, it would have backed up through the sink drain and overflowed the sink. The flood often comes from the lowest drain, which in many places is the shower.

Good point. The backup could not have been on the main line for the building, or else the flooding would have occurred in the lower floors. The flooding did not come out of your toilet or shower or tub either. So I think the blockage was in a drain line that was probably in a line under your sink but received kitchen drainage (presuming the floorplan of the 4th floor is similar) from the 4th floor.

 

[Sylvan]

Over 50 years in plumbing I have never seen an opening on a vent or waste line

I have seen hundreds of storm and sanitary lines used as a combination waste system

There never should have been an open pipe /fitting

 

[Reach4]

It's a standpipe with a built-in air gap. The black trap mixed with the PVC is unusual, however.

It's an airgap's job to spew sewage, isn't it?

 

[hj]

NO "competent" plumber would leave an OPEN standpipe in a cabinet below the sink level where ANY backup, (and there can be many causes of a backup), would overflow it. It is a "flood" waiting to happen.

 

[Reach4]

NO "competent" plumber would leave an OPEN standpipe in a cabinet below the sink level where ANY backup, (and there can be many causes of a backup), would overflow it. It is a "flood" waiting to happen.

Is there such a thing as a Not-OPEN standpipe?

https://terrylove.com/forums/index.php?threads/installing-a-standpipe-drain-for-dishwasher.17245/

See page 6 of 13
https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=1205 or page 7 of https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=5634

If there were no standpipe and the dishwasher hooked to the disposal, given the circumstances, I have to believe that the sewage would have overflowed the sink onto the floor during the vacation. Yes, there would have been a few gallons less, because the sink would hold a fair amount.