New sewage line issue?

[Mikev]

New sewage line issue

Hey guys, sorry if this is not the correct forum. Quick back story.

Live in older house that had clay pipe for sewer main. Had a belly and constant roots so I had the concrete dug up and a whole new line installed.

This was in March. I opened one of the floor drains because I noticed some sewer flies. Upon inspection I noticed water in the trap was brown and dirty. I decided to flush the toilet upstairs and noticed the trap “breath” as it flushed. Water slightly rose 1/4 inch for second and seemed to go back down. I opened the clean out and flushed again. Water seems to flow fine, doesn’t seem to be a clog or backup. (Shouldn’t be it’s brand new pvc pipe)

I have attached a picture of the plumbing before they filled with concrete. The yellow circle is the trap I am talking about. The line it is connected to is the kitchen sink line that flows into the Y and into main line. The line to the right is the toilet line. What could be causing the trap to get brackish and move when flushed? Could the pitch on the pipes not be correct?Sewer line photo

 

[Matt30]

It’s common for the water in the p-trap to tremor when tied in that closely to a branch. It’s just the positive and negative pressure in the system.

As for the dirty water I don’t have an explanation. Is there a trap priming device on it? Was it just filled with dirty water from day one?

 

[Mikev]

It’s common for the water in the p-trap to tremor when tied in that closely to a branch. It’s just the positive and negative pressure in the system.

As for the dirty water I don’t have an explanation. Is there a trap priming device on it? Was it just filled with dirty water from day one?

I may have an explanation for dirty water. I have a dehumidifier running down there, with the drainage hose running to that trap. I checked the hose and there is brown slime(bacteria) growing in there. I believe the bacteria may just be breeding in the trap