Hello! I recently purchased a home with a finished basement with a powder room. We have been experiencing waves of septic odors over the summer (we have a septic system). The epicenter of stink appears to be in the utility room where the sewer ejector pit resides. I'm not a plumber, but I am confused as to why the vent pipe would be connected to the main sewer pipe (see photo). Is this an approved method of venting? I appreciate your thoughts!