Plumbing

What's this pipe entering inspection chamber?

Anonymous user 23/02/2024 - 3.24 PM

Hi Trying to work out our existing drain connections and can't see what this higher pipe exit in our inspection chamber is for? http://i68.tinypic.com/24gsxag.jpg The bottom exit is the outlet from the toilet / shower which joins the main run but can't see anything that the higher pipe runs from (rest of the drains run to another chamber about 3 metres up). Hoping someone on here will have an idea as I thought foul connections had to enter at the bottom of the chamber and our gutter drains run to a separate system. Thanks.