Holdfast Training Services Trial Blog

I am trying to specify a connection detail for a 50mm rising foul into a 100mm dia gravity sewer.  Peak flow is 0.05l/s, assuming 50l per person per day and 15 people.  I have read about septicity causing illness in rising mains, Wessex Water describe it as:

• A common problem with foul pumping stations is a combination of low flows and long retention times. This results in bacteria multiplying in the anaerobic conditions. This is called ‘septicity’ and can occur in wet wells or rising mains.

I think that I need to provide a break chamber to slow the flow prior to it entering the gravity manhole.  The design information does not specify how the connection is terminated, and as the design life is 10+ years septicity could cause a problem.  Practically speaking, it will prevent the inside of the manhole becoming ‘splashed’ by high pressure flow.

If anyone has any experience on such connections it would be appreciated.

Thought it would be a useful issue especially for providing such infrastructure overseas and the need to control disease/illness.

Cheers,

Dan