Sewer Performance Criteria - Capacity 1

[rbergholz]

Most design standards for new construction of sewer pipelines are somethign like d/D of 0.5 for 15-inch pipe and greater.

But I'm interested in performance criteria of sewer pipelines that have been established for a while and perhaps are flowing at peak d/D of 0.85 but not surcharging. Just because it is above the design standard is not always justification for replacement.

Has anyone seen documented performance criteria for sewer pipelines (not design)?

Russ..

 

[RWF7437]

If it is not a problem, or likely to become one, who cares what d/D is as long as it is less than one ?

good luck dealing with people who see problems where none exist,

also Russ

 

[rbergholz]

This is a preventative measure. If d/D > 1, the problem already exists. Sorry but your reponse is useless to me and my client.

My point is/was what indicators are used by Districts to trigger upsizing of a pipeline due to capacity? The obvious one is surcharging (d/D > 1) I have heard that some districts do not conisder there to be a capacity problem until the manhole is surcharging at least 2-ft. Is this common?

Thanks..

 

[LHA]

RWF is correct. I've never heard of anyone replacing something which is not failing, unless failure is emminently certain. If the pipe is not overflowing, I doubt anyone will be able to justify money out of next FY budget to tear it out and replace it.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve