Water Quality Treatment in Raodside Swales

[orceng]

For water quality treatment in roadside swales in highway design, the normal residence time in the swale is 9 minutes to get full treatment. You will have portions of the runoff from the highway that will hit the swale at the downstream reaches and will not meet the 9mins before discharging into a culvert or pipe system. How is treatment requirements normally met for this portion of the highway?

 

[RWF7437]

" How is treatment requirements normally met for this portion of the highway?"

Arbitrarily.

 

[jgailla]

I see a lot of ditch checks used. They're basically short, wide weirs.