Automatic storm water sampling in a gravity pipe

[dwags]

Is anybody aware of any technical guidance relating to collecting automatic storm water samples in a gravity pipe that is 48" dia.? I am looking for specific guidance that will indicate the optimum height of the sample tube off the bottom of the pipe to prevent the suction of settled solids into the sample tube. Thanks.

 

[dicksewerrat]

The settled solids get washed to the rivers, too. I wouldn't worry about that. If you stay up in the top third, you will get the cleanest samples.