Best method to measure flowrate at sewer connection.
Best method to measure flowrate at sewer connection.
(OP)
We have been estimating the outflow of our process room by measuring the water input, however the Department of Environmental Quality has indicated that we should be measuring the outflow. We need to measure the flow to determine the monthly average water use (per day) and the daily maximum water usage to comply with our permit. Our waste treatment process is performed on a batch process roughly once a week with additional flow that does not need to be treated from overflowing rinse tanks with all waste water being delivered through a final pH adjustment tank before releasing it to the sanitary sewer. The problem is we only use about 3000 gallons per day and the drain line is 3" PVC pipe, so we don't have a pipe that is 'full' to use an ultrasonic or magnetic flow meter. Someone suggested an ultrasonic flow meter that designed to be used with a weir to measure the flow rate.
How are outflow measurements commonly measured? I figure most places that have environmental permits have a similar problem to measure their outflow.
Thanks for your help.
-Kirby
How are outflow measurements commonly measured? I figure most places that have environmental permits have a similar problem to measure their outflow.
Thanks for your help.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.





RE: Best method to measure flowrate at sewer connection.
"Someone" would be correct, suggest a v-notch
References
1. U.S. Dept. of the Interior, Bureau of Reclamation, 2001 revised, 1997 third edition, Water Measurement Manual, available for online use or download at: http://www.usbr.gov/pmts/hydraulics_lab/pubs/wmm/i...
RE: Best method to measure flowrate at sewer connection.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: Best method to measure flowrate at sewer connection.
http://www.aquatechnologygroup.com/ultrasonic-flow...
And they have a calculation for determining flow rate. At the minimum head allowed, .2 feet, I calculate the flow rate using their formula they provide (223 GPM * .2 ft ^2.5 = 4 GPM) for the narrowest V-notch weir and come up with a flow rate of 4 GPM, which is about twice what our average flow rate is. I left them my info to size a system, but I was wondering if there was a system designed for much lower and intermittent flow rates?
Thanks for your input.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: Best method to measure flowrate at sewer connection.
There are two options.
The first is to install the magmeter in a pipe dip so that the magmeter is always full.
The second method is to use the Flo-Dar:
http://www.hachflow.com/pdf/Flo-Station.pdf
You will need a sampling manhole with 6-Inch connections.
RE: Best method to measure flowrate at sewer connection.
RE: Best method to measure flowrate at sewer connection.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: Best method to measure flowrate at sewer connection.