Despite endeavours by many people there has been no clear, concise guidance on how to design a flow survey taking account of all the relevant factors (safety, flow characteristics etc) and also on how to go about checking the quality and integrity of the data. The UDG Event Duration Monitoring Good Practice Guide goes some way towards filling that gap but has concentrated more on what to do with the data once captured rather than how to capture it in the first place. So we are sharing our Golden Rules as presented at this autumn's CIWEMUDG Conference in Blackpool.
1) Determine WHAT you want to measure (flow, level, depth, pH, O2 etc).
2) Determine WHERE you want to take the measurements (manhole, sewer, Inlet Works etc).
3) Determine what measurement ACCURACY you require.
4) Determine the measurement INTERVAL you require (2 minute, 5 minute, hourly etc).
5) Ensure the measurement location has SAFE ACCESS at ground level.
6) Ensure the measurement location is SAFE TO ENTER for personnel.
7) Ensure the measurement location has suitable FLOW CHARACTERISTICS (avoid turbulence etc).
8) Choose the most appropriate measurement EQUIPMENT.
9) Check the equipment CALIBRATION and determine how calibration will be maintained.
10) Check the QUALITY of the recorded measurements.