ISCO LaserFlow – A solution for your PR19 flow monitoring requirements

What is PR19?

PR19 (Price Review 2019) sets pricing for the 2020-2025 period. The review sets out priorities for water companies. One of those priorities is Flow to Full Treatment (FFT).

What is Flow to Full Treatment?

FFT is the maximum possible flow a wastewater treatment works (WWTW) can treat before it's over capacity and the excess must be diverted to holding tanks. Previously, many works used CSOs (Combined Sewer Overflows) as part of their system; PR19 is closing that option.

What does this mean?

As part of PR19, WWTWs are now required to measure their FFT to achieve MCERTS (the Environment Agency's Monitoring Certification Scheme) compliance. This allows maximum flows to be diverted on-site to storm holding tanks. The contents of the tanks can then be pumped back to the inlet of the works during low-flow periods.

The PR19 driver brings three major requirements, which the Water Industry National Environment Programme describes as follows:


Install Event Duration Monitors on WWTW overflows where existing monitors can't be used.



Install MCERTS flow measurement close to the overflow where the existing flow monitoring cannot be used for FFT compliance. 



Provide MCERTS flow measurement for the first time where permitted dry weather flow is greater than 50m3/day.

How can you monitor FFT?

Many older WWTWs have outdated flumes or weir plates installed, or in some cases, no measurement on the inlet at all. If the existing primary device is deemed not fit-for-purpose due to damage, incorrect sizing, etc., it will need removing and/or replacing. Replacing a primary device under live flow conditions requires over-pumping and storage of the influent, the costs of which can sometimes be hundreds of thousands of pounds.

The Solution

The ISCO LaserFlow® is an ideal solution to the requirements set out under U_MON4 and U_MON5. It is a non-contact, area velocity sensor which can be installed directly above the flow channel. As it's non-contact and doesn't rely on a primary device such as a weir or flume, it can be installed under live flow conditions with no requirement to over-pump or stop the flow. Certified to MCERTS Class 2, the LaserFlow is the highest class, non-contact, area velocity sensor on the market today.

To find out more on the LaserFlow or to discuss your specific FFT requirement, please contact Matt Brownhill on 07867 136 542 or [email protected].​

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