Articles & Case Studies

MCERTS and the chocolate factory!

Posted: Tuesday 1st August 2006

Pipes and rivers oozing with gooey chocolate...unfortunately not.

When all the chocolate has been made, wrapped and put in your lunchbox, the only thing remaining is the waste discharge. For those that are not aware, such wastewater flow measurement discharges now fall under the MCERTS Self Monitoring Certification Scheme: it provides a network for consent holders to measure the flow of sewage or trade effluent to water courses or drainage networks and collect and report the monitoring data. Any flow over 50 cubic metres per day (50,000 liters).

The MCERTS scheme dictates that any flow monitoring system must be measured to an agreed accuracy of +/-8% and are inspected routinely by a squadron of MCERTS inspectors! However, many companies do not have any form of flow measurement and those that do probably do not meet the agreed standards of installation. As such, the Environment Agency and companies like RS Hydro are here to help companies provide accurate discharge flow measurement.

Although there are obvious costs for installing such monitoring equipment, there are benefits too: better process measurement and further potential for process optimisation and hence reduce the effect on the environment. The word Cadburys is a household name and RS Hydro have won a bespoke monitoring project to install 3 MCERTS open channel flowmeter at its famous Bourneville factory. Indeed many of us have even visited the visitor center to taste the freshly made chocolate. However, not every part of the process involves chocolate.

After all the chocolate bars and Easter eggs have been wrapped, the site's filtered wastewater is discharged into the local brook. RS Hydro have provided bespoke flow measurement solutions in the UK for nearly ten years and were invited to tender for the project which also involved other online measurement.

The objective is to provide a continuous water monitoring system (CWMS) for all three points, which feed into a brook. RS Hydro are to install three MCERTS accredited flow meters: two HydroRanger 200 flowmeters and a single OCMIII flow meter, all by Siemens-Milltronics. Both the Siemens OCM III and the HydroRanger are highly accurate non-contact flowmeters for open channels. Flowrates are calculated from the level of water passing over a primary structure like a v-notch, rectangular weir or flume.

The Siemens HydroRanger 200 flow meter provides an economical, low-maintenance solution. It uses proven continuous ultrasonic echo ranging technology to measure any water or wastewater up to 15 m (50 ft) in depth. The resolution is 0.1% and accuracy is 0.25% of range. This water flow meter is set apart from other contacting devices, because it is immune to problems caused by suspended solids, harsh corrosives, grease or silt in the effluent. This all enables high accuracy, easy set up and minimises the time required for maintenance. These factors make the Siemens HydroRanger 200 an attractive water flow meter for busy industrial applications.

The flow meters will be monitored using the FlowView.Net WebPortal ( which allows users to monitor their data on a daily basis and up to every 15 minutes using GPRS. Along with temperature, pH, total chlorine and free chlorine measurement, the flow meters will be powered using solar power as a mains connection proved to be more costly in the short- and long-term.

For more information please visit our website

Read the magazine online

July 2020

About the magazine »
Magazine archive »


Information for advertisers »

Pulsar New Banner
Huber Pulsar Button June 13 Water Aid Cranfield University British Water buttonwood marketing Harvey Communications wateractive