NEWMARKET, UK, 20 June 2017, June 20, 2017—


IDEXX, the global leader in rapid microbiological testing for water, today announced that South West Water has selected the Colilert®-18 method to detect the presence of E. coli and coliforms in its drinking water. The switch to Colilert®-18 from the traditional agar plate method followed a six-month comparison study between the two. The study concluded that Colilert®-18 was faster, more accurate and met the goals of the laboratory and operational scientists.

South West Water supplies a customer base of 1.7 million people throughout Cornwall and Devon and in small areas of Dorset and Somerset, and welcomes over 7.0 million visitors during the peak summer tourism months. Accurate and timely microbiological analysis is essential in delivering their goal of supplying good, safe drinking water that has the trust of their consumers.  South West Water merged with Bournemouth Water in 2016, which supplies drinking water to nearly half a million people in parts of Dorset, Hampshire and Wiltshire.

South West Water is the latest major UK utility to adopt the Colilert®-18 test which is also used extensively by Thames Water, South East Water and Essex & Suffolk Water. Providing confirmed results in 18 hours compared to the 48 hours it takes to run agar based tests and requiring no confirmation steps, Colilert®-18 was made the ISO 9308-2 standard for the enumeration of E. coli and coliform bacteria in all types of water in 2012 and was added to the European Drinking Water Directive in 2015, where it is now included as one of only two reference methods for coliform and E. coli detection.

“The quality of our water and safety of our customers is of paramount importance at South West Water,” commented Claire Coppin, South West Water’s Laboratory Manager. Claire added, “Switching to the Colilert®-18 test enables us to get water quality results in half the time compared to the agar tests that we ran previously. It is quick and simple to use and our studies showed it to be more accurate.” Chris Rockey, South West Water's Head of Water Quality added “Having confirmed results in a more timely manner helps us make confident decisions to ensure our consumers can have trust in their tap water; which is our (and their) number one priority”.

Andrew Headland, Senior Business Manager for IDEXX EMEA said, “Colilert®-18 has again demonstrated real value to a water operations team, providing accurate, rapid and cost effective results which facilitate confident decision making. The value of a long shelf life also means that South West Water will only need to order 2 to 3 batches per year compared to 2 to 3 batches per week for the agar based test. We are seeing significant interest in Colilert-18 from other major UK utilities as result of its speed, accuracy and ease-of-use.”

Colilert®-18 consists of a reagent powder, which is added to a standard 100ml water sample and then incubated for 18 hours in the case of presence/absence determination. This step takes less than 1 minute of hands-on time. The presence of E. coli and total coliforms is subsequently determined following incubation, with coliforms indicated by the sample turning yellow, and fluorescence indicating the presence of E. coli. Where quantification of a sample is required, IDEXX has developed a simple device known as a Quanti-Tray®, which consists of 51 individually sealable cells. The Quanti-Tray can also be incubated for 18 hours after which the fluorescent cells can be counted and quantified.

For more information contact: Richard Kerns at NEPR:

© 2017 IDEXX Laboratories, Inc. All rights reserved.
All ®/TM marks are owned by IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries.
The IDEXX Privacy Policy is available at

About IDEXX Water
IDEXX Laboratories, Inc. is a member of the S&P 500® Index and is the global industry leader in water microbiology testing. IDEXX provides a full line of tests that help ensure water quality and safeguard public health in communities worldwide. IDEXX entered the water testing market in 1993 with Colilert®, now one of the most frequently used testing methods for the detection of coliforms and E. coli in water worldwide. More recently, IDEXX launched Enterolert®-DW for detection of enterococci in drinking water and Pseudalert® for 24-hour detection of Pseudomonas aeruginosa in hospital water systems, pools, spas and bottled water. The Pseudalert® Test detects P. aeruginosa quickly to help safeguard against infections in sensitive populations. For more information, visit:

About South West Water
South West Water is part of Pennon Group plc. We provide reliable, efficient and high quality drinking water and waste water services throughout Cornwall and Devon and in small areas of Dorset and Somerset. South West Water came into being in 1989 with the privatisation of the water industry.  We inherited a water system suffering from a century of neglect but, thanks to the tireless work of our 1,300 employees, have brought the region's drinking water, sewerage systems and bathing waters into line with the stringent UK and European Union standards. This extensive programme of environmental improvement has resulted in some of the finest bathing waters in Europe, picturesque scenery and clean rivers with stunning wildlife. We believe that by investing in the future of our region, we are not only improving the quality of life for today's residents and visitors but are also taking responsibility for future generations. For more information, visit:
For more information about Bournemouth Water visit