New Test Technique Measures Light to Gauge Toxicity

Jan. 7, 2002
System developed for UK military now available to water companies in America

The world is a different place today than it was just a few months ago. Things that were once taken for granted – working in high-rise buildings, uneventful airline trips, opening the mail – have become beacons for safety concerns. For better or for worse, public water supplies have joined the expanding list of venues where security has become a growing and very public issue.

Granted, security measures do exist to safeguard our public water supply. Utilities routinely employ techniques such as chlorination, filtration, and ultraviolet treatment, to name a few. However, given the changes that have taken place in the world since September 11, 2001, the prospect for intentional contamination seems more possible than ever before. Hundreds of potential contaminants in a variety of forms could be introduced to the water supply. We want to have confidence that our existing security measures and analytics are adequate but with so many possibilities, how can we?

That’s why Severn Trent Services ( has made the Eclox™ Rapid Response Water Testing System available to public utilities. The system uses a luminometer to detect the presence of toxic substances in water, with full results available in as little as 30 minutes. Considering the implications of contaminated water on the general public, a 30-minute turn-around can be a lifesaver.

The system can be used to test for phenols, heavy metals, cyanide, pesticides, arsenic, even nerve agents, and numerous other contaminants, including urine and feces. It can also test for pH, conductivity, and for the presence of an acceptable chlorine level. The system, neatly compact in a briefcase-like housing, was originally developed by Severn Trent for military purposes in conjunction with the Nuclear, Biological and Chemical team of the United Kingdom Defense Procurement Agency. The science is based on original research conducted at the University of Birmingham in the United Kingdom. Prototypes were tested in the UK by the Ministry of Defence and by the United States Soldier Biological & Chemical Command (SBCCOM) in 2000, and production models went into use earlier this year.

Eclox uses a technique called Chemiluminescence to test water. This technique measures the generation of light from a chemical reaction when specific chemicals are mixed in water. The level of light generated in a sample is dependent on the quality of the water. Therefore this technique can be used as an indicator of water quality. It was also discovered that as the light-producing chemicals included an enzyme and an oxidant, the reaction was generally much more sensitive to those contaminants which tend to disrupt biological processes, i.e. those which are toxic.

The main test instrument is the luminometer, which gives a generic indication of the toxicity or potability of the water sample. Test results are presented in a simple and easy-to-understand form, therefore making it possible for field engineers to get “up to speed” on the unit quickly. The luminometer displays light emission curves and percentage inhibition values. Eclox does not directly measure bacteriological contamination. However, where this has occurred due, for example, to sewage being in the water, the Eclox will sensitively detect the chemical constituents of sewage waste.

The Eclox Rapid Response Water Testing System was honored recently by a panel of judges of the Institution of Chemical Engineers (IChemE) Awards for Excellence in Safety and the Environment in Europe. In declaring a special award for Eclox, one of the judges commented, “it could save more lives than the rest of the competition entries put together.” Severn Trent Services also received, for Eclox, the prestigious IWEX Innovation Award at this year’s International Water Exhibition in Birmingham, UK.

As of December 2001, the Eclox units became available to water companies serving the American public.