MHW Laboratories said that the advancement comes as municipalities address new evidence of contamination in US water supplies, including bacteria often found in sewage.

The method detects gadolinium and other rare earth elements that are a proven and reliable indicator of sewage contamination, offering a cost-effective tool for water purification and treatment plants and others to identify the presence of wastewater in recycled water, claimed MWH Laboratories.

MWH Laboratories now can analyze at ultra-low levels for gadolinium, a rare earth element typically injected into patients undergoing MRI scans to improve the imaging quality of the medical test. Once it passes through the body, gadolinium enters sewer systems. In samples of reclaimed water, a high level of gadolinium relative to other earth elements is one indicator of wastewater contamination.

MWH Laboratories can now identify a gadolinium anomaly,or excess levels of gadoliniumgadolinium, at parts per trillion (ppt) levels to determine the presence of wastewater despite extremely low concentrations or significant dilution.

The new method has been used by the US Geological Survey and researchers at the University of Queensland and will be used by MWH Labs for a study of reclaimed water in Florida set to begin this spring, sponsored by the Florida Department of Environmental Protection.

MWH Laboratories uses a Inductively Coupled Plasma Mass Spectrometer (Perkin Elmer 9000 ICPMS DRC2) equipped with sample handling capabilities, to measure the entire suite of rare earth elements at levels as low as 1ppt and then uses an algorithm to normalize the data and identify the presence of the gadolinium anomaly.

Dr Andrew Eaton, technical director of MWH Laboratories, said: ”This is a groundbreaking development for treatment plants charged with delivering clean water to the public as well as companies relying on clean water sources. Plants can add an extra level of certainty to their work, using the same samples that they are already testing and with minimal added expense.”