Experts from the Drinking Water Inspectorate found supplies contained benzoylecgonine, the metabolised form of the drug that appears once it has passed through the body. It is the same compound that is looked for in urine-based drug tests for cocaine.
Steve Rolles, from the drug policy think tank Transform, told The Sunday Times that the findings were an indication of the scale of the use of the drug in Britain today.
“We have the near highest level of cocaine use in western Europe,” he said. “It has also been getting cheaper and cheaper at the same time as its use has been going up.”
According to the charity DrugScope, there are around 180,000 dependent users of crack cocaine in England, and nearly 700,000 people aged 16-59 are estimated to take cocaine every year in Britain.
As well as benzoylecgonine, scientists also found traces of the common pain-killer ibuprofen and carbamazepine, a drug for treating epilepsy. The drinking water tested also contained significantly higher quantities of caffeine.
Assessing the risk from pharmaceuticals appearing in the water supply, a recent report from Public Health England found that the quantities of cocaine found were around a quarter of what appeared before treatment and, at a dose of just 4 nanograms per litre, was unlikely to represent a danger to the public.
“Intakes of the compounds detected in drinking water are many orders of magnitude lower than levels therapeutic doses,” the report said.
“Estimated exposures for most of the detected compounds are at least thousands of times below doses seen to produce adverse effects in animals and hundreds of thousands below human therapeutic doses.”
“Thus, the detected pharmaceuticals are unlikely to present a risk to health.”