Cocaine use is so widespread in the UK it has contaminated the nation's drinking water.
A report by the Drinking Water Inspectorate found traces of the metabolised form of the illegal drug, benzoylecgonine, in four sites across the country, even after filtration.
Ibuprofen and an anti-epilepsy drug were also found. The levels are not high enough to present a danger to the public.
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."
Steve Rolles of Transform told the Sunday Times: "We have the near highest level of cocaine use in western Europe. It has also been getting cheaper and cheaper at the same time as its use has been going up."
The charity DrugScope estimate 700,000 people aged 16-59 in the UK use cocaine every year with 180,000 addicted to crack-cocaine.
The report was highlighted by Labour MP, Jim Dobbin, who has called for closer monitoring to minimise the effects on consumers.