The environmental groupsaid leaked internal Shell documents showed the oil giant has pumped 487.5 million barrels of production water "contaminated with crude oil, solvents and other chemicals" into the Midyat aquifer from 1973 to 1994.
Royal Dutch Shell denied that it had acted irresponsibly or polluted drinking water supplies. Shell's Turkish unit "has always acted as a responsible operator and its activities did not represent a hazard to the local population or environment," the company said. "Shell has also safely drawn the drinking water for its own residential staff . . . and can confirm that there is no pollution at present."
Last spring a Greenpeace campaign sparked an international outcry that forced Shell to halt plans to dispose of its obsolete Brent Spar oil platform by sinking it in the North Atlantic. Late last year Shell was also accused of complicity in the repression of Ogoni tribesmen who claimed Shell operations had damaged their homeland in south-eastern Nigeria.
The Anglo-Dutch oil giant said its N.V. Turkse Shell (NVTS) unit began pumping production waste water into the aquifer during the 1970s before it was used for drinking water. Shell said the aim of underground injection to avoid environmental damage. The city of Diyarbakir, some 18 miles from the well, started using the water from Midyat in 1977.
During the 1980s the company decided to phase out the injection of waste water into the formation used for drinking water, and in the early 1990s it agreed with the Turkish government to inject the waste water into a deeper oil-bearing formation known as "Mardin".
Shell said that 45 per cent of the waste water will be injected into Mardin instead of Midyat by the end of 1996, with Midyat phased out by 1998 or earlier. NVTS was sold to the British-based Perenco oil concern at the start of the year but Shell said it was implementing a monitoring programme.
Greenpeace said the leaked documents show most of the money allocated to decreasing the amount of water injected into Mardin by 50 per cent by 1995 was withdrawn before the sale to Perenco.
The Turkish environment ministry declined to comment.