Senior members of the International Olympic Committee have urged the Olympic body and Russian authorities to investigate the dumping of construction waste that has raised concerns of possible contamination of the water supply in the Winter Games host city of Sochi.

The Associated Press revealed Tuesday that Russia's state-owned rail monopoly is dumping tons of waste into an illegal landfill in Akhshtyr, just north of the Black Sea resort town of Sochi, in violation of organizers' "zero waste" pledge for the Olympics. On a visit last week to the site, AP reporters saw trucks dump concrete slabs into a gigantic Russian Railways-operated pit filled with spray cans, tires and foam sheets.

Russian President Vladimir Putin, centre, and International Olympic Committee president Thomas Bach, left, exit a commuter train at the newly built Adler railway station in Sochi. Russian Railways is building the most expensive piece of Olympic infrastructure, a 48-kilometre highway and railroad link between the airport and the alpine venues that has already cost the government 270 billion rubles ($8.5 billion US). (Alexander Zemlianichenko/Associated Press)

"If this is true, I am astonished," Gerhard Heiberg, a senior Norwegian IOC member and marketing commission chairman, told the AP on Thursday. "This would be a breach of confidence between the Russian authorities and the IOC.

"I really hope we will be able to solve this and work together with the Russian authorities to hopefully do something about it, so they can keep their promise of zero-waste program."

Heiberg, who organized the 1994 Winter Games in Lillehammer, was speaking in a telephone interview.

"Somebody from the IOC should go and see this for him or herself and evaluate the situation," he said.

Dick Pound urges Russian authorities to explain

Canadian IOC member Dick Pound called for urgent action to determine the safety of the water supply.

"If you're the IOC, you say, 'Look, we've got this report. We're not in a position from Lausanne to assess it, but if it's true, this really does compromise your own citizenry, and it compromises the Games. Could you please give us a quick and reliable report on what the hell is going on?"

Trucks like the one above regularly dump construction waste in a gigantic pit outside Sochi filled with spray cans, tires and foam sheets. The landfill site is smack in the middle of a water protection zone where dumping industrial waste is banned. (Dmitry Lovetsky/Associated Press)

As a centrepiece of its Olympic bid, Russia promised the cleanest Games ever, saying it would refrain from dumping construction waste and rely on reusable materials.

In a letter obtained by the AP, the Environmental Protection Agency in the area where Sochi is located told the Black Sea resort's environment council in late August that it had inspected the Akhshtyr landfill and found "unauthorized dumping of construction waste as well as soil from excavation works."

The village lies in an area where dumping construction waste and soil is forbidden under the Russian Water Code. Moisture from the landfill seeps into underground springs that feed the nearby Mzymta River, which provides up to half the water supply in Sochi.

Games to be more environmentally friendly

The report on the dumping came during a week in which Sochi marked the 100-day countdown to the Feb. 7-23 games. It also comes as the IOC and Russian organizers hold the World Conference on Sport and the Environment in Sochi, a meeting intended to highlight positive steps in making the Games more ecologically friendly. New IOC president Thomas Bach is among those attending the conference.

Bach spoke at the three-day environment conference in Sochi, urging Olympic bodies to work together on green projects.

"Sport has long been well aware of this responsibility and is moving forward with many like-minded partners by setting a good example," he said, according to an IOC press release. "The Olympic movement has already shown the international community how sport can make a tangible contribution to reducing environmental impacts. We are helping in the search for sustainable solutions by providing highly practical guidelines and strategies, for implementation globally, but also locally."