The environmental organisation Zelyony Patrul, or Green Patrol, has urged Muscovites to avoid drinking water directly from the tap this spring.

The organisation's director, Roman Pukalov, said that seasonal flooding had washed large volumes of contaminated water into reservoirs and drinking water from these reservoirs was not recommended.

"Numerous effluent discharges were documented in Tver Region's Ivankovskoye Reservoir, which supplies Moscow," RIA Novosti quoted Pukalov as saying last week. While conducting the "Velikiye Reki Rossii" expedition, which examined three regions including the Tver Region, the ecologists said they uncovered numerous violations of environmental laws.

"Around the Istra Reservoir there is a huge number of cottage settlements, which, naturally, lack purification facilities and are located within the reservoir's protected buffer zone. Also located within the zone are many other small organisations and enterprises, such as car washes, that discharge storm water runoffs without purifying it," Pukalov said.

"The Istra Reservoir has become almost unfit for gathering drinking water, despite the huge efforts taken by Rosvodokanal water utilities firm, and the firm agrees with us on this matter," he added.

Given the current ecological situation, Zelyony Patrul recommended avoiding drinking tap water, since besides the problems with the reservoirs, the spring thaw had flooded the Volga River with water created from melted snow.

State water utilities company Mosvodokanal's general director Stanislav Khramenkov also singled out the Istra Reservoir as being particularly threatened by effluent flows.

"We are particularly worried about the state of the Istra Reservoir," said Khramenkov, adding that the reservoir's water quality was very low.

"Over the last five years, about 8,000 hectares of land has been given over to commercial construction."

He said that the construction of purification facilities had been forgotten and that insufficiently cleaned run-off was finding its way into the reservoir. He called upon managers of commercial enterprises to take necessary measures to ensure the health of the reservoir.

Natural Resources and Ecology Minister Yury Trutnev also said the reservoirs located around Moscow were in an unsatisfactory state and were judged to be either polluted or very polluted.

He said, however, that Moscow's water-supply systems were equipped with powerful filters that neutralised the harmful components. "The water supply's water meets sanitary norms," said Trutnev. "Speaking of water, I can say I prefer not 'purified' water, but 'uncontaminated' water."

Despite Mosvodokanal general director Khramenkov's concern over Istra's water quality, the press secretary of Mosvodokanal, which provides Moscow's water supply, saw little reason for alarm.

"Mosvodokanal considers the information provided by Zelyony Patrul as misleading," Mosvodokanal's press secretary Larisa Danilina told RIA Novosti last week. According to Mosvodokanal-accredited laboratories, the quality of spring's freshet water matched the same levels observed over many years. The levels of phosphates, ammonium nitrogen and microbiological components were on the whole even lower than during freshets of previous years, the press secretary said.

"The Moscow water supply's reservoir system of plays its own particular barrier role, preventing the introduction of contaminants into the water intakes of the treatment plants," said Danilina. She added that spring's freshet occurred smoothly over the first days of April, without any sharp water-level rises on any main rivers.

"Over the course of this year's freshet, Muscovites did not experience any changes in water quality in comparison with the prior period," said Danilina.