Samples collected so far indicate water quality in quake-hit areas have remained basically unchanged and are eligible for drink by Wednesday, the Ministry of Environmental Protection said here in Beijing.

The samples were collected along the Yangtze River and its distributary rivers from Panzhihua in southwestern Sichuan Province, Yibin in southern Sichuan, Leshan in central Sichuan and Luzhou in southeastern Sichuan, and Yichang in Hubei Province, where the Three Gorges Dam is.

Water quality in Panzhihua, Yibin, Luzhou, and Yichang were graded level II, the second best out of five water quality categories.

But samples taken from Leshan indicates an over-concentration of dissolved oxygen, marking water quality there level IV.

The ministry dismissed a hearsay on the Internet warnings that a chemical leak in the Dujiangyan City had polluted the water sources of Chengdu, the provincial capital of Sichuan.

"Environmental authorities in Chengdu have been closely monitoring the quality of drinking water in the city for the past few days, and have found nothing abnormal," the ministry said, adding that the Chongqing Municipality is also free of quake-induced environmental pollution currently.

But the ministry did quote two chemical leak incidents in Sichuan Province.

Shifang City, 60 kilometers northwest of Chengdu, reported a sulphuric acid and liquid ammonia leakage on Monday afternoon, and Deyang, 20 kilometers away from Shifang, also reported a leak of ammonia.

The leakage were quickly controlled by local authorities in both cases, according to the Ministry.

"The Ministry of Environmental Protection is also checking for possible water and air pollution in the quake-hit areas, and have sent supplementary monitoring equipment to quake-hit areas where original equipment has been damaged during the quake."

(Xinhua News Agency May 14, 2008)