China still has more than 242 million rural residents and 33 million rural teachers and students who have no sustainable access to safe drinking water, a senior official said on Wednesday.

Before 2015, all residents in rural areas will gain access to safe drinking water sources, Chen Lei, minister of water resources, said at a bimonthly session of the National People's Congress Standing Committee on Wednesday.

Water supply construction such as building piped supplies and protected wells are encouraged in rural areas, Chen said, adding that expanding the urban piped water supply system to rural areas should be given priority in the future.

China has been making efforts to improve rural drinking water sources. By the end of 2011, about 266 million rural residents and nearly 15 million rural teachers and students gained access to better drinking water sources since 2006, according to statistics from the ministry.

The figure means China has met the internationally agreed Millennium Development Goal to halve the proportion of people with no safe drinking water well ahead of a 2015 deadline.

Shanghai Securities News reported in December last year that during the 12th Five-Year Plan (2011-2015) period, the total investment in improving rural drinking water sources would be about 170 billion yuan ($27 billion), about 100 billion yuan more than the amount from 2006 to 2010.

One big challenge, according to water experts, is that groundwater pollution is spreading from urban to rural areas, where there are fewer sewage treatment facilities and more fertilizer is used.

In 2008, more than 200 residents of two villages in South China’s Guangxi Zhuang autonomous region were poisoned by arsenic-contaminated water, which was believed to have been discharged from a nearby metallurgy factory.

Besides improving rural drinking water sources, Chen also said implementation of water-saving irrigation projects will also be accelerated in rural China.