BEIJING -- China will ensure the safety of drinking water by the year 2015 in rural areas, where it still remains unaccessible to more than 100 million people, a senior official said Thursday.

Safe drinking water is that which reaches standards for four indicators: quality, quantity, level of convenience, and assurance rates.

At the end of 2012, 298 million people in rural areas were suffering from lack of access to safe drinking water, but by the end of this year, 63 percent of them will have safe water, said Li Guoying, vice minister of water resources.

The problem for the remaining 110 million people, including 15 million students and teachers in rural areas, will be solved in the following two years, he said while responding to legislators' inquiries on infectious diseases at the ongoing bimonthly session of the National People's Congress (NPC) Standing Committee.

The government has allocated nearly 179.1 billion yuan (29 billion U.S. dollars) for drinking water safety projects from 2005 to 2012, Li said.

For the next few years, authorities will expand the water supply network to more rural areas, strengthen the monitoring of water quality and improve environmental protection in water resource areas, he said.

Unsafe water is one of the main reasons for the spread of infectious diseases, lawmakers said.