BEIJING, Jan. 24 (Xinhua) -- To better conserve groundwater resources, more professional monitoring wells that can test water quality have been set up across China, according to the Ministry of Natural Resources.

By the end of last year, the number of monitoring wells nationwide had risen to more than 10,100 compared with 5,100 in 2017, and 93 testing indexes for groundwater have been added to monitoring results, China Daily reported Thursday, citing data released by the China Geological Survey (CGS), an institute under the ministry.

Li Wenpeng, senior engineer at the CGS, said that previously they had often used local residents' monitoring tools, but now their own tools are more professional and evenly distributed across the country.

"About 3.5 million square kilometers in 31 provinces, including major plains, basins and cities, are covered with standardized wells. It's like equipping groundwater spots with eyes, which helps us make decisions regarding conservation," he said.

The latest data from the Ministry of Water Resources shows that in 2017, the country's groundwater supply was 101.7 billion cubic meters, 16.8 percent of the total water supply.

However, an environmental report released by the Ministry of Ecology and Environment in May said that more than 60 percent of the groundwater was graded as poor quality in 2017.

Li said that more indexes can be provided by the monitoring system in time to help with evaluation and protection of groundwater quality.

Specific wells have been arranged for different layers to make the monitoring clear and results more accurate.

Big data and cloud platforms have been also established, so the wells can send the results automatically and immediately to the monitoring center.

Although China's monitoring technology has been modernized and is in the top tier of the world, the number of monitoring facilities is far from enough and engineers still cannot manage to take groundwater samples to test using the current technology, Li said.