Nearly 60 percent of areas in China that were surveyed were found to have a "very poor" or "relatively poor" quality of underground water last year, a new report showed on April 22.

Among the 4,778 spots across 203 cities that were investigated by the Ministry of Land and Resources, underground water quality was ranked "relatively poor" in 43.9 percent of them and "very poor" in another 15.7 percent last year, according to the report, which is released by the ministry annually.

According to China's underground water standards, water of relatively poor quality can only be used for drinking after proper treatment. Water of very poor quality cannot be used as a source of drinking water.

The result means 59.6 percent of underground water could not be directly drunk last year, up from 57.4 percent from 2012.

On a year-by-year basis, water quality became worse in 754 monitored spots, but improved in 647 areas.