The quality of Beijing’s air and water improved in 2016, according to a report released on June 2 by the Beijing Municipal Environment Protection Bureau.

Wastewater treatment sees results

The drinking water reserves of the city were expanded to more than 1,300 square kilometers. Chemical oxygen demand (COD) and ammonia nitrogen, the two key water discharge pollutants, were down 7.7 and 8.1 percent respectively.

According to Qiao Shufang, the director of the bureau’s environment monitoring department, more wastewater treatment plants and water recycling facilities were put into use in 2016, with a total treatment capacity of 6.72 million cubic meters of wastewater per day.

Good air quality days increase steadily

Beijing‘s average density of PM2.5, the airborne particles smaller than 2.5 microns in diameter, was 73 micrograms per cubic meter in 2016, representing a year-on-year drop of 9.9 percent.

The report also indicated a year-on-year decrease in densities of other air pollutants, including sulfur dioxide, nitrogen dioxide, PM10 and carbon monoxide.

In 2016, Beijing had 198 days where the air quality was considered “good”, an increase of 12 days from 2015. The number of “heavy air pollution” days stood at 39, seven days fewer than in 2015.