SHENZHEN recorded only three hazy days last year, the lowest number since 1988, a major victory in the city’s battle against air, water and soil pollution, according to a government report delivered to a local legislature meeting Tuesday. The number was nine in 2019.

The annual average PM2.5 concentration was reduced to 19 micrograms per cubic meter in 2020, the best in the city’s air quality monitoring history. The days with good air quality also reached 97 percent of the total days.

In terms of water treatment, 159 blackened and smelly rivers have been cleaned up. The water quality of the city’s five major rivers – the Maozhou, Shenzhen, Guanlan, Longgang and Pingshan rivers — has improved immensely and met national standards for surface water. All 13 reservoirs now meet the standards as a drinking water source.

Pollution index in the seawater quality of the city’s offshore areas, which cover 1,145 square kilometers along a 260.5-kilometer coastline, has dropped 0.9 percent over the previous year, the report said. The seawater quality in the eastern offshore area has reached Class I of the national seawater standard.

In 2020, Shenzhen promoted low-carbon green development while combating pollution. Around 1,155 low-end and heavily polluting enterprises were closed. A total of 400,000 new-energy vehicles were put into use and 600,000 old and yellow-labeled vehicles were phased out. The city now runs  entirely electric bus and taxi fleets.

The city has 310 rivers with flow areas of more than 1 square kilometer each. The combined length of rivers stands at 999 kilometers. During the city’s development, many rivers were tainted and polluted, producing nefarious odors.

In 1993, the city set up a water resources bureau bearing responsibility for water-related projects including planning, water supply, conservation, drainage, sewage treatment, drought prevention and flood control.

(Han Ximin)