On October 22, the Ministry of Ecology and Environment released a report via its WeChat account detailing the state of surface water quality in China for the third quarter of 2024 and the first nine months of the year.

**Overall Situation**

In the third quarter, the results showed that 78.8% of the 3,641 monitored national surface water assessment sites had water quality rated as good (Class I-III), reflecting a 1.5 percentage point increase from the previous year. Conversely, only 0.8% of the sites were rated poor (Class V), which represents a slight decline of 0.1 percentage points year-on-year. The main indicators exceeding standards were chemical oxygen demand, permanganate index, and total phosphorus.

From January to September, the proportion of sites with good water quality remained high at 88.5%, marking a 1.4 percentage point increase compared to last year. The percentage of poor quality sites decreased slightly to 0.7%. Again, the major exceeding indicators were the same: chemical oxygen demand, permanganate index, and total phosphorus.

**Water Quality in Major Rivers**

In the third quarter, the seven major river basins—including the Yangtze, Yellow, Pearl, Songhua, Huaihe, Haihe, and Liaohe—along with rivers in the northwest, southwest, and the Zhejiang-Fujian region, saw 81.9% of the monitored sites report good water quality. This is a 1.4 percentage point increase year-on-year, with poor quality sites remaining steady at 0.6%. The primary exceeding indicators were also chemical oxygen demand, permanganate index, and total phosphorus. Notably, rivers in the northwest, southwest, and the Yangtze basin showed good quality, while the Pearl and Yellow river basins reported satisfactory conditions; however, the Liaohe, Songhua, Haihe, and Huaihe basins experienced slight pollution.

For the January to September timeframe, 90.0% of sites in these river basins reported good water quality, an increase of 0.8 percentage points from the previous year. Poor quality sites saw a decrease to 0.4%. Key indicators that exceeded standards included chemical oxygen demand, permanganate index, and five-day biochemical oxygen demand, with good conditions reported for rivers in the Zhejiang-Fujian area, Yangtze basin, and both northwest and southwest rivers.

**Water Quality in Key Lakes and Reservoirs**

In the third quarter, of the 208 monitored key lakes and reservoirs, 67.3% were rated as good, down 4.9 percentage points year-on-year, while 4.3% were deemed poor, an increase of 0.5 percentage points. The main indicators exceeding standards included total phosphorus, chemical oxygen demand, and permanganate index. Among 202 lakes and reservoirs assessed for nutrient status, only one was classified as severely eutrophic, while ten were moderately eutrophic, and 63 were mildly eutrophic. Taihu exhibited good quality with mild eutrophication, while Chaohu and Dianchi faced slight pollution and moderately eutrophic conditions. Erhai showed good quality and moderate nutrient levels, similar to Danjiangkou Reservoir.

From January to September, water quality improved, with 78.6% of the 210 monitored lakes and reservoirs rated as good, a 4.0 percentage point increase. The percentage of poor quality remained stable at 4.3%. Key indicators again focused on total phosphorus, chemical oxygen demand, and permanganate index.

**Municipal Insights**

During the first nine months of 2024, the top 30 cities in terms of good national surface water quality included Liuzhou, Zhangjiajie, and Guilin, while the bottom 30, reflective of poorer water quality, comprised cities such as Shangqiu, Wujiaqu, and Kaifeng. The analysis of specific monitoring sites indicated notable changes, with certain sites seeing significant improvements, while others reflected deteriorating conditions.

This report underscores the ongoing efforts and challenges China faces in maintaining and improving its water quality across various regions.