"The color of the water in the Hantan River area has improved, but the water quality has deteriorated a bit."

Water pollution in the Hantan River basin, a UNESCO World Geopark, has increased slightly.

From 2022 to last year, the Gyeonggi Institute of Health and Environment investigated and analyzed six items, including chromaticity, biological oxygen demand (BOD), total organic carbon (TOC), suspended matter (SS), total nitrogen (TN), and total phosphorus (TP), and published the "Hantan River Water System Water Quality Evaluation Report."Four cities and counties,

Yangju, Pocheon, Dongducheon, and Yeoncheon, collected monthly samples and analyzed and evaluated the data by the Northern Support of the Institute of Health and Environment.

Samples were collected at 60 locations in the Hantan River in 2022 and 52 locations last year.According to the

report, the chromaticity of the Seollaegyo Bridge, the lowest downstream of the Hantan River, improved slightly from 18 degrees in 2022 to 17 degrees last year, but fell short of the target standard of 15 degrees.

Chromaticity is a water pollution indicator that shows the degree of color, and dye components contained in water are difficult to biologically decompose, so the more dye components there are, the higher the chromaticity.

The river that has the greatest impact on the chromaticity of the Hantan River is Shincheon, a tributary, and the Sincheon Sewage Treatment Facility and Dongducheon Sewage Treatment Facility account for the highest proportion of chromaticity in the Sincheon Water System.

BOD, which represents the degree of contamination of organic matter in the water, was measured from 2.4mg/l in 2022 to 3.1mg/l last year, and TP, the concentration of phosphorus contained in the water, was measured from 0.050mg/l in 2022 to 0.067mg/l last year, respectively, increasing the pollution level slightly.

"In winter and spring, when precipitation is low, effluent from sewage treatment facilities accounts for a large portion of river maintenance water, and facilities of public sewage treatment facilities need to be improved," said an official at the Gyeonggi Institute for Health and Environment. "The livestock farms and the wastewater plant in the Ministry of Health and Environment, which directly discharges wastewater, are also major water pollutants."