Water Quality in Hantan River Basin: Improved Color but Increased Pollution Levels

Gyeonggi-do Institute of Health and Environment Publishes 'Hantangang Watershed Water Quality Assessment Report'
Water Quality Survey on 6 Items Including River Color in Hantangang Watershed from 2022 to 2023
Report Includes Water Quality Trends and Pollution Evaluation by Watershed

The water pollution levels in the Hantan River basin, which has been re-designated as a UNESCO Global Geopark, have shown a slight increase.

Scenery of Sewolgyo Bridge. Provided by Gyeonggi Province

The Gyeonggi-do Institute of Health and Environment announced on the 22nd that it has published the "Hantan River Basin Water Quality Assessment Report," analyzing six items including color, biochemical oxygen demand (BOD), total organic carbon (TOC), suspended solids (SS), total nitrogen (TN), and total phosphorus (TP) from 2022 to 2023 in the Hantan River basin.

This survey was conducted through collaboration where the four cities and counties of Yangju, Pocheon, Dongducheon, and Yeoncheon collected samples monthly, and the Northern Branch of the Gyeonggi-do Institute of Health and Environment analyzed and evaluated the data. Sampling sites within the Hantan River numbered 60 in 2022 and 52 in 2023.

Among the target points, the lowermost part of the Hantan River, "Sewolgyo," showed a slight improvement in color from 18 degrees in 2022 to 17 degrees in 2023, but it still fell short of the target standard of 15 degrees. Color refers to a water pollution indicator that shows the degree of coloration. Dye components contained in the water are substances that are biologically difficult to decompose, and the more of these components there are, the higher the color value.

The biochemical oxygen demand (BOD), which indicates the degree of organic pollution in the water, was measured at 3.1 mg/L in 2023, up from 2.4 mg/L in 2022, and total phosphorus (TP), the concentration of phosphorus in the water, increased from 0.050 mg/L in 2022 to 0.067 mg/L in 2023, confirming a slight increase in water pollution levels.

Cover of the Hantan River Basin Water Quality Assessment Report. Provided by Gyeonggi Province

Meanwhile, the river that has the greatest impact on the color of the Hantan River is the "Sincheon," where the Sincheon Wastewater Treatment Plant and Dongducheon Wastewater Treatment Plant, which have large discharge volumes, accounted for the highest color proportion in the Sincheon water system.

An official from the institute stated, "During winter and spring when rainfall is low, the discharge from wastewater treatment plants accounts for a significant portion of the river maintenance water, so facility improvements for public wastewater treatment plants are necessary," and emphasized, "Livestock farms scattered around and some wastewater businesses that directly discharge wastewater are also major sources of water pollution."

The institute distributed the "Hantan River Basin Water Quality Assessment Report," which includes trends in water quality changes and pollution evaluations by water system, to the four cities and counties and related organizations, and posted it on the websites of the Gyeonggi-do Institute of Health and Environment and the Gyeonggi Water Information System for public access.

Lee Myung-jin, head of the Northern Branch of the Gyeonggi-do Institute of Health and Environment, said, "If the color reduction plan for the Sincheon water system public wastewater treatment facilities continues to be promoted, the ecological value of the Hantan River Global Geopark can be better protected," adding, "The Hantan River is a natural asset that both residents and tourists must cherish, and we will do our best to establish it as a healthier and more beautiful waterfront ecological space."