Tancheon in Seongnam Maintains 'Class I' Water Quality for Three Consecutive Years, Proving Itself as a Clean Urban Stream

'BOD 1.59 mg/L' in Seongnam's Tancheon Stream
Significant Water Quality Improvement Through Sediment Dredging

The water quality of the Tancheon Stream in Seongnam, Gyeonggi Province, has maintained an 'average Class I' level for three consecutive years.

Tancheon Stream, Dunchon-dong, Sujeong-gu, Seongnam City. Provided by Seongnam City

According to Seongnam City on May 15, monthly measurements of the biochemical oxygen demand (BOD) at 10 locations along the Tancheon—such as Oribo, Gumi Bridge, Dolma Bridge, Sunae Bridge, and Banga Bridge—showed results of 1.65 mg/L (milligrams per liter) in 2023, 1.58 mg/L in 2024, and 1.59 mg/L in 2025.

These figures fall within the 'good' grade for river water quality, which is classified as Class I (standard: 2 mg/L or less).

The city believes that continuous dredging work to remove sediment accumulated on the beds of Tancheon and its tributaries, as well as removal of floating debris from the stream, have been effective in improving water quality.

Over the past three years, a total of 78,937 cubic meters of sediment have been dredged and 90,660 liters of floating debris have been removed.

Additionally, during the repair and reinforcement of 15 bridges within the Tancheon section (from August 2024 to August 2025), embankment work was carried out and drainage conduits were installed to ensure smooth water flow in the affected areas.

Tancheon, Dunjeon-dong, Sujeong-gu, Seongnam. Provided by Seongnam City

Regular inspections of 37 nearby riverside businesses have also been conducted to block the inflow of pollutants.

A Seongnam City official stated, "We are mobilizing all administrative resources to comprehensively manage Tancheon's water quality," and added, "Through continued water quality improvement projects, we aim to make Tancheon a pleasant waterfront space and a healthy ecological stream that citizens can enjoy."

The Tancheon originates in Giheung-gu, Yongin, passes through the Seongnam section (15.7 km), flows through Seoul, and eventually empties into the Han River. The total length of the stream is 35.6 km, making it a semi-major watercourse.

This content was produced with the assistance of AI translation services.