Ulsan Institute of Health and Environment: Taehwagang River Water Quality Rated 'Good' or Higher

Analysis of Measurement Data Over 27 Years Since 1997

The Ulsan Institute of Health and Environment announced on the 24th that, according to a study on the spatial and temporal characteristics of water quality changes in Taehwagang, Ulsan's representative river, the water quality was found to be at least in the "Good" grade.

The water quality assessment standard, Biochemical Oxygen Demand (BOD), is classified as follows: Excellent (1 mg/L or less), Good (2 mg/L or less), Slightly Good (3 mg/L or less), Fair (5 mg/L or less), Slightly Poor (8 mg/L or less), Poor (10 mg/L or less), and Very Poor (over 10 mg/L).

This study was conducted at a total of 10 sites along Taehwagang: 2 upstream, 4 midstream, and 4 downstream locations. It analyzed the concentration status of water pollutants in each section of the Taehwagang water system measured over 27 years, from 1997 to 2023.

The analysis showed that the average BOD concentration in the upstream areas (Deokhyeon, Jiheon) was between 0.4 mg/L and 0.6 mg/L throughout the period, indicating an Excellent grade.

In the midstream areas (Bansong, Daeam, Mangseong, Guyeong), the average BOD concentration improved from 1.4 mg/L in 1997 to 1.2 mg/L in 2023.

In the downstream areas (Samho, Taehwa, Hakseong, Myeongchon), the average BOD concentration also showed significant improvement, dropping from 10.0 mg/L in 1997 to 1.6 mg/L in 2023.

An official from the institute stated, "Taehwagang, which was once a 'river of death' with an annual average BOD concentration exceeding 10 mg/L, has now transformed into an ecological river," adding, "We expect this study to serve as basic data for the improvement and management of Taehwagang's water quality, as well as to provide momentum for hosting the 2028 International Garden Expo and promoting Ulsan as an ecological city."