Why Did a Dead River That Couldn't Even Flow Become an 'Ecological Stream'?

100% ‘Separate Sewer System’ Project Revitalizes the River

Transformation into a River of Life... Birth of ‘Taehwa River National Garden’

Story of an Industrial City and Industrial Capital: ‘The Miracle of Ulsan’

What is the reason that a heavily industrialized city, known as the ‘industrial capital,’ can also embrace an unpolluted ‘river of life’?

The key to transforming the ‘dead’ water, which was once unusable even for agricultural purposes, into first-class water quality lies in the drainage facilities. This is because the sewage pipes are different.

This is the story of Ulsan City, which played a pivotal role in industrialization and rapid economic growth in the 1960s. It is also the industrial capital that helped South Korea grow into one of the world’s top 10 economies today.

Along with early economic growth during industrialization came the stigma of being a polluted city. The Taehwa River, Ulsan’s lifeline, became a ‘dead river’ shunned by citizens as it was filled with wastewater and all kinds of garbage, losing its vitality and becoming uninhabitable for fish.

To revive the ‘dead river’ Taehwa, Ulsan City established the ‘Basic Sewerage Maintenance Plan’ in 1987 and actively embarked on the ‘separated sewer system project,’ including blocking domestic wastewater inflow into the Taehwa River and laying branch pipelines.

With the launch of the third elected government in 2002, Ulsan aimed to create an eco-friendly city on the foundation of economic growth by declaring ‘Eco-Polis Ulsan’ (2004) and establishing the ‘Taehwa River Master Plan’ (2005), which gave momentum to water quality improvement policies for the Taehwa River.

The ‘separated sewer system project’ to save the Taehwa River involved separating sewage and stormwater and connecting them to domestic sewage pipes, which was intensively promoted from 1995 to 2010.

Overview of the Classification System Project for Drainage Facilities.

First, from 1995 to 2008, 132.5 billion KRW was invested to block domestic wastewater inflow into the Taehwa River by maintaining 261 km of sewer pipes.

Then, from 2008 to 2010, 27 billion KRW was invested to maintain 40 km of sewer pipes.

Additionally, in 2006 and 2008, the ‘sewer pipe lease-type private investment project (BTL)’ was introduced, and with a total investment of 181 billion KRW, the ‘separated sewer system project’ was implemented in areas such as Eonyang, Samnam, Dudong, Duseo, Sangbuk-myeon in Ulju-gun, and Bangojin in Dong-gu.

The water quality of the Taehwa River, which was 11.3 ppm in biochemical oxygen demand (BOD) in 1996?unusable even for agricultural water and classified below Grade 3?improved to 3.2 ppm in 2004 and 1.9 ppm (Grade 1) in 2011 as a result of the separated sewer system project.

The water quality of the Taehwa River, which was once inhospitable to fish, improved to Grade 1, allowing anadromous fish such as salmon, sweetfish, and yellow corvina to return, and endangered otters to inhabit the area.

As the natural ecosystem of the Taehwa River rapidly recovered, Taehwa River Grand Park, the Ten-ri Bamboo Grove and walking trails, ecological gardens, and flower beds were created, culminating in the ‘miracle’ of the birth of the ‘Taehwa River National Garden’ on July 19, 2019.

Ulsan’s ‘separated sewer system project’ has continued since 2011, and it is currently the only one among the 17 metropolitan cities and provinces nationwide to have established a ‘100% separated sewer system (total length 4,795 km).’ Ulsan has established itself as a leading city in the sewage sector.

Since all the sewer pipes were installed, facilities to treat sewage also had to be supported. Ulsan City newly established the following sewage treatment plants to expand sewage treatment capacity: ▲Eonyang Sewage Treatment Plant (capacity 45,000 m³/day), ▲Bangojin Sewage Treatment Plant (capacity 140,000 m³/day), ▲Gulhwa Sewage Treatment Plant (capacity 47,000 m³/day), ▲Nongso Sewage Treatment Plant (capacity 100,000 m³/day), and ▲Gangdong Sewage Treatment Plant (capacity 7,000 m³/day).

Along with expanding sewage treatment facilities, continuous installation of sewer pipes increased the ‘sewerage coverage rate’ from 48% at the time of Ulsan’s elevation to metropolitan city status in 1997 to 72% at the time of the Eco-Polis Ulsan declaration in 2004, reaching 99.3% as of 2023.

Ulsan Taehwa River, transformed from a death river where fish struggled to survive into a first-class water quality river.

Ulsan City is accelerating urban and Taehwa River environmental improvements by investing a total of 75.5 billion KRW in projects such as ‘old sewer pipe maintenance’ as part of the 8th elected mayor’s pledges.

To respond to various urban developments such as the lifting of development restrictions, a total of 430 billion KRW will be invested to newly build and expand sewage treatment facilities with capacities of △Bangojin 40,000 m³/day, △Onsan 40,000 m³/day, △Hoeya 20,000 m³/day, △Eonyang 15,000 m³/day, △Cheongnyang 30,000 m³/day (new), and △Yeocheon 64,000 m³/day (new).

Kim Doo-gyeom, Mayor of Ulsan City, emphasized, “Sewage facilities are social infrastructure that preserves water quality and the natural environment,” adding, “We will make every effort to create a pleasant urban living environment that citizens hope for and to preserve the water quality of the Taehwa River through active investment in the sewage sector.”

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