"Aging Sewage Systems Concentrated in Major Cities... Replacement Facilities Need to Be Considered"

There is an urgent call for management and response to the aging of public sewage treatment facilities concentrated in major cities such as Seoul and Gyeonggi.

A guide sign placed at the sewer tunnel construction site near Isu Station in Seocho-gu, Seoul, last June. / Photo by Yonhap News

According to the Ministry of Environment's 'Sewage Statistics' cited by the Korea Construction Industry Research Institute in its Construction Trend Briefing (No. 927) on the 15th, out of 4,281 public sewage treatment facilities nationwide as of 2020, 47 are aged facilities that have been in operation for more than 30 years.

By region, about 30% of all aged facilities were found to be in Gyeonggi-do (15 facilities). Seoul has 4 facilities, all of which are aged. Most of the sewage treatment facilities are reported to be large-scale facilities discharging more than 500 tons.

Sewage systems consist of drainage equipment, pipelines, and treatment plant facilities. Wastewater discharged from homes, restaurants, and other places is sent through sewage pipelines to treatment plants, where pollutants are removed before being discharged into rivers. The domestic sewage coverage rate is about 95%, with 4,339 treatment facilities and a treatment capacity reaching 26.79 million tons per day.

In the case of sewage pipelines, aging is more severe than that of water supply pipelines. Of the 163,098 km of domestic sewage pipelines, 40.2% have been buried for more than 25 years. The proportion of aged water supply pipelines is only 19.9%.

By city and province, more than half of the sewage pipelines in Seoul, Busan, Daegu, Incheon, Gwangju, and Daejeon have been buried for over 25 years. In particular, Daegu showed the highest level among the 17 cities and provinces, with this proportion at 70.1%.

The Korea Construction Industry Research Institute emphasized the need to prepare alternatives as aged public sewage treatment facilities are concentrated in populous and high-usage areas such as Seoul and Gyeonggi.

Um Geun-yong, a research fellow at the Korea Construction Industry Research Institute, said, "Seoul should consider planned alternatives such as sequential maintenance or installation of replacement facilities," adding, "Since sinkholes can also occur due to leaks in sewage pipelines, aged sewage pipelines should be replaced quickly to prevent soil contamination and ensure citizen safety."

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