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[Asia Economy Reporter Lim Cheol-young] It has been found that the risk of corrosion of Seoul's water supply pipes due to soil is low.

According to Seoul City on the 26th, the Seoul Water Institute conducted the first nationwide study by a local government on the impact of soil on the corrosion of underground water supply pipes and released the results. The research findings will be used as basic data for scientifically installing and managing water pipes in the future.

The study found that the soil corrosiveness in Seoul is "low," and therefore, the risk of corrosion of underground water supply pipes due to soil is minimal. To analyze how soil affects pipe corrosion, the institute collected soil samples from around water pipes during water pipe construction across Seoul over the past five years (January 2016 to December 2020), analyzing about 300 soil samples.

The soil samples were collected by taking about 1kg of soil surrounding the water pipes at sites of water supply or leakage repair during water supply construction, sealed, and analyzed in the institute's laboratory. The research team comprehensively analyzed evaluation factors based on the corrosion assessment method of the American National Standards Institute (ANSI) to assess the degree of corrosiveness. Corrosion factors such as pH, soil resistivity, soil moisture content, redox potential, and oxides affecting soil corrosiveness were analyzed on the collected samples.

As a result, Seoul's average soil evaluation index by district ranged from 3.0 to 5.0 points, indicating "low" soil corrosiveness. The total soil evaluation index (ANSI modified) scores of 0?2 points indicate "almost none," 3?5 points "low," 6?9 points "moderate," and 10 or above "high" corrosiveness.

In countries with high soil corrosiveness like the United States and Japan, polyethylene (PE) film is applied to water pipes before burial, but Seoul's low corrosiveness means that simply ensuring proper drainage of moisture around the pipes with sand backfill during water supply construction can minimize external corrosion, according to the study.

Additionally, based on this research, the institute visualized the degree of corrosiveness by soil grade on a map by sampling location, allowing the characteristics of soil to be understood and utilized during water pipe construction. Visualized data such as average soil corrosion scores by district, soil sample collection locations, and corrosion evaluation item locations are available for anyone to view on the "Smart Seoul Map" (http://map.seoul.go.kr/spm/).

Lee In-geun, Director of the Seoul Water Institute, said, "This study is part of efforts to supply tap water more safely through scientific research on the environment where water pipes are installed," adding, "Our institute will continue to conduct various studies related to the water supply field to safely deliver clear and clean tap water to every household."

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