2024. 2. 23. 09:41ㆍCivil Servant in S.Korea/Civil Servant journal
Usually, reports of sewage leaks are received from citizens, and upon receipt, on-site investigations are conducted. If issues with public sewage facilities are identified, direct construction work is carried out. If the problem is deemed to be with private sewage facilities, temporary measures are implemented, and guidance for necessary construction is provided. In this journal, we aim to present a case where a defect in a public sewage pipe was discovered, reported, followed by the preparation of a report, and finally, the completion of the necessary construction work.
Public Work of Water Control in Seoul
(Part1: Sewer Inspection and Construct)
1. Reciving a report about sewage leakage
summer on 2024, from a citizen whose basement was flooding. They reported that water was entering their basement whenever it rained, and with the imminent onset of heavy rainfall, we moved quickly to investigate and take action, recognizing the potential risk of flooding if prompt measures were not taken.
Especially when defects occur in public facilities, the damage can escalate to affect multiple homes. Therefore, we verify the status of public facilities through sewage network maps. Upon inspection, we found a sewage pipe for the Bokgaecheon stream(a covered channel used as a sewer) at the back of the complaint site.
2.On-Site Investigation:
Due to obstruction by buildings, identifying the leakage point was not possible visually. However, during the on-site investigation, it was observed that water was seeping through the concrete wall located below the building on the right side. Given the absence of foul odor, it seemed to be leakage from domestic water or rainwater rather than sewage. However, visual confirmation of the leakage point was not possible due to the obstructing building.
3. Specific Investigation
3-1. Special Solution Investigation:
In cases where visual confirmation of the leakage point is not feasible, a special solution is used to detect the presence of leakage.
- Inspection of Private Sewage Systems:
Since there was no odor from the sewage treatment plant and considering the location of the pipes, suspicion fell on the rainwater drainage system. Special solution was applied to the rooftop drains, but no leakage was detected.
- Inspection of Public Sewage Systems:
Cracks in public sewage pipes or rainwater collection systems can also cause leaks. Therefore, a special solution was applied in these areas, but no leakage was detected.
3-2. CCTV Inspection:
CCTV cameras are inserted into the sewer pipes to identify any leakage points. Since detecting small cracks alone is difficult, the expertise of professionals is required.
The inspection revealed poor overall condition of the sewer pipes, with the structure of the Bokgaecheon stream remaining intact. Leakage points were identified in the upper part of the pipes, causing rainwater leakage through the cracks during periods of heavy rainfall.
4. Implementation of Construction:
Based on the confirmed cracks in the pipes, a report was prepared, and the construction company was instructed to proceed with repair work.
Since water should not flow through the work area, a manhole was installed at the top (red circle) to pump out water, and the direction of water flow in the newly installed manhole was redirected using a converter.
Due to the difficulty of excavation work in the Covered stream sewer system, manual labor was required to apply cement to the exterior wall of the stream. Fortunately, despite heavy rainfall the day after the work, swift action prevented any damage to the affected house, enabling us to safely pass through the rainy season.
I remember being extremely flustered as a newcomer at the time. While this issue was resolved smoothly, challenges can arise in the field due to various factors such as terrain, financial constraints, and stakeholder relationships. In such situations, it's essential to make wise decisions and handle the situation sensibly to prevent further damage.