(1) Rainfall, drainage
Manhole wastewater is discharged to the bottom sediment using mud pumps. The pipelines requiring descaling are sectioned, with the method of segmentation based on pipe diameter and length. Sections consist of two manholes with the same diameter.
(2) Diluted Sludge
High-pressure water trucks fill the segmented manholes with water, using a plunger to stir the sludge in the manholes and sewage pipes, diluting the sediment; manual labor must continuously agitate the sludge until it is sufficiently diluted with water.
(3) Sewage Extraction
The mud in the two inspection wells was cleaned out using a vacuum cleaner truck. The remaining small amount of mud in the two wells was then flushed out of the well chamber with a high-pressure water jet, further diluted, and finally, it was completely vacuumed out.
