Sewerage Systems Office

Construction of Neihu Sewage Treatment Plant mainly includes civil work, treatment system and landscaping; where the main construction started on February 13, 1998. The Design Volume of Phase-1 sewage treatment was 150,000CMD. The Sewerage Systems Office itself started its operation after the successful acceptance inspection on July 22, 2004. The Design Volume of Phase-2 sewage treatment was 240,000CMD; the expansion was completed for operations in 2016. The operations, maintenance and management of the plant was outsourced since July 1, 2020,

The original design of the Class-2 treatment unit is of the VIP Method, which is capable of effective removal of nitrogen and phosphorus; currently we have changed active sludge treatment unit into step-type VIP method. The Class-2 treated water is discharged into the Keelung River after sodium hypochlorite disinfection, a portion of the treated water undergoes circulation of mechanical filtration and Ultrafiltration (UF) for recycled use.

1. Design Intake Flow: 240,000CMD
2. Design Intake Quality:BOD₅: 185mg/L ,SS: 190mg/L
3. Effluent quality:BOD₅≤30mg/L、SS≤30mg/L
4. Recycled Water:Design Capacity: 20,000CMD，Ultrafiltration (UF) System: 200CMD Design Capacity

1. After entering the plant, the sewage passes through a Bar Screen and Sedimentation Pool for removing debris, sand and gravel from the water protecting pumps; it then enters the Primary Clarifier for removing part of organic substances and most suspended solids from the water.
2. The supernatant from the Primary Clarifier then enters the Class-2 Biotreatment Unit (in Stepped VIP) and then the Secondary Clarifier, for sedimentation; after that, the treated water is disinfected with sodium hypochlorite to remove germs and becomes the effluent before being discharged into the Keelung River.
3. Effluent from the Class-2 biotreatment is disinfected with sodium hypochlorite; part of it is filtered by automatic filters and the Ultra-Filtration System for recycled use in the plant, as well as for external use, for maximum recycling .
4. Starting from 2007, scum and sludge separated from the primary and secondary clarifiers have been incorporated into the process of the Dihua Sewage Treatment Plant via a dedicated pipeline and sieve dregs are hauled to incinerators for incineration.
5. In order to prevent odors of hydrogen sulfide and ammonia from affecting operators in the plant and causing air quality and environmental issues to nearby residents, the exhaust gas is collected with ducts and treated by wet chemical cleansing and odor removal facilities before being released into the atmosphere, thereby complying with air quality requirements of the environment.

1. The Neihu Plant is the first semi-underground sewage treatment plant in Taiwan designed using a concept of a totally covered configuration that can prevent odors produced by treatment facilities from escaping and dispersing.
2. The superstructure of the plant, an area of 3.8 hectare, is programmed as a sports park equipped with pools, PU tracks, extreme sport facilities, rock climbing field, children’s playground, and even models of the sewage treatment plant for demonstrating its procedures, which may benefit leisure activities of citizens and emphasize environmental education for the public.
3. Suggestions are made for using recycled water for flushing the toilet, for cleaning public environments, for irrigating plantations and maintaining landscaping, for washing large vehicles, for sprinkling roads to eliminate flying dust, thereby setting examples in re-using the recycled water.

Ever since the completion and start of its operations, the project has not only alleviated the load of centralized treatment for the sewerage systems in Taipei City but also functioned to supplement the flow of the Keelung River for increasing its self-cleaning capability and volume accommodating capacity.