Advanced Water Purification System

In order to deliver premium tap water with upgraded quality, the Seoul Metropolitan Government has applied an advanced water purification system with ozone and granular active carbon (charcoal) process to the standard water purification method at the Yeungdeungpo Purification Center in 2010. It will expand the system to six purification centers by 2015. Considerably improved from the existing purification technology, the advanced water purification system eliminates materials that generate the unpleasant taste and smell of tap water as a result of water quality deterioration during dry season as well as traces of organic matter including residual antibiotics.

Membrane Filtration Water Purification Plant

The membrane filtration process (to replace sand filtration), which was successfully installed in the Yeongdeungpo Water Purification Plant established in 2010 jointly by the Ministry of Environment, Seoul Metropolitan Government, and private enterprises, is based on a more precise filtration method than conventional ones to supply water. This eco-friendly, state-of-the-art technology not only reduces the use of chemicals such as flocculent by more than 50% but also simplifies maintenance; thus realizing a budget reduction effect. It carries significance as the first case of core membrane filtration technology localization in Korea and as the largest-scale membrane filtration purification facility.

Dispersed Chlorine Injection System

Although tap water chlorination is a necessary step in ensuring the hygiene and safety of tap water by destroying harmful microorganisms, it inevitably adds an unpleasant smell to drinking water. To remove this smell, a system wherein only a minimum amount of chlorine is added primarily in the purification plant and again in the reservoir has been adopted. The “dispersed chlorine injection system” to disperse chlorine injection across a multiple number of stages significantly reduces the unpleasant smell of chlorine.

Guidelines for Healthy, Tasty Water

Considering citizens’ increased interest in health, the Seoul Metropolitan Government has established guidelines consisting of ten categories in order to deliver “healthy, tasty water” as an evolved form of “clean, safe water” by reflecting citizens’ need for healthy, tasty water; it is applying the guidelines to the entire waterworks operation and management processes.

Revenue Water Ratio of 95.7%

The Seoul Metropolitan Government has achieved the same revenue water ratio as that of advanced countries by improving water supply pipes and blocking the water supply piping network as well as through systematic leak prevention and scientific supply volume management, and management of quantity of use without leakage. The revenue water ratio in 2021 was 95.7%, up 40.5% from 1989 (55.2%). Through the improvement in the revenue water ratio, the production quantity over the last 32 years (1989 to 2021) was reduced by 13.52 billion ㎥, with achievement of economic effects in accordance with the improvement of revenue water ratio of 10.46 trillion Won (on the basis of the unit cost of production in 2021).

*Target of Revenue Water Ratio in 2022 : 96%

Maintenance of Water Piping

Since the lifespan of water pipes expires and corrosion occurs inside the pipes, leading to damage, frequent water leak, and rust formation, old pipelines are replaced to prevent water pollution in the course of water supply. To establish an optimal piping network, an old-piping maintenance project began in 1984 and a 13,349 km (99.7%) section of the waterworks piping has been replaced by the end of 2021. In addition, the maintenance of the remaining 2.9 km old pipes, which has not been done due to causes such as the control of road excavation, is to begin for completion once the causes are resolved

Water Distribution Network Blocking System

According to the basic waterworks maintenance plan, the Seoul Metropolitan Government has established a block system to convert the complicated waterworks piping network consisting of 105 medium blocks and 2,037 small blocks into a grid-shaped block network so as to monitor th e water volume, quality, and pressure on a real-time basis and to analyze the revenue water ratio. Through this, the government not only ensures efficiency of water supply pipe operation but also reduces water leak by maintaining an appropriate water pressure; thus promoting an improvement in the revenue water ratio. This way, the government is managing waterworks facilities systematically. 

Systematic Leak Prevention

Waterworks Authority is systematically improving old pipelines that are subject to frequent water leaks by analyzing the causes of the leak. In addition, it is performing extensive monitoring and surveillance in areas that are prone to water leak, such as subway stations and main pipelines. At the same time, Waterworks Authority has introduced a flow monitoring system, which is a scientific water flow monitoring system, in order to detect leaks preemptively and repair the affected areas.

Scientific Water Supply Management

Flowmeters are installed in 611 locations, which include the water pipes, service areas, blocks, booster stations, and reservoirs, aside from the construction of a flow surveillance system for the real-time monitoring of flow, pipe pressure, and water level as well as early detection of signs of water leak. To improve the accuracy of the flow meter system, periodic calibration inspection and improvement of old flow meters are continuously promoted.

Management of quantity of use without omission

Quantity of use is being managed without omission by means of prevention of illegal water supply, through compliance with the time for reading the water meter, accurate evaluation, management of multiple number of source of supply, re-development and frequent inspection of water supply facilities in the re-construction regions, etc.