Busan City Waterworks Headquarters Announces Pre-Inspection and Response Measures for Water Purification Process

Strengthening Water Purification Processes to Prepare for Summer Bird and Larvae Occurrence

Sanitation Improvement Projects, Installation of Filter Gates and Microfiltration Screens, etc.

The Busan Metropolitan City Waterworks Headquarters has conducted a preliminary inspection of the entire process of tap water production and supply and announced its own response measures to ensure the safety of tap water from summer algae blooms and larvae, as temperatures are expected to be higher than average and the number of heatwave days is expected to increase this summer.

Water Sprinkling Facility (Mulgum Water Intake Station).

The main measures include ▲suppressing algae inflow at the water intake ▲removing algae and larvae entering the water treatment plant ▲responding to high-concentration algae outbreaks. To suppress algae inflow, double algae barriers are installed at the intake, and spraying facilities are operated. To remove the inflowing algae and larvae, high-efficiency coagulants are used, the backwash cycle of the filtration beds is shortened, and facilities for medium chlorine injection are installed and operated. Additionally, ozone treatment facilities will be improved to optimize the water purification process.

In particular, if high-concentration algae persist, an advanced oxidation process (ozone/hydrogen peroxide) will be operated, and powdered activated carbon (PAC) will be additionally injected. To this end, the headquarters invested 12 billion KRW (5.4 billion KRW from the national government and 6.6 billion KRW from the city) to install powdered activated carbon storage and injection facilities at the Deoksan and Hwamyeong water treatment plants.

Regarding the algae toxin substances that caused controversy last year, to ensure the safety of tap water, in addition to microcystin-LR designated as a monitoring item by the Ministry of Environment, nine other types of algae toxins (microcystin-RR, LA, YR, LF, LY, anatoxin-a, nodularin, cylindrospermopsin, BMAA) are being additionally monitored. The water purification process operation will be strengthened by increasing ozone injection concentration immediately upon issuance of an algae warning.

Last year, the maximum number of harmful cyanobacteria cells at the Mulgeum intake point, Busan’s water source, was 532,648 cells/㎖, the highest since 2012, and the algae warning was issued for 196 days, the longest period on record.

Currently, compared to the previous year, rainfall and upstream dam discharge are higher, delaying the proliferation period of harmful cyanobacteria. However, depending on weather conditions, the environment can easily become conducive to the spread of algae and larvae at any time, necessitating thorough preparation and countermeasures.

Additionally, as a policy to prevent tap water contamination caused by small organisms (such as chironomid larvae), a sanitation improvement project for water treatment plants has been implemented.

Types of Major Larvae Causing Complaints.

Specifically, the measures include ▲weeding of vacant land and filling of water puddles for environmental improvement ▲sealing of filtration beds, installation of double doors, air curtains, fine insect screens, and insect traps to prevent inflow ▲improvements to outflow blocking facilities such as upgrading the collection system under filtration beds, installing filter gates at the granular activated carbon outflow section of Deoksan water treatment plant, and installing fine filtration nets at the outflow sections of other water treatment plants.

A representative of the Busan Metropolitan City Waterworks Headquarters stated that even if facilities that fundamentally block the inflow, breeding, and outflow of small organisms at water treatment plants are installed and operated, regular cleaning of water tanks and removal of habitats for small organisms are essential to fully ensure the safety of tap water at faucets. They urged households and building managers to take an interest in this matter.

The city’s water treatment plants and reservoirs obtained ISO 22000 Food Safety Management System certification in 2021 and have continuously improved process management levels. To create a safe tap water production environment, joint inspections of water treatment plant sanitation management for the summer season have been conducted annually in cooperation with the Nakdong River Basin Environmental Office and the Basin Water Support Center.

This year, joint inspections of four water treatment plants were completed in May, and in June, a preliminary inspection of the algae outbreak response posture is planned.

The headquarters has been promoting the construction of intake towers to improve the Maeri and Mulgeum intake facilities, which are vulnerable to external factors such as massive algae growth due to climate change. To secure national funding, continuous visits and consultations were held with the National Assembly, Ministry of Economy and Finance, and Ministry of Environment. As a result, the recently announced Ministry of Environment’s ‘Comprehensive Algae Countermeasure’ includes improvements to the Mulgeum intake facility, enabling the securing of national funds and full-scale project promotion.

Song Sam-jong, head of the Busan Metropolitan City Waterworks Headquarters, said, “Since the number of algae cells decreases as water depth increases, we will make every effort to build an intake tower capable of deep-water intake.” He added, “In the long term, securing clean raw water through diversification of water sources is important, but until all conditions are met, we will continuously strive to produce and supply tap water that citizens can drink with confidence through improvements to water treatment facilities and optimization of the water purification process.”

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