Recently, it was confirmed that some larvae were found in six water purification plants in addition to the Incheon Gongchon Water Purification Plant, which was designated as the origin of the larvae found in tap water in Incheon.

The Ministry of Environment recently inspected 49 water purification plants nationwide where activated carbon filter paper (active carbon paper), which is a water purification facility applied to the Gongchon Water Purification Plant, was installed for 15 to 17 days. Some said it was discovered today (21st).

Activated carbon is an area presumed to be a breeding site for the midget larvae found in tap water in Incheon.

It means that the larvae hatched from activated carbon flowed through the water purification plant and drainage to the home without being filtered.

Activated carbon is a black porous carbon material produced through the activation process of raw materials such as wood, sawdust, and coal, similar to charcoal.

It is used in the advanced water treatment process together with ozone to remove traces of organic substances that cannot be removed by the existing standard water treatment process.

In addition to Gongchon Water Purification Plant, other water purification plants where caterpillars were found on activated carbon are Bupyeong, Hwaseong, Gyeonggi, Samgye, Yangsan Beomeo, Ulsan Hoeya, Uiryeong Hwajeong Water Purification Plant.

However, larvae were found on the surface of activated carbon outside of Incheon, but no larvae were found at the end of the water purification plant, at the end of the pipeline, and at the receiving end (where tap water was used).

As in the case of Incheon, the larvae are not propagated on activated carbon, but the place where larvae were found on the surface of activated carbon is not expected to affect tap water when considering the subsequent treatment process.

The Ministry of Environment took measures to replace the activated carbon immediately after the larvae were found, and to increase the cleaning or ozone injection rate.

In the case of Incheon, after the caterpillar was discovered, a filter screen was installed to monitor 111 fire hydrants, 10 drainage basins, and 13 consumer meters 24 hours a day to find the results of finding the larvae twice a day.

In addition, 12 of the water purification plants subject to inspection had operational problems, such as not installing an insect screen.

The Ministry of Environment had to complete supplementary measures by the 23rd to the water purification plants where the problem was pointed out and report the matter to the Ministry of Environment.

The Ministry of Environment judged that the occurrence of additional larvae in the Gongchon and Bupyeong Water Purification Plants was blocked, and it would be resolved if only the remaining larvae in the water supply and drainage pipelines were discharged.


The Ministry of Environment also began an emergency water transfer investigation from 435 general water purification plants nationwide on the 17th and is expected to be completed this week.

However, the Ministry of Environment explained that in the case of a general water purification plant that only undergoes a standard treatment process, there is little possibility of larvae due to a short backwash cycle compared to an activated carbon water purification plant.

On the other hand, as complaints were raised that worm larvae were found in tap water in other areas of Incheon until yesterday, the local government, the Environment Agency, and the Waterworks Support Center jointly conducted a field survey and found that this was not a problem in the process of supplying water.

In the case of civil complaints that occurred in Seoul, larvae were not found in tap water, and it was more likely that this was due to external factors such as drainage.

In Busan, mosquitoes and fly larvae have been found, but the investigation suggests that they occurred in sewers.

Other regions, such as Hwaseong and Paju, also seemed to have been introduced from outside, such as water outlets, because larvae were not found in water purification plants, drainage basins, and reservoirs.

The Ministry of Environment is planning to call on the priority of safety management of tap water, such as ordering thorough management of water purification facilities, drainage basins, and reservoirs by holding a video conference with the heads of the Ministry of Environment's Environment Minister Jo Myung-rae today.


He also said that he would immediately report the complaint to the local environmental agency, and plan to support the water resources specialists in the watershed support center for prompt field investigation and response.

In addition, each local government promptly discloses information on the homepage by analyzing the causes of complaints when complaints are filed, and residents are encouraged to immediately report any unusual matters to the local government or the relevant departments such as the Environmental Agency.

In order to respond to the detection of tap water larvae, Kyung-yoon Jeong, head of the Han River Basin Environment Office, was at the site to assist in the accident recovery. Incheon Metropolitan City and the Hangang Basin Environment Office formed an expert joint precision investigation team to investigate the propagation of organisms on activated carbon. In progress.

The Ministry of Environment decided to thoroughly control insect repellent to prevent biological organisms from entering the activated carbon while improving the water supply design standards by discussing with experts when it was confirmed that the caterpillar was leaked due to facility problems.

Along with this, we plan to operate'Advanced Water Treatment Operations Guidelines', including guidelines for the use and management of activated carbon, to spread it to local governments, and to operate the nation's Ministry of Environment's Tap Water Caterpillar Response Center.

The Ministry of Environment said that the possibility of polluted tap water flowing into water pipes is unlikely to contaminate the tap water supplied and whether it is harmful, but it should be used only as living water and refrain from drinking.

In addition, he emphasized that the advanced water treatment process is necessary to remove traces of harmful substances, and that the facility will be expanded, but special attention should be paid to prevent recurrence of similar cases.

(Photo = readers provided, Yonhap News)