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there is a small insect coming out of the tap water in Incheon tomorrow (23rd), it will enter the second week. In the water purification plant, larvae are currently being investigated at the place where water is filtered through activated carbon, a kind of charcoal. It should have been cleaned frequently, but it wasn't, and it seems likely that larvae were formed due to insufficient facilities to prevent insects.

Reporter Kang Min-woo.

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Of the seven water purification plants in the country where caterpillars were found in activated carbon filters, only two water purification plants in Incheon traveled to homes through water pipes.

The joint research team noted that the cleaning cycle for activated carbon filters was too long.

In both water purification plants, the filter is cleaned by spraying water from bottom to top once every 20 days. It is three times longer than the Yeongdeungpo water purification plant in Seoul, which receives water from the same water intake.

There are no standards for how often to clean every few days.

Due to the nature of the filter, debris such as organic matter is placed under the filter, and because of the water flow, the caterpillars descending down move further down in search of food and often do not clean.

[Yang, Young-Cheol/Eulji University Professor of Health and Environment Safety: Fine organic particles are deposited under activated carbon. Isn't the midget larva the best organic material to eat? So the more caterpillars move under activated carbon… .]

It is presumed that the installation of insect screens to prevent worms was also insufficient, but even in closed water purification facilities, some have to leave doors and cannot completely block worms.

You should have kept the worms out, or washed them frequently to create an environment where the larvae couldn't inhabit, but none of them worked.

The Ministry of Environment belatedly announced that it would supplement the nation's water purification facilities and establish standards for cleaning cycles.

(Video coverage: Park Hyun-cheol, Video editing: Seung-jin Lee, CG: Jun-ho Lee)