Worm-like creatures that were first found in tap water in Incheon were detected at seven water-purifying facilities across the country, the government confirmed Tuesday, suggesting that water contamination wasn’t limited to just Incheon.

The Ministry of Environment’s three-day inspection which ended Friday found larvae of nonbiting midge and other organisms at seven out of a total of 49 water treatment centers with an activated carbon filtering system.

They are two facilities in Incheon and one each in Hwaseong, Gyeonggi Province; Ulsan; and Uiryeong, Gimhae and Yangsan in South Gyeongsang Province, the ministry said. Contaminated filters have been replaced at those sites, along with other emergency sanitation measures, officials said. The sites were also told to conduct maintenance improvements and report the results by Thursday.

On top of the carbon filtering facilities, the ministry has also kicked off an emergency inspection on all 435 regular water-purifying centers in the country starting Friday.

So far, there has been no report of a bug problem, the ministry added.

The tap water crisis first began in Incheon where nearly 500 people reportedly found worms in bathrooms and kitchen sinks. Public fear has now spread to other areas including Seoul, Busan and some cities in Gyeonggi Province, with several citizens reporting similar encounters. 

The ministry and local governments, while investigating those reports, said in most cases, external sources were suspected, other than contamination of tap water itself.

Seoul’s inspectors raised the possibility Monday that the bugs and other organisms could be from sewage systems, not from tap water pipes.

In Incheon, a total of 508 complaints have been filed between July 9 and last week by residents who claimed to have found worms in their tap water. City officials have collected creature samples from 149 of the reported cases.

The Environment Ministry set up a team of experts Thursday to investigate the sources of contamination and come up with comprehensive measures to improve the management of drinking water. It plans to upgrade sanitation measures to prevent bugs from entering water filters in the first place while implementing certification programs for maintenance guidelines.

By Ko Jun-tae (ko.juntae@heraldcorp.com)