All of South Korea’s regular water purification centers are free of larvae or bugs, an Environment Ministry inspection has found, amid public worries that the country may be experiencing a tap water contamination crisis.

The Ministry of Environment said in a press briefing Tuesday that all 435 regular water treatment facilities in Korea had been inspected and no bugs or other foreign organisms were found in their water reservoirs or distribution lines.

A small number of larvae were discovered in filtration sections within centers in Hapcheon, South Gyeongsang Province; Gangneung, Gangwon Province; and Muju, North Jeolla Province. Ministry officials say this is no cause for concern because the worms were found only in filters, meaning no foreign organisms are in the tap water supplied to households. Water goes through filters, reservoirs and distribution pipes before reaching homes.

The emergency inspection, which took 10 days and ended Sunday, was prompted by a series of complaints filed with multiple municipalities and district governments. People had reported finding worm-like creatures in kitchens and bathrooms, supposedly from the tap.

The larva problem first emerged in Incheon, where nearly 500 people reported such encounters, and then became an issue in other cities, including Seoul, Busan and Daejeon.

Authorities in an earlier inspection found that activated carbon filtering systems -- used at 49 water treatment centers in the country -- were the problem. Larvae and other organisms were detected in the filtering systems of two facilities in Incheon and one each in Hwaseong, Gyeonggi Province; Ulsan; and the South Gyeongsang Province communities of Uiryeong, Gimhae and Yangsan. Those filters were replaced and other emergency sanitation measures were taken.

Separately, the Seoul Waterworks Authority said Tuesday that no problems were found with any of its water purifying systems and facilities. The city had received around 50 complaints from residents from July 14 to Sunday.

To reassure the public despite finding no immediate evidence of water contamination, the Environment Ministry said it will swiftly conduct maintenance on old water pipes throughout the country. The ministry vowed to pay extra attention to facilities supplying tap water to areas that reported problems during the latest crisis.

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