[Curiosity Lab] 'This' Is More Abundant in Ulleung Than Samda Jeju

Jeju Island, the Land of Three Abundances for Women... Ulleungdo is Oda with Water and Juniper
Rainwater from the sky seeps into the volcanic island's ground, so no water worries
Jeju developed Samdasu, but Ulleung's development is slow
With removal of obstacles like regulations, it may come out as early as the first half of next year

Scenery of Ulleungdo Photo by Ulleung-gun

Both Ulleungdo and Jeju Island are volcanic islands and popular tourist destinations. However, their sizes differ. Jeju is the largest island, and based on the size of a soccer field, about 200,000 fields could fit on it. In contrast, Ulleungdo is about 9,000 fields in size, making it roughly 20 times smaller. Jeju Island is called Samdado (三多島), meaning "many stones (石多), many winds (風多), and many women (女多)." Ulleungdo is referred to as the island of 3 mus (無) and 5 das (多). The 3 mus represent no thieves, no pollution, and no snakes, while the 5 das refer to water (水), beauty (美), stones (石), wind (風), and fragrant trees (香). Both Jeju and Ulleung are islands, yet there is no talk of water shortage because they are volcanic islands. Rainwater seeps into the ground, becoming volcanic bedrock water or spring water. The reason Ulleung has abundant water is similar but also different.

Nari Basin is the only flat area on Ulleungdo. It measures about 1.5 km east to west and about 2 km north to south. Nari Basin is a caldera formed when part of the crater collapsed after a volcanic eruption. Baekdusan’s Heaven Lake and Hallasan’s Baengnokdam are also calderas. Although Nari Basin is a caldera, water does not accumulate there. Thanks to pumice, which is light enough to float on water, even during the rainy season with heavy precipitation, water does not pool but seeps underground. The spring water that gushes out at a rate of 20,000 tons per day and Bongrae Waterfall, with a flow of 3,000 tons per day, are landforms created due to the presence of pumice. The spring water source is a special feature unique to Ulleungdo. Jeju Island is famous for its drinking water called Samdasoo.

Scenic View of Ulleung Jukdo Island
[Photo by Ulleung-gun]

According to Jeju Development Corporation, the source of Jeju Samdasoo is rainwater. It was discovered that rainwater falling at an altitude of 1,450 meters within Hallasan National Park seeps underground to form the water. This area is a pristine, untouched natural region with more rainfall than other areas.

The time it takes for rainwater to seep underground and become drinking water is called groundwater age or groundwater residence time. According to the final report of the Comprehensive Survey on Jeju’s Hydrogeology and Groundwater Resources (2000), the groundwater age of Jeju Samdasoo is between 18 and 22 years. The Samdasoo produced today is rainwater that fell 18 to 22 years ago, slowly passing through volcanic bedrock layers that act as a natural water purifier.

Even with such extraction, will the water run dry? In Jeju’s case, 43.5% of rainwater infiltrates the ground to become groundwater, showing a groundwater recharge rate more than three times higher than other regions in Korea. Only 0.09% of the groundwater recharge is used for Samdasoo, so the impact on Jeju’s groundwater is minimal.

Scenery of Nari Basin, Ulleung [Photo by Ulleung-gun]

Then why is there no drinking spring water on Ulleungdo? According to Ulleung County, the estimated spring water is highly mineralized and of excellent taste, classified as pristine first-class water. Ulleung County uses 3,000 cubic meters per day for water supply and 9,000 cubic meters per day for hydropower generation, while the remaining water flows directly into the sea. For over ten years, a drinking spring water project has been promoted on Ulleungdo. The plan is to utilize some of the spring water that currently flows into the sea, sell it as bottled spring water to improve the poor financial independence of the region, and create jobs for local residents. Therefore, the spring water is called "Blue Gold."

In September 2017, Ulleungdo selected LG Household & Health Care Ltd. as a private business partner and established the public-private joint corporation Ulleung Sammul Co., Ltd. Most drinking spring water in Korea is extracted from bedrock, but Ulleung Sammul is developing a project to use spring water directly. However, the project stalled due to differing interpretations of whether the spring water qualifies as tap water. Current Water Supply Act prohibits anyone from bottling or reprocessing tap water for sale. On the other hand, Ulleung County argues that the spring water flows through intake pipes to a water purification plant and is used as tap water, but since the water is drawn directly from the intake pipes before the purification plant, it is not tap water.

Jeju Samdasoo production line view
[Photo by Jeju Development Corporation]

The project received a green light after the Board of Audit and Inspection’s preliminary consulting judged the Ministry of Environment’s legal interpretation to be incorrect. Earlier, on the 23rd of last month, Gyeongbuk Province announced that it had granted a drinking spring water manufacturing license to Ulleung Sammul Co., Ltd. If the water quality remains stable after one year of sealed storage, the drinking spring water is expected to be marketed around May next year.