Korea Hydro & Nuclear Power discharged 172.6 billion tons, accounting for 46.6% of total

No standards for water temperature or chemical discharge; no related research conducted

Rep. Song Ok-ju: 'Concerned about harm to fishers and marine ecosystem — management standards needed'

Photo is unrelated to the article. [Getty Images Bank]
Photo is unrelated to the article. [Getty Images Bank]

South Korea's major power companies discharged more than 370 billion tons of thermal wastewater into the sea over the past five-plus years, raising concerns about the impact on marine ecosystems. The seawater used to cool heat generated during power generation is released back into surrounding waters at temperatures significantly higher than the ambient sea, yet no standards exist for discharge water temperature or chemical content. Korea Hydro & Nuclear Power alone paid 168.8 billion won ($127 million) in fishing compensation over the same period.

Data submitted to Democratic Party of Korea lawmaker Song Ok-ju of the National Assembly's Agriculture, Food, Rural Affairs, Oceans and Fisheries Committee by the Ministry of Climate, Environment and Energy showed that the six major domestic power companies discharged a combined approximately 370.2 billion tons of thermal wastewater into the sea from 2021 through August this year.

Korea Hydro & Nuclear Power led all companies with 172.6 billion tons, accounting for 46.6 percent of the total. Korea Southern Power followed with 63.6 billion tons, then Korea Midland Power with 37.6 billion tons, Korea Western Power with 37.4 billion tons, Korea South-East Power (KOEN) with 31.8 billion tons, and Korea East-West Power with 27.2 billion tons.

Thermal wastewater refers to seawater drawn in to cool power generation equipment and then discharged back into the ocean. It is typically released at temperatures about 7 degrees Celsius above the surrounding seawater.

When large volumes of thermal wastewater enter coastal waters, the resulting rise in sea temperature and drop in dissolved oxygen can disrupt the habitat of marine life. Chemicals such as chlorine, used during the cooling process to remove biofouling organisms, as well as the physical impact of water intake and discharge, are also cited as factors that can harm plankton and other marine organisms.

The core problem, critics say, is the lack of adequate standards for managing the marine environmental impact of thermal wastewater discharge. Song noted that major countries including the United States, Canada and Japan regulate thermal wastewater discharge by law, but South Korea has in effect no separate regulatory standards for either the chemical content of cooling water or its discharge temperature.

Research on the issue has also been lacking. Data obtained by Song showed that not a single research project related to thermal wastewater was carried out from 2021 through August this year.

Meanwhile, fishing compensation payments have continued. Korea Hydro & Nuclear Power paid a total of 168.8 billion won in fishing compensation related to thermal wastewater impacts from 2021 through this year. Despite ongoing compensation to fishers living near power plants, disputes over thermal wastewater discharge remain unresolved.

"There are serious concerns about harm to fishers and disruption to marine ecosystems caused by thermal wastewater discharge from power plants, yet there are no discharge regulations and research remains inadequate," Song said. "Reasonable discharge standards must be established as soon as possible so that the issue can be managed systematically."


adastra@heraldcorp.com