A notice that reads "COVID-19 test kits available" is put up in a pharmacy in Seoul on Friday. (Yonhap)

South Korea is seeing a pronounced rise in the levels of COVID-19 in wastewater as the number of confirmed cases continues to swell throughout this month and is expected to peak in late August, health authorities said Sunday.

The surge in wastewater virus concentrations -- one of the key gauges to track and estimate community spread -- has more than quadrupled from late April to early August.

Amid the ongoing summer COVID-19 wave, the average concentration of the virus at local sewage plants stood at 47,640 copies per milliliter for the second week of August (Aug. 4-10), data from the Korea Wastewater Surveillance program, run by the Korea Disease Control and Prevention Agency, showed.

The corresponding figure for the fourth week of April (April 21-27) was below the 10,000 mark per milliliter but reached 13,336 in the fourth week of July (July 21-27) and 24,602 in the first week of August (July 28-Aug. 3), according to the KDCA.

The concentrations are based on samples taken from 84 sewage treatment plants across the country to estimate how many COVID-19 cases are occurring in different areas, the KDCA explained.

Health authorities have been using the water waste surveillance method since April last year to assess and trace the number of COVID-19 patients within communities.

The latest data showed that the virus levels in 14 regions -- except North Gyeongsang Province, Jeju and North Jeolla Province -- increased more than the previous week.

In line with the surge in virus levels in wastewater, the country is also seeing an increase in the number of patients hospitalized with COVID-19, the KDCA noted.

The number of newly admitted patients for the second week of August came to 1,359 -- the highest level this year and a twofold increase from 477 in the fourth week of July. The figure also accounted for approximately 66 percent of newly admitted patients, according to the KDCA.

With the summer COVID-19 wave showing little signs of slowing, officials said they plan to secure sufficient treatments for 260,000 COVID-19 patients and start supplying them this week.

Health authorities added that they will have treatments available nationwide by the end of this month and will begin administering vaccines effective against the COVID-19 variant KP.3, which made up nearly 45.5 percent of the cases in the country last month.

Health Minister Cho Kyoo-hong said during a parliamentary hearing at the National Assembly on Friday that the government was "carefully monitoring" the summer resurgence and plans to secure more beds at public medical institutions to cope with the increase in cases.

The KDCA, however, noted that the current resurgence has not led to a significant increase in the rate of critically ill patients or fatalities compared with previous COVID-19 waves.

The KDCA also recommended wearing facial masks when visiting crowded spaces, ventilation, handwashing at regular intervals and covering mouth and nose when coughing or sneezing to prevent the spread of the virus.