The bloom, driven by hot weather and nutrient runoff containing phosphorus and nitrogen from nearby hills, has led to excessive algal growth. Heavy rains have exacerbated the situation by washing these nutrients into the lake.
On Sunday, Seoul issued an algal bloom alert for three sections of the Han River, which flows through the city and empties into the West Sea, also known as the Yellow Sea. The rapid spread of algae in these areas was linked to reduced water discharge from the Paldang Dam and increased sunlight.
In response, the Han River Basin Environmental Office has enhanced water purification efforts at 18 facilities in the Paldang area by adding activated carbon and increasing the frequency of drinking water quality inspections from once to twice a week.