Sungai Belik in Bantul Severely Polluted with Organic Waste, Causing Mass Fish Deaths
Water sample tests from Sungai Belik in Pandes I, Pleret, Bantul have been released. The Bantul Environmental Agency (DLH) states there is severe organic pollution in the river water, causing foam and resulting in numerous fish deaths.
Acting Head of DLH Bantul, Fenty Yusdayati, said nine indicators were tested from the Sungai Belik water sample. The results show only three indicators remain within normal limits.
“Out of the nine indicators tested, only three are still within normal limits: pH 7.8 mg/L, nitrate as N 6.48 mg/L, and detergent 0.63 mg/L,” Fenty said when contacted by reporters on Friday (8/5/2026).
Meanwhile, other indicators such as Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), phosphate, and ammonia exceed environmental quality standards. It should be noted that BOD and COD are important parameters for measuring the level of organic pollution in water.
“The BOD value reaches 4,215.3 mg/L while COD is 15,012.5 mg/L. These values are extremely high and indicate very severe organic pollution levels,” she stated.
Therefore, Fenty recommends routine monitoring of water quality every three months. Additionally, resampling from the IPAL outlet and DAM Pandes, as well as improvements to the communal IPAL, especially the control tank.
“We will also conduct outreach to users of the communal IPAL so that waste discharged into the treatment channel does not trigger river pollution again,” she said.
Previously reported, a video post showing residents collecting dead fish from the Sungai Belik flow in Pandes I, Wonokromo, Pleret, Bantul went viral on social media. The head of Pandes suspects the fish deaths were due to exposure to liquid waste, while the Environmental Agency (DLH) has taken samples of fish and water for laboratory testing.
“This morning, Sungai Belik Pandes, Wonokromo, Pleret, Bantul was hit by waste. The river water was full of foam, causing fish to die. This is not the first time it has happened; it has occurred before, and the repeated incidents suggest the perpetrators are not deterred,” said the Instagram account @merapi_uncover as seen by detikJogja on Monday (20/4).
Head of Pandes I, Budi Cahyono, confirmed the incident. Budi revealed it happened that morning around departure time for work.
“It’s true, the incident occurred around 8 a.m. Initially, residents saw foam in the Dam Belik Pandes I water, and upon checking, many fish were gasping (fainting),” he said when met in Pandes I, Bantul, on Monday (20/4).
According to Budi, the number of gasping fish was very large. Residents used buckets and even suitcases to collect the fish.
“The number of fish is a lot, perhaps thousands, because one of my residents got a suitcase full of fish, and others used large buckets. The fish species were noisy ones like wader, tawes, tilapia, red devil, and sapu-sapu fish,” he said.