Yogyakarta PUPESDM Department Analyzes Mysterious Fires at Seyegan Residence in Sleman

The Yogyakarta Special Region Public Works, Housing and Mineral Resources Energy (PUPESDM) Department suspects the recurring mysterious fires at Mutfiati’s residence in Seyegan, Sleman, over the past week were caused by organic gas emanating from a septic tank. Head of the department, Anna Rina Herbranti, explained the suspicion arose because the soil in Seyegan and surrounding areas is dominated by young Merapi deposits, including volcanic sand, tuff, volcanic ash, breccia, and alluvial sediments from Mount Merapi’s activity. ‘These young volcanic lithologies are typically loose materials and lack the capability to serve as hydrocarbon source or reservoir rocks required in hydrocarbon systems,’ Anna stated when contacted on Friday, 29 May 2026. Additionally, Anna noted that based on regional geological structures, the Seyegan area lacks major structures such as active faults, folds, or sedimentary basins that could form subsurface gas accumulation systems. ‘Thus, the region does not exhibit geological characteristics supporting natural gas potential,’ she added. Based on these facts, Anna suspects the mysterious fire phenomenon in Seyegan is likely due to organic gas, possibly originating from septic tanks. The terrain in Seyegan, Anna explained, is dominated by young volcanic deposits such as sand, clay, and volcanic ash, which are porous. This allows gas from septic tanks to seep to the surface through pores or fissures. ‘Spontaneous fire points can be influenced by various factors, including environmental conditions, presence of flammable materials, possible local organic gas accumulation, or non-geological technical factors,’ Anna said. ‘In this case, field observations indicate methane gas accumulation from septic tanks. If there are small fissures or poorly compacted fill layers, gas can more easily rise to the surface,’ she added. Anna further stated that the department, along with Sleman Disaster Management Agency (BPBD), PLN Sleman UP3, and academic experts, will visit the site tomorrow for handling. ‘The PUPESDM Department continuously monitors and coordinates with Sleman BPBD and PLN. Today, two fire points are still emerging,’ she concluded. Previously, residents of Padukuhan Mriyan X, Margomulyo, Seyegan, Sleman were alarmed by repeated fires that burned household items in one residence. Police investigations suggested the fire originated from a methane gas leak from a septic tank. The homeowner, Mutfiana, said the fires had occurred over the past two days, initially igniting fabric. ‘It started Saturday night at midnight. Initially, fabric caught fire, then spread to door frames,’ Mutfiana told journalists on Sunday, 24 May. Meanwhile, officers from Sleman Police Station’s Inafis team and DIY Police’s Gegana unit promptly visited the scene for investigation. Preliminary findings suggested the fire was triggered by methane gas from the septic tank. ‘According to Gegana unit’s examination, the fire was caused by a methane leak from a septic tank with non-compliant gas venting, allowing gas to enter the house and ignite,’ said Seyegan Police Chief AKP Pujiono when confirmed on Sunday, 24 May.