Bangkok is moving ahead with plans to transform part of the long-serving On Nut waste disposal facility into a Green Eco Park, while stepping up efforts to tackle odour complaints and preparing to launch real-time public monitoring of smell levels.
Bangkok governor Chadchart Sittipunt visited the On Nut waste disposal facility in Soi On Nut 86 on Saturday to inspect progress on site rehabilitation, odour-control measures and the long-term redevelopment of the area into a combined waste management and green space area.
Mr Chadchart said the facility, in place for more than 30 years, covers about 580 rai and was originally used as a landfill site. Over the past four years, the Bangkok Metropolitan Administration (BMA) has planted more than 48,000 trees across the area, turning former waste disposal zones into forested land.
He said the city was preparing to develop trail-running routes and recreational areas for public use. Trees relocated from construction projects across Bangkok have also been replanted at the site as part of efforts to preserve the city's tree stock and expand green space.
"Trees are assets of the city," Mr Chadchart said.
The governor said biodiversity had begun to return to the area, with various bird species and wildlife now being observed.
Deputy Bangkok governor Pornphrom Vikitsreth said odour complaints were largely linked to two ageing composting plants with capacities of 600 tonnes and 1,000 tonnes. The facilities use older composting systems that generate unpleasant smells.
The contract for the 600-tonne plant will expire at the end of 2026, while the 1,000-tonne facility is due to cease operations in June 2027. Both areas are expected to be converted into additional green space after their contracts end.
The BMA has intensified oversight of the facilities by installing electronic odour-monitoring devices known as e-Noses, CCTV systems and improvements designed to prevent odour leakage. Waste disposal operations are also monitored daily.
Mr Pornphrom said e-Nose devices measure odour intensity in Dilution to Threshold (D/T) units. Most readings have remained between 0 and 3 D/T, while stronger odour episodes have reached about 5 D/T, still below the standard threshold of 9 D/T.
Mr Chadchart said data from the e-Nose monitoring network would be made available online this week to allow residents to track odour levels in real time.
The BMA's longer-term vision is to redevelop the site into a Green Eco Park, with roughly half the area allocated to green space and the rest dedicated to enclosed waste management systems, including environmentally friendly waste-treatment technologies.
The facility already includes plans for a 1,000-tonne waste-to-energy incinerator, a biogas plant that converts waste into electricity, enclosed transfer stations and a dedicated wastewater treatment system.
Governor Chadchart said odour problems had not yet been fully resolved but said the city was working within contractual and legal frameworks to improve conditions while developing the site into a model for sustainable waste management and urban greening.
