Ulaanbaatar, March 30, 2026 /MONTSAME/. First Deputy Governor of the Capital City Davaadalai Tumendalai and relevant officials conducted an inspection in the Biocombinat area of the 12th khoroo of Khan-Uul District.

According to water quality index assessments, the section where treated wastewater from the Central Wastewater Treatment Plant is discharged—particularly along a western branch of the Tuul River—has been identified as the most polluted stretch.

During the visit, the First Deputy Governor Davaadalai noted that the Tuul River originates in the Khentii mountain range and flows for 882 km. Monitoring conducted at 10 points between 2022 and 2024 showed very high levels of pollution downstream of Songino area. He recalled that the Central Wastewater Treatment Plant, built in 1964 with a capacity to treat 160–180 cubic meters of wastewater per day, has not been modernized, contributing significantly to the river’s pollution.

He added that a new treatment plant is being constructed with support from the Millennium Challenge Corporation and is scheduled to be commissioned in May this year. Following its completion, phased clean-up measures will be implemented to restore the Tuul River, with eight priority areas identified. In addition, the “Khargia” industrial wastewater treatment facility, commissioned in 1974, is operating beyond capacity, leading to contamination by heavy elements.

To address this, the city is implementing a project at the Emeelt Eco Industrial Park to build Mongolia’s first wastewater treatment facility dedicated to treating pollution from the leather and hide-processing industry. Davaadalai also noted that a draft resolution to launch a “Save the Tuul River” campaign is being prepared for submission to the Citizens’ Representative Khural of Ulaanbaatar.

Head of the Capital City Environment Department Munkhbayar N.,stated that the Tuul River runs for 115 km through seven districts of Ulaanbaatar. Between the Central Treatment Plant and Altanbulag soum, approximately 21 km of the riverbed has accumulated sludge layers 20–40 cm thick, while a further stretch downstream to Lun soum has around 5 cm of sediment. Studies by international organizations suggest that the pollution can be removed through mechanical cleaning, and German equipment available at the Water Agency could be used for sludge extraction.

Water engineer.Baranchuluun Sh., said that both treated effluent and emergency discharges from the Central Treatment Plant are entering the river. A 2022 study found sludge deposits of 40–50 cm thickness in some sections, describing the situation as “a real disaster.” He also pointed to abandoned gravel quarries upstream that have not been rehabilitated, further worsening flow conditions. He stressed the need for both river channel regulation and pollution removal, noting that contaminants continue to flow downstream as far as Lun soum bridge and, at times, to the confluence of the Orkhon and Tuul rivers.

B.Erdene, head of the Mongolian Remote Sensing Association, noted that more than 100 unreclaimed pits—ranging from 50 cm to 5 meters deep—were identified in a census conducted seven years ago. She warned that polluted water is affecting livestock that depend on the river, raising serious food safety concerns at the national level.

Environmental officer Ts.Saruulbayar noted that the area known as “Nogoon Bulan” in Khan-Uul District was once a clean and scenic recreational site, but has become heavily polluted in recent years due to the overcapacity of the treatment facility.