MRTA explained the water seepage incident in the Purple Line tunnel at Wongwian Yai intersection, confirming that the water volume is under control, with no impact on the structure and no road subsidence. The Prime Minister visited the site and ordered strict safety monitoring.
A water seepage incident occurred inside the underground railway tunnel's sump pit about 30 meters below street level at Wongwian Yai intersection, within the Purple Line construction area from Tao Poon to Rat Burana (Kanchanaphisek Ring Road) contract 4, spanning Phut Bridge to Dao Khanong, on 8 July 2026.
The Mass Rapid Transit Authority of Thailand (MRTA) clarified that the water seepage is presumed to be from the joint area of the sump pit, which does not affect the tunnel’s structural integrity. The contractor for contract 4 is urgently conducting ground improvement to stop the water seepage, alongside closely controlling the seepage volume following engineering principles. Currently, the water seepage is controlled, causing no road or adjacent building subsidence. MRTA has instructed the construction supervision consultant PMCSC2 and contract 4 contractor to continuously inspect and monitor the stability and safety of nearby buildings.
At 11:00 p.m. on 8 July, Prime Minister and Minister of Interior Anutin Charnvirakul, along with Deputy Prime Minister and Minister of Transport Phiphat Ratchakitprakarn, Minister of Transport’s deputies Siripong Angkasakulkiat, Pattaraphong Pattaraprasit, Sanphet Boonyamanee, and Deputy Minister of Interior Worasit Liangprasert, visited the site to follow up on the situation.
The Prime Minister and Minister of Interior ordered MRTA to increase safety surveillance of nearby buildings continuously to ensure public confidence and safety as a priority, and to prepare emergency response plans. The Department of Disaster Prevention and Mitigation (DDPM) and police officers are supporting these efforts.
For more information from MRTA, visit www.mrta.co.th, the official Facebook page of the Mass Rapid Transit Authority of Thailand, or call MRTA’s Call Center at 0 2716 4044. Information on the Purple Line project is available at www.mrta-purplelinesouth.com, the Purple Line Facebook page for Tao Poon - Rat Burana, Line @mrtpurpleline, and the Purple Line South TikTok channel.
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