The Mass Rapid Transit Authority of Thailand (MRTA) visited the Purple Line South tunnel, affirming efforts to quickly resolve water and sand leakage issues using engineering techniques to reduce ground surface movement. They emphasized that construction progress has surpassed 70%, with completion expected as planned in 2027.
At 3:00 p.m. on 10 July 2026, Mr. Montri Dechasakulsom, Chairman of the Mass Rapid Transit Authority of Thailand (MRTA), Mr. Katphachon Udomthamphakdi, MRTA Governor, and Mr. Kitti Ekkawalap, MRTA Assistant Governor and Acting Deputy Governor (Finance), inspected the site to monitor the situation.
Mr. Kitti stated that this location is undergoing repairs to reduce water and sand leakage. The faster the leakage is controlled, the sooner ground and road surface movement can be halted, using engineering techniques. Construction progress on the Purple Line South underground train currently exceeds 70%. Contract 4 is nearly 100% complete and expected to finish within this month. Contract 3 remains, with the first tunneling machine currently near Sam Yot Station and the second near the Constitutional Court. Overall, the project is expected to be completed by October 2027.
Looking back to Wednesday morning, reports indicated water leakage inside the tunnel. Contractors attempted repairs but could not stop the leak due to underground water pressure reaching about 20 meters at the site. This caused flooding inside the tunnel. Officials are pumping water out at a rate of 50 cubic meters to maintain water levels, preserving the pressure inside the tunnel. If the water were removed entirely, external water would flow in. The ongoing rainy season is considered a challenge because it increases underground water problems.
To assist residents near the affected area, MRTA and contractors coordinated with Bangkok Metropolitan Administration to provide temporary accommodations and cover expenses. A coordination center has been established at the site to facilitate assistance; affected residents can come there to request help.
Additionally, the construction of Sam Sen underground station, which previously faced problems, is expected to reopen by the end of 2027. MRTA currently has two projects under construction: the Purple Line South and the Purple Line North.
MRTA confirmed strict adherence to construction protocols. Whenever water leakage is detected during construction, work at that point is halted and repairs are made to dry the area before proceeding to the next phase. Therefore, no quality issues have been reported so far. However, the true cause of this incident will require further investigation to establish the facts.