Wastewater Treament Plant



Mahidol University, Salaya Campus has used the oxidation pond as the central wastewater treatment plant since 1981. However, as a consequence of growing in numbers of building and population (i.e. staffs and students), the system is overcapacity. Moreover, the process is also decadent due to operation and insufficient maintenance. This problem provokes the leakage of wastewater to the public water sources, and eventually the water pollution. As a result, Mahidol University conducted the study, survey, and design of the new central treatment plant for handling the increasing wastewater from every building in the campus. The design capacity of the new plant is 600 m3/day. The first phase will serve for wastewater from student dormitories, Ban-Mahidol.

  1. To improve the efficiency of the university's wastewater treatment plant in order to meet the discharged water quality standard (Category I) of the Pollution Control Department (PCD), which the biochemical oxygen demand (BOD) is less than 20 mg/l.
  2. To be a long term solution and prevent the problem of wastewater discharge to public water source
  3. To promote a good surface water and wastewater management programs in Mahidol University
Design area.

The designed site covers the area of approximately 2 rai including the wastewater treatment process in the west of Mahidol University, Salaya Campus, Nakornpathom province.


The construction will be finished within 210 days and is now under the procurement process.

Phase 1 can serve the wastewater capacity of 1500 – 1800 m3/day from 9 student dormitories, the multi-purpose builiding, and the MU cafeteria. The system contains a grit chamber, an aeration pond, a sedimentation pond, sludge dewatering process, and the operator office with chemical warehouse. The wastewater collection system from the dormitories 1 – 11, except the dormitory no. 5, is also included.


Phase 2 consists of 1 aeration pond, 1 sedimentation pond, sludge dewatering building, and chlorination tank. The equalizing tank will be placed under the field behind the dewatering building. The collection system for this zone contains a the capacity of 3000 – 3600 m3/day.


Phase 3 contains 2 aeration and 2 sedimentation ponds with a collection system for the remaining wastewater from other zones. The capacity of this phase is 6000 m3/day.