Management Efficiency Evaluation of Water Supply Systems in North-Eastern Region of Thailand

This paper presents key findings of a comprehensive research aimed at evaluating the management efficiency of water resources and water supply systems in Thailand. The study was carried out in 4 North-Eastern provinces: Nakhon Ratchasima, Chaiyaphum, Surin, and Buri Ram. Four management aspects were examined, namely water resource, water quality, health risk, and engineering. Twenty-seven village water supply systems (VWSSs) and ten city water supply systems (CWSSs) were systematically selected and investigated. The 2 groups represent small systems in rural areas and big systems in city areas, respectively. Water samples were collected once in the rainy season and another in the dry season. For VWSSs, results indicated that 7 reservoir-using systems would have insufficient raw water ranging from 6 - 12 months per year in the next 20 years. Treated water from both surface-water and groundwater VWSSs, in some cases, had color, fecal coliform, and total coliform values which exceed drinking water standards; and had less than 0.02 mg/L residual chlorine, indicating lack of disinfection protection. Multi-route risk assessment revealed several cases of total cancer risk values higher than 10-6, though the HI values seemed to indicate no risk of concern. Evaluation of the engineering aspect predicted that 44% of the plants would have inadequate treatment capacity in the long-run. For CWSSs, it was found that most of the raw water resources ? large reservoirs and major rivers ? can accommodate the future water needs in the next 20 years. Most plants also have the capability to reserve excess water for usage in the dry season and have adequate reservoir sizes. A few water quality parameters were not conforming with standard, e.g. color, iron, and residual chlorine, which could be due to inappropriate operating condition. The health risk study revealed that the THMs levels were within the drinking water standards but the health risk was high in certain cases. On the other hand, the heavy metals were within standards and acceptable risk level. Most of CWSSs have a successful and efficient operation due to the appropriate structure of the organization and knowledgeable plant operators. Some plants, however, have high electricity cost which leads to loss of money in the operation. Comparison of VWSSs and CWSSs results help to understand their current management situation and discrepancy. The research outcomes are beneficial to water supply plant operators and administrators in rural and urban areas and can support relevant parties in management improvement.