. In this study examination of label information physical and microbiological qualities was performed in 30 clear-plastic and 3 opaque-plastic bottled drinking water products distributed in city municipality of Ubon Ratchathani. Results showed that 12 clear-plastic (36%) and 3 opaque-plastic (9%) bottled drinking water samples had no expiry date on the product labels which were discordant to the criteria for drinking water in sealed containers imposed by the Ministry of Public Health of Thailand no. 383 (2017). Odorless appearances of all drinking water samples were observed. Values of pH in 4 clear-plastic (12%) and 3 opaque-plastic (9%) bottled drinking water samples were in the ranges of 6.21±0.00–6.29±0.03 which were below the allowable limit (pH 6.5–8.5). All bottled drinking water products contained numbers of total coliform and fecal coliform bacteria less than 2 MPN/100 mL and were devoid of E. coli. Therefore based on the quality of clear-plastic and opaqueplastic bottled drinking water products distributed in city municipality of Ubon Ratchathani 1 5 samples (45%) did not meet standard for drinking water in sealed containers declared by the Ministry of Public Health of Thailand (1981 and 2017) owing to no expiry date labeled on the products and pH value below 6.5.

In this study water quality standard of bottled drinking water distributed in Ang Thong Province was investigated. The results showed that clear plastic bottled drinking water presented completely label information and MFD./EXP. clearly appearance and odourless presented in all samples while Total Dissolved Solid (TDS) of tested clear plastic bottled drinking water samples were in a range of 1±0.00 to 277±0.00 mg/L. Coliform bacteria and fecal coliform bacteria of all tested water samples were less than 2.2 MPN/100 mL and E. coli and total heterotrophic bacteria were not found in all samples. pH values of 18 tested samples were less than 6.5 (60.00%) plastic bottled drinking water samples. Tested opaque plastic bottled drinking water samples showed completely label information and MFD./EXP. clearly appearance and odourless found in all samples while TDS of tested opaque plastic bottled drinking water samples were in a range of 12±0.00 to 13±0.00 mg/L. Coliform bacteria and fecal coliform bacteria of tested water samples were less than 2.2 MPN/100 mL and E. coli and total heterotrophic bacteria were not found in all samples. pH values of 3 tested samples were less than 6.5 (100.00%). Indeed assessment of both types of bottled drinking water samples distributed in Ang Thong Province Thailand based on 6 qualities assessment of standard for drinking water in sealed container set by Ministry of Public Health of Thailand revealed that the tested clear and opaque plastic bottled drinking water samples met the standard for 40.00% and 0% based on pH respectively.

In this study pH physical and microbiological qualities of clear and opaque plastic bottled drinking water produced in Buriram Province Thailand were investigated. Samples of bottled drinking water (N=22) were 8 clear plastic bottles and 14 opaque plastic bottles. Results showed that pH value of all samples were in a range of 6.04 ± 0.03 to 7.61 ± 0.01 in which 7 samples were not acceptable according to the criteria for drinking water in sealed containers declared by the Ministry of Public Health of Thailand. Coliform bacteria in all tested samples were less than 1.8 MPN/100mL and none of E. coli was detected. Therefore consumers of bottled drinking water produced from Buriram province should be aware of health safety because some drinking water products were unacceptable in terms of pH value.

The objective of this research was presented a decision support making process for efficiency improvement of drinking water processing using retrofit technique for machine and equipment rehabilitate. This methodology was applied Analytic Hierarchy Process (AHP) for selecting an appropriate maintenance sub-contractor. To complete the research existing water purifying machine and tools were inspected to assess its capacity. Future capacity of the purifying machine was also identified. Consequently machine and tools such as water tank and water filter were inspected for retrofitting for the example water tank water filter water quality control and bottle packing. Finally the analytic hierarchy process was utilized to select the most appropriate maintenance sub-contractor. In this process both qualitative and quantitative processes were analysed. The result of this research has been found that this multicriteria decision making process could be used to support the decision making investment process of water purification retrofit unit at Faculty of Engineering Rajamangala University of Technology Phra Nakorn efficiently. Furthermore it could be reduced bias from decision makers while the decision was accepted by all stakeholders.