Characteristics and Qualities of Tap Water, Sealed Drinking Water and Free Drinking Water in North Dakota, USA

Abstract

In this study, some qualities of tap water, drinking water in sealed containers and free drinking water in North Dakota, USA were investigated. Thirty-two samples of tap water showed transparency, no disgusting odor, values of total dissolved solids (TDS) and pH in the ranges of 205.00±5.20 - 519.67±2.89 mg/L and 8.43±0.06 - 10.27±0.21, respectively. These results indicated that 96.88% of the tap water had pH value over acceptable limits (6.5 - 8.5) recommended by World Health Organization (2011). All thirty-two samples of free drinking water were transparent, odorless, and demonstrated levels of TDS and pH ranging from 32.22±0.58 - 890.00±2.65 mg/L and 8.43±0.12 - 10.57±0.23, respectively. Therefore, 87.50% of the free drinking water in this study was over the allowable values of potable-water-supply quality imposed by Department of Health (2010) owing to exceeding pH value of 8.5. Lastly, all bottled drinking water and gallon bottled drinking water (17 samples) were clear and odorless suitable for consumption, and had an expiry date, label information, and types of plastic container on the products, values of TDS and pH ranging from 1.00±1.00 - 82.67±1.53 mg/L and 6.50±0.10 - 10.40±0.00, respectively. Consequently, drinking water in plastic container (5.88%) was discordant with the criteria set by Ministry of Public Health of Thailand, Notification no. 61 (1981), due to pH value over 8.5. In conclusion, almost all tested drinking water in sealed containers met the criterion, except 1 sample having exceeding pH. Tap water and free drinking water had other good examined properties, but they had high alkalinity attributable to the basic condition of natural raw water. Alkaline water may generate health benefits and require further an additional study.