Evaluation of Yangon city tap water quality and the efficacy of household treatment

Yangon was one of the first cities in Asia to establish a tap water system. However, the city's water supply infrastructure now lags far behind those of other regions as a consequence of political instability over the last six decades. The installation of disinfection facilities in the tap water system and the enactment of the Myanmar National Drinking Water Quality Standard (MNDWQS) were accomplished only recently during the short period of democratic government. Due to the lack of reliable published information, the suitability of the tap water for drinking remains unclear to city residents. The quality of tap water and bottled water in the central business district was examined to assess compliance with the MNDWQS. The results showed that 95% of tap water delivered to homes was contaminated with Escherichia coli or coliform bacteria. Only 14% of bottled water was free of E. coli and coliform contamination. The efficacy of household treatment devices was tested, and ceramic purifiers (CPs) and reverse osmosis (RO) devices were found to be highly (>99%) effective for E. coli elimination. RO devices performed better in terms of dissolved organic carbon reduction at 60% compared with 43% reduction with CPs.