Assessing microbes safety of rural drinking water in Ya'an, China

In this study, based on the total conforms (TC) and total bacteria (TB) detected in rural drinking water resources (RDWR) of Ya'an, and applying exponential model and β-Poisson model of "low microbe content risk assessment", the quantitative evaluation of risk associated with TC count and TB in 221 water samples was developed. Results showed the annual risk values (ARV) of all the water samples were generally consistent within one order of magnitude, indicating the β-Poisson model and the exponential model were consistent when simulating the ARV associated with TC and TB. According to the requirements of Sanitary Standard for Drinking Water (GB5749-2006) and of Quality Standard for Groundwater (GB/T14848-93), TB and TC fail to meet the standard in most RDWR within the studied area. This study quantitatively reflected the relationship between the quality of RDWR and the residents' health, assisting the comprehensive evaluation of the health risk, improving the water supply and ensuring drinking water safety.