Assessing the risks of microbial and chemical contamination of drinking water in villages around Zahedan in 2019

Providing quality, safe and hygienic drinking water is one of the most important goals of human societies, and insanitary and unhealthy water consumption brings irreparable risks to humans in the short and long term. Therefore, the health of the community depends on the provision of optimal drinking water. The aim of this study was to determine the chemical and microbial quality of groundwater resources in suburban villages of Zahedan city and to evaluate the hazards of unhealthy water use in terms of chemical and microbial quality in the autumn season of 2019. The type of study was descriptive-analytical, the method of data collection, the field presence of the researcher with the necessary utensils and tools, and in this understanding, the quality of 16 groundwater resources of villages around Zahedan was evaluated in terms of physicochemical and microbial characteristics. The results showed PH, TDS, electrical conductivity, salt, cadmium, lead, and arsenic metals in drinking water in autumn were 7.51 ± 0.47, 2857 ± 0.47 mg/l, 4324 ± 3614 µs / cm, 2.25 ± 2.18 parts per thousand, 0.2194 ± 0.5337, 0.35 ± 0.16, 1.61 ± 1.22 μg / l, respectively. In 87.5% of Coliforms, 56.25% of Escherichia coli, 62.5% of Pseudomonas aeruginosa and 14.58% of intestinal enterococci, respectively. Only one groundwater source had residual free chlorine content of 0.6 mg / l. Therefore, it can be concluded that the chemical quality of groundwater resources in the villages around Zahedan is desirable in terms of pH and cadmium, lead and arsenic metals, but in terms of other chemical parameters studied in a number of villages is undesirable. The microbial quality of the groundwater resources under study is not at the desired level due to the lack of proper chlorination and requires more supervision of the Rural Water and Sewerage Company and rural health centers and the management of water operators in this field.