In the decentralized water supply sources all tacsons, except 6 tacson, had an unfavorable self-purification
processes and incompleteness of nitrification activity. Therefore the average annual indicators in the water samples, carried out in 1 – 5 tacsons, increased in dynamics by the nitrogen ammonia: from (0.24±0.05) to (0.43±0.20) mg/dm3, i.e. in 2.0 times, in comparison with content of nitrates: (5.95±0.06) to (14.72±5.57) mg/dm3, which increased in 2.5 times (p < 0.001). It was proved that water from decentralized sources in the 1 – 5 tacsons of Dnipropetrovsk region did not correspond to the GOST 7525:2014 caursed by the high concentration of nitrites and nitrates between 2008 and 2014 year. Thus, according to
the average annual indicators was identified high level of nitrites (42.5 MAC), nitrates (1.2 MAC) in the 1 tacson; (1.4 MAC) of nitrites and (2.0 MAC) of nitrates in the 4 tacson. Unfavorable nitrification activity in the decentralized drinking water sources in all tacsons of Dnipropetrovsk region, except 6 tacson, in 2008 – 2014 years was shown incompleteness of the self-purification water in the rural settlements, causing primary morbidity among peasants as well as the blood and blood – forming organs, methemoglobinemia among infants due to a consumption of water from wells. In the centralized water supply sources of all tacsons was identified poor self-purification, as well as nitrogen ammonia decreased in dynamics for 2008 – 2014 years, while nitrites and nitrates contents increased. Only in the 2 tacson was significant decreased in dynamics of ammonia nitrogen (1.2 MAC) against rising of the nitrates levels (2.3 MAC) (p < 0.001). However, overnormal oxidation (1.09 MAC) in 2014, with increasing in dynamics for 2008 to 2014 year described organic nature of pollution in the given tacson. All tacsons of Dnipropetrovsk region, except 2 tacson, did not correspond to some indicators: 1 tacson – nitrites (30.9 MAC) in 2012; 3 tacson – nitrogen ammonia (1.06 – 1.52) MAC in 2009, 2011, (1.42 MAC) in 2012, 2013, (1.36 MAC) in 2014; 4 tacson – oxidation (1.33 – 1.15) MAC in 2008, 2014; 5 tacson – nitrogen ammonia (1.02 MAC) in 2011, nitrites (1.6 MAC) in 2014, oxidation (1.21 MAC) in 2010. Recommended collective installations of drinking water purifiers, primarily in the medical – preventive and children's educational institutions in all rural tacsons of Dnipropetrovsk region
