ECOLOGICAL CONDITION OF DECENTRALISED WATER SUPPLY SOURCES IN DROGOBYCH DISTRICT

Abstract

The deterioration of the ecological state and pollution of all water sources has made the preservation of drinking water quality an urgent problem that needs to be addressed at all levels of government. The study of the ecological state of well water in some settlements of Drohobych district, namely Drohobych, Skhidnytsya, Stebnyk, Nahuyevychi, Bolekhivtsi, Dobrohostiv, Ulychne, Nove Selo, was carried out seasonally during 2020–2021. The environmental status of decentralised water supply sources was determined by hydrochemical and sanitary-bacteriological indicators. The study of hydrochemical indicators showed that the content of chlorides and phosphates does not exceed the MPC, so such water can be considered suitable for drinking. However, the content of ammonium ions in all well water exceeds the standard values by 1.5 to 3 times. We consider that the high ammonium content is caused by fertiliser being washed away from agricultural fields along with precipitation, and by the improper location of wells near cesspools and livestock holding areas. The winter MPL values were significantly lower than in autumn and summer, but in Drohobych, Stebnyk, Nahuyevychi and Bolekhivtsi these values exceeded the norms. The values of the total microbial count exceeded the MPC by 1.5–3 times. The permissible value of the coliform index for wells is no more than 10 CFU per 1 cm3 of water. Our research showed that the water from Drohobych did not meet the standard throughout the entire study period, and samples from Skhidnytsia and Litynia did not meet the standard during the summer study period.