TY JOUR TI THE STUDY OF THE QUALITY OF DRINKING WATER OF THE CHECHEN REPUBLIC KW drinking water KW threshold limit value KW oil products KW heavy metals KW Chechen Republic KW pol-lutants hardness KW of water city of the Shawl KW city of Grozny KW villages of Alleroy KW Alkhan-Churt KW Itum-Calais KW Katar-Yurt KW Tsentaroy KW village Kalinovskaya KW Khankala JO Bulletin of KSAU AU Ilkhaeva, Z.S. AU Khasaeva, A.I. AU Askhabova, K.N. AU Ozdykhanov, M.S. PY 2017 IS PB Krasnoyarsk State Agrarian University