Evaluation of groundwater quality of Kelkit (Gümüşhane) region

In this study, the quality of the groundwater of the center of Kelkit district, located in the south of Gümüşhane province, was investigated. In this context, two periods of sampling were carried out: the dry (June 2023) and the rainy (September 2023) period. The physical parameters (temperature, pH, Eh, electrical conductivity and dissolved oxygen) of the samples obtained were measured in situ in the field and major anion-cation (HCO3-, CO3-2, Cl‒, SO4-2, NO3-, NO2-, Ca+ 2, Mg+2, Na+, K+) and trace element concentrations (Si, Al, As, B, Ba, Br, Co, Cr, Cu, Fe, Mn, Mo, Ni, Sr, Sb, Ti, V and Zn ) was determined in a laboratory environment. The results obtained from the analyses were evaluated in terms of drinking irrigation water availability according to the World Health Organization (WHO) and Water Pollution Control Regulation standards. In addition, the water type of all samples taken from groundwater and Kelkit stream were examined with the Piper diagram and their usability as irrigation water with the US Salinity Laboratory and Wilcox Diagram. According to the Piper diagram; More than half of the groundwater samples of the Kelkit region are of the "calcium-magnesium-bicarbonate" water type. Three of the samples are in the "Mixed type waters" class during the dry period and two during the rainy period. According to the Wilcox diagram; While groundwater samples are generally in the "Good-usable" water class during dry and rainy periods, according to the US Salinity diagram; It was observed that the water samples taken from the wells generally represented water in the C3‒S1 class, and a few of them represented water in the C2‒S1 class. In the measurements made in major cation analyses, it was observed that Mg⁺² and K⁺ cations exceeded the limit values according to drinking water standards. In major anion analyses, it was determined that nitrate and fluoride values exceeded the limit value specified according to TS 266 drinking water standards. In trace element analyses, B, Fe, and Mn values remained above the limit specified according to TS 266 standards.