Impact of thermal water on environment case study of Mila and Guelma region, Algeria

A hydrochemical characterization of the waters of the study region (North-East Algeria) was carried out following samples taken at 36 thermal springs and their effluents during May 2022. The analysis of the waters allowed to establish the chemical facies and their classification according to the Stuyfzand's method and to deduce the aptitude of these waters for irrigation and the risks of salinity. The results revealed physico-chemical characteristics, relatively, variable. Q-mode cluster analysis was applied to the thermal water, generated four (4) groups clusters. Group1 represent a group of waters with low salinity dominatedby Na-HCO3; Stuyfzand's classification indicated that the waters are fresh-brackish with moderate to moderately high alkalinity. Taking into account the classification of Richards; we were able to identify the presence of the C3S1 class for the majority of the stations. The C3S1 class designates waters that can be used without any particular control for the irrigation of crops that are moderately tolerant to salts. These waters have average EC values of 3616.3µS/cm allowing their use in a less restrictive way for irrigation. Potential environmental effluents from the thermal spas could pollute both irrigation and drinking water, which represents a danger to the health of the region's inhabitants.