High arsenic levels in water resources resulting from geogenic resources: A case study from Muratlar Region, NW Turkey

Abstract

A large number of the studies on arsenic (As) in groundwater have been carried out over the last decades and a high concentration of this element has been identified in different parts of world. Muratlar Region in the northwest of Turkey is one such area having complex geology of widespread volcanic succession with active tectonics and geothermal fluids. This natural setting serves as a suitable environment for the presence of high levels of arsenic in groundwater in Muratlar Region. Arsenic was determined to be presented in water samples taken from wate resources in the Muratlar Region during 2009-2010. High concentrations of arsenic were seen in the east of Muratlar Region, where densely settled argillic alteration outcrops were present. The maximum As concentration was 150 ppb. Chemical analyses revealed that arsenic was exceeding the maximum allowable limits depicted in the national and international standards for drinking water quality. The main reason for obtaining high arsenic concentrations is related to longer retention times of water resources in altered (argillic, silicification) volcanic rocks. Water-rock interaction is an important mechanism in determining the overall quality pattern of groundwater resources in this region.