Abstract:
The monitoring system in the Ogosta River valley is specifically designed to investigate the dependence of spatial distribution of arsenic in groundwater on the environmental settings of a floodplain which is contaminated with sulphides from mine tailings. The location of 25 piezometers takes into consideration the geomorphological features of the floodplain and the level of arsenic contamination of the soil. A testing ground for studying the impact of high river flow events on arsenic mobilization and migration from the soil to the alluvial aquifer and the river, has been organised in the active floodplain. It combines two piezometers in lower and higher sections of the active floodplain, a set of sensors and suction cups installed in the soil profile, a hydrometric station, as well as a weather station, all equipped with telemetry systems. The organised monitoring system is the basis for turning the Ogosta River valley into a testing area for studying and modelling the arsenic fate in polluted river floodplains.