Natural Attenuation of Emerging Pharmaceuticals by Bank Filtration in Addressing Regional Groundwater Management Issues - Dimkic et al. page 08


Its geological structure is, for the most part, made up of Pleistocene and Holocene gravels and sands.  Sediment thicknesses are not uniform:  7 to 20 m in the riverside area, approximately 2 m in the northwestern portion of the alluvion, and about 35 m in the Žarkovac area (Figure 10). Hydraulic conductivities of the water-bearing medium range from 1x10-4 to 1.2x10-3 m/s (Project NPV46B, 2006). The strata underlying the sandy-gravelly deposits consist of aleurites and sands (fine-grain and medium-grain), with Pont coal and clay deposits. The strata overlying the water-bearing sequence are comprised of semi-permeable aleurites, aleuritic sands and bog clays. The thickness of these deposits is 2-24 m, and the average hydraulic conductivity is 2.5x10-7 m/s.

figure_10
Figure 10: Characteristic lithological sections trough the Kovin-Dubovac site (Project NPV46B, 2006)

This area is under the influence of backwater caused by the Iron Gate HPP dam and is actively protected by a system of drainage canals and pumping stations which control groundwater levels. The development of this groundwater source will have a positive impact in that it will reduce the burden on the drainage system which protects riparian lands. Predictions of the impact of future abstraction is this area suggest that 2400.L/s of water can be tapped from the riverside zone, at a distance of 100 m from existing levees, at a well drawdown of about 6 m.

The water quantity is adequate to fully satisfy public water demand in 13 municipalities of central and northern Banat through the year 2030.
The water is of the calcium-carbonate type, moderately hard, with minor pH fluctuations in the neutral reaction range.  Low values of sodium and potassium cations and chloride anions have been registered. Slightly increased organic substances (KMnO4 consumption) were detected at only two piezometers. The iron and manganese content is generally elevated, and a somewhat high arsenic content has been detected at only three locations.