Manganese pollution of drinking water extracted from the terrace of Vacha River

Abstract

The presented study is aimed towards determining the reasons for manganese pollution of drinking water extracted from the terrace of Vacha River. The results show that this is due to the seepage of from the artificial lake, formed after the construction of a small hydropower plant. Another possible reason is the natural accumulation in the upper parts of the river terrace of poorly soluble in water manganese compounds that turn into soluble ones as a result of changes in the redox environment, which take place in the conditions of very intensive groundwater extraction.

Hydrogeological models for the conditions causing the occurrence of manganese in wells for groundwater extraction from the terrace of the Vacha River, Southern Bulgaria

“…1) before its confluence with the Maritsa River. As we noted in a previous publication (Benderev et al, 2021), the problem arises in the beginning of 2020, when in the groundwater extracted in the region and used as a source of drinking water in the village of Brestovitsa, Plovdiv Region, an increased concentration of Mn is established. For a short period, the concentration increased up to values above 1 mg/L at a permissible limit for drinking water of 0.05 mg/L.…”

“…In the first part of our research, it was established that the Mn contamination of groundwater is localized in the upper aquifer of the alluvial https://doi.org/10.52215/rev.bgs.2022.83.3.259 complex, which is not isolated in the four pumping wells installed in 1984 along the Vacha River, providing the drinking water supply for the villages of Kadievo (W1) and Brestovitsa (W2, W3, and W4). As main reasons for this pollution are indicated (i) the seepage of Mn-contaminated waters from the artificial lake formed in an old arm of the Vacha River after the construction of the Kadievo small hydropower plant and (ii) the natural accumulation in the upper parts of the river terrace of poorly soluble in water manganese compounds that turn into soluble ones in the conditions of very intensive groundwater extraction (Benderev et al, 2021). The second part of the research, which is the subject of this publication, examines the possibility of a quick solution to the problem with the drinking water supply for the village of Brestovitsa by duplicating the compromised pumping wells W2, W3, and W4.…”