Influence of using compressed air for performing wells, to the results of physical-chemical analysis of water

The compressed air is often used for purpose of drilling or quality developing and flushing the piesometers and water wells. This paper suggests, that the dissolved oxygen, which is injected in groundwater, can retain in a large area for a long time after the performing and cleaning of the piezometers and water wells, which objectively, might have an affect on the testing results of physical and chemical composition of groundwater samples when we test water wells in the first time. The paper presents results of testing that influence, in the Neogene aquifer in the Stanari settlement, near of city of Doboj, and in the alluvial aquifer in the Kozluk village near city of Zvornik, by correlation of test results immediately after the performing of water wells and later, during their usage. In order to eliminate this problem in the future, this paper offers proposals, change of the usual procedure of hydrogeological research. It will bi possible to examine the effect of aeration of groundwater in the aquifer, during the performing of the wells.