Czynniki kształtujące zasoby i chemizm wód podziemnych w rejonie aglomeracji gdańskiej

The purpose of this article is to identify the main factors influencing groundwater resources and chemistry in the area of the Gdańsk agglomeration. Two groups of factors were identified: natural – including physico-geographical location, geological structure and hydrogeological conditions and also anthropogenic impact. The studied area is located within a few morphological units: Kashubian Lakeland, Coastal Terrace and Żuławy Gdańskie (Gdańsk Delta Plain). Each of the above unit is characterized by diverse geological structure and lithology of sediments, which in turn affects the diversity of hydrogeological conditions of multiaquifer formations from Pleistocene to the Upper Cretaceous. Groundwater circulation system includes so-called Gdańsk aquifer system. The main recharge area of covers the Kashubian Lakeland. The discharge zone ncludes Coastal Terrace and Żuławy Gdańskie. The aquifers are confined to varying degree which has a direct impact on the rate of contaminants migration. Anthropogenic pollutions are induced by: industry, transport, development and intensive exploitation of groundwater resources. The geogenic risks that affect aquifers in of the Gdańsk agglomeration are: salt water intrusion, brines ascent and fluoride hydrogeochemical anomaly in water from the Upper Cretaceous aquifer in Żulawy Gdańskie.