The Ladoga Lake is one of the greatest Lakes in Europe and connects with the Baltic Sea via river Neva. In the article we try to describe the problem of pollution in the Ladoga Lake and the Gulf of Finland (eastern part of the Baltic) via groundwater discharge. Groundwater discharge is one of well unknown value there. Geologically Northern part of the Ladoga Lake lies under the Baltic Schield (cristalline rock) that presented by granites, gneisses, etc., sometimes which are covered Quaternary sediments. Southern part of the Ladoga Lake spread under Russian Platform including sediments of Visean and Cembrian age (shales, sands, limestone, sandstone, etc.) with thickness up to tens meters [1].There are several groundwater aquifers relate within the Ladoga Lake basin, in general with Qaternary age and taking important part in total groundwater value in the region.The Ladoga Lake is under serious technogenic pressure now being as a receiver of waste water from different industries. Wastewater in coastal zone presents great dangerous for the Ladoga Lake environment. The Gulf of Finland is on the junction of two major geological basement structures - the Baltic Shield and the Russian Platform with great variety of hydrogeological parameters. Interaction of sewater and groundwater is dynamic and different from north to southwards being reflected in groundwater discharge and chemical composition of water.