EN
Radon-222 concentration in surface water, wells water and tap water in the main towns and villages which are located in area of Karkonoskie Plateau has been quantitative determined. The measurements were performed using the alpha liquid scintillation counting method. Majority of waterworks in Karkonoskie Plateau is supplied with the ground water in which the radon concentration is high from 87,5 Bq/1 to 818,1 Bq/1. The waterworks in Karpacz are supplied with the surface water, which main characteristic is low radon concentration (below 10 Bq/1) and with the ground water have a high radon concentration (to 541 Bq/1). Radon-222 concentration in water of individual wells was similar to concentration in the ground water.