Assessment of OSL groundwater monitoring program

Abstract

Increasing population, water demand, climate-change-induced droughts and growing strain over water resources demands better management. Groundwater is the largest distributed source of freshwater and fulfills one-third of the world’s freshwater withdrawals. Therefore, countries are realizing its importance and applying measures to keep it free of pollution. Groundwater reservoirs face different risks of contamination depending upon their global location. In the northern hemisphere, deicers are widely used to keep roads and airport runways open for winter operation as well as to prevent accidents. On airports, Formate and acetate based products are used for runways while propylene glycol is used as anti-freeze on the airplane itself. De-icers are a potential source of contamination at the Oslo International Airport (OSL) which lies above the largest rain-fed aquifer of Norway. Certain regulations are applied on the management of the airport to ensure the purity of groundwater resource underneath. Airport management has developed a monitoring program to ensure the compliance. This study aims to assess the monitoring program and its strengths and weaknesses in complying with regulations regarding groundwater balance and contamination risk from deicers. Chemical and physical parameters measured over 67 monitoring wells during last 20-years is analyzed. Fluid elevation levels are used to estimate approximate water table by interpolation. Water quality of aquifer is compared with background values and drinking water standards. Retention time of a contaminant plume is estimated using a real example from the data. After above mentioned analyses, the monitoring program was found to be compatible in preventing and monitoring contamination.