Påverkan på Valboåsen från verksamheter inom Svedens industriområde samt närliggande områden : hot mot grundvattnets kvalitet och kvantitet?

Abstract: The aim of this work was to find out what potential contaminants from roads, residential area and businesses within Svedens industrial area that can affect groundwater quality and quantity. Data collection was from SGU, VISS, internal material from Gävleborg county Administrative Board and Gävle municipality archive. GIS software ArcGIS was used to create the map images in the work. The studied area is located approximately ten kilometers west of Gävle city and consists of the esker Valboåsen, which is a glacifluvial deposit that in its central parts consist of coarse material that is overlaid by sand, clay and silt. North of esker Valboåsen there are the river Gavleån which has an inflow to the groundwater in the esker. This inflow represents the largest part of the groundwater recharge. In addition to the inflow from Gavleån there is also a natural groundwater recharge from precipitation surplus and artificial infiltration of surface water from Gavleån pumped up to a infiltration pond where the water then is infiltrated into the ground. The groundwater from the esker supplies about 82 000 inhabitants of whom 12 000 are supplied from outlet wells within the study area. If a groundwater of good qualitative and quantitative status should be guaranteed in the long term it is important that the protection of bodies of water is sufficient today. Some key documents in water planning are the water supply plan, the VA-plan and master plan. The aim of the Water supply plan is to identify the water bodies and describe the quality and quantity of these. A VA-plan focus at the technical solutions needed to use and protect the water resources. The master plan is a good tool to facilitate long-term planning of water resources and that a long-term sustainable use can be guaranteed. The pollutants that has been used in the greatest quantities of Svedens industrial area is heavy metals, solvents and oils. The risks of spreading to the esker groundwater are large since the industrial area is right next to and also on top of Valboåsen and that river Gavleån goes along with the northern parts of the esker. The esker Valboåsen has today classed of having a good quantitative and qualitative status, but the risk of not achieving any of these by 2021 is large. The wells in the area have a high capacity of groundwater outlet. In the esker Valboåsen elevated levels of manganese, iron, conductivity, chloride, sulfate and lead occur. Low levels of environmental toxins have also been identified by perfluorinated substances, pesticides (BAM, atrazine, atrazindesetyl), bentazone, tri- and tetrachloroethene, DEHP, bisphenol A and drug residues. The substances present in elevated levels in Gavleån are arsenic, zinc, anthracene, fluoranthene, DEHP, chloroalkanes and mercury. Many of these substances have been added to the groundwater by anthropogenic influence but the contamination source is difficult to identify because many pollutants can be transported long distances with water, air and particles. Therefore, the cause of some of the elevated values could not be attributed to the businesses, roads and residential area that are within the study area.