Finnish Well Water Quality in Rural Areas Surrounded by Agricultural Activity
In this study 136 wells (88 shallow and 48 deep) from rural areas in Western and Eastern Finland were analyzed during the years 2005 and 2006. The objectives of this study were to assess the general quality of the wells based on conventional indicators and novel organic matter analyses with the aid of High Performance Liquid Size Exclusion Chromatography (HPLSEC). In addition, the possible effects of the site specific characteristics of the water quality indicators of the wells were assessed. The results showed that 30 % of the wells did not fulfil one or more health-based criteria set for drinking water and 77 % had technical and aesthetic defects. The main problems were the presence of faecal bacteria, high nitrate concentrations, low pH and high colour. Site characteristics such as well depth, the presence of animals, crop fields and onsite wastewater purification systems were found to have negative effects on a series of water quality indicators. HPLSEC provided detailed information on the organic content of the well water samples, the data offered by this method was used to estimate roughly the leaching of organic matter into wells and its origin as either soil/surface water or wastewater. Shallow and deep wells were found to be vulnerable to the leaching of organic matter from soil/wastewater.