Quality of Groundwater in Western Thessaly the Problem of Nitrate Pollution

The results of a research study about the groundwater quality in western Thessaly, that took place during the period 2001-2002, are presented in this paper. The study included two samplings during May and August of 2002. In May the water table is at high level while at the end of the summer the level of the water table is as low as it can be. Fourteen sampling stations were selected and the samples were received from deep wells. In addition to nitrogen compounds, several other chemical parameters were measured. UV-Vis Spectrometry, Atomic Absorption Spectrometry and Emission Spectrometry were used for the chemical analyses. The groundwater of region Farsala has been found to contain very high nitrate concentrations and also high concentrations of calcium, nitrite and bicarbonates. The increased nitrate level in groundwater is a major problem, caused by the fertilizers that are used in most areas with intensive agriculture like Thessaly. The concentrations of heavy metals were very low. The ionic ratios of major cations indicate that the groundwater originates mostly from calcareous aquifers and there is a constant water flow. The classification according to conductivity, chloride concentration and degree of alkalinity characterizes the groundwater as water of medium quality that can be used for irrigation at soils with good conditions of leaching.