Assessment of Surface Drinking Water Resources of Turkey in Terms of Water Quality Standards

Monitoring and assessment of surface drinking water resources is vital for human life. As it is known, many diseases are caused by contaminated waters. Surface water resources quality was classified in terms of treatment potential by using 41 conventional parameters in Turkey. It is not insufficient to take these conventional parameters into account alone due to the fact that there exist new developments in application of varying level of different chemicals generated as part of daily activities. The main objective of this study is to recommend some changes for the water resources quality classification of Turkey by investigating the No Observed Adverse Effect Limit (NOAEL) and Lowest Observed Adverse Effect Level (LOAEL) classifications of different pollutants. These pollutants are associated with highest and lowest doses at which there was not an observed toxic or adverse effect, respectively. This new evaluation scheme will allow integration of new pollutants, i.e., micropollutants, and monitoring as per the findings of this study. A detailed site-specific monitoring was also undertaken by collecting samples from 283 of surface water locations at four times during the year across Turkey. The results obtained in this study indicate that, even if there is a pressure in terms of micropollutants in surface water resources of Turkey, the problem in terms of conventional parameters are more dominated and the water quality problems in Turkey have been exacerbated in terms of microbiological indicators such as total coliform, fecal coliform and fecal streptococcus. It is also important to note that the heavy metal concentrations originated from the site-specific geological formation were detected in the surface drinking water resources of Turkey.