The overall methodology which was applied for the realization of the project concerning the monitoring of the chemical quality of irrigation water bodies (surface and groundwater) was based on protocols, methods and techniques developed over the years  by the scientific personnel of the Pesticide Science Laboratory of Aristotle University of Thessaloniki, Greece and on  widely accepted methods published in international scientific journals.

• the selection and description of  the Stationary Sampling Sites (SSS)  established for the monitoring of water chemical quality of the rivers, lakes, soil drainage canals and groundwater irrigation wells, the criteria exercised for the selection of these SSS, the total number of SSS established on each aquatic body as well the frequency of either water  or sediment sampling.

Venetikos River

Vegoritida Lake

• the methods and/or protocols used for the in situ measurements (pH, temperature, dissolved oxygen content and % oxygen saturation, Redox, conductivity, concentration of total dissolved solids and  Secchi disk and depth measurements for lakes) and the analysis of anions, cations including heavy metals (total and soluble forms), ammonium salts, total phosphorus content, Boron, alkalinity, hardness, pollution indicators such as BOD5, COD, chlorophyll content and evalution of the ecological quality using a test based on Vibrio fischeri and pesticide residue determinations.

The methods applied for the analysis of pesticide residues (parent compounds and important metabolites and/or degradation products), caffeine and other organic pollutants monitored in both aqueous and sediment samples were based on Liquid Chromatography-Mass Spectrometric and Gas Chromatography-Mass Spectrometric (LC-MS/MS and GC-MS/MS) techniques.
 

The above two methods based on LC-MS/MS and GC-MS/MS, respectively,  derived after appropriate modifications of already published analytical methods by the scientific personnel of the Pesticide Science Laboratory of Aristotle University of Thessaloniki, Greece.

The evaluation of results, for both in situ measurements and analytical data, was based on appropriate statistical analysis of all data, comparisons with respective National and International or EU established standards, appropriate irrigation water quality characteristics,  environmental dispersion mechanisms of pesticide residues, ecotoxicological criteria and use of environmental indicators such as the presence/absence of caffeine and diphenylamine in both surface and ground water bodies.  The wealth of analytical data  accumulated for all the parameters  investigated was stored and handled by the help of an electronic data bank operated on ACCESS; the data were also  presented by use of  the Geographical Information System (GIS).

For the evaluation of the data special emphasis was given to:

• the calculation of the annual mean  and respective mean and  standard deviation values for the entire monitoring period of the project (2010-2012) for each  investigated parameter.

• consideration and comparison of the annual mean values or maximum concentrations found with  the respective  limits on concentrations of the priority substances listed in Annex I of the Directive on Environmental Quality Standards (Directive 2008/105/EC) of the European Parliament and the Council on Environmental Quality Standards in the field of the water policy.

• consideration was also given to the concentration  limits of  pollutants and other substances listed in the EU Directives concerning the quality characteristics of  drinking water (Directive 98/83 EK of 3/11/1998) and  the Directive  2006/118/EC of the European Parliament  and of the Council of 12/12/2006 for the protection of groundwater against pollution and deterioration.

 Chimaditida Lake

Zazari Lake

Small Prespa Lake

• Classification of surface and ground water bodies suitable  for irrigation purposes   was based on the  Sodium Absorption Ratio (SAR)  and the respective  electrical conductivity measurements  as described in  the American Classification System of Irrigation Waters.

• Statistical analysis of pesticide residue data by use of Box and Whisker Plots was used for the estimation of the levels and concentration ranges of the inevitable and unavoidable environmental contamination occurring due to the use of pesticides in the agricultural production under the local soil and climatic conditions and agricultural practices exercised in the different basins of the Macedonia-Thrace and Thessaly. This statistical analysis also allowed for the confirmation of the existence or operation of point pollution sources and also helped in identifying and locating additional  point pollution sources of aquatic systems.

The methodologies  and the criteria applied for the evaluation of the analytical data used in the process of  characterization of both surface and ground water bodies  are described in detail in Appendix I.