Comparative evaluation of river chemical status based on WFD methodology and CCME water quality index

G D Gikas; G K Sylaios; V A Tsihrintzis; I K Konstantinou; T Albanis; I Boskidis

doi:10.1016/j.scitotenv.2020.140849

Comparative evaluation of river chemical status based on WFD methodology and CCME water quality index

Sci Total Environ. 2020 Nov 25:745:140849. doi: 10.1016/j.scitotenv.2020.140849. Epub 2020 Jul 15.

Authors

G D Gikas¹, G K Sylaios², V A Tsihrintzis³, I K Konstantinou⁴, T Albanis⁵, I Boskidis⁶

Affiliations

¹ Laboratory of Ecological Engineering and Technology, Department of Environmental Engineering, School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece. Electronic address: ggkikas@env.duth.gr.
² Laboratory of Ecological Engineering and Technology, Department of Environmental Engineering, School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece. Electronic address: gsylaios@env.duth.gr.
³ Centre for the Assessment of Natural Hazards and Proactive Planning & Laboratory of Reclamation Works and Water Resources Management, Department of Infrastructure and Rural Development, School of Rural and Surveying Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece. Electronic address: tsihrin@otenet.gr.
⁴ Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece. Electronic address: iokonst@uoi.gr.
⁵ Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece. Electronic address: talbanis@uoi.gr.
⁶ Laboratory of Ecological Engineering and Technology, Department of Environmental Engineering, School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece.

PMID: 32731066
DOI: 10.1016/j.scitotenv.2020.140849

Abstract

The Water Framework Directive (WFD) methodology, proposed by the Ministry of Environment and Energy of Greece (WFD-MEEG), and the Canadian Council of Ministers of Environment Water Quality Index (CCME-WQI) are comparatively applied to evaluate the chemical status of a major transboundary river. Water quality parameters were monitored at 11 sites along the main stream of the river and its main tributaries, and at five sites in the reservoirs, on a monthly frequency, in the period from May 2008 to May 2009. Water temperature (T), dissolved oxygen (DO), pH, and electrical conductivity (EC) were measured in-situ, while water samples were collected for the determination of total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrite-, nitrate- and ammonium-nitrogen, total Kjeldahl nitrogen (TKN), ortho-phosphates (OP), total phosphorus (TP), and chlorophyll-a (Chl-a). The water samples were also analyzed for the determination of seven heavy metals (i.e., Cd, Pb, Hg, Ni, Cr, Cu, Zn) and 33 priority substances, as listed in Annex II of EU Directive 2008/105/EC. The results showed that the physicochemical parameters (i.e., T, DO, pH, EC, inorganic nitrogen, TKN, OP, TP, TSS, and Chl-a) were within the natural range. The mean concentration of the measured heavy metals did not exceed the limits set by WHO (2003, 2017) for drinking water. Regarding the priority substances, some of them (i.e., anthracene, fluoranthene, and polyaromatic hydrocarbons) were measured in various stations at higher concentrations than the Annual Average Environmental Quality Standards (AA-EQS). Based on the WFD-MEEG methodology, the river water was in the 'good' quality class, while according to CCME-WQI the river quality ranged from 'marginal' to 'good' category. It seems that CCME-WQI is stricter than WFD-MEEG but could be a WQI appropriate for use.

Keywords: CCME water quality index; Heavy metals; Nestos river; Nutrients; Priority substances; Water Framework Directive.