The Environmental Impact of a Complex Hydrogeological System on Hydrocarbon-Pollutants’ Natural Attenuation: The Case of the Coastal Aquifers in Eleusis, West Attica, Greece

The study area is the Thriassion Plain, an important area, in antiquity, surrounding the famous ancient town of Eleusis, 20 km west of Athens. The modern town and port and the entire area were heavily industrialized (1965–1995) coupled with unregulated urban and agricultural development. The presence of two crude oil refineries and other oil-related industries have strongly impacted the entire environment, including soils, waters and sediments of the broader area. The purpose of this work is to better understand how a multi-layered groundwater system affects the potential underground spread of certain fuel volatile compounds, namely the BTEX (benzene, toluene, ethylbenzene and total xylenes) as well as their attenuation after their direct or indirect release into the aquifer system. The spatial distribution of BTEX in groundwaters show that they were concentrated mainly in four rather restricted locations. Three of them were spotted, as expected, in the close vicinity of known pollution sources (a military airfield and two crude oil refineries). The other one corresponds to an abandoned site with no outstanding pollution sources where wells exist, eventually used for illegal dumping of oily wastes. It is important that the concentrations decrease significantly from autumn to spring. This decline could be characterized as natural attenuation, related to natural dilution phenomena and a flushing out of pollutants discharging through underwater springs to the sea during the rainy period (October to April). This, in turn, could be associated to the specific geological conditions affecting the hydrology, such as the unconsolidated non-permeable deposits and the multi layered formations of the area’s aquifers.

[1]  G. Kontakiotis,et al.  Advances in the Coastal and Submarine Groundwater Processes: Controls and Environmental Impact on the Thriassion Plain and Eleusis Gulf (Attica, Greece) , 2020, Journal of Marine Science and Engineering.

[2]  D. Kyriazis,et al.  Geochemical evolution of the Thriassion Plain groundwaters, Attica, Greece , 2020, Environmental Monitoring and Assessment.

[3]  Q. Xue,et al.  Pollution characteristics of aromatic hydrocarbons in the groundwater of China. , 2020, Journal of contaminant hydrology.

[4]  A. Karageorgis,et al.  Geochemistry of major and trace elements in surface sediments of the Saronikos Gulf (Greece): Assessment of contamination between 1999 and 2018. , 2020, The Science of the total environment.

[5]  Á. Borja,et al.  Using a holistic ecosystem-integrated approach to assess the environmental status of Saronikos Gulf, Eastern Mediterranean , 2019, Ecological Indicators.

[6]  G. Kontakiotis,et al.  Planktonic foraminiferal abnormalities in coastal and open marine eastern Mediterranean environments: A natural stress monitoring approach in recent and early Holocene marine systems , 2018 .

[7]  G. Stamatis,et al.  CONTRIBUTION TO HYDRAULIC CHARACTERISTICS OF PLIO-PLEISTOCENE DEPOSITS OF THRIASSION PLAIN OF ATTICA , 2017 .

[8]  G. Stamatis,et al.  Origin of halogens and their use as environmental tracers in aquifers of Thriassion Plain, Attica, Greece , 2017, Environmental Earth Sciences.

[9]  E. Dotsika,et al.  Organic matter characterization and copper complexing capacity in the sea surface microlayer of coastal areas of the Eastern Mediterranean , 2015 .

[10]  G. Roberts,et al.  Fault specific GIS based seismic hazard maps for the Attica region, Greece , 2015 .

[11]  Observations on the circulation of the Saronikos Gulf: A Mediterranean embayment sea border of Athens, Greece , 2010 .

[12]  N. Evangeliou,et al.  A preliminary study of particle dynamics in the water column of Saronikos Gulf, Greece, by using Th-234/U-238 disequilibrium approach , 2010 .

[13]  N. Conispoliatis,et al.  Anthropogenic Heavy Metal Pollution in the Surficial Sediments of the Keratsini Harbor, Saronikos Gulf, Greece , 2009 .

[14]  S. Varnavas,et al.  Assessment of Aliphatic and Polycyclic Aromatic Hydrocarbons and Trace Elements in Coastal Sediments of the Saronikos Gulf, Greece (Eastern Mediterranean) , 2008 .

[15]  A. Valavanidis,et al.  Polycyclic aromatic hydrocarbons in surface seawater and in indigenous mussels (Mytilus galloprovincialis) from coastal areas of the Saronikos Gulf (Greece) , 2008 .

[16]  E. Gidarakos,et al.  In-well air sparging efficiency in remediating the aquifer of a petroleum refinery site , 2008 .

[17]  G. Nakos.  Pollution of soil and vegetation in the Thriasian Plain, Greece , 1982, Plant and Soil.

[18]  D. N. Asimakopoulos,et al.  Distribution of trace metals in the sediments of Elefsis Gulf , 2004 .

[19]  R. Chakraborty,et al.  Anaerobic degradation of monoaromatic hydrocarbons , 2004, Applied Microbiology and Biotechnology.

[20]  C. Karavitis,et al.  ENVIRONMENTAL MANAGEMENT APPROACHES AND WATER RESOURCES IN THE STRESSED REGION OF THRIASSION, GREECE , 2002 .

[21]  Isaac R. Kaplan,et al.  Forensic Environmental Geochemistry: differentiation of fuel-types, their sources and release time , 1997 .

[22]  K. Lambeck.  Sea-level change and shore-line evolution in Aegean Greece since Upper Palaeolithic time , 1996, Antiquity.

[23]  John R. Odermatt,et al.  Natural chromatographic separation of benzene, toluene, ethylbenzene and xylenes (BTEX compounds) in a gasoline contaminated ground water aquifer , 1994 .

[24]  J. Pawliszyn,et al.  Analysis of organic compounds in environmental samples by headspace solid phase microextraction , 1993 .

[25]  J. Salanitro,et al.  The Role of Bioattenuation in the Management of Aromatic Hydrocarbon Plumes in Aquifers , 1993 .

[26]  J. Pawliszyn,et al.  Analysis of Substituted Benzene Compounds in Groundwater Using Solid-Phase Microextraction , 1992 .

[27]  Chien T. Chen.  UNDERSTANDING THE FATE OF PETROLEUM HYDROCARBONS IN THE SUBSURFACE ENVIRONMENT , 1992 .

[28]  M. Scoullos.  Lead in coastal sediments: The case of the elefsis gulf, Greece , 1986 .