SIVRAD: an integrated system for the assessment of the environmental risk from solid waste landfills - Guidelines

In recent years, the contamination of the underground resources from landfill leachates is recognised as a serious socio-economic and environmental problem in many countries. In fact, the existing not adequately controlled and abandoned sites, constitute a serious sanitary and environmental problems. The choice of the waste disposal site must necessarily arise from a rigorous study based on the joint assessment of the environmental hazard of the same plant and the hydrogeological characteristics and the degree of intrinsic vulnerability to pollution of the aquifers. In the present paper an integrated system for the assessment of the environmental risk from solid waste landfills is proposed. The integrated analysis of the intrinsic vulnerability of the aquifer system and the estimate of the intrinsic potential hazard caused by the landfill expressed in terms of danger index allow to evaluate the suitability of the sites to host a landfill and to define the reclamation priority and monitoring system for the existing landfills. As concerns new landfills, the proposed methodology could also support a better construction strategy and the protection of the surrounding environment. Finally, this methodological approach was applied in landfills located in different geological and hydrogeological contexts.

Using intrinsic vulnerability and anthropogenic impacts to evaluate and compare groundwater risk potential at northwestern and western coastal aquifers of Sri Lanka through coupling DRASTIC and GIS approach

Groundwater vulnerability assessment has become a crucial step in successfully protecting groundwater against pollution. An attempt of this study has been made to evaluate groundwater contamination risk using intrinsic vulnerability and land-uses in Vanathavillu, Kalpitiya and Katana area in Sri Lanka, using coupled DRASTIC with GIS as feasible methodology. The findings reveal that the groundwater in the areas under study falls under very low to high contamination risk. The higher risk of contamination has been identified in most of the Kalpitiya (about 82%) with the moderate along the beach in the west and next to Puttalam lagoon in the northeast and southeast. This is mainly due to pollution risk inherent with intense vegetable cultivation, over pumping, shallow groundwater tables and permeable sandy soil. Vanathavillu is under very low to moderate contamination risk, in which the moderate risk (about 13%) has especially been found the center, central southwest and west of the area. The relative less deep groundwater tables, possible seepage from the underlying limestone aquifer and less permeable red earth soil could be cause for the moderate risk in the area. Furthermore, results show that the Katana has low to moderately high groundwater contamination risk. Nitrate has a good agreement with the different pollution risk classes and that nitrate can be used as an indicator of aquifer degradation inherent with land-use activities in the coastal areas. Groundwater quality monitoring network should be set up to minimize the anthropogenic acts, particularly in high and moderate contamination risk zones.

Intrinsic and specific groundwater vulnerability using the GOD method as a pre-operational baseline assessment of an unconventional hydrocarbon industry

In the middle of the São Francisco basin, the sub-basins of Indaiá and Borrachudo river highlight the considerable potential for unconventional hydrocarbon exploration. The present study seeks to evaluate the groundwater resource's intrinsic and specific vulnerability in the Indaiá and Borrachudo basins as an environmental baseline study for further development in the shale gas industry. The overlay and index GOD method was applied to assess the aquifer's intrinsic susceptibility regarding the Groundwater confinement (G), the Overlying Strata (O), and the Depth of the groundwater table (D). The specific vulnerability assessment considered the intrinsic vulnerability and the land cover/use of the area, concerning the diversity and the toxicity of pollutants inherent in each anthropogenic activity. The results indicate that 52.69%, 25.12%, and 17.57% of the aquifer area have Medium, High, and Extreme intrinsic vulnerability, respectively. The specific vulnerability assessment suggests an overall vulnerability reduction due to the low anthropogenic stress on the basin. Three gas research wells overlay moderate intrinsic vulnerability. One well is above the high vulnerability area, which concerns how the unconventional industry could develop regarding groundwater susceptibility in this ecosystem.