Application of water quality index to evaluate groundwater quality (temporal and spatial variation) of an intensively exploited aquifer (Puebla valley, Mexico)

Abstract

The spatial and temporal variation of water quality in the urban area of the Puebla Valley aquifer was evaluated using historical and present data obtained during this investigation. The current study assessed water quality based on the Water Quality Index developed by the Canadian Council of Ministers of the Environment (CCME-WQI), which provides a mathematical framework to evaluate the quality of water in combination with a set of conditions representing quality criteria, or limits. This index is flexible regarding the type and number of variables used by the evaluation given that the variables of interest are selected according to the characteristics and objectives of development, conservation and compliance with regulations. The CCME-WQI was calculated using several variables that assess the main use of the wells in the urban area that is public supply, according to criteria for human use and consumption established by Mexican law and international standards proposed by the World Health Organization. The assessment of the index shows a gradual deterioration in the quality of the aquifer over time, as the amount of wells with excellent quality have decreased and those with lower index values (poor quality) have increased throughout the urban area of the Puebla Valley aquifer. The parameters affecting groundwater quality are: total dissolved solids, sulfate, calcium, magnesium and total hardness.

Hydrogeochemistry and water-rock interactions in the urban area of Puebla Valley aquifer (Mexico)

“…3. Geological map and geological cross-section W-E of the Puebla Valley aquifer (Salcedo-Sánchez et al, 2016). 2300 mamsl elevation that matches the Zahuapan riverbed elevation.…”

“…The study area focus on the urban zone, vegetation cover and land use has changed in the Puebla Valley aquifer area over the time, currently the urban area of Puebla city represents 70% of the metropolitan area ( Fig. 2), this percentage will increase like the last 20 years due the urbanization and industrialization phenomena in the area (INEGI, 2010;Salcedo-Sánchez et al, 2016). This situation was intensified by the establishment of an industrial zone at north of the city and the construction of infrastructure like roads, producing the urban expansion towards the west.…”

“…The combination of these three reactions is termed dedolomitization (Appelo and Postma, 2005;Sacks and Tihansky, 1996). Evidence of dedolomitization reactions and common ion effect is illustrated by concurrent increases in sulphates, calcium and magnesium concentrations in the upper aquifer by upwelling of mineralized water from deep aquifer (Salcedo-Sánchez et al, 2016).…”

“…Groundwater is the most important source for water supply in Puebla city, intense urban and industrial development have placed high demand of groundwater resources and also these resources are at greater risk to degradation of quality. Furthermore, this development of the area make groundwater a critical resource for human activities (Salcedo-Sánchez et al, 2016;Gárfias et al, 2010;Flores-Márquez et al, 2006). According to Flores-Márquez et al (2006) and Gárfias et al (2010), the most significant effect is the degradation in the quality of freshwater in the upper aquifer due to mixing with sulphydric water which rises from the deep aquifer.…”

Spatial and Temporal Variations in Water Quality and Land Use in a Semi-Arid Catchment in Bolivia

“…Kannel et al [34] used WQI to evaluate spatial and seasonal changes in surface water quality in a river basin in Nepal, whereas Debels et al [35] calculated WQI in order to characterise the spatial and temporal variability in surface water quality in a river basin in Chile on the basis of nine physicochemical parameters periodically measured in the basin. A WQI was also applied by Salcedo-Sánchez et al [36] when evaluating spatial and temporal variations in groundwater quality in the urban area of an aquifer in Mexico.…”