Water Quality and Hydrogeochemical Characteristics of Some Karst Water Sources in Apuseni Mountains, Romania

Abstract

Human activities and natural factors determine the hydrogeochemical characteristics of karst groundwaters and their use as drinking water. This study assesses the hydrogeochemical characteristics of 14 karst water sources in the Apuseni Mountains (NW Romania) and their potential use as drinking water sources. As shown by the Durov and by the Piper diagrams, the chemical composition of the waters is typical of karst waters as it is dominated by HCO3− and Ca2+, having a circumneutral to alkaline pH and total dissolved solids ranging between 131 and 1092 mg L−1. The relation between the major ions revealed that dissolution is the main process contributing to the water chemistry. Limestone and dolostone are the main Ca and Mg sources, while halite is the main Na and Cl source. The Gibbs diagram confirmed the rock dominance of the water chemistry. The groundwater quality index (GWQI) showed that the waters are of excellent quality, except for two waters that displayed medium and good quality status. The quality of the studied karst waters is influenced by the geological characteristics, mainly by the water–rock interaction and, to a more limited extent, by anthropogenic activities. The investigated karst waters could be exploited as drinking water resources in the study area. The results of the present study highlight the importance of karst waters in the context of good-quality water shortage but also the vulnerability of this resource to anthropogenic influences.

Health Risk Assessment in Southern Carpathians Small Rural Communities Using Karst Springs as a Drinking Water Source

“…Although the guideline values set for Mn, Cr, Ni, and Pb by the WHO and EU Directive 2020/2184 are different, the WQI values calculated based on the two thresholds, as well as the water quality status, were similar. The results are similar to the studies on karst springs quality conducted in other regions of Romania (Dobrogea in south-eastern Romania and the Apuseni Mountains in north-western Romania), revealing the water-rock interaction and anthropogenic activities to be the main drivers of water quality [ 4 , 31 ]. In these regions, the quality of the spring waters was excellent and good, with a slight variation of the WQI values [ 4 , 31 , 33 ].…”

“…The results are similar to the studies on karst springs quality conducted in other regions of Romania (Dobrogea in south-eastern Romania and the Apuseni Mountains in north-western Romania), revealing the water-rock interaction and anthropogenic activities to be the main drivers of water quality [ 4 , 31 ]. In these regions, the quality of the spring waters was excellent and good, with a slight variation of the WQI values [ 4 , 31 , 33 ].…”

“…The concentration of NO 3 − ranged between 0.26 and 11.0 mgL −1 , the highest values being found in GWR9. The higher nitrate concentrations in some of the spring waters and some of the seasons (e.g., GWR7 in A20) were probably due to the presence of bats in the Gaura cu Muscă Cave, just above the spring [ 31 ]. The concentrations of NO 2 − and PO 4 3− were undetectable in all of the studied springs, in all seasons.…”

Radiological Risk Assessment for Karstic Springs Used as Drinking Water in Rural Romania

“…Water-soluble radon could Atmosphere 2021, 12, 1207 2 of 12 increase indoor radon activity, which is known to cause lung cancer [16] and has also been linked with induced stomach cancer [21]. Additionally, contamination of the public drinking water supply by chemical and biological pollutants occurs often in Romania according to scientific [22][23][24] and public records (National Institute of Public Health). One specific example is represented by the spring waters in karstic regions which originate from groundwater.…”

Application of Inductively Coupled Plasma Spectrometric Techniques and Multivariate Statistical Analysis in the Hydrogeochemical Profiling of Caves—Case Study Cloșani, Romania

“…The water characteristics in caves are influenced by water-rock interactions, recharge and discharge processes and anthropogenic activities in the area [9]. The mineral weathering may change the water salinity and element concentrations due to the dissolution at certain pH and redox conditions [7,[10][11][12]. The dissolution/precipitation, heteroor homogeneous acid/base reaction, phase transition, hydration/dehydration, microbial processes and redox reactions are the most common processes that can take place in a cave environment [13].…”