Hydrogeochemical Characteristics and Assessment of Drinking Water Quality in the Urban Area of Zamora, Mexico

Abstract

This work assessed the groundwater hydrogeochemistry and the drinking water quality of 10 wells supplying the urban area of Zamora, Michoacán, Mexico. Two sampling campaigns were conducted in May 2018 (dry season) and November 2018 (wet season) to describe the chemistry of the water and its interaction with the rock. Physical and chemical constituents (temperature, pH, electrical conductivity, color, turbidity, solids, total hardness, total alkalinity, chemical and biochemical oxygen demands), major components (Ca2+, Mg2+, Na+, K+, SO42−, PO43−, HCO3−, CO32−, Cl−, N-NO3−, and N-NH3), as well as trace elements (As, Fe, Mn, Ba, Al, Sb, Co, V, Cu, Cd, Cr, Ni, Zn, Tl, Pb) were analyzed. Results showed groundwater with a slight tendency to alkalinity. The hydrogeochemical facies observed are Ca2+-HCO3− in all sites. Hydrochemical diagrams indicate immature, cold, non-saline, and uncontaminated water with short residence time. Water–rock interaction predominates. The water in the study area is appropriate for drinking use according to Mexican and international regulations with an excellent quality in 7 wells and good in the other 3.

Drinking Water Quality Mapping Using Water Quality Index and Geospatial Analysis in Primary Schools of Pakistan

“…The schools with an increase in nitrate concentration in ground water may also indicate the possible presence of other harmful agricultural pesticides and residential contaminants [11,40], as shown in Figure 4. In our study, the presence of nitrate in both ground and surface water was largely due to untreated sewage discharge, agricultural activities, decaying of animals, plants, and excreta [31,32]. In present study settings, the agriculture activities mainly rely on pesticides and fertilizer use, such as urea, diammonium phosphate, etc.…”

“…For chloride and total hardness, a titration-based standard method was adopted [17,30]. For the determination of phosphate and nitrate, a UV-visible spectrophotometer-based standard method was used [31].…”

“…In addition, deviation of Cl-in surface water from the standard is a result of anthropogenic activities such as fertilizers and coal containing sulfide along with minerals with sulfate derivatives from air pollutants [40]. Moreover, the elevated Cl-concentration might be due to surface water infiltration contaminated with salts and also results from geologic matter through dissolution of alkaline earth metal salts [31]. The WQI of schools ( Figure 4) in central Sindh that primarily used groundwater indicated an overall good quality drinking water; over half (53%) of the schools have excellent drinking water, 21% possess good quality drinking water, followed by 18% with poor water, 6% with very poor water, and 1% with water that is unsuitable for drinking.…”

“…Sources of elevated hardness are generally the same as for chloride. The hardness in water mainly indicates availability of magnesium and calcium ions which exist mainly in sandy rocks specifically found in limestone [31].…”

Use of Heavy Metal Content and Modified Water Quality Index to Assess Groundwater Quality in a Semiarid Area

“…Grading water quality indicators largely depends on indicator concentration and the rate of relative toxicity. One of the most applicable methods is Water Quality Index (WQI) that summarizes the quality of water for drinking and other purposes [3,20,21]. This index provides a single number as a measure of overall water quality at a specific location and time.…”