GROUNDWATER QUALITY IN ALGERIA: THE CHALLENGE OF WATER STRESS AND POLLUTION

The physicochemical and bacteriological quality of groundwater was assessed to show the impact of the agriculture and human activities in the Triffa Plain located in North-East of Morocco. The current levels of contamination of the groundwater were estimated by analysing electrical conductivity, nitrate, nitrite, ammonia, orthophosphate, and indicators of faecal pollution content. Water samples from 55 locations were collected during two period of time, the wet and the dry season of the year 2016. Result obtained indicated that most samples are highly contaminated. The electrical conductivity varied from 800 to 9 100 μS∙cm−1. Nitrate levels ranged from 25 to 216 mg·dm−3, with 78% of samples exceeding the critical level value set at 50 mg·dm−3. Nitrate concentrations are slightly higher during the wet period in 73% of studied cases. Nitrite rarely exceeded the normal rate fixed by World Health Organization and reached 0.90 mg·dm−3. Ammonia and orthophosphate contents do not exceed these norms. The study revealed a wide contamination of groundwater by microbial agents such as, total coliforms, faecal coliforms and faecal streptococci, with content ranged from 0 to 14 000, 0 to 5 000 and 0 to 5 000 CFU·(100 cm3)−1 respectively, confirming the impact of septic tanks, wastewater discharge into rivers without treatment, and the use of animal waste on the ground water vulnerability. Samplings and measurements were carried out according to the international standard ISO 13395, ISO 11732 and ISO 15681-2 for chemical compounds and ISO 9308-1 and ISO 7899-2 for microbiological numerations.

Impacts of natural and anthropogenic factors on microbiological water quality indicators along an urban riverine tropical wetland  Flavia Byekwaso1,3,6, Guenter Langergraber2, Gabriele Weigelhofer1,3, Rose Kaggwa4, Frank Kansiime5,  Thomas Hein1,31 University of Natural Resources and Life Sciences, Vienna (BOKU), Department of Ecosystem Management, Climate and Biodiversity, Institute of Hydrobiology and Aquatic Ecosystem Management, Gregor-Mendel-Strasse 33, 1180 Vienna, Austria2 University of Natural Resources and Life Sciences, Vienna (BOKU), Department of Landscape, Water and Infrastructure, Institute of Sanitary Engineering and Water Pollution Control, Muthgasse 18, 1190 Vienna, Austria3 WasserCluster Lunz, Dr. Kupelwieser-Promenade 5, 3293 Lunz am See, Austria4National Water and Sewerage Corporation, P.O. BOX 7053, Kampala, Uganda5 Makerere University, Department of Environmental Management, P.O. BOX 7062, Kampala, Uganda6 Ministry of Water and Environment, Climate Change Department, P.O BOX 20026, Kampala, UgandaABSTRACT Water quality monitoring is essential for understanding seasonal variations in microbiological indicators and their implications for public health. Waterborne bacteria and pathogens are a significant cause of human diseases, especially in developing countries.  The study aimed to understand the factors that cause seasonal changes in the concentrations of microbiological water quality indicators along a riverine tropical wetland. In total, 144 water samples were collected for 12 months at six sites along Lubigi wetland in Kampala, Uganda, receiving varying stormwater and wastewater inputs from urban water infrastructure during the dry and wet seasons. Water samples were analysed using specific microbiological assay tests for Escherichia coli, faecal coliforms, heterotrophic plate counts, Enterococcus and Salmonella species. Generally, the highest concentrations of microbial contamination were detected during the dry season at all sites. There was a decreasing trend in microbial contamination for all the selected five microbiological indicators with increasing distances from the sources of stormwater and wastewater inflows in the upstream reaches towards the downstream areas of Lubigi wetland. Nitrogen compounds, Escherichia coli, faecal coliforms, Enterococcus and Salmonella species originated from stormwater, whereas wastewater discharges delivered primarily phosphorus compounds, organic matter and heterotroph plate counts. E. coli and heterotrophic plate counts were positively correlated with water temperature and salinity. E. coli, faecal coliforms and heterotroph plate counts were positively associated with Biological Oxygen Demand (BOD5). Escherichia coli, faecal coliforms and Enterococcus species were positively correlated with NH4-N. Escherichia coli, faecal coliforms, and heterotrophs dominated with high concentrations during the dry seasons, while Enterococcus and Salmonella species were more prevalent in the wet season. Escherichia coli, faecal coliforms and Salmonella showed insignificant logarithmic reductions during both seasons, showing when the carrying capacities of Nsooba main channel and Lubigi sewage treatment plant systems were exceeded. Enterococcus species showed no reduction in both seasons, which implied continuous high in-stream contamination. Heterotrophs showed significantly higher logarithmic reduction during the wet season than in the dry season. This suggested a concentration reduction during the wet season and loading/increase in the dry seasons. Our research findings may be used by the public health sector to understand relationships between the occurrence of surface water quality microbiological indicators and the prevalence of diseases through strategic seasonal monitoring and evaluation in Kampala and the region.

ObjectiveWater quality plays a pivotal role in environmental health, with direct implications for ecosystems and human populations. This study offers a novel and comprehensive evaluation of four distinct water sources in northeastern Algeria raw wastewater (RWW), treated wastewater (TWW), Oued surface water (OSW) from Oued El Azzabi, and groundwater (GW) addressing a significant research gap in integrated water quality monitoring in semiarid regions. Unlike previous studies, this work integrates both physicochemical and microbiological indicators over a full annual cycle to assess the effectiveness of wastewater treatment and its environmental impact.MethodsA cross-sectional analysis was conducted using monthly samples collected from January 2023 to January 2024. Physicochemical parameters such as pH, turbidity, electrical conductivity, nutrients, and organic matter (5-day biological oxygen demand), along with microbiological indicators (total coliforms, fecal coliforms, fecal streptococci, sulfite-reducing clostridia, and aerobic mesophilic bacteria), were assessed. The water quality index (WQI) was used to synthesize the results and evaluate the overall water quality across sources.ResultsTWW met national and international standards, demonstrating the effectiveness of the Ain Beida treatment plant. In contrast, RWW showed high contamination levels, highlighting critical health risks. OSW displayed seasonal pollution patterns, especially during summer, due to runoff and human activities. GW exhibited relatively stable quality but indicated persistent low-level contamination. The WQI scores confirmed these findings, offering a comprehensive overview of spatial and temporal quality variations.ConclusionsThis study contributes valuable insights into water resource management in semiarid regions, emphasizing the importance of systematic monitoring and effective wastewater treatment. The results highlight the need for adaptive management strategies and underscore the potential of TWW as a safe alternative for agricultural or industrial reuse. These findings serve as a foundation for policy development and future research in similar ecological contexts.

Onsite wastewater disposal systems (OWDS) are used extensively in the Black Hills of South Dakota where many of the watersheds and aquifers are characterized by fractured or solution-enhanced bedrock with thin soil cover. A study was conducted during 2006-08 to characterize water-quality effects and indicators of OWDS. Water samples were collected and analyzed for potential indicators of OWDS, including chloride, bromide, boron, nitrite plus nitrate (NO2+NO3), ammonia, major ions, nutrients, selected trace elements, isotopes of nitrate, microbiological indicators, and organic wastewater compounds (OWCs). The microbiological indicators were fecal coliforms, Escherichia coli (E. coli), enterococci, Clostridium perfringens (C. perfringens), and coliphages. Sixty ground-water sampling sites were located either downgradient from areas of dense OWDS or in background areas and included 25 monitoring wells, 34 private wells, and 1 spring. Nine surface-water sampling sites were located on selected streams and tributaries either downstream or upstream from residential development within the Precambrian setting. Sampling results were grouped by their hydrogeologic setting: alluvial, Spearfish, Minnekahta, and Precambrian. Mean downgradient dissolved NO2+NO3 concentrations in ground water for the alluvial, Spearfish, Minnekahta, and Precambrian settings were 0.734, 7.90, 8.62, and 2.25 milligrams per liter (mg/L), respectively. Mean downgradient dissolved chloride concentrations in ground water for these settings were 324, 89.6, 498, and 33.2 mg/L, respectively. Mean downgradient dissolved boron concentrations in ground water for these settings were 736, 53, 64, and 43 micrograms per liter (ug/L), respectively. Mean dissolved surface-water concentrations for NO2+NO3, chloride, and boron for downstream sites were 0.222 mg/L, 32.1 mg/L, and 28 ug/L, respectively. Mean values of delta-15N and delta-18O (isotope ratios of 14N to 15N and 18O to 16O relative to standard ratios) for nitrate in ground-water samples were 10.4 and -2.0 per mil (0/100), respectively, indicating a relatively small contribution from synthetic fertilizer and probably a substantial contribution from OWDS. The surface-water sample with the highest dissolved NO2+NO3 concentration of 1.6 mg/L had a delta-15N value of 12.36 0/100, which indicates warm-blooded animals (including humans) as the nitrate source. Fecal coliforms were detected in downgradient ground water most frequently in the Spearfish (19 percent) and Minnekahta (9.7 percent) settings. E. coli was detected most frequently in the Minnekahta (29 percent) and Spearfish (13 percent) settings. Enterococci were detected more frequently than other microbiological indicators in all four settings. Fecal coliforms and E. coli were detected in 73 percent and 95 percent of all surface-water samples, respectively. Enterococci, coliphages (somatic), and C. perfringens were detected in 50, 70, and 50 percent of surface-water samples, respectively. Of the 62 OWC analytes, 12 were detected only in environmental samples, 10 were detected in at least one environmental and one blank sample (not necessarily companion pairs), 2 were detected only in blank samples, and 38 were not detected in any blank, environmental, or replicate sample from either ground or surface water. Eleven different organic compounds were detected in ground-water samples at eight different sites. The most frequently occurring compound was DEET, which was found in 32 percent of the environmental samples, followed by tetrachloroethene, which was detected in 20 percent of the samples. For surface-water samples, 16 organic compounds were detected in 9 of the 10 total samples. The compound with the highest occurrence in surface-water samples was camphor, which was detected in 50 percent of samples. The alluvial setting was characterized by relatively low dissolved NO2+NO3 concentrations, detection of ammonia nitrogen, and relatively high concentr

Groundwater represents an important source for water supply in Mfou, Centre Region Cameroon. Increase in population has caused a shortage in availability of portable water; hence majority of the population depends on groundwater tapped through wells, boreholes and springs. Although this helps to meet their needs, the quality of water from these sources is unknown by the consumers. This study aimed at assessing the physicochemical and bacteriological quality of groundwater in Mfou, was done in order to determine the impact of anthropogenic pressure on water and to measure the health risks on users. A total of 23 wells and 4 boreholes were sampled in April 2022 which corresponds to the minor rainy season. Microbiological analyses comprised the prevalence of total coliforms (TCs), Escherichia coli, fecal coliform, Streptococcus spp, Salmonella spp, shigella spp, vibrio spp and staphylococcus spp. Physico-chemical parameters including temperature, pH, electrical conductivity, total dissolved solids (TDSs), salinity, dissolved O2 were measured to characterize these waters. The results showed variation of pH from 3.52-6.81, temperature 24.04-27.4°C, electrical conductivity 24-361 μS/cm, dissolved O2 27.1-61.9% mg/l, TDSs and Salinity from, 15-176 mg/l and 10.2-97.3ppm respectively. Results of specific Microbes isolated (Total Fecal Coliforms) / colony forming units/ml, reveals Total coliform Enterobacteria spp. (3-200), Total feacal coliform E. Coli (1-70), Streptococcus spp(02-05) Salmonella spp(1-22) Shigella spp(2-4) Staphylococus spp(2-20) Vibrio spp.(0) Comparing results with WHO standards reveals, about 40% were not good for direct consumption as they were contaminated with one or more bacteria. The water contamination would be the consequence of the closeness of boreholes to latrines and domestic wastes dumping sites. There is a need to educate the population on the water quality, the importance of clean and healthy surroundings near water sources and also common treatment methods to improve the water quality and reduce waterborne diseases. Keywords: Groundwater, quality assessment, biophysicochemical characterization, health and safety.

Irrigation impact on water quality and aquifer vulnerability in Kala Oya basin, Sri Lanka

This report describes the bacteriological results of a ground-water study conducted from 1993 to 1995 as part of the U.S. Geological Survey's National Water-Quality Assessment Program in the Lower Susquehanna River Basin study unit. Water samples collected from 146 household supply wells were analyzed for fecal-indicator organisms including total coliform, fecal coliform, Escherichia coli (E. coli), and fecal streptococcus concentrations. Supporting data used in the interpretations are selected water-quality constituents, wellconstruction information, and the environmental setting at the well site including land use, physiography, and bedrock type. Water from nearly 70 percent of the wells sampled had total coliform present and thus was not suitable for drinking without treatment. Fecal coliforms were found in water from approximately 25 percent of the sampled wells, f. coli testing was not conducted in 1993. Approximately 30 percent of the 88 sampled wells had waters with f. coli. Fecal streptococcus bacteria was present in water from about 65 percent of the wells sampled. Bacteriological contamination was more likely to occur in water from wells in agricultural areas than in water from wells in forested areas. Water from wells sampled in the Ridge and Valley Physiographic Province was more likely to have bacteria than water from wells in the Piedmont Physiographic Province. Differences in bacterial concentrations among bedrock types are only statistically significant for E. coli. Bacterial concentrations are weakly related to well-age but not to other well characteristics such as the total well depth or the casing length. Relations exist between bacterial concentrations and selected water-quality constituents. Most wells from which water was sampled did not have sanitary seals and very few were grouted. This may have contributed to the number of detections of bacteria. It is uncertain whether the bacteria detected are the result of widespread aquifer contamination or sitespecific factors. NATIONAL WATER-QUALITY ASSESSMENT PROGRAM INTRODUCTION The U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program is designed to determine the occurrence and distribution of water-quality characteristics in ground water and surface water (Gilliom and others, 1995). Studies began in 1991 in the Lower Susquehanna River Basin study unit, hereafter termed the study unit. The occurrence and distribution of bacteria in ground water are important water-quality issues in the study unit. Ground water is an important source of household supply in the study unit. Private water-supply information from the U.S. Bureau of the Census (1990) for counties in the study unit shows a total of nearly 1,600,000 households, of which about 500,000 depend on ground water from private wells for their drinking water supply (table 1). Approximately 400,000 households are in Pennsylvania; the others are in Maryland. Because only parts of some counties are within the basin, these numbers overrepresent the number of households and private wells in the basin (table 1). To estimate the number of households and private wells, the number in each county was multiplied by the fraction of each county in the basin. Using this estimation, about 800,000 households and approximately 300,000 private wells are in the basin. Therefore, approximately 38 percent of the households in the study unit depend on ground water from private wells for water supply. Table 1. Private water-supply information from the 1990 U.S. Bureau of the Census for counties in the Lower Susquehanna River Basin study unit

Our study evaluated the physico-chemical and bacteriological quality of water wells and boreholes in the rural commune of Nihit in the Moroccan Anti Atlas. In this study, we assessed the physico-chemical qualities of the water such as pH, temperature, conductivity, turbidity, nitrate, nitrite, sulfate, mineral elements, and heavy metals. We also studied the bacteriological quality of the water in terms of microbial germs represented by Total Coliforms, Fecal Coliforms, Escherichia coli (E. coli), Intestinal Enterococci, and sulfito-reducing Clostridium.Apart from two points located upstream of the Douars, nitrate concentrations range from 60 to 290 mg.L-1, well above the permissible value according to the World Health Organization (50 mg.L-1). At some points, values reach concentrations of 4.1.103 CFU/100 mL, 1.9.102 CFU/100 mL, 60 CFU/100 mL, 1.8.103 CFU/100 mL, and 90 CFU/100 mL, respectively for total coliforms, fecal coliforms, Escherichia, intestinal enterococci and sulfito-reducing Clostridium. The presence of Total Coliforms, Fecal Coliforms, and E. coli in the water tested is an indicator of contamination by human or animal fecal matter, which may come from conventional septic tanks, untreated wastewater discharges, animal manure leaching, or runoff. On the other hand, the values of the other physicochemical parameters tested remain compliant with potable water standards.

Imprints of COVID-19 lockdown on the surface water quality of Bagmati river basin, Nepal

The quality control of wastewater treatments was monitored using selected novel and classical physicochemical and microbiological indicators, and the associations of the treatments with the effluents was analyzed. The microbiological indicators monitored were heterotrophic plate count (HPC), total coliforms (TC), fecal coliforms (FC), fecal streptococci (FS), sulfite-reducing clostridia (SRC), Pseudomonas aeruginosa, and Salmonella spp. The stages of wastewater treatment also were evaluated through determination of ammonia; biological oxygen demand (BOD(5)); chemical oxygen demand (COD); chloride; conductivity; suspended dissolved and total solids; fats; nitrate, nitrite, and total nitrogen; pH; phosphate and total phosphorus. Additional indicators included the Escherichia coli growth inhibition (IGEC) bioassay for assessing whole effluent toxicity, spectral determinations between wavelengths (lambda) 190-650 nm, and total (TP) and soluble (SP) protein contents. Of the more common physicochemical parameters, only BOD(5), COD, suspended and total solids, and fats showed a statistically significant reduction between raw water and effluent; for the microbiological indicators, significant reduction was seen only for HPC, FC, and Ps. aeruginosa. We suggest that determinations of Ps. aeruginosa be commonly used as an indicator of wastewater quality. Spectral analysis--most notably the values of absorbance at 225, 255, and 295 nm-revealed a statistically significant correlation with several physicochemical parameters. Statistical analysis of SP and TP values showed them to be good indicators of contamination. The quantitative study of Salmonella spp. and the results of the IGEC bioassay show the need for close control of infectious and toxic risks in wastewater and effluents.

Rapid urbanization and population growth in the upper Athi River basin in Kenya have increased the strain on the sub catchments water supply and sanitation situation. Due to increasing demand, inadequate supply of drinking water and lack of sanitation facilities, people in the sub-catchment are increasingly reliant on groundwater as a primary or supplementary water source. However, the use of on-site wastewater systems and agricultural pollution, mainly from runoff containing fertilizers, pesticides, herbicides, and faeces, pose a threat to groundwater in the sub catchment. Subsequently, the current study was conducted in the Thiririka sub catchment, Kiambu County, Kenya, to determine the safety of groundwater sources and to examine the factors influencing groundwater quality in the catchment area. This study assessed the influence of anthropogenic activities on the physical, chemical, and bacteriological quality of groundwater in the Upper Athi River basin of Kenya between April and June 2022. Twenty variables were analyzed and compared with water quality standards to determine hydro chemical characteristics, evidence of contamination, and suitability of groundwater. Shallow wells (SW) had higher concentrations of major ions and key parameters than boreholes (BH), such as alkalinity (7%), turbidity (96%), nitrates (92%), sulfates (48%), phosphates (93%), chlorides (77%), potassium (84%), sodium (30%) and fecal coliforms (99%) significant at p < 0.01. Concentrations of eleven water quality variables however were comparable in both systems. Farming, animal husbandry, and pit latrines were negatively but significantly correlated with the water quality of SW explaining substantial amounts of variation (≤ 45%) in concentrations of water quality variables. Ionic and coliform levels increased with decreasing distance and vice versa. IDW interpolation maps were generated in ArcGIS software to determine the spatial variability of groundwater quality in the basin. Anthropogenic activities such as pit latrines and animal husbandry impaired the quality of groundwater which in most cases was not potable.

Trends in water quality of some wells in Saudi Arabia, 1984–1989

Radioactivity and geochemistry of selected mineral-spring waters in the Western United States; basic data and multivariate statistical analysis

PDF HTML阅读 XML下载 导出引用 引用提醒 基于ArcGIS的下辽河平原地下水脆弱性评价及空间结构分析 DOI: 10.5846/stxb201403280580 作者: 作者单位: 辽宁师范大学城市与环境学院,辽宁师范大学城市与环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 教育部高等学校博士点基金(2012123611000);国家自然科学基金(40501013) An ArcGIS-based analysis of groundwater spatial structure and groundwater vulnerability in the lower reaches of the Liaohe River Plain Author: Affiliation: College of Urban and Environment,Liaoning Normal University,College of Urban and Environment,Liaoning Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以下辽河平原为研究区,通过选取1991、2000和2010年3个代表年的相关参数,在DRASTIC模型基础上构建评价指标体系进行地下水脆弱性评价,并以地下水中氮元素浓度为响应指标通过显著性检验,在此基础上借助GS+、ArcGIS和Geoda095i等软件的制图功能和空间统计分析功能,对下辽河平原地下水脆弱性的空间分布特征、变异规律以及空间关联格局进行研究分析,结果表明:①1991-2010年下辽河平原地下水脆弱性总体上呈先增后减趋势,空间分布上以沈阳市为中心的地下水高脆弱区向南部沿海方向扩散;②1991-2010年研究区地下水脆弱性Moran's I表现为较强正相关现象,且关联程度呈略微下降趋势;③1991-2010年研究区地下水脆弱性局部空间自相关和显著性水平均发生了明显的变化;④研究区内地下水脆弱性受结构性因素和随机性因素共同作用,且随机性因素在3个时期内有逐步上升趋势。研究成果反映了研究区地下水脆弱性空间结构的变异规律及驱动机制,为决策者在未来地下水污染防治方面提供相关参考依据。 Abstract:High-quality groundwater bodies with relatively stable water volumes, good water quality, and a high resistance to pollution are widely distributed throughout the world. They play an important role in, among other things, the domestic water supply, economic development, and maintaining the integrity of the geological environment and ecological balance. However, with rapid socio-economic development, increasing human demand for water has resulted in increasing pressure on, and unreasonable use of, groundwater bodies. Consequently, groundwater systems throughout the world are subject to varying degrees of pollution and destruction, one result of which is an increasing disequilibrium between the supply of and demand for water resources.The field of international hydrogeology is concerned with evaluation of groundwater vulnerability, which is considered a basic task in the development and protection of groundwater resources. Currently, groundwater vulnerability is thought to result from characteristics of the groundwater system itself and anthropogenic factors; research into groundwater vulnerability can support groundwater protection. GIS, together with the contraposed index method, is the most popular tool for calculating groundwater vulnerability indices. Because the hydrogeological environment is not under the complete control of human activities, a thorough understanding of groundwater vulnerability and the causes of its variation is necessary for environmental managers to enact preventive and pollution control measures.This study was based on the DRASTIC model. Groundwater parameters for 3 years (1991, 2000, and 2010) were used to calculate the distribution of groundwater vulnerability in the lower reaches of the plain of the Liaohe River, using ArcGIS. Groundwater nitrogen concentration was used as a response index to test the reliability of results. Using the mapping and spatial statistical analysis functions in GS+, ArcGIS, and Geoda095i, we evaluated and analyzed the spatial distribution, variation, and spatial correlation patterns of groundwater vulnerability in the tested area. Results showed that:1) Overall groundwater vulnerability initially decreased but then showed a trend of increase from 1991 to 2010, and high-vulnerability areas were distributed from the regions around Shenyang to the south coast. 2) From 1991 to 2010, groundwater vulnerability showed a strong positive autocorrelation (Moran's I), the degree of which showed a slight downward trend. 3) Over the study period, marked changes have occurred in local spatial autocorrelation of groundwater vulnerability and its significance levels. 4) Groundwater vulnerability in the study area was influenced by a combination of structural and random factors. While the random factors have gradually increased over time, structural factors remain important. This study highlights the causes of variation in groundwater vulnerability and the mechanisms that drive its spatial structure in the study area and can provide a reference for policy makers to support development of groundwater pollution control and protection plans. 参考文献 相似文献 引证文献

Bacteriological composition of groundwater and its role in human health