Groundwater Resources, Challenges and Treatments Processes
The United Nations (UN) considers water as human rights since people use it for their lives’ sustenance and enjoyment. While growing or producing food uses water, more pivotally for us to survive as a species we need to consume water. People’s apsects of water sources refers to
surface water as important source. However, of all of the global usable freshwater people use, approximately 98 percent of it is groundwater (Fetter, 2001). Groundwater is the water contained beneath the surface in rocks and soil, and is the water that accumulates underground in aquifers. Groundwater is precious, because it provides fresh water for domestic, agricultural, industrial and ecological purposes. In lots of regions worlwide, groundwater has become a precious resource for mankind for supplying for drinking, agriclture, and industry. For many communities, it may be used as economical option (WHO, 2006). This is in part because groundwater is typically of more stable quality and better microbial quality than surface waters. Groundwaters often require little or no treatment to be suitable for drinking whereas surface waters generally need to be treated, often extensively. There are many examples of groundwater being distributed without treatment. It is vital therefore that the quality of groundwater is protected and treated if public health is not to be compromised. Statistics for the use of groundwater as a source of drinking-water are scanty, but the importance of this resource is highlighted by figures published in many parts of the world including Europe, Asia, USA and Africa. The proportion of groundwater in drinking-water supplies in some European countries. The data show that reliance upon groundwater varies considerably between countries; for example, Norway consists of only 13 percent of its drinking water from groundwater sources, while Austria and Denmark use groundwater resources almost exclusively for drinking water supply. A global estimate of over 30% of the world’s population depending on groundwater (EEA, 1999; UNECE, 1999).
Based on its intrinsic condition, groundwater ultilization is frequently accepted as good source of drinking rather than that of surface water, due to microbial quality state. Not all groundwater is fit to drink (potable). Due to the rapid economic development and population growth, the pressure imposed on groundwater environment is becoming more and more intensive and extensive. Nevertheless, groundwater has been threatened from the various negative impacts in term of quality and quantity, and it is readily contaminated and outbreaks of disease from contaminated groundwater sources are reported from countries at all levels of economic development (WHO, 2006). Groundwater is vulnerable to contamination due to ever increase in human acts and other anthropogenic stresses (i.e. urbanization, fertilizer and pesticide application, and sewage disposal) (Zaporozec, 2002). In general, pollution activities can be anthropogenic and natural. There has been reckoned that continuous contaminated land from unsustainable developments can seriously cause future contamination and may lead to severe health hazard and consequently to waterborne diseases. Water-related disease remains one of the major health concerns in the world. Most groundwater originates as excess rainfall infiltrating (directly or indirectly) at the land surface. As an effect, anthropogenic activities of human have threatened quality of groundwater. The pollution of aquifers occurs where the subsurface contaminant load generated by manmade discharges and leachates (from urban, industrial, agricultural, and mining activities) is inadequately controlled, and in certain components exceeds the natural attenuation capacity of the overlying soils and strata that is based on Foster et al. (2002).
Groundwater may not meet the standards because it contains dissolved constituents coming from diverse sources. Common examples of constituents coming from natural sources are nitrate, chloride, phosphate, sulfate, iron, manganese, total dissolved solids and other dissolved cations and anions. Additionally, groundwater also may not meet the standards because it composes of organic liquids, dissolved organic and inorganic constituents, or pathogens that came from anthropogenic sources combined with natural sources (Fetter, 1999). Throughout the world, there is evidence of contaminated groundwater leading to outbreaks of disease and contributing to background endemic disease in situations where groundwater sources used for drinking have become contaminated (Zaporozec, 2002). In common freshwaters in the terrestrial aquatic environment, the principal dissolved components of groundwater are the six major ions sodium (Na+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), bicarbonate (HCO3-) and sulphate (SO42-). These elements depend on human activtities and hydrogeological conditions of the area, so that the degree of pollution has variability. These cations and anions normally comprise over 90% of the total dissolved solids content, regardless of whether the water is dilute rainwater or has a salinity greater than seawater. Minor ions include potassium (K+),dissolved iron (Fe2+), strontium (Sr2+) and fluoride (F-) while aqueous solutions commonly also contain amounts of trace elements and metal species. Normally, potential water quality problems in groundwater pose severe human helath hazard, due to the presence of:
High turbidity, colour, iron, manganese
Chloride
Fluoride
Too much carbon dioxide
Low pH
Sulphide/Sulsphate
High hardness/Total dissolved solid
Low oxygen level
Pathogenic micro-organisms (contaminated wells)
Pesticides, arsenic, nitrite/nitrate (agriculture and sanitation)
Other contamination (oil, chemicals)
Through natural conditions and processes, some of these elements can be attenuated in subsurface medium depending on soil/rock media and groundwater properties. The attenuation can be found through several processes, which indlucing (i) Residence time in the ground as a hygienic barrier, (ii) Filtering that produces residence time of pollutant greater than that of water, (iii) Degradation of organic material via physical, biological and chemical degradation, and (iv) Redox processes through ion exchange, oxidation, precipitation, and Vyredox method for oxidation of iron/manganese (Slide presentation of Hem, 2019). However, the groundwater is still found not free from the contamination due to overloaded activties on land surface. In this context and inherent with the increasing reconnaissance of the importance of groundwater resources, efforts are rising and essential to have proper protection, treatment, improvement, development, and management plans to use groundwater sustainably.
The United Nations (UN) considers water as human rights since people use it for their lives’ sustenance and enjoyment. While growing or producing food uses water, more pivotally for us to survive as a species we need to consume water. People’s apsects of water sources refers to
surface water as important source. However, of all of the global usable freshwater people use, approximately 98 percent of it is groundwater (Fetter, 2001). Groundwater is the water contained beneath the surface in rocks and soil, and is the water that accumulates underground in aquifers. Groundwater is precious, because it provides fresh water for domestic, agricultural, industrial and ecological purposes. In lots of regions worlwide, groundwater has become a precious resource for mankind for supplying for drinking, agriclture, and industry. For many communities, it may be used as economical option (WHO, 2006). This is in part because groundwater is typically of more stable quality and better microbial quality than surface waters. Groundwaters often require little or no treatment to be suitable for drinking whereas surface waters generally need to be treated, often extensively. There are many examples of groundwater being distributed without treatment. It is vital therefore that the quality of groundwater is protected and treated if public health is not to be compromised. Statistics for the use of groundwater as a source of drinking-water are scanty, but the importance of this resource is highlighted by figures published in many parts of the world including Europe, Asia, USA and Africa. The proportion of groundwater in drinking-water supplies in some European countries. The data show that reliance upon groundwater varies considerably between countries; for example, Norway consists of only 13 percent of its drinking water from groundwater sources, while Austria and Denmark use groundwater resources almost exclusively for drinking water supply. A global estimate of over 30% of the world’s population depending on groundwater (EEA, 1999; UNECE, 1999).
Based on its intrinsic condition, groundwater ultilization is frequently accepted as good source of drinking rather than that of surface water, due to microbial quality state. Not all groundwater is fit to drink (potable). Due to the rapid economic development and population growth, the pressure imposed on groundwater environment is becoming more and more intensive and extensive. Nevertheless, groundwater has been threatened from the various negative impacts in term of quality and quantity, and it is readily contaminated and outbreaks of disease from contaminated groundwater sources are reported from countries at all levels of economic development (WHO, 2006). Groundwater is vulnerable to contamination due to ever increase in human acts and other anthropogenic stresses (i.e. urbanization, fertilizer and pesticide application, and sewage disposal) (Zaporozec, 2002). In general, pollution activities can be anthropogenic and natural. There has been reckoned that continuous contaminated land from unsustainable developments can seriously cause future contamination and may lead to severe health hazard and consequently to waterborne diseases. Water-related disease remains one of the major health concerns in the world. Most groundwater originates as excess rainfall infiltrating (directly or indirectly) at the land surface. As an effect, anthropogenic activities of human have threatened quality of groundwater. The pollution of aquifers occurs where the subsurface contaminant load generated by manmade discharges and leachates (from urban, industrial, agricultural, and mining activities) is inadequately controlled, and in certain components exceeds the natural attenuation capacity of the overlying soils and strata that is based on Foster et al. (2002).
Groundwater may not meet the standards because it contains dissolved constituents coming from diverse sources. Common examples of constituents coming from natural sources are nitrate, chloride, phosphate, sulfate, iron, manganese, total dissolved solids and other dissolved cations and anions. Additionally, groundwater also may not meet the standards because it composes of organic liquids, dissolved organic and inorganic constituents, or pathogens that came from anthropogenic sources combined with natural sources (Fetter, 1999). Throughout the world, there is evidence of contaminated groundwater leading to outbreaks of disease and contributing to background endemic disease in situations where groundwater sources used for drinking have become contaminated (Zaporozec, 2002). In common freshwaters in the terrestrial aquatic environment, the principal dissolved components of groundwater are the six major ions sodium (Na+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), bicarbonate (HCO3-) and sulphate (SO42-). These elements depend on human activtities and hydrogeological conditions of the area, so that the degree of pollution has variability. These cations and anions normally comprise over 90% of the total dissolved solids content, regardless of whether the water is dilute rainwater or has a salinity greater than seawater. Minor ions include potassium (K+),dissolved iron (Fe2+), strontium (Sr2+) and fluoride (F-) while aqueous solutions commonly also contain amounts of trace elements and metal species. Normally, potential water quality problems in groundwater pose severe human helath hazard, due to the presence of:
High turbidity, colour, iron, manganese
Chloride
Fluoride
Too much carbon dioxide
Low pH
Sulphide/Sulsphate
High hardness/Total dissolved solid
Low oxygen level
Pathogenic micro-organisms (contaminated wells)
Pesticides, arsenic, nitrite/nitrate (agriculture and sanitation)
Other contamination (oil, chemicals)
Through natural conditions and processes, some of these elements can be attenuated in subsurface medium depending on soil/rock media and groundwater properties. The attenuation can be found through several processes, which indlucing (i) Residence time in the ground as a hygienic barrier, (ii) Filtering that produces residence time of pollutant greater than that of water, (iii) Degradation of organic material via physical, biological and chemical degradation, and (iv) Redox processes through ion exchange, oxidation, precipitation, and Vyredox method for oxidation of iron/manganese (Slide presentation of Hem, 2019). However, the groundwater is still found not free from the contamination due to overloaded activties on land surface. In this context and inherent with the increasing reconnaissance of the importance of groundwater resources, efforts are rising and essential to have proper protection, treatment, improvement, development, and management plans to use groundwater sustainably.
