The water contamination is a widely common problem relating to the field of environmental and water resource engineering. It requires very sophisticated techniques to prevent the occurrence of contamination in ground or shallow water resources by all available prevention methods. This research discusses the different sources of ground water contamination and the effects of contaminated water on the health and environment. In addition to some details about the protection methods to keep water usable and finally recommendations and conclusion.

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GROUNDWATER CONTAMINATION
Abdulrahman Ahmed Salah - 43780375
Ground Water Engineering - 803662
Civil Engineering Department
Umm Al-Qura University
Abstract
The water contamination is a widely common problem relating to the field of
environmental and water resource engineering. It requires very sophisticated techniques to
prevent the occurrence of contamination in ground or shallow water resources by all
available prevention methods. This research discusses the different sources of ground water
contamination and the effects of contaminated water on the health and environment. In
addition to some details about the protection methods to keep water useable and finally
recommendations and conclusion. This research is a part of the fulfillments of the Ground
Water Engineering course.
1. Introduction
Water contamination may occur for any available water resource and may make it
unusable water due to the change in the water properties. Water contamination is a main
problem of the globe, which needs ongoing assessment and reconsideration of water
resource policies around the world neither by the governments or any relating authorities.
Water contamination is one of deaths and diseases causes, and that it is the reason for the
deaths of more than 14,000 people daily. [1] Approximately, statistics show that 90% of
the water in the cities of China is contaminated. [2] In 2007, almost 500 million of Chinese
had no access to safe drinking water. [3]
Groundwater is the term used to describe the water that is existed in soil pores beneath
the surface and in permeable geological formations. Sources of groundwater include
seepage from the land surface, such as rainwater, snowmelt and water also that permeates
down from the bottom of some lakes and rivers. [4] Fossil groundwater is water that has
been trapped in rock formations over geological time scales. Groundwater is a very
important source of freshwater, making up 97% of the accessible freshwater reserves in the
world. [5]
Water is considered as contaminated water when it is impaired by anthropogenic
contaminants and either does not support domestic uses, such as drinking water, or
undergoes a marked shift in its ability to support its constituent biotic communities, such
as fish. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes
commonly change the water quality and the biological status of water. [6]

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2. Background
Human activities usually resulted in Ground water contamination. Ground water is
easily become contaminated where high population density and human uses of the land is
intensive. Nearly, any activity whereby chemicals or wastes may be disposed to the
environment, either intentionally or by accident, has the potential to contaminate ground
water. When ground water becomes contaminated, it is difficult and expensive to purify.
Over 50% of the United States population depends on groundwater for drinking water.
Groundwater is also one of our most important sources of water for irrigation.
Unfortunately, groundwater is susceptible to pollutants. [7]
Water contamination may be caused by chemical, physical, radioactive or pathogenic
microbial substances. Contaminated used water currently produces large scale diseases and
deaths, accounting for approximately 50 million deaths per year worldwide, most of these
deaths occurring in Africa and Asia. Widespread consequences of water contamination
upon ecosystems include species mortality, biodiversity reduction and loss of ecosystem
services. Some consider that water contamination may occur from natural causes such as
sedimentation from severe rainfall events; though, natural causes, including volcanic
eruptions and algae blooms from natural causes constitute a minute amount of the instances
of world water pollution. The most problematic of water contaminants are microbes that
induce disease, since their sources may be interpreted as natural, but a majority result from
human activities. [9]
Materials from the land surface can move through the soil and end up in the
groundwater. For example, pesticides and fertilizers can find their way into groundwater
supplies over time. Road salt, toxic substances from mining sites, and used motor oil also
may seep into groundwater. Furthermore, it is likely for untreated waste from septic tanks
and toxic chemicals from underground storage tanks and leaky landfills to contaminate
groundwater. [9]
Contaminated drinking water always have serious health effects and in some cases,
lead to death. Diseases such as hepatitis and dysentery may be caused by contamination
from septic tank waste. Poisoning may be resulted from toxins that have leached into water
good supplies.
Ground water and surface water are interconnected and can be fully understood and
intelligently managed only when the surface waters and ground waters interrelation is
acknowledged. If there is a water supply well near a source of contamination, that well runs
the risk of becoming contaminated. If there is a nearby river or stream, that water body
may also become contaminated by the ground water [8]

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3. Groundwater Contamination Sources
Water contaminant sources can be categorized into two super categories: [9]
 Point sources: discharge from a factory or sewage outfall, and include many of the
common inorganic chemical water contaminants; and
 Non-point sources that include agricultural runoff, urban storm water runoff and
other area wide sources.
Fig. 1, below illustrates the most common sources of ground water contamination and
the interrelation between surface and ground water. These types of contaminants will be
discussed in details in the following pages of this research.
Fig. 1 Potential Sources of Contamination in Groundwater [UK Groundwater Forum]

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Ground water contaminates from natural sources or numerous types of human
activities. Residential, municipal, commercial, industrial, and agricultural activities can all
affect ground water quality. Contaminants may spread into the ground water from activities
on the land surface, such as releases or spills from stored industrial wastes; from sources
below the land surface but above the water table, such as septic systems or leaking
underground petroleum storage systems; from structures beneath the water table, such as
wells; or from contaminated recharge water. Another classification of ground water
contaminants is mentioned below:
A. Natural Sources:
Iron, manganese, arsenic, chlorides, fluorides, sulfates, or radionuclides, can
become dissolved in ground water naturally from rocks or soils. Decaying organic
matter, can move in ground water as particles.
Ground water that contains unacceptable concentrations of these substances is not
used for drinking water or other domestic water uses unless it is treated to remove
these contaminants. Some substances may cause health threats if consumed in
excessive quantities; others may produce an undesirable odor, taste, or color of
water. [8]
B. Septic Systems
Septic tanks, cesspools, and privies are most common types of ground water
contaminants. Improperly sited, designed, constructed, or maintained septic
systems can contaminate ground water with bacteria, viruses, nitrates, detergents,
oils, and chemicals. Along with these contaminants are the commercially available
septic system cleaners containing synthetic organic chemicals. Fig. 2, shows the
septic system causing contamination to the beneath ground water aquifer.
Fig. 2 Contamination by Septic System [myactivator1000.com]

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C. Sewage and waste water
Sewage water carries harmful bacteria, organic matter, inorganic salts, heavy
metals, viruses, nitrogen and chemicals that can cause serious health diseases.
Pathogens are known as a common water contaminant; The sewers of cities house
several pathogens and thereby diseases. Sewer pipes carrying wastes sometimes
leak fluids into the surrounding soil and ground water. Pipelines carrying industrial
chemicals and oil brine have also been known to leak, especially when the
materials transported through corrosive pipes. Fig. 3, below display a leakage in a
sewage pipe into water that seepage into the soil to the ground water causing
contamination.
Fig. 3 Sewage Pipes Leakage as Contaminant [pugetsoundblogs.com]

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D. Landfills
Thousands of tons of disposed solid waste of industrial landfills represent one of
the main contamination resources of groundwater. Landfills is defined as the
places where the garbage is taken to be disposed. Landfills must have a protecting
bottom layer to avoid contamination of water. Although, in some cases the
protective layer is cracked or damaged, so contaminants from the landfill can pass
through soil to the groundwater.
Fig. 4 Unregulated Landfill [www.emaze.com/@ALZZLFRO/Lithosphere]
Moreover, disposals from many household wastes are not sufficiently regulated,
so, the chemicals can leak into the ground water by means of precipitation and
surface runoff. Closed landfills can continue to pose a ground water contamination
threat if they are not covered with an impermeable material before closure to
prevent the leakage of contaminants by precipitation.
Fig. 5 Landfill Contaminants Action on Groundwater [www.atsdr.cdc.gov]

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E. Surface Impoundments
Surface impoundments include the natural topographic depressions, man-made
excavations and diked areas that primarily are made of earthen materials and which
hold liquid wastes. These uncovered areas are commonly used to volatilize and/or
settle materials. As many as 180,000 surface impoundments exist in the United
States. Like landfills, new surface impoundment facilities are required to have
liners, but even these liners sometimes leak. [8]
F. Chemical fertilizers and pesticides
Chemical fertilizers and pesticides are used to prevent damaging the crops by
insects and bacteria. They are help plants to grow. Though, when these chemicals
are mixed up with water, there will be harmful product for plants and animals.
Similarly, when it rains, the chemicals mix up with rainfall and flow down into
rivers and canals which pose serious damages for aquatic animals.
G. Injection Wells
An injection well is used to place fluid underground into porous geologic
formations. These underground formations may range from deep sandstone or
limestone, to a shallow soil layer. Injected fluids may include water, wastewater,
brine or water mixed with chemicals. [8] Injection wells are usually used for
collecting storm water runoff, collecting spilled liquids, dispose of wastewater, and
dispose of industrial, commercial, and utility wastes. The injection wells used in
region are typically shallow and include sumps and dry wells used to handle storm
water.
H. Urban development
More cities and towns are developed to encounter the population growth, they have
resulted in increased usage of fertilizers to increase the food production, soil
erosion due to deforestation, increase in construction activities, inadequate sewer
collection and treatment, landfills as more garbage is produced, increase in
chemicals from industries and produce more waste materials contaminating
groundwater.
I. leakage of Underground storage
Chemical and petroleum products through transported by underground pipes is
well known resource of contaminants of groundwater. Accidentals leakage may
happen anytime and cause damages to the environment and result in soil erosion.

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Resources of groundwater contamination are various and cannot be limited to specific
resources, however, we can say that any material from any resource can change the water
properties is a contaminant. Table 1, below show the groups of groundwater contaminants
by their type and origin.
Table 1 Ground Water Contaminant Categories and Examples
Category Common Contaminants
Physical
sediment or organic material suspended in the water of
lakes, rivers and streams from soil erosion
Chemical
Nitrogen
Bleach
Salts
Pesticides
Metals
Toxins produced by bacteria, and human or animal drugs.
Biological
Bacteria
Viruses
Protozoan
Parasites
Radiological
Cesium
Plutonium
Uranium

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4. Groundwater Contamination Impacts
The effects of groundwater contamination are widespread. Human infectious disease
are the most serious effects of water contamination especially in rural areas that are still
developing and where sanitation is hardly regulated. This might cause hundreds of
thousands of diseases in the contaminated groundwater areas. An average 7 million people
are sickened in the US from drinking polluted water yearly. [10] the problems are not only
of drinking water, but also domestic uses and swimming water.
Not only are we effected by water contamination but so are animals are affected and
damaged by groundwater contamination. Nitrogen, phosphorus, and other nutrients come
from groundwater contamination can make the area as a coastal zone and that means it can
stimulate harmful overgrowths of algae, can have direct toxic effects and result in low-
oxygen conditions. Some algae are toxic and zooplankton eat it causing the contamination
to go through the food chain and eventually harming use with disease or death.
The consequences of contaminated ground water are often serious. In some instances,
ground water contamination is so severe that the water supply must be abandoned as a
source of drinking water. In other cases, the ground water can be cleaned up and used again,
if the contamination is not too severe and if the municipality is willing to spend a good deal
of money. Follow-up water quality monitoring is often required for many years.
Health effects from groundwater contamination depend on the specific contaminants
in the groundwater. Contamination from groundwater often causes diarrhea and stomach
irritation, which can lead to more severe health effects. Accumulation of heavy metals and
some organic contaminants can lead to cancer, reproductive abnormalities and other more
severe health effects. [11] Fig. 6, shows effects of contamination on fish.
Fig. 6 Groundwater Contamination Effects on Animals [blogs.fanbox.com/]

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Effects of groundwater contamination could be classified into three main groups, so
they could be separately understood. Table 2, below shows the three groups of groundwater
contamination effects.
Table 2 Effects of Groundwater Contamination
Group Description Examples of effects
Health Effects
Health effects are
the most common
problems
associated with
groundwater
contamination.
Hepatitis
Septic systems may infect groundwater with
hepatitis due to human waste present in the
water supply.
Hepatitis is a very serious problem that causes
irreversible damage to the liver.
Dysentery
Dysentery induced by contaminated drinking
water by waste materials of human or animal in
nature.
Poisoning
Poisons from both nature and from human use
of pesticides and solvents can leach into the
water well if it is not placed correctly.
Poisons can make humans and animals very
sick and may cause death.
Bone tissue & tooth discoloration
Excessive consumption of fluoride can damage
bone tissue. Also, too much fluoride can cause
tooth discoloration in young children. [8]
Cholera or giardiasis
Mainly caused by contaminated water
Environmental
Effects
The environment
can be seriously
damaged when
groundwater is
contaminated.
Nutrient pollution [12]
Groundwater contamination is the cause of
nutrients certain types, it is necessary in small
amounts to become far too abundant to sustain
normal life in a given ecosystem.
Fish might start dying off quickly because they
are no longer able to process the water in their
water supplies
Animals could become sick from excessive
certain types of nutrients in the water they drink.
Plants may not be able to absorb water easily,
and the entire ecosystem of plants will suffer.

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Toxic water in ecosystems [12]
contamination of the surface water is increased
when the groundwater that supplies lakes,
rivers, streams, ponds, and swamps is
contaminated.
The contamination of surface water cause
destruction of the wetlands, which depend on
heavily on groundwater to recharge their lakes
and ponds.
Persistent organochlorine insecticides [13]
Lake sediments contains persistent
organochlorine insecticides can bioaccumulate,
harming the fish and birds that eat them.
Pyrethroid insecticides, though derived from
chrysanthemums, are extremely toxic to aquatic
organisms.
Soil Contamination
When the ground water become contaminated,
the soil over the contaminated aquifers will not
be useable.
Economic
Effects
The economy and
industries might
be easily
suffering and
negatively
affected when
groundwater
becomes
contaminated.
Agricultural activities
Once the groundwater is contaminated, this will
definitely damage the agricultural sector and
cause the death of plants and farms producing
various of needed corps.
As well as the vegetation needed for other
purposes such as soil stabilization in coastal
areas.
Depreciating value of land
contaminated groundwater in a given area, that
makes the area less capable of sustaining
human, animal, and plant life.
Industry instability
Several industries depend on the groundwater to
produce various products and keep running
factories efficiently.
If pH and quality of groundwater from a given
area changes, the industries will be less capable
to maintain stable production. This will affect
the economy.

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5. Groundwater Contamination Controlling Regulations
Once water is contaminated, it is expensive, difficult, and sometimes impossible to
remove contaminants. However, water contamination could be prevented by using some
protection regulations to keep water clean and mitigate any further contamination. Some
useful protection methods can be used such as:
1. Containing the contaminant to stop migration.
2. Treating the water after pumping it, and returning it to the aquifer.
3. Treating the ground water in place or treating the contaminant.
4. Allowing the contaminant to reduce naturally with monitoring, following the
implementation of an appropriate source control.
5. Some technologies to remove contaminants from groundwater can be used to
refine the water such as: [13]
a) Air stripping:
This process involves pumping out the contaminated water, then heating it to
evaporate the contaminant. The cleaned water is reinjected into the ground.
Pumping out contaminated water and absorbing the pollutant on activated
charcoal can remove less volatile compounds. [13]
b) Granular activated carbon:
Activated carbon is commonly used to adsorb natural organic compounds, taste
and odor compounds, and synthetic organic chemicals in drinking water
treatment. Adsorption is both the physical and chemical process of
accumulating a substance at the interface between liquid and solids phases.
Activated carbon is an effective adsorbent because it is a highly porous material
and provides a large surface area to which contaminants may adsorb. [14]
c) Advanced Oxidation
Advanced oxidation processes are a set of chemical treatment procedures
designed to remove organic and sometimes inorganic materials in water and
waste water by oxidation through reactions with hydroxyl radicals. [15]
Preventing contamination is apparently important. Drinking water suppliers have
discovered that watershed protection is cost-effective because it reduces contamination and
reduces the cost of drinking water treatment. A watershed is the area that drains into surface
or groundwater and keeping that area free from development and agricultural runoff are
among the goals of watershed protection. [14]

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groundwater treatment techniques can be mainly divided into two technologies as
following: [16]
 Ex-Situ Technology
Extraction of groundwater from aquifer, treat above ground. and return the
treated water to the aquifer. Extraction is done by pumping groundwater from
the well or trench and treat them.
Fig. 7 Ex-Situ Remediation Technology [16]
 In-Situ Technology
involves treatment of ground water within the aquifer in the sub-surface by
using thermal, chemical and biological treatment technologies.
Fig. 8 In-Situ Remediation Technology [16]

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Groundwater treatment techniques are not only limited to chemical and biological
mechanisms, but the best way is preventing water to contaminate in the first place. The
following ways could be insured and carried out by businesses and industries which can
decrease the contamination hazards: [17]
1. Install groundwater observation systems such as leak detection and repair systems
2. Reduction of the usage of toxic or hazardous raw materials.
3. Maintain storage tanks and pipelines to prevent leaks that leach to the groundwater.
4. Contaminants must be disposed, handled, and transported appropriately.
5. Landfills must be regulated and discharged and continuously monitored by local
authorities.
6. Get involved in water education for students to learn more about groundwater and
share knowledge with others.
7. The community can contribute severely to groundwater contamination beside the
industrial activities, but there should be effective steps by individual households to
minimize these affects such as:
 Cleaning chemicals that contain toxic substances should not be used
extensively.
 Drain chemicals, insecticides and motor oil should not be disposed in
community areas.
 paints, pesticides, detergents, and polishing materials should be properly
disposed of.

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6. Conclusion and Recommendations
This research provided the baseline information on the groundwater contamination. It
was found that groundwater is very important source of fresh water and that makes the
contamination prevention is an important action by the government or any related
authorities or organizations. The sources of groundwater contamination are various and
may cause contamination without any clear evidence of the contamination, so this will lead
to further contamination spreads widely in the same area.
The sources of groundwater contamination were mentioned in this research with
detailed description of their origins and effects on the groundwater. There are many
classifications that could be used for classifying the groundwater contaminants as discussed
in this research, depending on the types of materials and any activities causing groundwater
contamination.
The effects of groundwater contamination are clear and widely known for local
organization or even individuals, so that will be helpful preventing further groundwater
contamination. However, lots of violations could surely lead to more severe groundwater
contamination in the unregulated areas. Health effects are the most hazardous effects of
groundwater contamination and they are resulted from the wrong usage of groundwater
without any testing or curing before using it for drinking or other purposes.
The groundwater is a very important source for domestic use and also for industrial
purposes. This important source should be maintained clean and any potential source of
contamination should be prevented at first. There is a common rule said that “the best way
to deal with groundwater contamination is not to contaminate it in the first place”.
Very strict regulations should be admitted to secure the use of groundwater in cities or
rural areas. Extensive monitoring by professionals must be funded to study the current
situation of available sources of groundwater and measure the actual contaminated water,
then suggesting solutions for both treatment and prevention of further contamination.
Local organizations should carry out very specialized studies on the groundwater
sources, in addition to aware the residents about the importance of water and the right
methods of dealing with the water sources. Educational activities also could be useful
enhancing the awareness of the young generation about the water sources of their future.

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