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What is groundwater?

irrigate crops.

grounds surface or it can sit hundreds of feet down.
Aquifers are typically made up of gravel, sand, sandstone, or fractured rock, like limestone.
Water can move through these materials because they have large connected spaces that make
them permeable. The speed at which groundwater flows depends on the size of the spaces in the
soil or rock and how well the spaces are connected.


Groundwater supplies are replenished, or recharged, by rain and snow melt that seeps down into
the cracks and crevices beneath the land's surface. In some areas of the world, people face
other areas groundwater is polluted by human activities.

up and out of the well.

no longer be safe to drink.
The Hydrologic Cycle
Water is always on the move. From the time the earth was formed, it has been endlessly
circulating through the hydrologic cycle. Groundwater is an important part of this continuous
cycle as water evaporates, forms clouds, and returns to earth as precipitation.

The Hydrologic Cycle

Surface water evaporates from by energy of the sun. The water vapor then forms clouds in the
sky. Depending on the temperature and weather conditions, the water vapor condenses and falls
to the earth as different types of precipitation (rain, snow, sleet, hail). Some precipitation moves
from high areas to low areas on the earth's surface and into surface water bodies. This is known
as surface runoff. Other precipitation seeps into the ground and is stored as groundwater.

1.6 Water Quality

Water quality refers to the physical, chemical and biological attributes of water that affect its
ability to sustain environmental values (ANZECC and ARMCANZ 1994b, pg. 12). Water
quantity describes the mass of water and/or discharge and can also include aspects of the flow
regime, such as timing, frequency and duration.

Water of adequate quality and quantity is central to the health and integrity of the environment.
The presence or absence of water, and its quality, largely determines the species richness and
diversity of a particular region. It can also be a trigger to breeding and recruitment behaviours for
some species. Changes in the quality or quantity of water may result in immediate change in the
structure and function of ecosystems including the numbers and types of organisms that can
survive in the altered environment (ANZECC and ARMCANZ 2000).

Good water quality and quantity are not only important to support healthy ecological
communities, they are equally important for human water users. On 30th September 2010, the
United Nations Human Rights Council adopted a resolution recognising that the human right to
safe drinking water and sanitation is a part of the right to an adequate standard of living
(UNHRC 2010). The availability of adequate supplies of clean water is one of the most
important building blocks for economic and social structures of society. It determines the
viability of a region to support industries such as agriculture, fishing, irrigation, manufacturing
and mining. Over history, it has shaped the geographic distribution of human populations and
their quality of life and culture.

The NWQMS identifies six environmental values that are conducive to public benefit, safety,
health or aesthetic enjoyment and which require protection from the effects of pollution
(ANZECC and ARMCANZ 2000) and altered flow regimes. They are:

Aquatic ecosystems;

Primary industries (irrigation and general water uses, stock drinking water, aquaculture
and human consumption of aquatic foods);

Recreation and aesthetics;

Drinking water;

Industrial water; and

Cultural and spiritual values.

1.6.1 Water quality-quantity link in policy

Water resource management is an integral part of protecting environmental values and balancing
competing economic, environmental and social demands (ANZECC and ARMCANZ 2000).

Significant water reforms have taken place over the past two decades to improve the
management of water resources in Australia. The Council of Australian Government (COAG)
has been responsible for a number of national reforms in water policy. Major milestones include
the COAG Water Reform Framework Agreement of 1994 and the National Water Initiative
(NWI) in 2004. The principal COAG mechanism for the management of water quality is the
National Water Quality Management Strategy (NWQMS). Another initiative is the National
Urban Water Planning Principles, which provide governments and water utilities with the tools to
better plan the development of urban water and wastewater service delivery in a sustainable and
economically efficient manner.

Implementation of the NWQMS and NWI has led to a number of policy developments and
instruments that support the management of water resources, including the quality and quantity
of those resources. This section provides an overview of the NWQMS and the NWI. Both take
into account the complex link between water quality and quantity, to varying degrees, and aim to
assist in resolving some of these complexities for water managers. National Water Quality Management Strategy

The NWQMS encapsulates the key dimensions of water that are essential for life (i.e. quantity
and quality) (ANZECC and ARMCANZ 1994a). Although water quantity and quality are
naturally variable, they are also affected by human-induced changes associated with water use
demands and land use. Water quality, in particular, can be managed in some contexts using
technology to deliver end-use requirements (e.g. drinking water).

The NWQMS provides the policies, processes, guidelines, information and tools necessary for
government and the broader community to manage water resources sustainably with a primary
objective to (ANZECC and ARMCANZ 1994a, pg.4):

Achieve the sustainable use of the nations water resources by protecting and enhancing their
quality while maintaining economic and social development.
The NWQMS comprises three core considerationspolicies, process and guidelinesand is a
key component of the 1994 COAG Water Reform Framework. The NWQMS is primarily the
responsibility of the Standing Council on Environment and Water. All States and Territories are
committed to its implementation and have adopted a number of the policies and guidelines that
support the NWQMS, such as the ANZECC and ARMCANZ (2000) Australian and New
Zealand Guidelines for Fresh and Marine Water Quality.

The NWQMS is complemented by a number of natural resource management initiatives

including the Australian Governments Caring for Our Country program, the former National
Action Plan for Salinity and Water Quality and the former Natural Heritage Trust.

In a review of the NWQMS, Bennett (2008) suggested that the NWI be modified to include an
obligation to implement and report on the NWQMS. Like the NWC (2011), Bennett (2008) also
indicated that there was a need to maintain linkages between management of water quantity and
quality. These linkages are best captured at the catchment-scale and should reflect the
environmental values that guide the activities of water resource managers. These environmental
values should be waterway-specific, reflect consistent value-setting processes that are transparent
to stakeholders and incorporate all the activities water resource managers are responsible for (i.e.
water quality management, water quantity management and resource management). Bennett
(2008) proposed that this common value-setting approach would lead to integrated management
of water resources.

The NWQMS was developed jointly by governments, resulting in a nationwide approach to

water quality improvement which can be enhanced through incorporation of best-available
science and alignment with other water reform processes. The NWQMS is currently undergoing
a review of its strategic directions to improve its efficiency and effectiveness.

Refer to the following website for more information on the NWQMS. National Water Initiative

The NWI is an Intergovernmental Agreement signed at the 25 June 2004 COAG meeting. The
Tasmanian and Western Australian governments signed in June 2005 and April 2006,
respectively. The purpose of the NWI is to optimise social, economic and environmental
outcomes through the management of Australias water resources. The NWI aims to achieve a
nationally compatible market and regulatory and planning based systems for managing surface
and groundwater resources for rural and urban use that optimises economic, social and
environmental outcomes.

Elements of water management under the NWI are:

Water access entitlements and planning framework;

Water markets and trading;

Best-practice water pricing;

Integrated management of water for the environment and other public benefit outcomes;

Water resource accounting;

Urban water reform;

Knowledge and capacity building; and

Community partnerships and adjustment.

The relationship between water quantity and quality is captured under the integrated
management of water for the environment and other public benefit outcomes category. The
intent of this commitment is to identify environmental outcomes and develop and implement
management practices and institutional arrangements that deliver these outcomes.

The NWI is complemented by a number of other natural resource management initiatives such as
the Australian Governments Water for the Future initiative and programs funded through the
National Water Commission.

In 2011, the National Water Commission carried out its third biennial assessment of the NWI,
aimed at reviewing the extent to which the initiative has improved the sustainable management
of Australias water resources and contributed to the national interest. Recommendation 6 of this
review emphasises the importance of the relationship between water quality and quantity and the
need to further understand and embed this relationship in water management (NWC 2011: p.13),
as follows:
Recommendation 6: Water quality objectives should be more fully integrated into the reform
agenda, with better connections between water quality and quantity in planning, management
and regulation to achieve improved environmental outcomes. There is also a need for a more
coordinated and structured approach to urban water quality regulation at a national level.

Addressing Recommendation 6 is a critical task for the future of water resource management.
The NWI was developed to primarily target water quantity issues in the midst of a drought, and
includes a limited number of actions that specifically aim to maintain or improve the quality of
Australias water resources (NWC 2011). In general, there is a lack of integrated management of
water quality and water quantity issues. In summary the NWC (2011: p.12) states that:

Contemporary water management requires a recognition of the interactions between quality and
quantity and the potential economic uses of water of differing quality.

Actions to integrate water quality and quantity into water management require consideration of
the quantity and quality of inflows, particularly in relation to point and diffuse sources of
pollution. If the timing, magnitude, and duration of inflows are managed to optimise
environmental outcomes, but the quality of the environmental water is poor, then the intended
outcomes may not be realised and other impacts may occur. It is therefore important for water
managers to understand the quantity and timing of water needed by environmental assets,
the source of environmental water and the quality of that water in conjunction with watering

Refer to the following website for more information on the NWI:

1.6.2 The role of modelling in managing water quality and water quantity
Water quality and quantity is influenced by a complex array of both natural and anthropogenic
factors at the catchment scale through to the micro-scale. Contemporary thinking is moving to
using multiple lines of evidence in order to understand and manage these aspects of aquatic
systems. Coupling of routine monitoring data with modelling approaches is emerging as a useful
mechanism to understand, simulate and also communicate water quality and water quantity
relationships and the factors that influence them.
Flow, water quality, biological and other catchment data and information has been collected for
many years in most aquatic systems throughout Australia. These data sets provide valuable
information for developing a detailed understanding of how various ecosystems function.
Hence, these data sets are increasingly being used to develop and calibrate models that are
guiding decision making by water resource managers.

Two general types of models are used:

A fundamental model is a conceptual model. A conceptual model summarises the current

understanding of the key catchment processes, dependencies and impacts on the water
resource, and is typically presented graphically, in cross-section or block diagram format,
with supporting descriptions. Use of a conceptual model guides field data gathering
programs and help ensure that any subsequent numerical models are fit for purpose in
the level of detail it captures.

A numerical, or mathematical, model solves equations describing physical processes

using a step-wise approximation. Solutions are obtained by performing successively
improved approximations at each step until the numerical answer satisfies all the
equations being used. Such numerical models can be used to understand system processes
and assess the likely effects of proposed management actions.

The predictive power of models increases with data availability, ongoing research
into understanding catchment and in-stream processes and through incorporating algorithms into
models to reflect that increased understanding and additional data (SKM 2011).

For a scientific purpose, models can be useful for:

Improving the understanding of aquatic systems through integrating catchment,

hydrological, water quality and ecological factors;

Helping predict the impact of various water management options or changes to catchment
condition, and assisting in the optimisation of management solutions; and

Helping synthesise data and encapsulate current understanding of aquatic systems.

Models are often used to interpolate the available (but limited) data both in space and
time, as a cheaper and quicker option than intense data collection.
From a management perspective, models offer:

A means of education and communication. For example, where there are multiple
stakeholders in the development of a management plan, a model can be used to illustrate
the relative involvement of each of the stakeholders in the issues and the possible
solutions. A pre-requisite is that the stakeholders must have been involved in the
calibration of the model and must have developed trust in its reliability;

Setting reference conditions in modified systems;

Setting targets and objectives for water quality and targets for on-the-ground actions;

Checking compliance with management plans based on water quality variables.

Examples are the use of the Murray Darling Basin Authority (MDBA) model MSM-
BigMod in quantifying the Salinity Credits and Debits arising from the actions of
three States and the Commonwealth, and the Pilot (nutrient) Pollution Trading Scheme in
the lower Hawkesbury-Nepean (NSW); and

Guidance in the day-to-day management of systems.


Water quantity is a fundamental driver of water quality. The nature of the relationship between
water quantity and quality is complex and depends strongly on the characteristics of individual

Water quality can be directly attributable to the following three characteristics of catchment and
local hydrology, which cause daily and seasonal fluctuations in water quality:

Source of water (i.e. snow melt, rainfall/surface runoff, groundwater, tidal waters,
irrigation transfers, flow releases from dams, point and diffuse sources);

Hydrological variability, referred to as the flow/watering regime (i.e. magnitude, timing,

frequency and duration of flows); and

In-stream processes (i.e. transport/retention, evapo-concentration/dilution,

mixing/stratification, reaeration, nutrient and carbon cycling).
These three characteristics are discussed below.

3.1 Source of water

Water quality varies amongst different catchments and different types of aquatic ecosystems.
Much of this variation can be explained by the sources of water. Natural sources of water include
snow melt, rainfall/surface runoff, groundwater and tidal waters. Human-derived modifications
to catchments have altered the quantity, quality and balance of these natural sources, and
introduced new water movement pathways, for example irrigation transfers, flow releases from
dams, and point and diffuse sources. The quality of source water shapes the evolution and
ecology of aquatic ecosystems.

In natural, unmodified catchments, inputs to the water cycle include snow-melt and/or rainfall
with associated surface runoff to rivers and wetlands and groundwater recharge. Groundwater
discharge can support base flows in rivers, lakes and wetlands. The hydrology of lakes and
wetlands depends on their level of connection with water sources. Some lakes and wetlands are
connected to rivers, while others can be isolated and located within low points in the landscape
that receive rainfall runoff from the catchment. Estuarine and near-shore marine environments
have a unique blend of fresh catchment inflows and marine tidal waters. Each of these sources
are characterised by differences in water quality (e.g. temperature, salinity, alkalinity, nutrients,
organic carbon and metal concentrations), which can be also be a function of altitude,
topography, soil type and vegetation cover.

Human-derived catchment modifications and land use have not only altered the natural water
cycle, but have also changed the water quality of natural sources (Baker 2003; Quinn et al.
1997). For example, water tables in the Murray-Darling Basin have risen as a consequence of
extensive irrigation. This has led to increasing salinity in some streams from saline groundwater
discharge during low flows. Another example is the construction of large dams on waterways,
which has led to changed flow regimes and water quality downstream (e.g. cold water pollution)
(Bunn and Arthington 2002a; Poff et al. 1997). It is clear from the literature that water quality is
directly attributable to the following characteristics of the catchment:

Percentage of native vegetation and riparian zone cleared and/or replaced with other
species, (Bunn et al. 1999; Rutherford et al. 2004);
Extent and intensity of agriculture and nature of agricultural practices in a catchment,
including animal stocking rates and rates of application of fertilisers and other
agricultural chemicals (Byers et al. 2005; Sauer et al. 1999; Young and Huryn 1999);

Density of human population, urbanisation and effluent disposal practices (Brabec et al.
2002; Walsh et al. 2005); and

Catchment geology, mining and erosion (Jenkins 1998).

Dissolved and particulate substances, such as eroded soils, nutrients, salts, toxins, pathogens and
other contaminants, are transported from the surrounding catchment into aquatic ecosystems
after rainfall. They can enter waterways and wetlands by point or non-point (diffuse) pathways.
Point sources are typically continuous and from a specific location (usually a pipe or drain).
They include stormwater, sewage treatment plant or industrial discharges. Sewage treatment
plant wastewater discharges are common sources of nutrients in waterways. The load of point
source inputs to waterways is typically proportional to the level of urbanisation in the catchment
(Walsh 2000).

Non-point sources are not as easily identifiable. These sources of contaminants include runoff
from farms, roads or lawns and erosion within a catchment. Leakage from septic tanks or sewer
exfiltration from underground pipe networks can also be classified as diffuse sources. Nutrients
and suspended solids are common in non-point source runoff from farms and agricultural land,
from use of fertilisers, stock access to waterways and effluent management.

The geology and soils of a catchment can influence water quality, for instance, easily eroded clay
soils can lead to increased turbidity (Jenkins 1998). Soil erosion can also be related directly to
land use and, in particular, the amount of land-clearing (Prosser et al. 2003; Wallbrink 2004).
The major forms of soil erosion are gully, rill and stream bank erosion. All forms are caused by
poor ground cover, drought, intense rainfall and/or unstable soils. Erosion is a major source of
sediment, nutrients, and pesticides in surface water from catchments dominated by agricultural
land (Prosser et al. 2003). Influence from non-point sources increases markedly during periods
of heavy rainfall and increased runoff and is sometimes referred to as the 90:10 rule whereby
90% of contaminants are delivered to aquatic systems 10% of the time.
Mining operations (e.g. coal mining or coal-seam gas operations) may also affect water quality
through dewatering discharges to waterways/storages, generation of sediment-laden runoff,
chemical handling and storage, water and sewage operations, creek redirections and subsidence.
Contaminants of concern in mine-affected water include salts, heavy metals, anions, cations,
process chemicals, acid mine drainage and suspended solids (Hart 2008). One of the major
impacts to water quality can result from the cumulative effects of concurrent waste discharges
(including dewatering) from large numbers of mines in the catchment and also from the
discharge of floodwater from mines after heavy rainfall (DERM 2009).

3.2 Hydrological variability

Water quality responds rapidly to short-term changes in flow (Poff et al. 1997). Much of this
variability in water quality results from changes and relative contributions in the sources of water
(i.e. storm flows containing catchment runoff vs. base flows). Groundwater is an important
contributor to flows in many rivers and wetland systems. It is a relatively constant and stable
source of water compared with surface flows and can maintain water levels in ecosystems during
extended dry periods. Groundwater quality varies, and can often contain higher salinity levels,
dissolved nutrients and metals than surface water runoff. Therefore, water quality in river
systems and wetlands can vary depending on the relative proportion of groundwater
contributions to surface inflows.

Wetlands and lakes are inundated with water either permanently or seasonally. Unmodified
wetlands and lakes typically fill during the wet season and slowly dry during the dry season.
These wetting and drying cycles can be important ecologically as well as for water quality
purposes. The wet season filling refreshes water quality, diluting salinity levels and entraining
organic matter for food webs. The drying cycles are important for releasing carbon and nutrients
that promote subsequent growth by algae, bacteria, plants and animals (Corrick and Norman

In natural river systems, water quality is supported by a variable flow regime whereby each flow
component (e.g. high flows, low flows, cease to flows) fulfils particular functions to restore or
maintain water quality and a range of ecological and geomorphological functions (Bunn and
Arthington 2002a; Poff et al. 1997). For instance, low flows provide warm, clear conditions
suitable for nutrient cycling and primary production. Higher flows provide dilution of ions and
toxins and entrainment of a fresh supply of nutrients and carbon to support ecological services.
Cease to flow periods in temporary streams can dry out the sediments, releasing carbon and
nutrients that enables new life to flourish when flows return.

Extremes in flow variability, which occur during severe droughts and major floods, often cause
extremes in water quality. Although such extreme events have a low frequency of occurrence,
when they do occur, they often have major consequences for water quality in aquatic systems.
Water quality impacts from such extreme events can compromise the availability and suitability
of water resources for its environmental values and beneficial uses.

Droughts can cause rivers to experience prolonged low flows or cease to flow periods. Wetlands,
lakes and reservoirs experience very low water levels or dry out completely. Consequently, these
waterbodies may experience extremes in water temperature, low dissolved oxygen levels,
thermal or saline stratification of the water column, evapoconcentration of ions and toxins and
algal growth supported by calm, warm water conditions (Bates et al. 2008). Floods can cause
widespread catchment erosion resulting in unprecedented nutrient, suspended solids and toxicant
loads to fragile near-shore environments (Prosser et al. 2001). They can also cause sewage
treatment plants and sewers to overflow, delivering pathogens (including water-borne illnesses),
nutrients and toxicants to waterways (Howe et al. 2005).

Flow variability is closely related to the physical, chemical and biological components of water
quality. These are discussed in the next section (Section 3.3).

3.3 In-stream processes

Physical, chemical and biological processes that occur within a waterbody are important drivers
of water quality. These processes are described in Table 3-1. Each of these processes is
influenced by flow and can dictate the contaminant loads and in-stream concentrations. They can
either improve or degrade water quality. For example, sedimentation is an in-situ process that
occurs when the velocity of the flowing water slows to allow suspended particles to settle out.
This process increases water clarity, which is important to provide light for photosynthesis by
aquatic plants.
Table 3-1 In-situ physical, chemical and biological processes that affect water quality

Physical processes Description

Reaeration Reaeration is the transfer of oxygen from the atmosphere to a body of

water at the
air/water interface. It can be influenced by riffles or wind-induced
waves. It affects the dissolved oxygen levels.

Sedimentation Sedimentation is the settling of suspended particles. Rates of

sedimentation are determined by the size of the particles, the velocity
of the water and the ionic environment. Sedimentation affects the
water clarity.

Adsorption Adsorption is the reversible binding of molecules to a particle

surface. This process can bind dissolved phosphorus and pathogens
to particles.

Evapo-concentration Evapo-concentration is the process by which water is evaporated and

the substances present, particularly salts, concentrate.

Dilution Dilution is the process of making a substance less concentrated by

adding water. This can lower the concentrations of ions, toxins and
other substances.

Stratification Stratification is the formation of density layers (either temperature or

salinity derived) in a water body through lack of mixing. It can create
favourable conditions for algal blooms and can lower dissolved
oxygen levels in the bottom layers with the associated release of
nutrients, metals and other substances.

Heating/cooling Water temperature is determined primarily by air temperature and is

also impacted by stratification and flow/water level. Temperature
affects the rates of chemical and biological reactions. It also affects
Physical processes Description

the solubility of dissolved oxygen.

Chemical Processes

Precipitation of Precipitation is when a dissolved substance forms a solid that settles

minerals out of the water.

Flocculation Flocculation is the aggregation of colloidal (very fine) particles into

larger particles that then settle. This occurs in high salinity
environments (e.g. estuaries).

Chemical Chemical transformations of substances can occur through acid-base

transformations reactions or redox reactions. For example, changes to ammonia and
metal toxicity and/or availability occur under varying temperatures,
pH and oxygen levels.

Biological processes

Carbon cycling/ Carbon cycling involves the oxidation of complex organic matter into
decomposition of simpler forms (e.g. CO2, phosphate, ammonia, etc). It is one of the
organic matter key steps in the decomposition of organic matter. This provides
bacteria, protozoa and fungi (at the base of the foodweb) with the
energy for cellular metabolism and growth. This process consumes

Primary production Primary production is creation of new organic matter by

photosynthesis. Oxygen is produced during this process. Primary
productions occur in aquatic systems and include algae and
macrophyte growth.

Nutrient cycling The nutrient cycle describes how nutrients move from the physical
environment into living organisms, and then subsequently are
Physical processes Description

recycled back to the physical environment. This movement of

nutrients, sometimes referred to as nutrient spiralling is essential for
life, and is a vital function of the ecology of aquatic ecosystems.
There are four biological processes that participate in the cycling of
nitrogen. They are Nitrogen fixation: N2 NH4+, Decay: Organic N
NH4+, Nitrification: NH4+ NO2 NO3 and De-nitrification:
NO3 N2+ N2O.

Bioaccumulation General term describing a process by which chemical substances are

accumulated by aquatic organisms from water, either directly or
through consumption of food containing the chemicals.

Many of these in-stream processes have been affected by anthropogenic land uses such as
agriculture and urbanisation (Baker 2003; Quinn et al. 1997). This has affected the water quality
in many systems. Eutrophication is a symptom that an ecosystem has exceeded its assimilative
capacity of nutrients from excessive anthropogenic inputs (Heisler et al. 2008). Not all of the
available nutrients are able to be processed through nutrient cycling and therefore the water body
becomes nutrient enriched. The most acute symptoms of eutrophication are algal blooms.
Eutrophication results not only from point sources, such as wastewater discharges with high
nutrient loads (principally nitrogen and phosphorus), but also from diffuse sources such as run-
off from livestock feedlots or agricultural land fertilised with organic and inorganic fertilisers.
While diffuse sources dominate water quality during high flows, point sources generally
dominate water quality during periods of low flow due to dry weather contaminant discharges
(EPA Victoria 1995).

1.7 Basic Facts of Water pollution

also seep down and affect the groundwater deposits.


Domestic sewage

Refers to waste water that is discarded from households. Also referred to as sanitary sewage,
such water contains a wide variety of dissolved and suspended impurities. It amounts to a very
small fraction of the sewage by weight. But it is large by volume and contains impurities such as
vegetable waste, plant nutrient come from chemical soaps, washing powders, etc. Domestic
sewage is also very likely to contain disease-causing microbes. Thus, disposal of domestic waste
water is a significant technical problem. Sewage generated from the urban areas in India has
multiplied manifold since 1947.

Today, many people dump their garbage into streams, lakes, rivers, and seas, thus making water
bodies the final resting place of cans, bottles, plastics, and other household products. The various
substances that we use for keeping our houses clean add to water pollution as they contain
harmful chemicals. In the past, people mostly used soaps made from animal and vegetable fat for
all types of washing. But most of todays cleaning products are synthetic detergents and come
from the petrochemical industry. Most detergents and washing powders contain phosphates,
which are used to soften the water among other things. These and other chemicals contained in

Agricultural Run off

The use of land for agriculture and the practices followed in cultivation greatly affect the quality
of groundwater. Intensive cultivation of crops causes chemicals from fertilizers (e.g. nitrate) and
pesticides to seep into the groundwater, a process commonly known as leaching. Routine
applications of fertilizers and pesticides for agriculture and indiscriminate disposal of industrial
and domestic wastes are increasingly being recognized as significant sources of water pollution.

The high nitrate content in groundwater is mainly from irrigation run-off from agricultural fields
where chemical fertilizers have been used indiscriminately.

Industrial effluents

Waste water from manufacturing or chemical processes in industries contributes to water

pollution. Industrial waste water usually contains specific and readily identifiable chemical
compounds. During the last fifty years, the number of industries in India has grown rapidly. But
water pollution is concentrated within a few subsectors, mainly in the form of toxic wastes and
organic pollutants. Out of this a large portion can be traced to the processing of industrial
chemicals and to the food products industry. In fact, a number of large- and medium-sized
industries in the region covered by the Ganga Action Plan do not have adequate effluent
treatment facilities. Most of these defaulting industries are sugar mills, distilleries, leather
processing industries, and thermal power stations. Most major industries have treatment facilities
for industrial effluents. But this is not the case with small-scale industries, which cannot afford
enormous investments in pollution control equipment as their profit margin is very slender.

Effects of water pollution

The effects of water pollution are not only devastating to people but also to animals, fish, and
birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It
diminishes the aesthetic quality of lakes and rivers. More seriously, contaminated water destroys
aquatic life and reduces its reproductive ability. Eventually, it is a hazard to human health.
Nobody can escape the effects of water pollution.

The individual and the community can help minimize water pollution. By simple housekeeping
and management practices the amount of waste generated can be minimized.
Biochemical oxygen demand or BOD

The amount of organic material that can rot in the sewage is measured by the biochemical
oxygen demand. BOD is the amount of oxygen required by micro-organisms to decompose the
organic substances in sewage. Therefore, the more organic material there is in the sewage, the
higher the BOD. It is among the most important parameters for the design and operation of
sewage treatment plants. BOD levels of industrial sewage may be many times that of domestic
sewage. Dissolved oxygen is an important factor that determines the quality of water in lakes and
rivers. The higher the concentration of dissolved oxygen, the better the water quality. When
sewage enters a lake or stream, micro-organisms begin to decompose the organic materials.
Oxygen is consumed as micro-organisms use it in their metabolism. This can quickly deplete the
available oxygen in the water. When the dissolved oxygen levels drop too low, many aquatic
species perish. In fact, if the oxygen level drops to zero, the water will become septic. When
organic compounds decompose without oxygen, it gives rise to the undesirable odours usually
associated with septic or putrid conditions.


When fresh water is artificially supplemented with nutrients, it results in an abnormal increase in
the growth of water plants. This is known as eutrophication. The discharge of waste from
industries, agriculture, and urban communities into water bodies generally stretches the
biological capacities of aquatic systems. Chemical run-off from fields also adds nutrients to
water. Excess nutrients cause the water body to become choked with organic substances and
organisms. When organic matter exceeds the capacity of the micro-organisms in water that break
down and recycle the organic matter, it encourages rapid growth, or blooms, of algae. When they
die, the remains of the algae add to the organic wastes already in the water; eventually, the water
becomes deficient in oxygen. Anaerobic organisms (those that do not require oxygen to live) then
attack the organic wastes, releasing gases such as methane and hydrogen sulphide, which are
harmful to the oxygen-requiring (aerobic) forms of life. The result is a foul-smelling, waste-filled
body of water. This has already occurred in such places as Lake Erie and the Baltic Sea, and is a
growing problem in freshwater lakes all over India. Eutrophication can produce problems such as
bad tastes and odours as well as green scum algae. Also the growth of rooted plants increases,
which decreases the amount of oxygen in the deepest waters of the lake. It also leads to the death
of all forms of life in the water bodies.

1.7.1 Cause of Water Pollution

There are many specific causes of water pollution, but before we list the toppers, it's important to
understand two broad categories of water pollution:

Point source occurs when harmful substances are emitted directly into a body of water.
Nonpoint source delivers pollutants indirectly through transport or environmental change.

An example of a point source of water pollution is a pipe from an industrial facility discharging
effluent directly into a river. An example of a nonpoint-source of water pollution is when
fertilizer from a farm field is carried into a stream by rain (i.e. run-off).

Point-source pollution is usually monitored and regulated, at least in Western countries, though
political factors may complicate how successful efforts are at true pollution control. Nonpoint
sources are much more difficult to monitor and control, and today they account for the majority
of contaminants in streams and lakes.


Pesticides that get applied to farm fields and roadsidesand homeowners' lawnsrun off into
local streams and rivers or drain down into groundwater, contaminating the fresh water that fish
swim in and the water we humans drink. It's tempting to think this is mostly a farming problem,
but on a square-foot basis, homeowners apply even more chemicals to their lawns than farmers
do to their fields! Still, farming is a big contributor to this problem.

Fertilizers / Nutrient Pollution

Many causes of pollution, including sewage, manure, and chemical fertilizers, contain "nutrients"
such as nitrates and phosphates. Deposition of atmospheric nitrogen (from nitrogen oxides) also
causes nutrient-type water pollution.
In excess levels, nutrients over-stimulate the growth of aquatic plants and algae. Excessive
growth of these types of organisms clogs our waterways and blocks light to deeper waters while
the organisms are alive; when the organisms die, they use up dissolved oxygen as they
decompose, causing oxygen-poor waters that support only diminished amounts of marine life.
Such areas are commonly called dead zones.

Nutrient pollution is a particular problem in estuaries and deltas, where the runoff that was
aggregated by watersheds is finally dumped at the mouths of major rivers.

Oil, Gasoline and Additives

Oil spills like the Exxon Valdez spill off the coast of Alaska or the more recent Prestige spill off
the coast of Spain get lots of news coverage, and indeed they do cause major water pollution and
nproblems for local wildlife, fishermen, and coastal businesses. But the problem of oil polluting
water goes far beyond catastrophic oil spills. Land-based petroleum pollution is carried into
waterways by rainwater runoff. This includes drips of oil, fuel, and fluid from cars and trucks;
dribbles of gasoline spilled onto the ground at the filling station; and drips from industrial
machinery. These sources and more combine to provide a continual feed of petroleum pollution
to all of the world's waters, imparting an amount of oil to the oceans every year that is more than
5 times greater than the Valdez spill.

Shipping is one of these non-spill sources of oil pollution in water: Discharge of oily wastes and
oil-contaminated ballast water and wash water are all significant sources of marine pollution, and
drips from ship and boat motors add their share. Drilling and extraction operations for oil and gas
can also contaminate coastal waters and groundwater.


Mining causes water pollution in a number of ways:

The mining process exposes heavy metals and sulfur compounds that were previously
locked away in the earth. Rainwater leaches these compounds out of the exposed earth,
resulting in "acid mine drainage" and heavy metal pollution that can continue long after
the mining operations have ceased.

Similarly, the action of rainwater on piles of mining waste (tailings) transfers pollution to
freshwater supplies.

In the case of gold mining, cyanide is intentionally poured on piles of mined rock (a leach
heap) to chemically extract the gold from the ore. Some of the cyanide ultimately finds its
way into nearby water.

Huge pools of mining waste "slurry" are often stored behind containment dams. If a dam
leaks or bursts, water pollution is guaranteed.
Perhaps the worst offense in the category of mining vs. water pollution causes: Mining
companies in developing countries sometimes dump mining waste directly into rivers or other
bodies of water as a method of disposal. Developed countries are not immune from such


When forests are "clear cut," the root systems that previously held soil in place die and sediment
is free to run off into nearby streams, rivers, and lakes. Thus, not only does clear cutting have
serious effects on plant and animal biodiversity in the forest, the increased amount of sediment
running off the land into nearby bodies of water seriously affects fish and other aquatic life. Poor
farming practices that leave soil exposed to the elements also contribute to sediment pollution in

Chemical and Industrial Processes

Almost all bodies of water in the world have some level of pollution from chemicals and
industrial waste.
In India the Industrial town their are 34 billion liters per year (60%) of the most hazardous liquid
wastesolvents, heavy metals, and radioactive materialsis injected directly into deep
injected below the deepest source of drinking water, some pollutants have already entered
underground water supplies in India.

major industrial zones it surveyed.


Plastics and other plastic-like substances (such as nylon from fishing nets and lines) can entangle
fish, sea turtles, and marine mammals, causing pain, injury, and even death. Plastic that has
broken down into micro-particles is now being ingested by tiny marine organisms and is moving
up the marine food chain.

Sea creatures that are killed by plastic readily decompose. The plastic does notit remains in the
ecosystem to kill again and again.

Personal Care Products, Household Cleaning Products, and Pharmaceuticals

Whenever we use personal-care products and household cleaning productswhether they be

laundry detergent, bleach, or fabric softener; window cleaner, dusting spray, or stain remover;
hair dye, shampoo, conditioner, or Rogaine; cologne or perfume; toothpaste or mouthwash;
antibacterial soap or hand lotionwe should realize that almost all of it goes down the drain
when we do laundry, wash our hands, brush our teeth, bathe, or do any of the other myriad things
that incidentally use household water. Similarly, when we take medications, we eventually
excrete the drugs in altered or unaltered form, sending the compounds into the waterways.
Studies have shown that up to 90% of your original prescription passes out of you unaltered.
Animal farming operations that use growth hormones and antibiotics also send large quantities of
these chemicals into our waters.

Unfortunately, most wastewater treatment facilities are not equipped to filter out personal care
products, household products, and pharmaceuticals, and a large portion of the chemicals passes
right into the local waterway that accepts the treatment plant's supposedly clean effluent.

Study of the effects of these chemicals getting into the water is just beginning, but examples of
problems are now popping up regularly:

Scientists are finding fragrance molecules inside fish tissues.

Ingredients from birth control pills are thought to be causing gender-bending hormonal
effects in frogs and fish.

The chemical nonylphenol, a remnant of detergent, is known to disrupt fish reproduction

and growth.

In developing countries, an estimated 90% of wastewater is discharged directly into rivers and
streams without treatment. Even in modern countries, untreated sewage, poorly treated sewage,
or overflow from under-capacity sewage treatment facilities can send disease-bearing water into
rivers and oceans. In India raw sewage are directly sent into rivers, lakes, and bays every year by
leaking sewer systems and inadequate combined sewer/storm systems that overflow during
heavy rains. Leaking septic tanks and other sources of sewage can cause groundwater and stream
Beaches also suffer the effects of water pollution from sewage. About 35% of the beaches in the
India are put under water pollution advisories or are closed each year. It's clear that sewage is
part of the problem.

Air Pollution

We were doing WATER pollution causes! Well, surprisingly enough, air pollution contributes
substantially to water pollution. Pollutants like mercury, sulfur dioxide, nitric oxides, and
ammonia deposit out of the air and then cause problems like mercury contamination in fish,
acidification of lakes, and eutrophication (nutrient pollution). Most of the air pollution that
affects water comes from coal-fired power plants and the tailpipes of our vehicles, though some
also comes from industrial emissions.

Carbon Dioxide

According to the United Nations Environment Programme, a 15-year-long study of the role of
man-made CO2 in the earth's oceans found that the oceans had absorbed enough CO2 to already
have caused a slight increase in ocean acidification. The fear is that further CO2 uptake will
increase acidification even more and cause the carbonate structures of corals, algae, and marine
plankton to dissolve. This could have significant impacts on the biological systems of our


Heat is a water pollutantincreased water temperatures result in the deaths of many aquatic
organisms. These increases in temperature are most often caused by discharges of cooling water
by factories and power plants.

Global warming is also imparting additional heat to the oceans. The impact on marine life is
unknown at this point, but it's likely to be significant.

Many marine organisms, including marine mammals, sea turtles and fish, use sound to
communicate, navigate, and hunt. The ever-increasing din of noise from ship engines and sonars
has a negative effect. Because of this noise pollution, some species may have a harder time
hunting; others may have a harder time detecting predators; still others may just not be able to
navigate properly.

Even the dead are a cause of water pollution. In India, if a deceased person's family cannot afford
a funeral they may immerse the ashes of their loved one in the sacred Ganges Riveror they
may put the corpse itself in the river, this is the most important factor of water pollution in our
country not this some time people directly immerse the death body of their pet Animal like Cow
and Dog and like this another animal. One another factor is that we directly drop out our puja ka
saman in rivers. (Materials for Religious).

These are some basic facts on Water pollution in India, and our responsibility is that we should
try to save our water for future and motivate our community and our friends that the time is over
now save water for future.

1.8 Physical and Chemical Properties of Water

All matter has properties. We recognize a person by his face, voice, height, fingerprints, DNA,
and other factors.

The more properties identified, the better we know the person. In a similar way, matter has many
properties. The two basic types of properties associated with matter are physical and chemical.

Physical Properties

Physical properties do not change the chemical nature of matter. A physical change occurs in
shape, form, or appearance but no new substance is created. Examples of physical properties
include color, odor, hardness, texture, luster, volume or size, shape, solubility (ability to
dissolve), molecular polarity (positively or negatively charged), freezing, boiling and melting
points, taste, magnetism, density, salinity, absorbency, and many others.

Solubility and polarity are classified as physical properties because no new substances are
produced as a result of testing for these properties.
Classification of Matter

A substance is more easily identified when many properties have been recognized. Matter is
sorted and classified according to its properties. For example, the property of a substance being
metal or nonmetal determines part of that substances classification on the periodic table. Copper
is a metallic substance with a shiny, reddish-color, and a density of 89.2 grams per cubic
centimeter. It is nonmagnetic, and has good electrical conductivity.

Properties of Water

Properties of water you are familiar with are transparency, color, melting and freezing
temperatures, solubility, and other factors. There are other properties with which you may not be
as familiar. When electrons are not shared equally in a molecule, it is said to be polar. This is
the situation with water, H2O. The water molecule is neutral as a whole, but one end tends to be
positive and one end tends to be negative. Each end of one water molecule is attracted to the end
of another molecule. This attraction causes water molecules to stick together and create surface
tension. This is why it hurts so much to do a belly buster off the high diving board. The water
molecules will not separate easily to allow you to enter the water. A lot of the energy from your
fall is transferred back to your body. The sticking together of like atoms or molecules in the
above example is called cohesion. The sticking together of unlike atoms or molecules is called
adhesion, such as tape sticking to wrapping paper on a package. The two substances are not alike
yet they stick to each other.

Physical Change

Physical change in matter affects one or more of the physical properties of a substance. This
change does not alter the nature of the substance. For example, when you tear a piece of paper
into tiny pieces, you still have paper. It is in a different shape or form, but it has not changed its
chemical composition. Melting butter to add to popcorn at the movies is a physical change in the
state or phase of matter for the butter. Other examples of physical change are chopping wood,
bending a paper clip, adding ice to tea. Because a physical change does not involve changing the
chemical structure of the material, it can usually be changed back easily. If you mold silly putty
into a shape then decide you want to make it something different, you simply remold it into
something else. The ability to restore something to its original substance is a characteristic of
physical change. Some processes that produce a physical change are cutting, grinding, boiling,
freezing, melting, condensing, breaking, separating, chopping, splitting, mixing, tearing,
crushing and blending.

Chemical properties

Chemical changes deal with reactions of two or more substances and result in the formation of
new material. Chemical properties change the chemical nature of matter. Examples of chemical
properties are heat of combustion, reactivity with water or other materials, and pH. For example,
copper reacts with nitric acid to produce brown fumes. In the form of a compound, copper
chloride in the presence of aluminum, will decompose (break down) into copper and aluminum
chloride. Decomposition of copper with other chemicals is one of its chemical properties.

Chemical Change

A chemical change occurs when the composition of a substance is changed into a new product.
Chemical changes usually occur when two or more substances come in contact with each other,
or when heat is applied. As matter and energy cycle through the environment, atoms and
molecules are transformed and recombined

in different ways creating new substances. The new substances have different properties than the
original material. For instance, iron rusting (iron and oxygen reacting), or acid fizzing when it
comes in contact with limestone (acid and calcium carbonate reacting) are examples of chemical

Evidence of Chemical Change

The outcomes, or products, of a chemical reaction cannot easily be turned back into the original
substances. Once paper is burned, it cannot be restored to its original state. Indications of a
chemical change are change in color, production of gas (bubbles), production of a solid
(precipitate), creation of heat (exothermic reaction), or cooling (endothermic reaction), light
being given off and production of an odor. Not all chemical reactions show these indications in
any easily visible way, and these changes do not necessarily indicate a chemical reaction. These
are only visible evidences of activity that allow us to infer that a reaction is occurring on a
molecular level.
1.9 Standards for Drinking water

The Bureau of Indian Standards (BIS) has specified drinking water quality standards in India to
provide safe drinking water to the people. It is necessary that drinking water sources should be
tested regularly to know whether water is meeting the prescribed standards for drinking or not
and, if not, then, the extent of contamination/ unacceptability and the follow-up required.

Apart from BIS specification for drinking water, there is one more guideline for water quality,
brought out by Ministry of Water Resources, Government of India in 2005. This is known as
Uniform Protocol for Water Quality Monitoring. A need has arisen to have a separate uniform
protocol for Drinking Water Quality Monitoring in view of increasing risk of geogenic and
anthropogenic contamination.

Keeping in view requirement of preparing Uniform Drinking Water Quality

Monitoring Protocol, the Ministry of Drinking Water and Sanitation (MDWS), Government of
India constituted an Expert Group which prepared the Protocol. The Drinking Water Quality
Monitoring protocol describes specific requirements for monitoring drinking water quality with a
view to ensure provision of safe drinking water to the consumers.

Definition of drinking water quality

BIS has set specifications in IS10500 and subsequently the revised edition of IS 10500: 2012 in
Uniform Drinking Water Quality Monitoring protocol.

Some parameters apart from those mentioned in IS 10500: 2012 may also be measured if the
States deem it necessary. This standard has two limits i.e. Acceptable limits and permissible
limit in absence of alternate source. If any parameter exceeds the limit, that water is considered
unfit for human consumption.
Broadly speaking water is defined as unfit for drinking as per Bureau of Indian Standards, IS-
10500-2012, if it is bacteriologically contaminated (presence of indicator Uniform Drinking
Water Quality Monitoring Protocol bacteria particularly E-coli, viruses etc.) or if chemical
contamination exceeds maximum permissible limits (e.g. excess fluoride [>1.5mg/l ], Total
Dissolved Solids (TDS) [>2,000mg/l], iron [>0.3 mg/l], manganese[>0.3 mg/l], arsenic
[>0.05mg/l], nitrates [>45mg/l] etc.).

The latest drinking water specification and test protocol are -

Sl. Test Parameter IS: 10500-2012 Method of Test

No. Drinking Water Specification (Indian Standard
(Second Revision) IS:3025 Methods of
Sampling and Test
Requirement Permissible
for Water and Waste
(Acceptable limit In the
limit) Absence of
1. Odour Agreeable Agreeable IS:3025 Part 5
2. Taste Agreeable Agreeable IS:3025 Part 8
3. pH value 6.5 8.5 No relaxation IS:3025 Part 11
4. Turbidity, NTU, Max 1 5 IS:3025 Part 10
5. Total dissolved solids 500 2000 IS:3025 Part 16
(TDS), mg/l, Max
6. Total alkalinity as 200 600 IS:3025 Part 23
CaCO3, mg/l, Max
7. Total hardness as CaCO3, 200 600 IS:3025 Part 21
mg/l, Max
8. Calcium as Ca, mg/l, max 75 200 IS:3025 Part 40
9. Magnesium as Mg, mg/l, 30 100 IS:3025 Part 46
10. Chloride as Cl, mg/l, Max 250 1000 IS:3025 Part 32
11. Residual Free Chlorine, 0.2 1 IS:3025 Part 26
mg/l, Min*
12. Sulphate as SO4, mg/l, 200 400 IS:3025 Part 24
13. Nitrate Nitrogen as NO3, 45 No relaxation IS:3025 Part 34
mg/l, Max
14. Fluoride as F, mg/l, Max 1.0 1.5 IS:3025 Part 60
15. Total Iron as Fe, mg/l, 0.3 No relaxation IS:3025 Part 53
16. Coliform MPN/100 ml Shall not be detectable in any Indian Standard
100 ml sample IS:1622, Methods of
17. Faecal Coliform, Shall not be detectable in any Sampling and
Presence/Absence 100 ml sample Microbiological
18. E.coli, Presence / Absence Shall not be detectable in any
Examination of water.
100 ml sample

*Applicable only when water is chlorinated