3. "Sustainable development is development that meets the
needs of the present without compromising the ability of
future generations to meet their own needs. It contains
within it two key concepts:
•the concept of needs, in particular the essential needs of
the world's poor, to which overriding priority should be
given; and
•the idea of limitations imposed by the state of
technology and social organization on the environment's
ability to meet present and future needs."
The underground water is a permanent source of water
as the rate of the evaporation here is minimum. It is of
great importance for the following reasons:
•Where the surface water is not freely available
underground water is tapped by digging wells. Man uses
it for domestic purposes like drinking, washing, cook-ing,
etc.
•It can be used to irrigate the fields.
•It can be used for industrial purposes like in paper,
dyeing, jute and steel industries.
•It sustains vegetation on land. Some of the springs have
medicinal value for skin diseases and stomach problems.
4. The U.S. Geological Survey compares the water stored in
the ground to money kept in a bank account. If the money
is withdrawn at a faster rate than new money is deposited,
there will eventually be account-supply problems. Pumping
water out of the ground at a faster rate than it is
replenished over the long-term causes similar problems.
Groundwater depletion is primarily caused by sustained
groundwater pumping. Some of the negative effects of
groundwater depletion:
1)Lowering of the Water Table
Excessive pumping can lower the groundwater table, and cause wells to no longer be able to reach
groundwater.
2)Increased Costs
As the water table lowers, the water must be pumped farther to reach the surface, using more energy. In
extreme cases, using such a well can be cost prohibitive.
3)Reduced Surface Water Supplies
Groundwater and surface water are connected. When groundwater is overused, the lakes, streams, and
rivers connected to groundwater can also have their supply diminished.
4)Land Subsidence
Land subsidence occurs when there is a loss of support below ground. This is most often caused by human
activities, mainly from the overuse of groundwater, when the soil collapses, compacts, and drops.
5)Water Quality Concerns
Excessive pumping in coastal areas can cause saltwater to move inland and upward, resulting in saltwater
contamination of the water supply.
6. Water conservation encompasses the policies, strategies
and activities to manage fresh water as a sustainable
resource to protect the water environment and to meet
current and future human demand. Population,
household size and growth and affluence all affect how
much water is used. Factors such as climate change will
increase pressures on natural water resources especially
in manufacturing and agricultural irrigation.
Sustainability. To ensure availability for future
generations, the withdrawal of fresh water from an
ecosystem should not exceed its natural replacement
rate.
Energy conservation. Water pumping, delivery and waste
water treatment facilities consume a significant amount
of energy. In some regions of the world over 15% of total
electricity consumption is devoted to water management.
Habitat conservation. Minimizing human water use helps
to preserve fresh water habitats for local wildlife and
migrating waterfowl, as well as reducing the need to build
new dams and other water diversion infrastructures.
7. Rainwater harvesting is the accumulation and deposition of
rainwater for reuse before it reaches the aquifer. Uses include
water for garden, water for livestock, water for irrigation, and
indoor heating for houses etc.. In many places the water
collected is just redirected to a deep pit with percolation. The
harvested water can be used as drinking water as well as for
storage and other purpose like irrigation
Rainwater harvesting provides an independent water supply during regional water
restrictions and in developed countries is often used to supplement the main supply. It
provides water when there is a drought, prevents flooding of low-lying areas,
replenishes the ground water level, and enables dug wells and bore wells to yield in a
sustained manner. It also helps in the availability of clean water by reducing the salinity
and the presence of iron salts.(a)Makes use of a natural resource and reduces flooding,
storm water , erosion, and contamination of surface water with pesticides, sediment,
metals, and fertilizers. (b)Excellent source of water for landscape irrigation, with no
chemicals such as fluoride and chlorine, and no dissolved salts and minerals from the
soil.(c)Home systems can be relatively simple to install and operate and it may reduce
your water bill. (d)Promotes both water and energy conservation. (e)No filtration
system required for landscape irrigation.
In the state of Tamil Nadu, rainwater harvesting was made compulsory for every building to avoid
ground water depletion. It proved excellent results within five years, and every other state took it
as role model. Since its implementation, Chennai saw a 50 percent rise in water level in five years
and the water quality significantly improved. In Rajasthan, rainwater harvesting has traditionally
been practiced by the people of the Thar Desert. There are many ancient water harvesting systems
in Rajasthan, which have now been revived Water harvesting systems are widely used in other
areas of Rajasthan as well, for example the chauka system from the Jaipur district. At present,
in Pune, rainwater harvesting is compulsory for any new society to be registered. An attempt has
been made at Dept. of Chemical Engineering, IISc, Bangalore to harvest rainwater using upper
surface of a solar still, which was used for water distillation13
8.
9. Narmada Bachao Andolan (NBA) is a social movement consisting
of adivasis, farmers, environmentalists, and human
rights activists against a number of large dams being built across
the Narmada river. The river flows through the states of Gujarat,
Maharashtra, and Madhya Pradesh in India. Sardar Sarovar Dam in
Gujarat is one of the biggest dams on the river and was one of the
first focal points of the movement. Friends of River Narmada is the
unofficial website of the NBA.
Their mode of campaign includes hunger strikes and garnering
support from film and art personalities. Narmada Bachao Andolan,
with its leading spokespersons Medha Patkar and Baba Amte,
received the Right Livelihood Award in 1991.
There were groups such as Gujarat-based Arch-Vahini (Action
Research in Community Health and Development) and Narmada
Asargrastha Samiti (Committee for people affected by the Narmada
dam), Madhya Pradesh-based Narmada Ghati Nav Nirman Samiti
(Committee for a new life in the Narmada Valley) and Maharashtrabased Narmada Dharangrastha Samiti (Committee for Narmada
dam-affected people) who either believed in the need for fair
rehabilitation plans for the people or who vehemently opposed
dam construction despite a resettlement policy.
While Medha Patkar established Narmada Bachao Andolan in 1989,
all these groups joined this national coalition of environmental and
human rights activists, scientists, academics and project-affected
people with a non-violent approach.
10. Post-1947, investigations were carried out to evaluate mechanisms for
using water from the Narmada River. the Narmada Water Disputes
Tribunal was constituted by the Government of India on 6 October 1969
to adjudicate over the disputes. On 12 December 1979, the decision as
given by the tribunal, with all the parties at dispute binding to it, was
released by the Indian government. As per the tribunal's decision, 30
major, 135 medium, and 3000 small dams, were granted approval for
construction including raising the height of the Sardar Sarovar dam. In
1985, after hearing about the Sardar Sarovar dam, Medha Patkar and her
colleagues visited the project site and noticed that the project work
being shelved due to an order by the Ministry of Environment and
Forests, Government of India. What she noticed was that the people who
were going to be affected were given no information but for the offer for
rehabilitation. Furthermore, the officials related to the project had no
answers to their questions. While World Bank, the financing agency for
this project, came into the picture, Patkar approached the Ministry of
Environment to seek clarifications. She realized, after seeking answers
from the ministry, that the project was not sanctioned at all and
wondered as to how funds were even sanctioned by the World Bank.
They realized that the officials had overlooked the post-project problems.
Through Patkar's channel of communication between the government
and the residents, she provided critiques to the project authorities and
the governments involved. At the same time, her group realized that all
those displaced were only given compensation for the immediate
standing crop and not for displacement and rehabilitation. She organized
a 36-day solidarity march among the neighboring states of the Narmada
valley from Madhya Pradesh to the Sardar Sarovar dam site. The march
was resisted by the police, who according to Patkar were "caning the
marchers and arresting them and tearing the clothes off women
activists”
11. Using the right to fasting, Patkar undertook a 22-day fast that almost took
her life. In 1991, Patkar's actions led to an unprecedented independent
review by the World Bank. The Morse Commission, appointed in June 1991
at the recommendation of World Bank President Barber Conable,
conducted its first independent review of a World Bank project. This
independent review stated that "performance under these projects has
fallen short of what is called for under Bank policies and guidelines and the
policies of the Government of India." This resulted in the Indian
Government pulling out of its loan agreement with the World Bank. The
World Bank's participation in these projects was cancelled in 1995.
She undertook a similar fast in 1993 and resisted evacuation from the dam
site. In 1994, the Bachao Andolan office was attacked reportedly by a
couple of political parties, where Patkar and other activists were physically
assaulted and verbally abused. In protest, a few NBA activists and she
began a fast; 20 days later, they were arrested and forcibly fed
intravenously.
The Supreme Court's decision is still pending, seeking stoppage of
construction of the Sardar Sarovar dam. The court initially ruled the
decision in the Andolan's favor, thereby effecting an immediate stoppage
of work at the dam and directing the concerned states to first complete
the rehabilitation and replacement process. The Court deliberated on this
issue further for several years but finally upheld the Tribunal Award and
allowed the construction to proceed, subject to conditions. The court
introduced a mechanism to monitor the progress of resettlement pari
passu with the raising of the height of the dam through the Grievance
Redressal Authorities in each of the party states. The court’s decision
referred in this document, given in the year 2000 after seven years of
deliberations, has paved the way for completing the project to attain full
envisaged benefits. The court's final line of the order states, "Every
endeavour shall be made to see that the project is completed as
expeditiously as possible".
12.
13. Reclaimed water or recycled water, is
former wastewater (sewage) that is treated to
remove solids and certain impurities, and
used in sustainable landscaping irrigation or
to recharge groundwater aquifers. The
purpose
of
these
processes
is sustainability and water conservation,
rather than discharging the treated water to
surface waters such as rivers and oceans. In
some cases, recycled water can be used for
streamflow
augmentation
to
benefit
ecosystems and improve aesthetics.
The definition of reclaimed water, as defined
by Levine and Asaneo, is "The end product of
wastewater reclamation that meets water
quality requirements for biodegradable
materials,
suspended
matter
and
pathogens." In more recent conventional use,
the term refers to water that is not treated as
highly in order to offer a way to conserve
drinking water. This water is given to uses such
as agriculture and sundry industry uses.
14. With so much emphasis on the environment, and an ever-increasing demand for renewable water
resources, learning how to recycle water not only saves you money, but is also good for the planet.
Implementing reclaimable-water ideas and other comprehensive ecological solutions help protect aquifers
and replenish lakes, especially during droughts. For tips on how to recycle water, consider these ideas:
1) Initiate the appropriate recycling methods. While it is possible to
sanitize grey water, black water, and even sea salt water to a degree,
you may not be in a position to make the investment required, at least
initially. Predetermine your objectives with a clear budget in mind.
2) Conserve water in your everyday routine.
Conservation is a critical link to recycling, and there are numerous effective
ways to conserve water in the average household and in the yard.
•Simply turning off the faucet while brushing your teeth could save 300 gallons
of water a year.
•Cut back on shower time. Showering uses about 2.5 gallons of water per
minute.
•Wait till the dishwasher is full. It will use approximately 20 gallons.
•Training children how to use water wisely is crucial for a lifetime of good
conservation habits.
3) Compare the water bill before and after.
Depending on the methods you choose, recycling can be
expensive, but saves money in the long run. Eliminating bad
habits and reclaiming renewable water allows you the benefit of
saving precious life giving water and money without
compromising your lifestyle.
15. 4)Sanitize grey water.
Grey water is distinguished from black water as anything not
flushed down the commode. Water from showers, sinks,
laundry, and humidity from air conditioners fall into this
category, accounting for 50-80 percent of household waste
water. Sanitized grey water can be reclaimed for toilet tanks and
irrigation for lawns and gardening, especially during droughts.
A grey water harvesting system processes particles in grey water
through a complex system of filtration, straining, and
sterilization methods connected directly to your drainage pipes.
Storage tanks facilitated by an automatic control system
complete the process, allowing the water to be reused.
Grey water harvesting system can be purchased through
reputable dealers. Contact a dealer for consultation on the right
system for your needs.
5)Reclaim rainwater. Install a rainwater collection system from to
reclaim relatively fresh water from rain and condensation.
Rainwater collection systems may be regulated by various
authorities, so check with your municipal utility department to
proceed.
Rainwater is collected in a storage tank below gutter downspouts.
Roofs and gutters should be free of lead solder, paint, leaves, and
other foreign material to safely recycle rainwater for drinking.
Potable water, or water that is free from pollutants and is safe for
drinking, requires a higher concentration of filtration. Once the
rainwater is safely harvested, filtration and reverse osmosis are
required to make it potable
16. The cost of reclaimed water exceeds that of potable
water in many regions of the world, where a fresh
water supply is plentiful. However, reclaimed water is
usually sold to citizens at a cheaper rate to encourage
its use. As fresh water supplies become limited from
distribution costs, increased population demands, or
climate change reducing sources, the cost ratios will
evolve also.
Using reclaimed water for non-potable uses saves
potable water for drinking, since less potable water
will be used for non-potable uses.
It sometimes contains higher levels of nutrients such
as nitrogen, phosphorus and oxygen which may
somewhat help fertilize garden and agricultural plants
when used for irrigation.
The usage of water reclamation decreases the
pollution sent to sensitive environments. It can also
enhance wetlands, which benefits the wildlife
depending on that eco-system. For instance, The San
Jose/Santa Clara Water Pollution Control Plant
instituted a water recycling program to protect
the San Francisco Bay area's natural salt water
marshes.
17.
18. Hydroelectricity is the term referring to electricity generated
by hydropower; the production of electrical power through the
use of the gravitational force of falling or flowing water. It is the
most widely used form of renewable energy, accounting for 16
percent of global electricity generation – 3,427 terawatt-hours
of electricity production in 2010,[1] and is expected to increase
about 3.1% each year for the next 25 years.
Conventional (dams)
Most hydroelectric power comes from the potential energy of dammed water
driving a water turbine and generator. The power extracted from the water
depends on the volume and on the difference in height between the source and
the water's outflow.
Pumped-storage
This method produces electricity to supply high peak demands by moving water
between reservoirs at different elevations. At times of low electrical demand,
excess generation capacity is used to pump water into the higher reservoir.
Run-of-the-river
Run-of-the-river hydroelectric stations are those with small or no reservoir
capacity, so that the water coming from upstream must be used for generation
at that moment, or must be allowed to bypass the dam
Tide
A tidal power plant makes use of the daily rise and fall of ocean water due to
tides
Underground
An underground power station makes use of a large natural height difference
between two waterways
19. Tidal power, also called tidal energy, is a form of hydropower that
converts the energy of tides into useful forms of power - mainly
electricity. Although not yet widely used, tidal power has potential for
future electricity generation. Tidal power has traditionally suffered
from relatively high cost and limited availability of sites with sufficiently
high tidal ranges or flow velocities, thus constricting its total availability.
However, many recent technological developments and improvements,
both in design and turbine technology , indicate that the total
availability of tidal power may be much higher than previously
assumed, and that economic and environmental costs may be brought
down to competitive levels.
Tidal stream generator
Tidal stream generators (or TSGs) make use of the kinetic energy of moving water to
power turbines
Tidal barrage
Tidal barrages make use of the potential energy in the difference in height (or head)
between high and low tides. When using tidal barrages to generate power, the
potential energy from a tide is seized through strategic placement of specialized
dams. When the sea level rises and the tide begins to come in, the temporary
increase in tidal power is channeled into a large basin behind the dam, holding a
large amount of potential energy. With the receding tide, this energy is then
converted into mechanical energy as the water is released through large turbines
that create electrical power through the use of generators.
Dynamic tidal power
Dynamic tidal power (or DTP) is an untried but promising technology that would
exploit an interaction between potential and kinetic energies in tidal flows.
20. Geothermal energy is thermal energy generated and
stored in the Earth. Thermal energy is the energy that
determines the temperature of matter. The geothermal
energy of the Earth's crust originates from the original
formation of the planet (20%) and from radioactive
decay of minerals (80%). The geothermal gradient, which
is the difference in temperature between the core of the
planet and its surface, drives a continuous conduction of
thermal energy in the form of heat from the core to the
surface. The adjective geothermal originates from the
Greek roots γη (ge), meaning earth, and θερμος
(thermos), meaning hot.
21.
22. Hard water is water that has high mineral content (in contrast with "soft
water"). Hard drinking water is generally not harmful to one's
health, but can pose serious problems in industrial settings, where water
hardness is monitored to avoid costly breakdowns in boilers, cooling
towers, and other equipment that handles water. In domestic settings,
hard water is often indicated by a lack of suds formation when soap is
agitated in water, and by the formation of limescale in kettles and water
heaters. Wherever water hardness is a concern, water softening is
commonly used to reduce hard water's adverse effects.
Water's hardness is determined by the concentration of multivalent cations
in the water. Multivalent cations are cations (positively charged metal complexes) with a charge greater than
1+. Usually, the cations have the charge of 2+. Common cations found in hard water include Ca2+ and Mg2+.
These ions enter a water supply by leaching from minerals within an aquifer. Common calcium-containing
minerals are calcite and gypsum. A common magnesium mineral is dolomite. Rainwater and distilled water
are soft, because they contain few ions.The following equilibrium reaction describes
the dissolving/formation of calcium carbonate scale: CaCO3 + CO2 + H2O ⇋ Ca2+ + 2HCO3−
Calcium carbonate scale formed in water-heating systems is called limescale.Calcium and magnesium ions
can sometimes be removed by water softeners.
23. Temporary hardness is a type of water hardness caused by the
presence of dissolved bicarbonate minerals. When dissolved
these minerals yield calcium and magnesium cations (Ca2+,
Mg2+) and carbonate and bicarbonate anions (CO32-, HCO3-). The
presence of the metal cations makes the water hard. However,
unlike
the
permanent
hardness
caused
by sulfate and chloride compounds, this "temporary" hardness
can be reduced either by boiling the water, or by the addition
of lime (calcium hydroxide) through the softening process
of lime softening. Boiling promotes the formation of carbonate
from the bicarbonate and precipitates calcium carbonate out of
solution, leaving water that is softer upon cooling.
Permanent hardness is hardness that cannot be removed by boiling.
When this is the case, it is usually caused by the presence
of calcium sulfate and/or magnesium sulfates in the water, which do
not precipitate out as the temperature increases. Ions causing
permanent hardness of water can be removed using a water
softener, or ion exchange column.
Total Permanent Hardness = Calcium Hardness + Magnesium
HardnessThe calcium and magnesium hardness is the concentration
of calcium and magnesium ions expressed as equivalent of calcium
carbonate.Total permanent water hardness expressed as equivalent
of CaCO3 can be calculated with the following formula: Total
Permanent Hardness (CaCO3) = 2.5(Ca2+) + 4.1(Mg2+)
24. With hard water, soap solutions form a white precipitate (soap
scum) instead of producing lather, because the 2+ ions destroy
the surfactant properties of the soap by forming a solid
precipitate (the soap scum). A major component of such scum
is calcium stearate, which arises from sodium stearate, the
main component of soap:
2 C17H35COO- + Ca2+ → (C17H35COO)2Ca
Hardness can thus be defined as the soap-consuming capacity
of a water sample, or the capacity of precipitation of soap as a
characteristic property of water that prevents the lathering of
soap. Synthetic detergents do not form such scums.