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The term "Ground Water Quality" covers a
widespread meaning and is referred by an individual
depending on the suitability of ground water for the
intended use. Ground water quality is indicated by
the amount of dissolved or suspended inorganic or
organic materials in it through which it acquires
physical and chemical characteristics. Under natural
condition, the composition of ground water depends
on the composition of rainwater, soil strata and aquifer
materials and changes with time and space. With the
rapid development in urbanization, industrialization,
agricultural and mining activities, the
ground water contamination
with hazardous waste and wastewater is becoming a
common phenomenon. The water quality and human health
are closely related. The use of such contaminated
water for drinking purpose may cause an adverse impact
on human health. The determination of the physical,
chemical and bacteriological quality of ground water
is becoming essential to evaluate the water quality
for different purposes as per the water quality standards
laid down by different agencies.
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The CGWB, CR, Nagpur is carrying
out the ground water quality monitoring
in Maharashtra State and the Union Territory of Dadra
and Nagar Haveli for the past three decades to assess
the trend in the ground water quality and its suitability
for the different purposes. The required facility
for the analysis of ground water samples has been
established at the Regional Office, Nagpur. |
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Regional Chemical Laboratory |
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The Regional Chemical Laboratory of the CGWB, CR is
located in Nagpur and is well equipped with qualified
technical staff to undertake the analysis of ground
water, surface water and effluents samples for various
parameters. Under the World Bank assisted Hydrology
Project, the laboratory has been upgraded to level
II+ indicating that the laboratory is capable of carrying
out the analysis of water samples for heavy metals,
major ions in water, pollution related parameters
(COD, BOD) and bacteriological parameters. Presently,
the laboratory is analyzing nearly 2500 water samples
per annum received under different ground water quality
related studies undertaken by the Board. These samples
are analyzed for the various parameters depending
on the objective of study. The laboratory takes utmost
care to keep the highest possible standard of water
quality data generated through it. The validation
of the data through standard checks is carried out
before reporting the data. The laboratory also participates
in various Analytical Quality Control Exercises(AQC)
undertaken by the recognized laboratories and also
undertakes within laboratory AQC exercises. |
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Ground Water Quality Monitoring |
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The CGWB, CR, Nagpur is monitoring the ground water
quality of Maharashtra State and the Union Territory
of Dadra and Nagar Haveli (DNH) through a network
of above 1500 stations which mainly consist of dugwells
lying in shallow zone. These stations are monitored
four times in a year in the month of January, May,
August and November. The sampling of ground water
is carried out in the month of May (pre-monsoon) for
analysis of nearly 15 parameters, which include mainly
the major ions and harmful elements dissolved in ground
water. |
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Ground Water Quality Scenario in Maharashtra |
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The ground water quality monitoring carried out by
the board in Maharashtra State and the Union Territory
of Dadra and Nagar Haveli in the year 2004-05 through
its monitoring wells indicates that the ground water
quality is good in major parts of the state and union
territory (fig.1) and is dominated by the alkaline
earth-weak acid (Ca - HCO3) type of water
(fig.2). The total dissolved solids (TDS) in 54.3%
of ground water samples collected during ground water
monitoring was below desirable limit (500 mg/L) and
43.3% of samples show the TDS concentration between
the desirable and maximum permissible limit of BIS
drinking water standards indicating that the ground
water in the state is suitable for drinking purpose
(fig.3). The SAR values of 98.77% of samples were
found between 0 - 10 which show that the water is
good for irrigation purpose. However, classification
of the samples as per salinity and sodium hazard (U.S.
Salinity diagram) shows that majority of ground water
samples fall in medium salinity & low sodium and
high salinity & low sodium hazard zone (Table).
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Although, the results of ground water quality monitoring
study and specific studies carried out by the board
have shown that the ground water quality in some urban
and industrial pockets of Maharashtra State is undergoing
deterioration especially in the areas where chemical
and sugar industries are located. The concentration
of few toxic ions and load of organic matter in ground
water in the vicinity of these industries are increasing.
The contamination of ground water with nitrate due
to lack of proper sanitation facilities, disposal
of domestic waste and sewage in unlined channels and
agricultural activities in rural and urban parts of
the state is becoming a common phenomenon. The natural
contamination of ground water with fluoride in Yavatmal,
Chandrapur, Bhandara, Nanded, Osmanabad and Nagpur
district is also becoming common. The inland salinity
problem in Purna basin of Amravati, Akola and Buldhana
districts is making ground water management difficult.
A few cases of seawater ingression in coastal districts
of the State have also come into highlight during
the monitoring. |
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Recently, the board has carried out the ground water
quality monitoring for arsenic in the State and the
Union Territory. The results of the study indicates
that the concentration of arsenic in the ground water
of the monitoring wells (shallow aquifer) of State
and the Union Territory is 10 times lower than the
maximum permissible limit of BIS drinking water standards
for arsenic (0.01 mg/L). |
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Distribution of Total Dissolved Solids in Ground Water
in Maharashtra State and the Union Territory of Dadra
and Nagar Haveli (2004): |
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Classification
of Type of Ground Water in Maharashtra State and the
Union Territory of Dadra and Nagar Haveli (2004)
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Suitability of Ground Water in Maharashtra State and
the Union Territory of Dadra and Nagar Haveli for
Drinking Purposes.
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Classification of Ground Water in Monitoring Wells
of Maharashtra and the Union Territory of Dadra and
Nagar Haveli for Irrigation Purposes: |
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EC (mS/cm)
(Salinity hazard) |
NO. OF SAMPLES |
SAR (Sodium hazard) |
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<10 (low) |
10 – 18(medium) |
18 – 26(high) |
>26 (Very high) |
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<250 (low) |
81 |
81 |
- |
- |
- |
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250 – 750 (medium) |
245 |
245 |
- |
- |
- |
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750 – 2250 (high) |
428 |
427 |
1 |
- |
- |
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2250 – 5000 (very High) |
50 |
43 |
6 |
1 |
- |
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>5000 |
7 |
5 |
1 |
- |
1 |
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Total |
811 |
801 |
8 |
1 |
1 |
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Ground Water Contamination |
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The contamination of ground water from the manmade
and natural sources is causing a great threat to the
ground water system. The increase in urbanization
and industrialization are generating huge quantity
of waste and wastewater. The disposal of these waste
and wastewater without proper treatment on unlined
surface is finding its way to groundwater through
percolation. The increase in use of chemical fertilizers,
insecticide and pesticide in agricultural field has
also contaminated the ground water. In coastal area,
the increase in demand of water has led to excessive
abstraction of ground water due to which the problems
like sea water intrusion is arising. The excessive
abstraction of ground water and dewatering in mining
areas has also caused changes in geo-chemical environment
leading to appearance of hazardous metals like Arsenic
in ground water. The contamination of groundwater
due to release of elements like fluoride from its
naturally occurring minerals is also becoming cause
of concern. The absence of regular recharging of ground
water and increase in evapotranspiration rate under
natural conditions have given rise to inland salinity
problems. These contaminations of ground water from
anthropogenic and natural sources have led to
the undesirable change in the physical, chemical and
bacteriological quality of ground water making it
unsuitable for the drinking, irrigation and industrial
use. |
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The Central Ground Water Board, Central Region, Nagpur
has undertaken specific ground water pollution studies
in different parts of Maharashtra to study the impact
of natural and manmade activities on the ground water
quality. The results of these studies are summarized
under
Ground Water Pollution studies. |
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Water Quality and Human Health |
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The
water quality and human health are closely related.
The water causes 75% of diseases to the human beings.
It is estimated by World Health Organization (WHO)
that the 2000 million people in the developing world
do not have access to safe drinking water, which is
the cause of spreading of water borne diseases. The
concentrations of the several inorganic and organic
substances dissolved in water beyond acceptable range
may cause an adverse impact on human health. The harmful
effects on human body depending on the quality of
water are summarized below.
Effect of water quality on human health |
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PARAMETERS |
PROBABLE EFFECTS |
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Colour
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Makes water
aesthetically undesirable. |
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Odour |
Makes water aesthetically undesirable. |
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Taste |
Makes water aesthetically undesirable. |
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Turbidity |
High turbidity increases contamination/pollution |
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pH |
Indicative of acidic or alkaline waters, affects
taste and corrode water supply system |
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Hardness |
Affects water supply system (scaling), excessive
soap consumption, calcification of arteries,
may cause
urinary concretions, diseases of kidney or bladder
and stomach disorder. |
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Iron (Fe) |
Gives bittersweet astringent taste causes staining
of laundry and porcelain. In traces it is essential
for
nutrition. |
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Chloride (Cl) |
May be injurious
to some people suffering from diseases of hearts
and kidneys. Taste, indigestion, corrosion and
palatability are affected. |
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Residual free
Chlorine, |
Excessive free chlorine in drinking water may
cause asthma, colitis and eczema. (Only when
water is chlorinated) |
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Total Dissolved
Solids (TDS) |
Palatability decreases and may cause gastro-intestinal
irritation in human, may have laxative effect
particularly upon transits. |
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Calcium (Ca) |
Insufficiency causes severe rickets; excess
causes concretions in the body such as kidney
or bladder stones and irritation in urinary
passages. Essential for nervous and muscular
system, cardiac functions and in coagulation
of blood. |
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Magnesium
(Mg) |
Its salts are cathartic and diuretic. High concentration
may cause laxative effect particularly on new
users. Mg deficiency is associated with structural
and functional changes. It is essential as an
activator of many enzyme systems. |
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Copper
(Cu) |
Astringent taste but essential element in human
metabolism. Deficiency results in nutritional
anemia in infants. Large amount may result in
liver damage, cause CNS irritation and depression.
In water supply system, it enhances corrosion
of aluminum particular. |
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Sulphate (SO4) |
Causes gastro intestinal irritation with Mg
or Na can have a cathartic effect on users.
Conc. more than 750 mg/L along with Mg may have
laxative effect. |
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Nitrate (NO3) |
Causes infant methaemoglobinaemia (Blue Babies)
at very high conc., causes gastric cancer and
adversely affects CNS and cardiovascular system. |
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Flouride (F) |
Reduces dental carries, very high concentration
may cause crippling skeletal fluorosis. Less
than 1.0 mg/L is essential. |
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Cadmium (Cd) |
Acute toxicity may be associated with renal,
arterial hypertension, itai-itai disease. Cd
salts cause cramps, nausea, vomiting and diarrhea. |
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Lead (Pb) |
Toxic in acute and chronic exposures, burning
in mouth, severe inflammation of gastro-intestinal
tract with vomiting and diarrhea, chronic toxicity
produces nausea, severe abdominal pain, paralysis,
mental confusion, visual disturbances, anemia
etc. |
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Zinc (Zn) |
An essential element in human metabolism. Taste
threshold for Zn occurs at about 5 mg/L, imparts
astringent taste to water. |
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Chromium (Cr) |
Hexavalent state of Cr produces lung tumors,
can produce coetaneous and nasal mucous membrane
ulcers and dermatitis. |
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Arsenic (As) |
Causes skin damage, circulatory problems and
risk of skin cancer. |
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Antimony (Sb) |
Increase in blood cholestorel, decrease in blood
sugar. |
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Aluminum (Al) |
Leads to neurological disorders. |
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Barium (Ba) |
Increases blood pressure. |
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Beryllium (Be) |
Is carcinogenic (cancerous). |
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Cyanide (CN) |
Causes nerve damage, thyroid problem. |
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Mercury (Hg) |
Neurological and renal disturbances. Excess
causes gonad toxic and mutagenic effects and
disturbs the cholesterol metabolism. |
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Manganese (Mn) |
Essential as a cofactor in enzyme systems and
metabolism processes. Excess causes change in
appetite and reduction in metabolism of iron
to form hemoglobin. Imparts undesirable taste
and stains plumbing fixtures and laundry. |
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Selenium (Se) |
Leads to hair, finger loss, numbness in fingers
or toes, circulatory problems. |
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Boron (B) |
Affects CNS, may cause nausea, cramps, convulsions,
coma, etc. |
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Alkalinity |
Imparts unpleasant taste, may be deleterious
to humans in presence of high pH, hardness &
TDS. |
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Pesticides |
Imparts toxicity when it accumulates in organs
of human body affecting immune and nervous systems.
May be carcinogenic. |
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Phosphate (PO4) |
High conc. may cause vomiting and diarrhea,
stimulate secondary hyperthyroidism and bone
loss. |
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Sodium (Na) |
Harmful to persons suffering from cardiac, renal
and circulatory diseases. |
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Potassium (K) |
An essential nutritional element but in excess
is laxative. |
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Nickel (Ni) |
Non toxic element but may be carcinogenic (cancerous),
can react with DNA resulting in DNA damage. |
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Pathogenic Micro-
Organisms |
Causes water born diseases like Jaundice, Typhoid,
Cholera etc. produces infections involving skin,
mucous membrane of eyes, ears and throat. |
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Radioactive
Materials |
Increases risk of cancer |
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Water Quality Standards |
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Depending on the impact of various constituents of
water on human health crops and industrial processes,
certain standards have been laid down by the different
standard institutions like Bureau of Indian Standards
(BIS), Indian Council of Medical Research (ICMR),
World Health Organisation (WHO) and Food and Agriculture
Organization (FAO) of United Nations for deciding
the suitability of water for drinking and irrigation
use. These standards are summarized in the following
tables. |
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1. BIS Drinking Water Standards (IS 10500 –
91,Revised 2003) |
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SR.NO. |
PARAMETERS |
DESIRABLE LIMIT |
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