Water Use, Overuse, and Natural Contamination

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Water Use, Overuse, and Natural Contamination
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Water Mining
China
India
Iran
Israel
Jordan
Mexico
Morocco
Pakistan
Saudi Arabia
South Korea
Spain
Syria
Tunisia
United States
Yemen
Over-exploitation of renewable and non-renewable
aquifers
Withdrawals exceed recharge creating deficits in
the aquifer
Lack of contemporary recharge
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The Middle East
  GROUNDWATER . (Mm3/yr)  
COUNTRY Total use Non-renewable
Saudi Arabia 21,000 84
Bahrain 258 35
Egypt 4,850 18
Jordan 486 35
Libya 4,280 70
Yemen 2,200 32
Saudi Arabia and Libya, use 77 of the estimated
total world extraction of non-renewable
groundwater for urban supply and irrigated
agriculture.
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Pakistan
Falls in the water table between 1982 and 2000
range from 3 to 6 feet per year
Within 15 years Quetta will run out of water if
the current consumption rate continues
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Iran Water Refugees
Mashad
Villages Abandoned
over pumping by an average of 5 billion tons (3.7
Ma-f)of water per year
Equivalent to 1/3 Irans annual grain harvest
Water table falling by 8.5 feet per year
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Qa-Disi Aquifer
Paleowater 35,000 years old
Saudi farmers are now pumping water from
wells that are 4,000 feet deep
71 percent drop in wheat harvest from a high of
4.1 million tons in 1992 to 1.2 million tons in
2005,
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Yemen
water extraction exceeds the annual recharge by
a factor of five,
Water table dropping 6 meters (18 ft) per year
pumped dry by 2010
Options relocate the capital pipelines
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Other Large Deficits
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Shallow , unconfined aquifer depleted
Deficit feeds 100 million people
Level of the deep aquifer is dropping nearly 3
meters (10 feet) per year
Deep wells must reach more than half a mile to
tap fresh water
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India
Deficit of 80 million acre-feet
Deficit feeds 200 million
Failure of 246 surface irrigation projects
21 million wells
600 electric pumps (1 of GDP)
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water table falling by 20 feet per year
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5 acres of land
Pumps 3200 gallons/hr Irrigates alfalfa for 64
hours 24 times per year
4.9 million gallons water/yr
Yield 6.5 gallons milk/day
4.9 million gallons gt 2400 gallons milk (2000
gallons water/ gallon milk)
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United States
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United States
1/3 of irrigation water comes from groundwater
The 3 largest aquifers are in arid/semi-arid
regions
Ogallala Aquifer Midwest Central Valley
Aquifer California Southwest Aquifer
System Arizona, Utah, Nevada
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Deficit of 30 million acre-feet
High Plains Aquifer (Ogallala)
¼ gone in areas of Texas, Oklahoma, Kansas
Water table declines up to 100 feet in some areas
Central Valley Aquifer (California)
Pumping 15 more water than is replaced
Water storage capacity has declined by 50
Southwest Aquifer (Utah, Nevada, Arizona)
Pumping 50 more water than is replaced
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Growing 2 acres/hr
Phoenix Arizona
Among the highest water users
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Tucson
tripled in population over the last 40 years
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Central Arizona Project
Canal 335 miles long
44 billion gallons/yr
7 lost to evaporation
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Use, Overuse, Quality
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Contaminant Sources
USTs Landfills Septic systems Urban
Runoff Agriculture Industry Rainfall
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Natural Groundwater Contaminants
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India
21 million wells
Tapping water as deep as 1,000 meters
water table falling by 20 feet per year
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Deeper Wells and Fluoride
Naturally occurring element in Granite which
dissolves into the groundwater
Water near the surface is generally unaffected
Lowering water tables deeper wells
Deep groundwater contains high fluoride levels
fluoride in water can be a cumulative poison
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Intentional Fluoridation of Water in the U.S.
Fluoridation became an official policy of the
U.S. Public Health Service in 1951. By 1960
water fluoridation had become widely used in the
U.S. reaching about 50 million people. By 2006,
69.2 of the U.S. population on public water
systems were receiving fluoridated water.
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How does it work?
Tooth enamel is made of a mineral called
hydroxyapatite
Ca5(PO4)3OH
Bacteria in the mouth create acids (H)
Hydroxyapatite is subject to dissolution by acids
(H)
Fluoridation changes the chemical composition
of hydroxyapatite to a crystal less subject to
acid dissolution
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Sodium fluorosilicate (Na2SiF6)
Sodium fluoride (NaF)
Ingestion of fluoridated water increases the F-
concentration in saliva
F- replaces OH in hydroxyapatite making
fluoroapatite
F-
Ca5(PO4)3
OH
Fluoroapatite is less soluble in acid than
hydroxyapatite
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Fluoride concentrations In U.S. tap water
0.6 1.1 mg/L
Lower values in warm climates
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Fluoride levels gt 1.5 mg/L
Dental Fluorosis
Intake
1.6 to 6.6 mg/day
Colorado Brown Stain
Permissible fluoride limit in India is 1.2 mg/L
Fluoride levels between 5-25 mg/L have been found
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Fluoride levels gt 10 mg/L
Skeletal Fluorosis
Intake
9 mg/day to 12 mg/day
Fluorosis has risen from 1 million to 25 million
and now to 60 million people in India.
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Groundwater and Arsenic
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Arsenic is Naturally Occurring
occurs primarily in association with
sulfur-containing minerals
mean values of arsenic content in soils, the
earths crust, and sediments are between 1.5,
and 7.7 mg/kg
Natural waters, in general, contain low levels of
total arsenic
Mobilization of arsenic in the environment arises
from anthropogenic activities related to mining
and ore processing, metallurgy, agriculture, wood
preservation, and industry.
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Inorganic Forms of Arsenic
AsO4-3
AsO3-3
Arsenite
Arsenate
High Oxygen
Low Oxygen
Arsenite is more toxic than arsenate, interfering
with enzyme activities which catalyze metabolic
reactions
Arsenite compounds are also more mobile in the
environment due to higher solubility compared to
arsenate compounds
Both arsenate and arsenite are chronic
accumulative toxins
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The Worlds Largest Mass Poisoning
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Bangladesh and W. India
ranked among the world's 10 poorest countries
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Floodplain and Delta of the Ganges and
Brahmaputra Rivers.
Himalayas
Floodplain area paralleling a river that is
periodically inundated
Ganges-Brahmaputra Delta
Deltas are formed from the deposition of
sediment carried by the river as the flow leaves
the mouth of the river
Accumulation of thick muds in the floodplains and
deltas
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Prior to 1970s
One of the highest infant mortality rates in the
world Principally due to waterborne disease.
Ineffective water and sewage systems Periodic
monsoons and floods
water-borne pathogens
cholera, dysentery
Deaths Due to Surface water contamination
250,000/yr
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Deaths Due to Surface water contamination
250,000/yr
The Solution Tap groundwater resources

• easy
• inexpensive

First 1 million were sunk with aid from World
Governments UNICEF World Bank
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Infant mortality and diarrheal illness reduced by
50
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Wells in Floodplain and Delta Sediments
Natural erosion of arsenic to water- bearing
units.
Well depths between 20m and 100 m
Water Bearing Muds
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WHO/U.S limit 10 ppb Bangladesh limit 50 ppb
Some wells contain 500 - 1000 ppb
Majority of wells gt 50 ppb arsenic
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Exposure Estimates
Above 50 ppb 35 million Above 10 ppb 57 million
Early Symptoms Skin lesions and
thickening Strong skin pigmentation
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2003 Studies
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83 million people
Bihar 40 wells contaminated
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Red River Delta
11 million people First wells sunk 7 years ago
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Next Floridas Aquifers
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Sea Levels
Temporary reestablishment of carbonate
deposition
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Vulnerability
One gallon of gasoline can contaminate 1 million
gallons of drinking water
1 ppm
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Metals Nutrients Pesticides Petroleum Solvents