Urbanization is a major driver of land use change globally, with over 50% of the world's population now living in urban areas. Urbanization can impact groundwater through altered hydrology, including changes to recharge rates and flow paths. Groundwater is also polluted by many sources associated with urbanization, such as sewage leakage and landfill leachate, which can introduce pathogens, nutrients and chemicals. Septic tanks and road de-icing also contribute to urban groundwater pollution. Proper management of urban wastes and protection of natural hydrology is needed to limit the effects of urbanization on groundwater resources.

1. NATIONAL INSTITUTE OF TECHNOLOGY
RAIPUR
URBANIZATION & GROUNDWATER
POLLUTION
PRESENTED BY:-
SHIKHAR CHERPA
M.TECH-6TH SEM.
APPLIED GEOLOGY

2. PRESENTATION LAYOUT
 Introduction.
 Impact of urbanization in groundwater
 Pollution of groundwater..
 Direct & Indirect Source.
 Source of groundwater pollution.
 Source of Urbanization & causes.

3. INTODUCTION
 urbanization is the major process, which is now
affecting the land.
 Over 50% of the Earth’s population now lives in cities
and it is estimated that by 2025 this will increase to
over 67%
 Megacities and urban sprawl cover large areas of all
continents except Antarctica.
 The conversion of natural, agricultural, and other low-
population density lands to cities or urban areas
changes to the hydrology of the area.

5. IMPACT OF URBANIZATION IN
GROUNDWATER
 ALTERED TOPOGRAPHY:
Urbanization tends to level off the landscape for ease of
construction and for roadway design. Over time, low-lying
areas are filled in and elevated areas lowered.
 ALTERED VEGETATION:
Changes in the rates and distribution of evapotranspiraton
can alter recharge and groundwater flow directions.
 GROUNDWATER TEMPERATURES:
The urban heat island effect is well documented. Urban
areas are hotter than adjoining rural areas.

6.  CHANGING WATER TABLE ELEVATIONS:
Water tables can either fall or rise with urbanization.
Groundwater extraction in urban area can either increase
or decrease with time. So there is chance to change in
water table elevation.
 CONSTRUCTION AND PUMPING EFFECTS:
Various construction activities and designs affect the
groundwater. If the water-table is close to the surface or if
deep tunnels or subways are being built, dewatering or
depressurization may be required that can lower water
tables for considerable periods of time.

7. Pollution is a modification of the physical,
chemical and biological properties of water,
preventing its normal use in various applications.
The degradation of natural quality of
groundwater.
Pollution shall signify any degradation of
natural quality, while contamination shall be
reserved for pollution that constitutes a hazard to
human health.

8. Direct & Indirect Sources
It is easier to control pollution that comes from a distinct
source than pollution that does not come from a
distinct source.
 Direct sources: discharge pollutants at specific locations
through pipes, ditches, or sewers which can be traced and
identified (e.g., factories, sewage treatment plants, mines, oil
wells, oil tankers);
 Indirect sources: can not be traced to a single site of discharge
(e.g., acid deposition, substances picked up in runoff, seepage
into groundwater);
 Indirect source water pollution from agriculture is largest source
of water pollution (64% of pollutants into streams & 57% of
pollutants entering lakes).

10. Sources:
The major sources of groundwater pollution can be
classified as urbanization, industrial, and agricultural
and miscellaneous.
Urbanization Sources and Causes:
urbanization water pollution consists of waste water
from homes and commercial establishments.
 Sewer leakage:
 Leakage may be results from defective sewer pipe,
breakage by tree roots, rupture from heavy loads,
fracture from heavy loads and seismic activity etc.
 Sewer leakage can introduce high concentration of
nitrate, possibly bacteria into groundwater.
 In industrial areas heavy metals such as As, Cd, Cr,
Co, Cu, Fe, Pb may be within the waste water.

11. Solid waste:
 Landfills are simply refused dumps.
 A landfill may of any land area serving as a
depositing of urban or municipal solid waste.
 Leachate from a landfill can pollute groundwater
if water moves through the fill material.
 Another possible sources include precipitation,
surface water infiltration, percolation water from
adjacent areas and groundwater in contact with
the fill.
 Important pollutants frequently found in
leachate include Fe, Mn, Cl, NO3, hardness and
trace elements.

12. Liquid waste:
 Waste water in an urban area may originate from domestic
uses.
 These waste waters can be reused after some treatments which
accomplished by three methods
i. Irrigation – waste water is applying by spraying, ridge and
furrow and flooding.
ii. Infiltration- Percolation – effluent is applied by spraying or by
spreading in basins.
iii. Overland flow – wastewater is spread over the upper reaches
of sloped terraces and allowed to flow across a vegetated
surface runoff.
 Wastewater can introduce bacteria, virus, and inorganic and
organic chemicals into the groundwater.
 Chlorination of wastewater can produce additional potential
pollutants.

13. Roadway Deicing:
 Application of deicing salts (sodium chloride) to
streets and highways in winter may results pollution of
groundwater.
Urban areas with winter temperatures below freezing
are affected the most. But it has increasing demand for
maintaining streets, highways in safe driving conditions
throughout the winter.
The salts have produced widespread degradation of
groundwater quality.

14. Septic tanks and cesspools
 A septic tank is a watertight basin intended to separate
floating and settle able solids from the liquid fraction
of domestic sewage and to discharged this liquid with
its dissolved and suspended solids into the biologically
active zone of soil mantle through a subsurface
percolation systems.
 A cesspool is a large buried chamber with porous walls
designated to receive and percolate raw sewage.
 Domestic sewage adds minerals to groundwater,
bacteria, virus, and phosphorous is generally retained
by soil system, but significant quantities of nitrogen
can be added to groundwater.

15. CONCLUSION
 1. Decreasing of groundwater recharge due to
urbanization. because there is drafting of groundwater
is more as compare to the surface water.
 2. Improper disposal of domestic waste is percolate
down and contaminated the groundwater.
 3. Plastic and polythene is more harmful because it’s
react with the groundwater and get polluted.
 4. Sewer leakage also contaminate the groundwater.
 5. Urbanization is used a very large area to settlement,
for that they remove the forest and land use. Therefore
chance to decrease the capability of soil, and when water
will percolate down that’s not filtrate due soil
degradation.