Summary report of the study
on
“ Post-Clearance
Environmental Impacts and Cost-benefit Analysis of Power Generation in India”
Conducted
by
National Environmental Engineering Research Institute
February, 2006
Introduction
Power generating units are mega project, which require not only huge capital investment but also various natural resources like, fossil fuels and water, thus create some impacts on the environment and generate a stress in the local eco system. Although stringent norms have been made by the regulatory agencies to control and mitigate the damages cost to the environment by the power plants, the efficacy and efficiency of the regulatory measures not been studied in detail. Therefore, a study was awarded by the Ministry of Statistics and PI to National Environmental Engineering Research Institute (NEERI). The study includes following three Thermal, one Gas and one Hydroelectric project.
2. The study has assessed the
environmental impacts caused by these power plants and has tried to monetise
those impacts in order to facilitate a better understanding of the
impacts. The external impacts
pertaining to the air, water, noise, land, biological and socio-economic
components of the environment are enumerated below.
3. Coal based thermal
power plants affect the air quality of the surrounding region more than natural
plants. Around the coal based plants
the ambient sulphur dioxide concentration was in the range of 20-25 pg/m3 in and around Ramagundam. In case of Chandrapur Super Thermal Power
Station the concentration of SO2 varied from 3.61-18.9 ug/m3 , NOx varied
from 8.89-26.55 ug/m3 and SPM from 52.6-193.2 ug/m3. The concentration of SO2, NOx and SPM varied
from 3-37, 5-34, 65-482 ug/m3, respectively in and around Gandhinagar Thermal Power Plant (GTPP)
Ambient NOx concentration in case of natural gas based power plant
was found to be in the range of 5-7 ug/m3 . From the epidemiological data of the area
surrounding the Ramagundam coal based plant, it has been observed that around
6.5% of population living within a 2 km radius of the plant suffers from
respiratory disorders, while the figure decreases to 3.2% at a distance of 2.5
km and becomes negligible (0.91%) at over 5 km from the plant. Thus it can be inferred that people living
within 5 km radius of coal based power plant suffer from respiratory aliments.
4. The emission levels depend on the standards specified by the
concerned State Pollution Control Board.
The health effects attributable to NOx ,the Principal
pollutant emitted from a natural gas plant even within a 2 km radius are
negligible.
5. Although two other gases, carbon dioxide and ozone are
not considered in traditional EMPs, the
high amount of carbon dioxide emission (0.9-0.95 kg/kwh) from thermal power
plants contribute to global warming leading to climate change is significant
enough. Ground level ozone, which is
formed due to photolytic reactions of NOx is not monitored in India
and the paucity of accurate models to predict their levels, the impacts due to
ozone cannot be quantified.
6. The normal operation of a hydroelectric plant does not
affect the air environment. Latest
studies have found that the levels of harmful greenhouse gases like methane
emitted due to decomposition of vegetation submerged under water can be
significant. Detailed research
regarding such emissions is still under pregensis.
7 The water requirement
for a coal-based power plant is about 0.005-0.18 m3/kwh while that
for a natural gas plant is about 0.003 m3/kwh. At Ramagundam Super Thermal Power Plant
(RSTPP) the water requirement has been reduced from about 0.18 m/kWh to 0.15m3/kwh
after the installation of a treatment facility for the ash pond decant. At Chandrapur also major part of treated
effluent is utilized for ash slurry preparation, while part of the ash pond
overflow is discharged into the river.
8. The wastewater
treatment facilities adopted by the thermal power plants are generally
sufficient to attain the standards stipulated by the concerned regulatory
authority, used in the cooling towers
is generally disposed off at temperature 4-50 C above the prevalent
surface water temperature, which can harm the local aquatic biota. In order to avoid such thermal pollution,
the power plants dispose off the effluent by means of a long and open channel,
due to which the temperature of the effluent comes down to the level of that of
the surface water by the time it reaches the receiving body. Therefore, no loss of fisheries of other
aquatic biota was observed due to thermal pollution by power plants.
9. Water slurry is used to take the ash from the power plant to
the ash pond for disposal. There are two
impacts associated with the ash pond decant.
The first point is that this water slowly seeps into the ground while
carrying with it the ash leachate. The
water may contain harmful heavy metals like boron, which have a tendency to
leach out over a period of time. Due to
this the ground water gets polluted and may become unsuitable for domestic
use. This point also could not be
determined factually as there was no systematic testing of ground water for the
presence of heavy metals. The second
factor affecting the water environment is the release of ash pond decant into
the local water bodies. At RSTPP, it
was found that the ash pond decant leaked into a small natural channel and
later joined the Godavari river. This
could be because of bad dyke design or a deliberate attempt to dispose off the
water without any treatment. Such
release of ash pond decant tends to deposit ash all along its path thereby
causing fugitive dust nuisance when it dries up. Also when such water mixes with a water body, it increases the
turbidity of the water body thereby decreasing the primary productivity. This is harmful to the fisheries and other
aquatic biota in the water body.
Similarly in case of Chandrapur, though efforts have been made to
recycle 100%, a part is still discharged into the river. In Gandhingar Thermal Power Plant(GTPP), the
treated effluent is discharged into the non-perennial Sabarmati river. However, based on NEERI’s studies the
authority have put up appropriate environmental management plants to reuse the
treated effluent.
10. In the case of hydroelectric plants water environment is
affected due to the stagnation of water in the reservoir. If the reservoir
accumulates runoff from agricultural fields, the water may contain high amounts
of fertilizer and pesticide residues, which may accumulate in the
reservoir. However, in the case of Koyna Hydro Electric Project (KHEP), as it
was at the upper reaches of its catchment, there were no agriculture fields at
its upper reaches. Another point of
consideration is that the formation of dam blocks the migratory path of certain
fresh water fishes. In the case of
Koyna river, since the water flow upto the site of dam was quite rapid, there
was very small presence of fisheries.
Therefore, there has been no loss to fisheries due to the construction
of the dam.
11. The exposure of employees to high noise levels is more in the
coal based thermal power than in the natural gas based or the hydroelectric
plant. In the case of effect of noise levels of the power plants on the local
population, it has been observed that based on the stipulated requirements of
various environmental bodies, the power plants have taken up sufficient
measures like tree plantations to attenuate the noise levels outside their
premises. However, the increased
transportation activities due to the operation of the power plants have led to
an increase in noise levels in the adjacent localities. But since transportation activities do not
fall under the purview of the power plants, no specific measures have been
taken for the same.
12. The land requirement per mega watt of installed capacity for
coal, gas and hydroelectric power plants is 0.1-4.7 ha., 0.26 ha. and 6.6. ha.
respectively. In case of coal based
power plants the land requirement is generally near the area to the coal mines.
While in the case of gas-based it is any suitable land where the pipeline can
be taken economically. Land requirement
of hydroelectric power plants is generally hilly terrain and valleys. Loss of agriculture land in case of gas
based power plant was 168 ha. and hydroelectric was 230 ha. or 0.13 ha/MW. In case of coal based plants, the site was devoid
of any forest while in case of gas-based plant it was primarily agricultural
land. Loss of forest for KHEP was 1150 ha.
13. 321 ha., 2616 ha. and 74 ha. of land were used to dispose
flyash from the coal based plants at Ramagundam, Chandrapur and Gandhinagar
respectively. Due to this there is
change in natural soil properties. It
becomes more alkaline due to the alkaline nature of flyash.
14. The effect on biological environment can be divided into two
parts, viz. the effect on flora and the effect on fauna. Effect on flora is due to two main reasons land
acquisition and due to flue gas
emissions. Land acquisition leads to
loss of habitat of some species. Los of
such habitat or forests has not been there for the thermal power plants while
in the case of hydroelectric plants, there has been a loss of 1150 hectares of
forest land. However, in the case of
KHEP there has not been any permanent loss of flora and faunal species due to
land acquisition. The effect of flue
gas emissions on flora is still being studied all over the world and only a
limited amount of knowledge has been acquired of the same. Therefore, it is quite difficult to
ascertain and quantify the impacts of such emissions on the flora.
15. In the case of Jhenor-Gandhar Gujarat Power Plant(JGGPP), it
was found that the construction of raw water reservoirs has attracted a large
number of birds into the area.
Therefore, it can be inferred that the NOx emissions from the
power plants have not caused any impact on the faunal species. In the case of RSTPP no such activity was found after the construction of the
balancing reservoir. As the region is
generally devoid of forests and therefore lacking in faunal species, no
conclusion regarding the effect of flue gas emissions on the species could be
reached.
16. The study of the effects of a power plants on the
socio-economic environment is based on three parameters, viz. Resettlement and
Rehabilitation (R&R), effect on local civic amenities and work related
hazards to employees of the power plants.
The R&R required for the coal based power plant at Ramagundam was
about 3761 persons (1.8 persons per MW of installed capacity), for
hydroelectric plant was about 9069 persons (5.2 persons per MW of installed
capacity) and was nil for natural gas plant.
The R&R activities were carried out after giving suitable
compensation to the affected people and therefore their costs have been
internalized in the account books of the respective projects. These details were not available for Chandrapur
and Gandhinagar power plants.
17. The development of civic amenities due to the setting up of
any power project is directly proportional to the size of the project. The same has been observed to be the highest
for the coal based plants followed by the natural gas based plant and lastly
the hydroelectric plant. The work
related accidents too follow the same pattern.
The coal based plant has the highest number of accidents due to
hazardous working conditions followed by the natural gas plant and the
hydroelectric plant.
18. External
Environment Costs are about Rs. 0.1067 per kwh for RSTPP, 0.0646 per kwh for
Chanderpur Super Thermal Power Plant(CSTPP) and 0.0614 per kwh for Gandhinagar
coal-based power plants, Rs. 0.0202 kwh for natural gas-based power plants and
Rs. 0.0054 per kwh for hydroelectric plants.
For the purpose of evaluation, external costs can be differentiated into
three major categories, namely ecosystem costs, agriculture costs and health
costs.
19. Ecosystem costs are
the costs due to damage accrued to the local ecosystem during and after the
inception of a power project. This cost
is negligible for coal-based and natural power plants and is Rs. 0.001 per kwh
for hydroelectric plants. The ecosystem
costs are mainly due to the loss of forests and habitats of wild animals as a
result of land acquisition for the power plants. Also in the case of thermal power plants the cost of damage to
the ecosystem due to air pollution is also a factor. But as the global database regarding the impacts of air pollution
on forests and the ecosystem as the whole not comprehensive enough to allow for
the monetization of the impacts, the same could not be carried out in this
study.
20. In the case of damage to local aquatic ecosystem due to
wastewater discharge, the quantification of impacts like loss of fisheries is
possible only after an assessment over a certain time period or after
comparison of pre-project and post project data. However, it has been seen that such data is not generated or
mentioned by Indian power plants.
Hence, the quantification of impacts to aquatic biota has not been
possible.
21. The other damage due to
land acquisition is to the agriculture sector.
The loss of agriculture due to loss of land has been calculated to be
Rs. 0.0002-0.0084 per kwh for coal-based power plants, Rs. 0.0007 per kwh for
natural bas-based power plant and Rs. 0.001 per kwh for hydroelectric plant.
22. The cost of
health impairments form an important chunk of the external costs of coal based
power plants but such costs are absent in hydroelectric project and negligible
in case of natural gas power plants.
The cost of health effects have been found to be Rs. 0.00013-.047 per
kwh of electricity generation in the case of coal based plant at Ramagundam and
Rs. 0.001 per kwh for natural gas power plants. This data could not be quantified for GTPS.
23. Apart from the above mentioned three major external costs, the
costs due to soiling of paints and plasters in the case of Ramagundam thermal
power plant come to about
Rs. 0.00015 per kwh of
electricity generation.
24. The total external cost of a power project has been found to
be maximum for a coal based project at Rs. 0.1067 per kwh followed by a natural
gas plant with external cost of Rs. 0.0202 per kwh and a hydroelectric project
with Rs. 0.0054 per kwh as external costs.
The high external cost of coal-based generation is mostly because of
health impacts and global warming caused by the flue gases from such
plants. These two costs account for
about 39% and 0.48% respectively of the total cost of coal based
generation. These figures are prone to
uncertainty because of two factors.
Firstly the sulphur content in coal varies from anywhere between 0.4%
(found in some Indian coal) to about 4% (in some European Coal). The sulphur content in the coal of the case
study considered here was about 0.6%.
Any increase in this value will definitely have an incremental effect on
the external cost. Second factor is the
cost of global warming attributable to carbon dioxide and other greenhouse
gases emissions. This cost is
calculated in terms of Net present value of future damages due to global
warming. This value depends upon the
discount factor considered. As there is
no global consensus on the use of a fixed discount rate, a range of $5 to $125
was suggested by IPCC for each tonne of carbon emissions. Hence the global warming costs, which have
been calculated for $5 per tonne of carbon emissions, can only have upward
mobility.
25. The cost of health
effect due to Ramagundam coal-based power plant has been calculated at Rs.
0.047 per kwh. This value pertains to a
semi-carbon region with maximum population concentrated with a 2 km radius of
the power plant. For any rural
setting, this value will go down, while for an urban site this value will
increase. The same will also be true
for costs of soiling of paints and plasters.
26. Another major
factor of uncertainty in the case of thermal power plants is the installed
capacity of the plant. Since the cost
of impacts like health effects depend on the concentration of the various
pollutants in the ambient air, the costs will increase proportionately with the
installed capacity. This is because
higher capacity power plants will discharge larger amounts of pollutants into
the ambient air and therefore the associated external costs will also increase.
27. In the case of
hydroelectric plants, the construction of reservoir is the principal source of
external costs. The various costs like
loss of forests, loss of agriculture, health effects etc. depend on the location and nature of the
reservoir. If the reservoir is
constructed in the upper reaches of the catchment i.e. in the hilly region, the ecosystem loss will be more
compared to social loss. However, if
the reservoir is constructed in the plains, the opposite will be true. Also less amount of area is required in case
of dam on the upper reaches, wherein the reservoir become long and narrow,
thereby not requiring extensive resettlement and rehabilitation activities.
28. The findings of this
study on the post-clearance environmental impacts of various generation
platforms can be utilized for not only understanding the environmental concerns
but also for augmenting the existing environmental management plans for
utilization by environmental law environment agencies and also for policies and
decision making. However, in any case
it should be understood that they are only broadly indicative of the type of
power plants prevalent in the country and may not necessarily be representative
of the ground level scenario of each power plant. Hence, instead of these results the methodology used for this
study should be utilized in case of a requirement of external cost of any
specific project.
Ø The results of the present study have
thrown up some important aspects, which should be considered while fixing
environmental standards for not only power plants, but other industries.
Ø
Emission
standards should be based for the total quantity of pollutant emitted and not
for the amount of pollutant per unit volume of emissions, as the present case.
Ø
As it has
been observed in the case of RSTPP and CSTPS plants, waste water treatment
plant system may be modified so as to reuse the wastewater, which will decrease
the water consumption to 0.15-0.18 m3 kwh of generation. Therefore, specific guidelines should be
developed for the reuse/recycling of wastewater from thermal power plants.
Ø
No specific
guidelines exist for development of greenbelt in residential areas, the same
should be developed so as to minimize the impact of air pollution on the surrounding population.
Ø
In the case
of pithead plants, instead of specially demarcated areas, the ash should be
used to fill up discarded portions of mines, especially underground mines. Detailed guidelines for the same need to be
formulated, which should also be applicable to the mining industry.
Ø
Regular
monitoring of ash leach ate for heavy metals should be carried out to check
groundwater contamination.
Ø
Use of low NOx burners should be made mandatory for
natural gas power plants. These burners
not only are more efficient than conventional ones, but also do not require
steam irrjection for NOx control,
thereby reducing water requirement.
Ø
Recycle/Reuse
of water should be made compulsory which will further reduce the water
requirement of the plant.
Ø
Extra
treatment should be given to the effluent to reduce its temperature prior to
its disposal.
Ø
Periodic
monitoring of pesticides concentration in accumulated water should be made
mandatory
Ø
Daily
monitoring of seismic records should be given emphasis
Ø
Application
of suitable measures for fisheries conservation should be undertaken.
Ø
Health camps
and free medical check-up should be encouraged for local population of at least
10 km radius from the plant site.
Apart from the normal health check-up, emphasis should be given to
specific diseases originating due to emission of different pollutants.
Ø
Strict and
regular medical check up with
respect to hearing abilities should be made compulsory for the employees.
Ø
A quarterly or half yearly monitoring
of soil and the crops grown in the region should be done. Soil should be analysed for its fertility
status. Types of crop diseases
generally encountered, variation in the crop yield should be included in the
report.
Ø
Incase of
thermal power plants, fly ash management should be given due importance. Double sprinkling systems should be employed
to arrest the dispersion of dust particles.
Ø
During
the planning stage due weightage should be given to Reservoir Induced
Seismicity. At the time of construction
phase, the contractors/builders should make use of materials which are more
earth-quake proof. Regular monitoring
of earthquakes should be undertaken during the implementation stage. General awareness camps for the local
population should be held at regular intervals. People should be well informed about the emergency preparedness
plans.