Environmental Impact Assessment of A Proposed 2640 MW Thermal Power Plant at Sompeta Using RIAM

Coal is the only natural resource and fossil fuel available in abundance in India. Consequently, it is used widely as a thermal energy source and also as fuel for thermal power plants producing electricity. India has about 90,000 MW installed capacity for electricity generation, of which more than 70% is produced by coal-based thermal power plants. Hydro-electricity contributes about 25%, and the remaining is mostly from nuclear power plants (NPPs). The problems associated with the use of coal are low calorific value and very high ash content. The ash content is as high as 55– 60%, with an average value of about 35–40%. Further, most of the coal is located in the eastern parts of the country and requires transportation over long distances, mostly by trains, which run on diesel. About 70% oil is imported and is a big drain on India’s hard currency. This paper evaluates an Environmental Impact Assessment (EIA) using the Rapid Impact Assessment Matrix (RIAM). It considers all 4 components: physical / chemical, biological / ecological, social / cultural, economic / operational. These are then evaluated using universal criteria common to all impact consideration. Figures and tables made comparisons much easier. This Matrix was applied to the EIA of the future Coal based thermal power plant at Sompeta village in Srikakulam District, Andhra Pradesh. *Corresponding author: Seshagiri Rao Boddu, Department of Civil Engineering, Dadi Institute of Engineering and Technology, Anakapalle, India, Tel: 089242 21122; E-mail: bsrmecivil@gmail.com Received March 30, 2016; Accepted April 29, 2016; Published April 30, 2016 Citation: Boddu SR, Prasanth SN, Prasad SB (2016) Environmental Impact Assessment of A Proposed 2640 MW Thermal Power Plant at Sompeta Using RIAM. J Civil Environ Eng 6: 229. doi:10.4172/2165-784X.1000229 Copyright: © 2016 Boddu SR, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Introduction
Nagarjuna Construction Company has proposed to set up a 4 x 660 MW (Phase-I: 2 x 660 MW and Phase-II: 2 x 660 MW) coal based power plant at Sompeta village and Mandal, in Srikakulam district of Andhra Pradesh. The cost of the total project is Rs/-12,000 Crores which includes Rs/-1177 Crores for environmental protection measures. The land identified for the proposed project site is 762 hectares. The project site is generally plain with an average site elevation of about 2.0 m above mean sea level [1].

Details of proposed project
The proposed power plant will be operated on coal as main fuel to generate 2640 MW of power. Pulverized coal fired boilers with super critical technology will be installed in the project. The details of the proposed power project are given below in Table 1.

Environmental base line data
The 10 km radial distance from the plant boundary has been considered as study area for Environmental Impact Assessment (EIA) baseline studies. Environmental monitoring for various attribute like meteorology, ambient air quality, surface and ground water quality, soil characteristics, noise levels and flora and fauna have been conducted at specific locations and the secondary data collected from various Government and Semi-Government organizations.

Land use
The land use pattern of the study area has been studied by analyzing the available secondary data published in the District Primary Census abstract of the year 2001.

Soil quality
A total of ten samples within 10 km radius of the plant site were collected for assessment of soil quality. The baseline environmental monitoring studies were carried out from 1 st March 2009 to 31 st May 2009. The sampling was carried out study period. The pH of the soil extracts varied from 6.7 to 7.7 indicting neutral to slightly alkaline. The electrical conductivity was observed to be in the range of 232 µS/cm to 336 µS/cm. The nitrogen values range between 321.1 kg/ha to 55.4 kg/ha. The nitrogen content in the study area falls in very less to fewer categories. The phosphorus values range between 121.4 kg/ha to 172.3 kg/ha, indicating that the phosphorus content in the study area falls in more than sufficient category. The potassium values range between 63.4 kg/ ha to 109.8 kg/ha, which indicate that the soils have very less quantity of potassium. The chlorides were found to be in the range of 69.9 mg/kg to 236 mg/kg of soil.

Meteorology
On-site monitoring was undertaken for various meteorological variables in order to generate the site specific data. Data was collected every hour continuously from 1 st March to 31 st May 2009. The maximum and minimum temperatures recorded during the study period are 34.3ºC and 22.8ºC. The relative humidity found varying from 76.3% to 81.2%. The predominant winds are mostly from south west (25.5%) and south (13.7%) directions. The rainfall recorded during the study period was 15.5 mm [3].

Ambient air quality
To establish the baseline status of the ambient air quality in the study area, the air quality was monitored at 8 locations. The summary of the ambient air quality monitored is given below in Table 2.

Sea water quality
The results of analysis indicate that the pH ranges in between 8.0-8.1. The Total Dissolved Solids concentrations were found to be ranging in between 50600 mg/lit to 50700 mg/lit. The Chlorides and Sulphates were found to be in the range of 18570 mg/lit to 19072 mg/ lit and 1481 mg/lit to 1523 mg/lit respectively.

Ground water quality
The results of analysis indicate that the pH ranges in between 6.8 to 7.3 which are well within the specified standard of 0.5 to 8.5. The Total Dissolved Solids concentrations were found to be ranging in between 358 mg/lit to 1810 mg/lit. The Chlorides and Sulphates were found to be in the range of 78 mg/lit to 1105 mg/lit and 14.1 mg/lit to 128 mg/ lit respectively. The hardness was observed to be ranging from 185 mg/ lit to 960 mg/lit.

Flora and fauna
Based on the primary data collected by field visits and literature survey, there are birds from Australia and Siberia, known locally as "kondamkodi and nathagotta", which visit the natural habitat" beela". There are several animal species like varudu and peddhanakka which visit the habitat [4].

Socio-economic environment
As per 2001 census the study area consists of 155107 persons inhabited in the study area of 10 km radial distance from the periphery of the proposed plant. The males and females constitute 48.05% and 5.95% of the study area population respectively. The average household size of the study area is 4.3 persons. The density of the population reveals that the study area has an overall density of 102 persons per sq.km. In the study area, 6.615 of the population belong to Scheduled Castes (SC) and 11.13% of the population belongs to Scheduled Tribes (ST). The study area experiences average literacy rate of 50.20%. As per 2001 census records, altogether the main workers works out to be 27.65% of the total population.

Land use
The proposed thermal power plant (2 x 660 MW) shall be installed in around 27570 hectares of land at Sompeta village in Srikakulam district of Andhra Pradesh. The land is partially barren land, free from habitation and partially irrigated lands. The construction activities attract a sizeable population and influx of population is likely to be associated with construction of temporary hutment for construction work force. However, this will be only a temporary change and shall be restricted to construction period. As soon as the construction phase is over, the land use pattern modified to meet the requirement of construction phase shall be reversed. In view of the above, no change in land use pattern is envisaged due to construction and operation of the project. But the irrigated land will turn into a barren land thereby will become unfit for cultivation which is a cause of concern.

Solid waste
Ash is the major solid waste to be generated from the coal based power plant. Coal consumption of 12.5 MTPA at 85% PLF was considered for estimation of ash generation. Fly ash about 4.2 MTPA and bottom ash of 1.05 MTPA will be generated. This ash may lead to skin diseases when exposed over a long duration. This can be monitored by disposing off using High Concentrated Slurry Disposal (HCSD) technology.
The sludge generated from sewage treatment plant should be dried; vermin-composted and used as manure for greenbelt maintenance otherwise it may lead to the contamination of ground water.

Socio-economics
As the area is close to Sompeta town, the skilled people from the town will be available to work here. So, there will be no major change of local occupational scenario, though the establishment of the proposed project will increase the direct and indirect jobs and other economic opportunities. There will be some development of secondary service market, which will be beneficial to the local economy.

RIAM procedure
The impacts of the activities of the project are evaluated  according to the environmental components, and for each condition a classification is determined (using the pre-defined criterion), what provides an expected impact measure for environmental components. The importance of the evaluation criterion is divided in two groups: criteria relative to the degree of the relevance of the condition, and that individually can alter the resulting classification (A); criteria relative to the development of the condition but individually is not capable of altering the obtained classification (B). The value designated for each group of criteria is determined by the use of a series of simple formulas. Those formulas allow the determination, in well-defined bases, of the classifications for individual conditions. Positive and negative impacts can be demonstrated using scales that pass of negative values the positive ones through zero for the group criteria (A), where the value zero presents a condition of "any alteration" or "any relevance. " Using zero this way, in group A's criteria, it allows a single criterion to isolate conditions that don't present any alteration or which relevance is null for the analysis. However, the zero is a value avoided in the group B's criteria because, if the classification of all of criteria of that group was equal to zero, the final result of the ES would, naturally, be also zero.
Eventually, that situation of nullity of the magnitude of the impact could happen in group A's criteria that presented some relevance degree. To avoid this situation, the scale of group B's criteria uses the unitary value (1) as classification for no alteration/ without relevance.
A measure of the importance of the relevance condition (A1) is evaluated according to the space borders or interest of the man that will be affected. The scale is defined in the following way: This cumulative criterion (B3), where the effect of a condition will have a single direct impact or there will be a cumulative effect during the course of time, or, on the other hand, a synergetic effect with other conditions. Theoretically, the cumulative criterion is the mean used to judge the sustainability of a condition, and it should not be confused with a permanent situation or reversible condition. Its scale is defined in the following way: 1 -No alteration / not applicable; 2 -Non cumulative / of direct effect / singular;

-Cumulative / of indirect effect / synergetic;
The RIAM requests the definition of specific components of impact evaluation and each one of those environmental components falls upon one this four categories: Physical/Chemical (PC): Includes all physical and chemical aspects of the environment, including nonrenewable natural resources (non-biological) and the degradation of the physical environment through pollution.

Biological/Ecological (BE):
Includes all biological aspects of the environment, including renewable natural resources, conservation of the biodiversity, interaction between species and pollution of the biosphere.

Sociological/Cultural (SC):
Includes all human aspects of the environment, including social subjects that affect the individuals and the communities; with cultural aspects, it is included the inheritance conservation and human development.

Economical/Operational (EO):
To identify qualitatively the economic consequences of environmental change, temporary and permanent, as well as the complexities of administration of the projects inside the context of the activity project. After necessary calculations, the RIAM classifies the degree of the damage or benefit according to Table 3.

Results and Discussion
The description of the various components and the impact categories of a thermal power plant at Sompeta are given below in Tables 4-7 and the summary of their results are given in Table 8. The results obtained using RIAM for various components can also be represented with the help of histograms as shown in Figures 1 and 2.

Conclusion
Environmental impact assessment of the proposed thermal power plant at Sompeta has been carried out using Rapid impact assessment matrix method. The RIAM presents the overall results of the EIA study in an easy and transparent way. Potential environmental negative and positive impacts of 2640 MW Sompeta thermal power plant were identified and evaluated using RIAM. There is a majority of negative impacts due to the proposed project although positive impacts also occur. Most negative impacts relates to physicochemical components like surface and ground water quality, land use, surface temperature, soil    Biological and ecological components (BE)        fertility etc., biological and ecological components like flora and fauna, wildlife, fly ash, solid waste, sewage, etc., and also a few socio-cultural aspects like rehabilitation, loss of lives due to accidents, aesthetics, etc. The positive impacts due to the proposed project are housing or infrastructure, upliftment of the backward areas, employment, etc.
Hence it is observed that the project will bring economic development but at the same time it will degrade the environment. So the negative impacts can be minimized by adopting effective environmental management plan which includes mitigation measures for improving the eco-profile of the site area.