The physico-chemical conditions of air, water and soil, and biological conditions of the proposed Coal based Power Plant area (Rampal), Mongla and the Sundrabans were studied from August 2011 to July 2013 to assess the possible environmental impact on the Sundarbans and surrounding areas. Environmental Impact Assessment (EIA) of physical, biological, social and economic environment of the study areas indicate that most of the impacts of coal-fired power plant are negative and irreversible (-81) which can’t be mitigated in any way. It is indicating that climate, topography, land use pattern, air and water quality, floral and faunal diversity, aquatic ecosystems, capture fisheries and tourism of the Sundarbans and the surroundings areas would be affected permanently due to proposed coal fired power plant. Increasing of water logging conditions, river erosion, noise pollution and health hazards; decreasing of ground water table; loss of culture fisheries, social forestry and major destruction of agriculture would be happened due to coal fired power plant. The benefits of proposed coal fired power plant of Rampal is very poor (S+19) than that of negative irreversible impact (-81). So the proposed area is not suitable to establish the coal based power plant as the Sundarbans and surrounding areas would be affected permanently by establishing the proposed coal power plant.

Keywords: coal, power plant, rampal, the sundarbans, environmental impact

Coal based power plant produce electricity by burning coal in a boiler to heat water to produce steam. The steam, at tremendous pressure, flows into a turbine, which spins a generator to produce electricity. A typical 500-megawatt coal power plant creates more than 125,000 tons of ash and 193,000 tons of sludge each year which contain arsenic, mercury, chromium, and cadmium etc. and more than 75% of this waste is disposed of in unlined, unmonitored onsite landfills and surface impoundments as a result source of drinking water (ground water) is being contaminated and damage vital human organs and the nervous system.¹ According to the studies of Billings^1-3 ecosystems have been damaged sometimes severely or by the disposal of coal plant waste and heat. A coal power plant uses only 33-35% of the coal's heat to produce electricity and rest of the heat is released into the atmosphere and absorbed by the cooling water.⁴ Once the 2.2 billion gallons of water have cycled through the coal-fired power plant, they are released back into the lakes, rivers, or oceans with chlorine or other toxic chemicals which water is hotter (by up to 20-25° F) than the natural water that receives it and this "thermal pollution" can decrease fertility and increase heart rates in fish.¹

According to,² burning coal is a leading cause of smog, acid rain, global warming, and air toxics. Bangladesh government has decided to establish 1320MW coal-fired power plant at the mouth of the Sundarbans under Rampal upazila of Bagerhat district beside the Poshur river. The Bangladesh government signed a joint venture agreement with India’s state-run electricity generation company (National Thermal Power Company) on 29 January 2012 to implement this project. By implementing this coal-fired power plant the Sundarbans will be affected as the sundarbans situated only 9km downstream from the project site.^5,6 The Sundarbans- the largest single tract mangrove forest has been declared Ramsar Site and Natural World Heritage which is situated in the South-West area (21º 31′-22º 38′N and 89º 00′-89º 55′ E) of Bangladesh. It is intersected by a network of tidal canals, creeks and rivers. It is covered an area of 6000 km² of which 3956 km² mangrove forest lands and more than 1800 km² water bodies.⁷ This tidal forest is very rich with natural resources especially floral and faunal diversity like 66 species of plants, more than 200 fish species, 42 mammals, 234 birds, 51 reptiles, 8 amphibians, a lot of invertebrates etc.^8,9 More than 500 thousand peoples are directly and indirectly depending on the Sundarbans for their livelihoods as well as socio-economic purposes. Around 200 thousand people go to the Sundarbans regularly to collect the resources for their livelihoods; less than 200 thousand collect the resources seasonally and around 100 thousand people are doing business of the collected resources and they never go to the Sundarbans directly for resources extraction; roughly 22% people’s livelihoods are involved with the collection of wood resources; 5% are involved with the non-timber forest product; 69% are involved with the aquatic resources and 4% are involved with other purposes.^10,11

Government has acquired 1,834 acres of agriculture land in Satmari-Katakhali and Koigordashkathi areas under Rampal upazila to establish the power plant. Only 86 acres lands are kash land and rest of the lands are public lands which were used for rice and fish cultivations by the land owners. The government has also taken an initiative for dredging 10 kilometers of the Poshur river to allow easy access of ships carrying coal for the plant.^8,12 Due to an inadequate supply of local coal, the operator suggests to use imported coal. The Bangladesh government has decided to bring coal inside the Sundarbans through the Mongla sea port. Indian National Thermal Power Company and Bangladesh Power Development Board are the two signatories of the project. The proposed power plant will burn around 4.75 million tonnes of coal annually when more or less 0.71 million tonnes ashes and around 0.5 million tonnes sludge and liquid waste may be produced (CEGIS 2013). It would also emit a good amount of carbon dioxide (CO₂) - key factor for global warming - some other toxic gases and airborne particles, according to Union of Concerned Scientists, a USA-based group.^5,12 discussed on the types and levels of pollution of coal-fired power plant. The ground water and water of the Poshur river may be polluted by the huge amount of waste produced due to burning of the coal. Whereas the existence of strict laws to protect the environment and the wildlife, the government has recently decided to declare a part of the Poshur and Andharmanik rivers sanctuaries for dolphins (Sankar 2012). Due to the Ecologically Critical Area (ECA) rules no power plant should be set up within 12km of the Sundarbans buffer zone.¹³ The proposed project is 4km away from the buffer zone of the Sundarbans. According to Ministry of Environment and Forests (2010) of India, any thermal power plant can’t be established within 25 km from any natural forest or wild life habitats. But no such data or information on the possible environmental impact of proposed coal based power plant on the Sundarbans and Rampal areas are available. Under the circumstances, it has become imperative to institute an investigation on the estimation of coal-fired power plant hazards and their impacts on the floral and faunal communities of the Sundarbans and surroundings of the project area. The present study deals on the possible impact of coal-fired power plant of Rampal on the ecological and biological conditions of the Sudarbans and surroundings areas of the power plant. The findings of the study will help scientifically to assess the suitability of the coal based power plant in the proposed site.

The research was studied from August 2011 to July 2013 in 10 permanent stations of each study area (Rampal, Mongla and the Sundarbans). Monthly sampling was carried out and air, water, soil and biological samples were studied in the field and laboratory. Secondary data were collected from published documents and different government offices. All data were analyzed and potential environmental impacts were indentified and calculated by using standard tools and methodologies.¹⁴ The samples of the river Pashur and Maidara were collected by using a country boat. Water samples were collected from 10-25 cm depth by using a scale¹⁵ for physico-chemical analysis. A standard Secchi disc was used to measure the transparency of water while for water temperature a digital thermometer was used (Model No. 950). In situ measurements of total dissolved solids (TDS), conductivity, salinity, pH, and dissolved oxygen (DO) were carried out with the help of respective portable field meters. Titrimetric methods were used to determine free CO₂, CO₃ and HCO₃ alkalinities (Welch 1948). BOD₅, COD, NO₃.N and other chemical parameters were measured following APHA (1989). Total hardness, calcium and magnesium were estimated following.¹⁶ Phosphate and silicate were measured following.¹⁷ Air and Noise Pollution have been measured by using instruments with the help of Environmental Science Discipline, Khulna University, Khulna. Emission rate of Suspended Particle Matter (SMP), SO_X and NO_X were measured by using High volume sampler (Envirotech APM-415). Noise pollution was measured using Sound Level Meter (Lutorn, SL-4010). The sound level meter consists of microphone that converts the pattern of sound pressure fluctuations into an electrical voltage, amplifier and a voltage meter that is normally calibrated to read the decibel (dB). Shovels and large ladders were used to collect the soil samples according to¹⁸ Soil quality was determined in the laboratory by following.^19,20 The populations of aquatic and terrestrial plants in field were measured by following quadrat method (Ambasht 1974). Standard observations and monitoring methods²¹ (Foot/Pug marks per quadrat area/ a standard area curve) were followed for different faunal study. Latitude and longitude were measured by using a hand GPS meter (model GARMIN GPSMAP® 78s). Statistical analysis among the different parameters was done by following.²²

Environmental impact assessment (EIA)

Most of the development projects produce impacts onor changes in the state of natural environment. Of which some are positive and some are negative. Similarly, some positive and negative impacts have been identified for the Coal based Power Plant Project. The DOE (1997) guidelines for industries, ADB (2003) environmental assessment guidelines for initial environmental evaluation (IEE) and FPCO (1992) EIA guidelines were followed during impact assessment. Screening and scoping were used to determine the environmental issues and impacts for Coal fired Power Plant Project and identified as IECs. These issues and impacts had been evaluated in terms of distribution, quantity, quality, seasonality, ecological and socio-economic importance.
The sources of information for the scoping process were

1. Field visits and environmental survey;
2. Collected data from KDA, Khulna University, DPHE, BWDB, Meteorological Department, Bangladesh Atomic Energy Center, Upazilas, UPs, NGOs etc.
3. Meeting with chairmen, members, local people, govt. officials, teachers, social workers.

Selection of important environmental components (IECs)

Through the screening and scopingprocess (ADB 2003), the IECs relevant to environmental study of the proposed coal fired power plant project had been identified and presented in vertical column of table 15. The IECs are climate, topography, land use, flood, river erosion, drainage congestion, surface water pollution, groundwater table depletion, groundwater pollution, loss of wetlands, air pollution, noise pollution, loss of habitats and biodiversity, loss of capture fisheries and agriculture, human population, literacy, status of women, water supply, sanitation, electricity and telephone facilities, health services, human diseases, solid waste, urbanization, industrialization, employment, business opportunity, housing, transportation, markets and bazaars, traffic congestion, fire hazard and tourism.

Impact assessment matrix

The impact assessment matrix is presented in table 15 identified thepotential impacts of coal based power plant of Rampal. The assessment matrix was done in consultation with multi-disciplinary team members. When an impact could not be quantified, qualitative judgment was used based on professional experience. The scoring was done within a 21 point score scale ranging from –1 to –10 for negative impacts and +1 to +10 for positive impacts while “0” was used for no impact (neutral impact) (Pastakia and Jensen 1998).

The physico-chemical conditions of air, water and soil of the proposed coal fired area (Rampal), Mongla and Sundrabans were studied and data are presented in Tables 1-6. The biological components of the study area had also been studied (Tables 7-14) which are presented in the following pages. Wind direction for the last ten years of the study areas was north to south or north-west to south-east facing from the month of November to February in every year. In the study areas monthly average air temperature varied from 13.5 to 35 °C; relative humidity and rainfall varied from 65 to 86% and 7 to 320mm; SPM, NOx and SOx varied from 145 to 312 mg/m³, 12 to 109 µg/m³ and 9 to 61 µg/m³ respectively. Surface water temperature, TDS, conductivity, salinity, pH, DO, BOD₅, COD, total hardness and PO₄ varied from 22 to 35.5°C, 3 to 23 g/l, 4 to 16.6 ms/cm, 2 to 22 ppt, 7.1 to 8.9, 6.1 to 8.1 mg/l, 1.3 to 2.4 mg/l, 3.5 to 9.1 mg/l, 660 to 1210 mg/l and 1.53 to 2.55 mg/l respectively. Ground water arsenic varied from 0.01 to 0.21 mg/l. Soil pH, Sulpher and Iron were recorded from 7.3 to 8.1, 44.5 to 1031 micro-gram/g soil and 16 to 108 micro-gram/g soil respectively. During the period of study total 24 herbs, grasses and shrubs were recorded and among them 8 were rare in the project area and 2 were also rare outside of the project area. A total 47 natural woody plants and fruit trees were recorded and among them 5 were in extinct condition, 15 natural woody and fruit trees, and 8 natural woody and fruit trees were recorded as rare in the project and outside the project area respectively. Out of 36 medicinal plants and non-fruit trees 8 species were in extinct condition and 20 were recorded as rare in the project area; 14 medicinal plants and non-fruit trees were also recorded as rare outside of the project area. 6 aquatic macrophytes were recorded as rare out of 14 species. A total 59 species of shrimp, crab, mollusks and fishes were recorded but 18 fishes were extinct and 10 fishes were rare in the project area. 7 species of shrimp, crab and mollusks were also rare in the project area. During the period of study only 3 amphibians were recorded in the project area but 2 were rare. 11 reptiles were recorded in the project area but 2 were extinct and 4 were rare species. In the period of study 24 terrestrial and 10 wetlands birds were recorded but among them 7 rare and 3 extinct terrestrial birds, and 6 extinct and 2 rare wetlands birds were recorded. Only 11 mammals were recorded during the period of study but most of them were extinct in the project area and those were also threatened outside of the project area.

On the basis of present conditions of the study areas like physico-chemical conditions of air, water and soil; meteorological data (Tables 1-6) and, floral and faunal status (Tables 7-14) it can be concluded that inside and outside of the project area such as Rampal, Mongla and the adjacent Sundarbans are free from different types of pollution except salinity intrusion. More or less similar observations were also made by^22-25 recorded dolphins, crocodile, Maskedfinfoot, migratory birds, wild boar, deer, snakes, fishes, different mammals etc. inside the Sundarbans, in and around the rivers and their connected canals and creeks of the Sundarbans. Floral and faunal statuses (Table 7-14) are indicating that some plants and animals are already in extinct conditions and some are in rare conditions due to natural climatic hazards. Due to pollution of the coal fired power plant rest of the floral and faunal diversity will be destroyed by changing air, water and soil quality of the study areas. According to EIA study of CEGIS (2013) the proposed coal based power plant will discharge 51830 Metric Tons (MT) Sulfur di-oxide (SO_X) yearly and 17277 MT SO_X during dry season (16 November to 15 March) if power plant burn less sulfur content (<0.6%) coal; emission of Nitrigen di-oxide (NO_X) will be 31025 MT yearly and 10342 MT during dry season; 711750 MT ash will produce yearly and 237250 MT will produce during dry seasons; yearly 23783184060 gallons and during dry season 7927728020 gallons water will intake by this power plant from the Pashur river; yearly 10397020354 gallons water will be consumed and 13386163706 gallons cooling/ waste water will be discharged to the Pashur river directly or indirectly and ultimately polluted water flows to the Sunderbans as the Pashur meets the sea by flowing inside the Sundarbans. CEGIS (2013) also mentioned that after starting the Rampal coal based power plant the SO_X level will be reached 50.4 - 53.4 ìg/m³ and NO_X level will be reached 47.2- 51.2 ìg/m³ inside the Sundarbans if use best quality coal; whereas present SO_X level is 8 - 11 ìg/m³ and NO_X level is 16 - 20 ìg/m³ inside the Sundarbans. Last ten years wind flows directions (Table 1) and CEGIS (2013) produced wind flows diagram indicate that during dry season (from 16 November to 15 March) the Sundarbans will receive directly SO_X, NO_X and other gases from the power plant. As a result floral and faunal diversity of the Sundarbans will be affected gradually day by day and endangered species will be injured seriously in aquatic and forest floors as during dry season there is no possibility of dilute of gases by rainfall. Dispersion models of different gases of CEGIS (2013) indicate that SO_X, NO_X and other gases will flows up to 35 km inside the Sundarbans during dry season in every year. Surrounding agricultural (rice, shrimp etc.) lands and wetlands (the river Pashur, Maidara and other tidal canals) of the coal power plants will be affected by the leaching of toxic substances from deposited coal burned ashes; the ashes contain many heavy metals including arsenic, lead, mercury, nickel, vanadium, beryllium, barium, cadmium, chromium, selenium and radium, which are dangerous if released into environment (CEGIS 2013). These heavy metals can change the soil and water quality of the Sundarbans by mixing runoff rain water during rainy reason.¹² described on the emission level of different toxic gases and heavy metals of coal fired power plant. Human health hazards and possible impact on the Sundarbans due to coal-fired power plant have also been discussed by.⁵ The wind flow is indicating that the total study area i.e. Rampal, Mongla and the Sundarbans will be affected by the toxic gases and ashes of the coal based power plant in different seasons. Especially the Sundarbans will be affected during pick tourism period in the month of December to February. It is a matter to be concerned when the Sundarbans reserve forest is already facing threats from natural calamity, deforestation, rise in salinity and extinction of many species mainly due to human carelessness, ignorance and lack of implementation of laws, poaching and illegal wildlife trade.^26,27 Study of^28-30 on the impacts of oil spill on the Sundarbans indicates that sink of coal loaded ship created some problems for the biodiversity and ecological conditions of the Sundarbans.

Environmental Impact Assessment (EIA)^31-35 of physical, biological, social and economic environment of the Sundarbans and the surrounding areas indicate that most of the impacts of coal-fired power plant are negative and irreversible (-81) which can’t be mitigated in any way. It is indicating that climate, topography, land use pattern, air and water (surface and ground both) quality, floral and faunal diversity, aquatic ecosystems, capture fisheries and tourism of the Sundarbans and the surrounding areas will be affected permanently due to proposed coal fired power plant. Increasing of water logging conditions, river erosion, noise pollution and health hazards; decreasing of ground water table; loss of culture fisheries, social forestry and health hazards, and major destruction of agriculture will be happened due to coal fired power plant. These problems may be reversible after long mitigation process except agriculture. But all reversible mitigations are negative (total no. is -67).^36-38 Mitigation of agricultural loss will be very difficult and many people will become land less. Urbanization, development of markets/ bazaars, transportation and industrialization will be developed which may be sustainable but mitigation must be ensured. The total no. of sustainable mitigation is only +14 which indicates that the study area is not suitable for industrialization and urbanization. By establishing the coal fired power plant only electrification in the rural area, and very few job and localized business facilities will be increased. The benefits/facilities of proposed coal fired power plant of Rampal is very poor (S+19) than that of negative irreversible impact (-81). So environmentally, physically, socially and economically the selected area is not suitable to establish any type of coal based power plant. On the basis of IECs and EIA, coal based power plant will be act as “to add insult to injure” in the project area as well as on the Sundarbans, Rampal and Mongla areas. A long term research and intensive monitoring must be done to find out the detail information on the long term impact of coal based power plant on the biodiversity and ecological conditions of the Sundarbans before introducing the coal based power plant in Rampal. Otherwise the fragile ecosystem of the Sundarbans including its buffer zone could be threatened by the pollutants of the coal based power plant of Rampal.

None.

The author declares no conflict of interest.

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