ban meghnaghat

8/8/2019 Ban Meghnaghat

1/23

SUMMARY ENVIRONMENTAL IMPACT ASSESSMENT

MEGHNAGHAT POWER PROJECT

IN THE

PEOPLES REPUBLIC OF BANGLADESH

August 1997


2/23

ABBREVIATIONS

BPDB - Bangladesh Power Development BoardCCGT - Combined Cycle Gas TurbineEIA - Environmental Impact AssessmentSEIA - Summary Environmental Impact AssessmentTDS - Total Dissolved Solids

WEIGHTS AND MEASURES

dBA - decibels-acoustickm - kilometerm - metermm - millimeterMW - megawattskWh - kilowatthourug - microgram

NOTES

(i) The fiscal year (FY) of the Project company and ends on 31 December.(ii) In this Report, $ refers to US dollars.


3/23

CONTENTSPage

I. INTRODUCTION 1

II. DESCRIPTION OF THE PROJECT 2

III. DESCRIPTION OF THE ENVIRONMENT 2

A. Meteorology and Climatology 2B. Hydrology 3C. Existing Air Quality 3D. Existing Noise Levels 3E. Ecological Baseline 4F. Socioeconomic Baseline 4

IV. CONSTRUCTION IMPACTS AND MITIGATION MEASURES 4

A. Waste Disposal 4B. Transportation Impacts 5C. Air Quality Impacts 5D. Socioeconomic Impacts 5E. Ecological Impacts 6F. Acoustic Impacts 6

V. OPERATIONAL IMPACTS AND MITIGATION MEASURES 6

A. Atmospheric Emissions 6B. Air Quality Impacts 7C. Ecological Impacts 8

D. Solid Waste 8E. Socioeconomic Impacts 8F. Acoustics and Noise 8G. Visual Impacts 9

VI. ALTERNATIVES 9

VII. COST-BENEFIT ANALYSIS 9

VIII. INSTITUTIONAL REQUIREMENT ANDENVIRONMENTAL MONITORING PROGRAM 9

IX. PUBLIC INVOLVEMENT 10

X. CONCLUSIONS 10

MAPS 12

APPENDIX 14


4/23

I. INTRODUCTION

1. The Power System Master Plan for Bangladesh was completed in August 1995with Bank's assistance under technical assistance (TA).

1The master plan recommended the

priority development of the power plant at the Meghnaghat site, approximately 22 kilometers

(km) southeast of Dhaka, be given priority. This site is situated adjacent to the Meghna River,and is large enough to support up to 2,000 megawatts (MW) of generating capacity. A gasconnection is also available at approximately 200 meters (m) from the site boundary. The plantsite is close to the main demand for power, the capital city of Dhaka and the surroundingindustrial areas. Subsequently, the Overseas Economic Cooperation Fund of Japan completedthe feasibility study for the gas-fired combined-cycle power station at Meghnaghat on 5 August1997. The Bank retained consultants to prepare a feasibility study, and detailed engineeringand design from the first phase of the Meghnaghat power plant. Based on therecommendations within these feasibility reports and the Power System Master Plans, theBangladesh Power Development Board (BPDB) proposed to invite bids from the private sectorsponsors to develop a power station on the Meghnaghat site based on a combined cycle gasturbine (CCGT) technology utilising natural gas as the fuel. The site is to be developed in three

phases with each phase being approximately 300-450 MW in capacity. The 450 MW optionwas selected for the environmental impact assessment (EIA) as this is the project. However,the EIA covered all potential environmental impacts associated with Phase 1 (the Project) aswell as subsequent phase. The environmental studies covering other phases were included toascertain that the Project environmental impacts will not affect the implementation of thoseprojects. The detailed environmental impact assessments will have to be revised based on theactual operating conditions of the Project and the technology used in subsequent phases.

2. The assessment of specific potential impacts associated with the second phase.included atmospheric emissions and air quality, water abstraction and water quality, and noise.The assessment of these issues was considered necessary to ensure that Phase 2development can also proceed and that the cumulative environmental effects of Phase 1 and 2

have been quantified.

3. The full EIA was submitted to the Department of Environment of Bangladesh andissuance of a No Objection Certificate is expected in November 1997. Under the Bank'senvironmental assessment requirements and review procedures, this summary EIA (SEIA) isbeing circulated to the Bank's Board of Directors 120 days prior to their consideration of theloan proposal. The main EIA report is available at the Project office on request. The EIA andthe SEIA have not been assessed by the Bank. The Bank's assessment and evaluation of theEIA report and environmental impacts related to the Project will be included in thedocumentation when the Project is considered by the Board.

II. DESCRIPTION OF THE PROJECT

4. The proposed site at Meghnaghat is located on the main (west branch) ofMeghna River close to the Meghna Bridge of the Dhaka-Comilla highway. This locationequates to a point approximately 22 km southwest of Dhaka. The general area for the Project isshown in Map 1, while the actual location is shown in Map 2. Phase I of the proposed powerstation will consist of a combined-cycle gas turbine plant with a site-rated gross capacity ofapproximately 450 MW. It is intended that the gas turbine units will be fired continuously on

1 TA No. 1962-BAN: Preparation of a Power System Master Plan for $600,000, approved on 11 October

1993.


5/23

natural gas. The natural gas will be supplied by the existing 20-inch Bhakrabad-Dewra gaspipeline operated by the Titas Gas Transmission Company Ltd. The use of backup and auxiliaryfuels such as distillate oil are not anticipated and this contingency has not generally beenallowed for.

5. Several different plant configuration options are available to produce the nominal

output of 450 MW, but overall the environmental performance would not be significantlydifferent. Each option was considered in a two-plus-one CCGT arrangement with the hotexhaust gas from each gas turbine raising steam in one waste heat recovery boiler.

6. As the availability of fresh water at the site is relatively high, it is intended thatwater for all cooling purposes will be abstracted from the Meghna River via a submerged intakestructure. For all the uses of the water, except for cooling purposes, the possibility of usinggroundwater abstracted from boreholes will be considered. The resulting cooling waterdischarge will be returned to the Meghna River at a point downstream of the intake structure.

7. It is proposed that this Project will have a significant role in addressing currentshortfalls in Bangladeshs electricity requirements. For instance, recent figures indicate that

BPDBs firm installed generating capacity is insufficient to meet the demand if unit outages aretaken into account. Problems associated with a lack of firm capacity are compounded by hightechnical and nontechnical losses in the Bangladesh power system that were equivalent to 33.4percent of the net generation and 50 percent of the sales. This shortage of capacity has lead toload shedding and the need for such measures is likely to increase if a balance is to bemaintained between demand and generation capability. Therefore, the Meghnaghat project willform an integral part of providing additional electricity generation.

III. DESCRIPTION OF THE ENVIRONMENT

8. As part of the EIA, CONSULTANT undertook such a study examining thephysical parameters of climatic, hydrological, geological, air quality and acoustic conditions was

undertaken

A. Meteorology and Climatology

9. Bangladeshs position in Asia extends from a latitude of 22 to 28 N and alongitude of 88 to 92E. This places the country centrally within the Asiatic monsoon region.Bangladeshs relatively small size and general low-lying topography ensures that only moderatevariation occurs across the country in terms of precipitation, relative humidity, temperature, andwind speeds. Each of these climatological features was examined in the EIA.

10. The general pattern of precipitation, which consists entirely of rain, follows themonsoon pattern with the cooler, drier months of November to March, increasing rains in April

and May, and highest rainfall in the summer months of June to September when the prevailingwind direction from the southwest brings moisture laden air from the Bay of Bengal. Thisseasonal variation in rainfall has great significance for factors such as river flows, power plantcooling design, and dust generation during construction activities.

11. The observations of wind direction and wind speed made at the Dhaka airport,which is the nearest weather station to the site, for the period January 1974 to December 1994illustrate that the monsoon phenomena is much less pronounced around the Project site andDhaka in terms of reversal. For instance, the predominant wind direction for the year is from thesouth with the percentage occurrence being 20 percent. Pasquill stabilities were derived for Zia


6/23

International Airport in Dhaka using information collected as part of the airport normalmeteorological monitoring program. Pasquill stability defines the dispersion of pollutant in theair. The predominant Pasquill stabilities for the year are D and F/G with these occurring for 20.7and 38.7 percent of the year, respectively. Category D is neutral while F/G is highly stable. Thehigh incidence of category D is explained by its predominance at nighttime under all but thelowest wind speeds. Other Pasquill stabilities that occur for a significant proportion the year

include A/B and B, which both have frequencies of the order of 10 percent. A summary of themeteorological conditions is given in the Appendix, Table 1.

B. Hydrology

12. The Meghna River flowing past the site has a width of approximately 1,000 mand a depth of up to 10 m. The river at this point is subject to a semidiurnal tidal regime with amaximum tidal range of 0.3 m. Discharge of the river is marked by tidal flows in the monthsfrom November to May with low net discharge volumes between February and April. Themaximum recorded flow prior to 1988 was 15,200 cubic meter (m3)/second (sec). The waterquality of the river is shown in the Appendix, Table 2.

13. At present, utilisation of groundwater occurs in the two villages immediatelyadjacent to the site with simple wells used for its extraction. Although tidal movements ofsaltwater have led to contamination of the aquifers with brackish water in other areas ofBangladesh, the position of the proposed site many kilometers from the coast makes such anevent unlikely. The approximate depth to the water table during the dry season was estimatedin previous studies as being 6 m although the depth to the top of the main aquifer isapproximately 50 m. The groundwater quality is shown in the Appendix, Table 2. Thegroundwater at the Meghnaghat site has a total dissolved solids (TDS) content of less than 500milligrams (mg)/liter (l). Other inferred information regarding groundwater quality relates to theconcentrations of silica and iron. Dissolved silica concentrations in the groundwater inBangladesh are usually of the order of 15 to 30 mg/l, while iron concentrations range from 1 to10 mg/l. While a particularly high groundwater pH is not recognised at the site, the solubility of

silica and iron is anticipated to be low, and the ranges given above are believed to be realistic.

C. Existing Air Quality

14. To establish baseline air quality, a three-month monitoring program was initiatedin January 1996. Eight locations were identified within the study area to include both rural andpopulated areas. Some of these locations were considered most likely to experience air qualityimpacts arising from the operation of the power plant. Monitoring for sulfur dioxide (SO2) andnitrogen dioxide (NO2) were carried out at each site using diffusion tubes. Ambient levels of SO 2and NO2 in the study area are within relevant air quality standards and guidelines although theestimated one-hour values may sometimes exceed the World Bank guidelines. Details of the airquality monitoring results are shown in the Appendix, Table 3.

D. Existing Noise Levels

15. Since no previous noise surveys have been conducted at the site, it wasnecessary for engineers of the consultants to undertake a study designed to establish anacoustic baseline onto which potential impacts from the proposed plant may be superimposed.Even with the dredging and piling that was being undertaken during the survey, the results werebelow the World Bank daytime noise criterion of 65 decibels-acoustic (dBA). These results havebeen combined with the predicted plant contribution and are discussed in greater detail in the


7/23

appropriate sections. The monitoring results of the noise levels are from various location in thevicinity of the Project are shown in the Appendix, Table 4.

E. Ecological Baseline

16. The site is similar in character to many areas of alluvial delta in Bangladesh, with

the mixed crop vegetation it supports being typical of other rivers such as the Ganges andJamuna. Crops cultivated at the site include rice, other grains, and vegetables. Oil seeds arealso cultivated without the need for irrigation practices. Habitat-wise, the area includes the ruralhouseholds and villages; open fields; artificial and natural water bodies (lentic and lotic);monoculture tree plantations, and agro forests. Although a number of endangered and rarespecies were identified by indigenous ecologists as being present in the study area, whichextended for 10 km, none of the species present at the site are believed to be locally, nationally,or internationally rare or threatened.

F. Socioeconomic Baseline

17. A socioeconomic survey was conducted at the site and the methodology adopted

gathered both primary and secondary information. The primary information was gatheredthrough a socioeconomic survey at the site using interviews with representatives of affectedvillages. Secondary data is based on past reports and Government statistics. The followingvillages were examined in detail because of their proximity to the site and also housing. Peoplewho own land on the proposed site and hence would be potentially affected by noise, air qualityand socio-economic issues live in Islampur, Ganga Nagar, Dhadghata, and Khurbanpur. Theprinciple findings of the socioeconomic survey are that the level of services provision is very lowwith only limited access to fresh water supplies, provisions for sewage treatment and disposal,and electricity. The overall level of employment is low with the majority of work being heavilyreliant upon land and adjacent water bodies. Although a number of medium-sized industries doexist in close proximity to the site, these are of limited significance for the inhabitants of theareas villages.

IV. CONSTRUCTION IMPACTS AND MITIGATORY MEASURES

18. The principal phases of the construction consist of the engineering, procurement,construction, commissioning, plant testing, and start-up. Within these stages, the main site-related impacts include (i) those associated with the disposal of excavated material andother wastes, (ii) those associated with increased traffic volumes, (iii) air quality, (iv)socioeconomic, (v) ecological impacts arising from land disturbance, (vi) acoustic, (vii)visual, and (viii) water quality. Appendix, Table 5 shows the applicable air quality standards inBangladesh used in the study together with the World Bank standard for power projects, whileAppendix, Table 6 shows the water quality standards in Bangladesh, and Appendix, Table 7shows the noise standard.

A. Waste Disposal

19. The quantities of solid waste generated will be primarily from site clearanceactivities, although other waste materials likely to be generated as a result of constructionactivities include pallets, packing crates, timber offcuts, and waste concrete and cement. Allcombustible wastes not suitable for reuse will be incinerated at the site while mineral wasteswill be either removed or land filled at the site. The site is a depressed area and will requirefurther filling. The unsuitable soil material from site clearing and preparation will be used as fill


8/23

material within the Project site. As approximately 300 to 500 personnel will be employed duringconstruction, the installation of a portable septic tank at the site will be necessary witharrangements being made with local municipal authorities for the collection of the resultingsludge. No hazardous or special wastes requiring specialist disposal routes will be produced asa result of the construction activities

B. Transportation Impacts

20. Using the projected labor and materials requirements, additional trafficassociated with the power plant construction will be generated. For instance, this illustrates theadditional numbers of buses, minibuses, vans , cars, and jeeps associated with transporting theworkforce to and from the site. The Project will provide basic transport facilities for its workersand engineers. The impact on the existing transport facilities is not expected to be significant.

21. Additional lorries and trucks will add less than 2 percent to the overall traffic flowat any one time, and it has been assumed that the most likely scenario will be that deliveries tothe site are spread evenly throughout the hours between 0700 and 2000. As the maximumhourly traffic flow is currently relatively low even at peak periods, it has not been necessary to

time deliveries to coincide with the lulls identified by the traffic survey. It is proposed that alllarge or heavy plant items imported will be transported by barge along the Meghna River.Furthermore, no significant obstacles to transportation such as overhead telephone or electricitylines were identified during the study. In contrast to deliveries of more conventional packagedmaterials and equipment, the movement of heavy or oversized loads will be closely coordinatedwith the appropriate authorities to result in minimal disruption to local traffic.

C. Air Quality Impacts

22. The air quality impacts from the construction phase will mainly be restrictedto (i) the potential for dust generation from transportation and construction activities, and(ii) increased vehicular emissions related to the transportation of personnel and materials to

and from the site. Furthermore, the operation of construction equipment such as earthmoversand bulldozers will contribute toward atmospheric emissions.

23. Outside of the monsoon months of July, August, and September, a method forreducing dust generation such as the dampening down of roads would normally be necessary.However, in view of the need to conserve potable water wherever possible, this option isproposed only on the basis that wastewater or river water is employed. The principal productsof the combustion of hydrocarbon fuel in compression ignition and spark ignition engines arecarbon dioxide (CO2), nitrogen, and water vapor. However, since these engines havecombustion efficiencies significantly lower than 100 percent, appreciable quantities of fuelundergo incomplete combustion resulting in carbon monoxide (CO); unburnt carbon or soot;hydrocarbons (HC); and other organic species. In addition, at the high pressures and

temperatures associated with the engine cylinders, a proportion of atmospheric nitrogen isoxidised to oxides of nitrogen (NOx). Certain mitigatory measures may be adopted to limitatmospheric impacts to as great an extent as possible. For instance, the transportation ofpersonnel and materials will be scheduled such as to avoid periods of peak flow wherecongested conditions are more likely, and to reduce the overall number of vehicularmovements. In addition to careful traffic management, close adherence to the recommendedmaintenance regime will be applied to both on-site and off-site vehicles.

D. Socioeconomic Impacts


9/23

24. Resettlement is not an issue as no families are located on the proposed site nowthat the village of Islampur is outside the site boundary. Income levels should increase ifemployment is provided to family members who already own land on the site. This additionalincome will also have a positive impact on the local economy in general.

E. Ecological Impacts

25. In terms of construction, thermal power plants typically have the most potentialfor impacts as a result of habitat loss, physical disturbance, or noise. The proposed plant willencompass approximately 100 hectares of land that consists principally of agriculture land.This marginal habitat is considered to have a relatively low ecological value since it is almostubiquitous in Bangladesh. Furthermore, its value is low in relation to both species diversity andproductivity. None of the species believed to be present have any special value conferred uponthem as a result of rarity or protection status. Given the semiurban nature of the site,most of the animal species present would be expected to have behavioral and physiologicaladaptations that suit them to an existence in close proximity to human activities. Therefore, theimpact associated with noise and physical disturbance are unlikely to be significant.

F. Acoustic Impacts

26. Work on the construction sites has a number of features that distinguish it fromwork in permanent industrial installations. For the proposed plant, the main features of the workis that it is of a temporary and intermittent nature, the locations of the work areas are not fixed,and the work is out of doors. All these factors combine to make the control of noise fromconstruction activities more complex. It is intended that the vast majority of work will take placeon normal working days and between the hours of 0700 to 1900. There are the occasionalexceptions, for instance, when concrete pouring has to continue into the evening because ofthe nature of such work. Generally, the contractor will attempt to avoid work during the eveningand night.

V. OPERATIONAL IMPACTS AND MITIGATION MEASURES

A. Atmospheric Emissions

27. The combustion of fossil fuels for power generation inevitably results in emissionof gaseous pollutants to the atmosphere. The pollutants of potential concern are SO2; NOx;CO; and CO2. The emissions of SO2 are dependent on the sulfur content of the gas. Typically,this is extremely low for gas and, in comparison to coal- and oil-fired plant, is consideredinsignificant. For the purposes of this assessment the sulfur content of the gas is assumed tobe 0.002 percent. The emission rate complies with both the Bangladesh and World Bankemissions standards. The combustion of fossil fuels generally produces two forms of NOx. The

two oxides are nitric oxide (NO) and NO2. The proportion varies depending on the combustiontechnology. In the case of gas turbines, approximately 90 percent of the NOx is present as NOwith the remainder being NO2. Once NO enters the atmosphere, it reacts with ozone and otherchemicals in the air and oxidizes to NO2 with time. As the health effects of NO2 are far greaterthan those of NO, atmospheric emissions will be discussed in relation to NOx. Conversely, whendiscussing air quality reference is made to NO2. The proposed turbine units will employ dry-lowNOx combustors, the emissions of this pollutant will be equivalent to 25 parts per million (ppm)or 50 mg/cubic meter of air at 0C and one atmospheric measure (Nm3) thus easily complyingwith the requirements of Bangladesh and the World Bank.


10/23

B. Air Quality Impacts

28. The stack height in Bangladesh is calculated using a formula based on SO2emission rates. This means of stack height determination was developed for coal-fired powerstations in India and is not considered applicable to the proposed CCGT, where the main

pollutant of concern is NOx. The stack height for the proposed CCGT plant was initiallydetermined by using a method developed in the United Kingdom based upon the proceduregiven in Her Majestys Inspectorate of Pollution Guidance Note D1. To verify this method for theMeghnaghat plant area, dispersion modeling techniques were used to calculate maximumground-level concentrations of NO2 for a range of stack heights. The model used for thisassessment was SCREEN3. This model is fully approved by the United States EnvironmentalProtection Agency for the calculation of maximum short-term concentrations of nonreactivepollutants emitted from a single source. The results of the SCREEN3 modeling indicate that theoptimum stack height for open cycle operation is 35 m. For combined-cycle operation a stackheight of 60 m is recommended. Such stack heights would allow the development of Phase 2and other developments in the area to also proceed. The reduction in groundlevelconcentrations of NOx by combining the flues into one multiflue stack is not significant. Short

term concentrations were modeled using the Industrial Source Complex Short Term 3 (ISCST3) model, while annual averages have been modeled using Industrial Source Complex LongTerm3 (ISCL3). Using this model, the maximum annual average ground-level contribution fromthe proposed power station would be 1.4 ug (microgram)/m

3at a location approximately 7,750

m from the site. When added to the existing background concentration of 12-19 mg/m3, theresults are well below the World Bank Guideline of 100 mg/m

3. The maximum annual average

ground level concentration for Phases 1 and 2 would be 2.8 ug/m3

at a distance 7,500m fromthe Phase 1 smoke stack which, when added to the background levels, again indicate that theWorld Bank guideline would not be exceeded.

29. The Industrial Source Complex model discussed above is not considered validfor wind speeds less than 1 m/s. Meteorological observations at Dhaka Airport indicate that

calms (winds of less than 1m/s) are experienced for 48 percent of the year. To assess theimpact of emissions during calm conditions a simple box model (diffusion model) was used toestimate NOx concentrations. Using the Box Model, the one hour average concentration of totalNOx was calculated to be 423 mg/m3 for emissions associated with Phase 1 of the proposedpower station. Conversion of NOx to NO2 during the nighttime is likely to be very low (in theorder of 10-20 percent) because of the absence of ozone and sunlight that would indicate a onehour maximum concentration of 42-84 mg/m

3, which is well within the World Bank and World

Health Organisation air quality guidelines. These results also indicate that the addition ofPhases 1 and 2 of the power station would not give rise to these guidelines being exceeded.The ten hour average concentration of total NOx was calculated to be 42.3 ug/m3 for Phase 1which, with a 10-20 percent conversion rate, indicates that the average night time concentrationof NO2 would be 4-8 up/m

3. As a worst case assumption, these values may be added to the

results of ISCLT3 modeling and ambient monitoring results. This would suggest an annualaverage concentration of 28 mg/m

3for Phase 1 and 37 mg/m

3for Phases 1 and 2, which are

both below the World Bank Guideline of 100 mg/m3. he results of the projected air and qualityimpact are shown in Appendix, Table 8.

C. Ecological Impacts

30. The operational phases of thermal power plants typically have the potential forecological impacts associated with noise and disturbance, atmospheric pollution, abstraction,and discharge of aqueous effluents, and with the management and disposal of solid wastes.


11/23

With respect to noise impacts, the significance of this issue is limited. For instance, although anumber of avian, mammalian, reptilian, and insect species are certainly present at the site,none of these are thought to be listed as rare, endangered, or protected. Furthermore, thosethat are present are likely to have behavioural or physiological adaptations that make themsuited to life in close proximity. As both short- and long-term ground-level concentrations ofNO2 and SO2 from the Power-plants will adhere to the appropriate limits at all times,

significant impacts upon local flora and fauna are not expected. With the levels of thedischarges of all effluents meeting the World Bank and Bangladesh environmental qualitycriteria, no deterioration is anticipated in the ecological quality of local surface waters orgroundwaters.

D. Solid Waste

31. Small quantities of low-volume general power station wastes such as woodenpellets, cladding, etc. and sewage sludge will be generated. Some hazardous waste will beproduced following acid cleaning of the boilers, which normally occurs only once a year. Thiswaste will be removed from the site by licensed contractors for disposal to a designated landfilldisposal site.

E. Socioeconomic Impacts

32. The involvement of the local residents in project activities may bring aboutsignificant effects on their socio-economic life. The Project would provide permanentemployment and a more stable income, thereby providing an opportunity for them to improvetheir basic living standards while also stimulating the local economy. Similarly, the arrival ofmigrant workers from outside the region may also stimulate the local economy in thesurrounding areas, by providing opportunities for services in the form of small restaurants andshops offering day-to-day needs. In their social activities, the interaction between migrantworkers and the local residents will reveal a difference in lifestyles that may disrupt harmoniousrelationships between the two factions. Such a difference may also be increased by

dissatisfaction on the part of the local residents.

F. Acoustics and Noise

33. Analysis of the proposed Projects contribution to noise in the local environmentwas undertaken using a spreadsheet developed in-house by the consultants. This spreadsheetutilises noise data for noise-generating equipment, and evaluates the noise contributions fromthe plant over a specified area. In this case, an area was used that envelopes the proposed sitedevelopment and the nearby villages.

34. The contribution of the proposed power station to ambient sound pressure levelswas modeled for each of the seven monitoring locations. The predicted sound pressure levels

that would arise due to the operation of Phase 1 and Phase 2 of the station were thencalculated from the monitoring results and modeled contribution. The results indicate that theoperation of both Phases 1 and 2 would not give rise to the Bangladesh or World Bank noisecriteria being exceeded in the vicinity of the power station. These results are based on anelevated observed ambient noise level due to river dredging activity at the time of monitoring.Results of the projected noise impact are shown in the Appendix, Table 9.

G. Visual Impacts


12/23

35. Overall, the issue of visual intrusion is not seen to be of significant importancebecause the area has little recreational value and is not used for tourism. Therefore, the needfor power far outweighs the possible impacts on visual intrusion.

VI. ALTERNATIVES

36. Bangladesh is a relatively flat country. There are no deep canyons along themajor river system suitable for hydroecletric projects. It does not have any active geothermalfield. Electricity could be generated using coal or oil. The coal resources are limited and thepotential oil fields are still undeveloped. On the other hand Bangladesh has a good natural gasfield which that is developed. The natural gas in Bangladesh is low in sulfur with a very highheating value. The composition of the natural gas is in the Appendix, Table 10. Natural gas isalso an ideal fuel considering the proximity of the Project site to the capital Dhaka. Natural gasgenerates very low quantities of particulate, sulfur dioxide and with a suitable boiler low oxidesof nitrogen. The Meghnaghat site was selected based on the availability of natural gas, andwater, proximity to the demand, and the existing uses of the land. For the proposed site andfuel, combined-cycle gas turbine units of 300 - 450 MW capacity offers a high cycle efficiency,relatively short construction times, favorable environmental performance, and a relatively

compact design.

VII. COST-BENEFIT ANALYSIS

37. The Project benefit was estimated at $600 million and the project cost includingthe environmental monitoring program and mitigation measures will cost $375 to $400 million.The Project has an estimated economic internal rate of return of 16 percent.

VIII. INSTITUTIONAL REQUIREMENT AND ENVIRONMENTAL MONITORING

38. Monitoring of certain parameters during both the construction and operationalphases of the power station is essential to ensure that impacts are fully evaluated and thatnecessary mitigation measures are applied. This is necessary to demonstrate compliance withany current and future standards. We would anticipate that monitoring will apply to thefollowing: (i) fuel quality, (ii) stack emissions, (iii) liquid discharges, (iv) noise, (v) ecology, (vi)ambient air quality, (vii) ambient water quality, (viii) socio-economics, and (ix) public complaints.

39. Those parameters will be measured once a week for six months after Project start-up.Subsequently, the sampling and monitoring frequency will be reduced to once a month. Ifcomplaints are received, the monitoring frequency will be adjusted to weekly or biweeklydepending on the nature of the complaints. The Project will maintain an environment and safetyunit to be headed by a professionally qualified in environmental and safety measures. The unit

will implement the Site Environmental Monitoring Plan and also the Environmental ManagementPlan to encourage general site environmental awareness. The unit will be responsible forobtaining, reporting, and maintaining all environmental data records and for correctimplementation of the public complaints and emergency procedures to be included in theDisaster Management Plan. The environmental and safety unit will report directly to themanaging director of the Project. The unit will also collate all the monitoring results and once ayear provide the Bank and other Project financiers a copy of the monitoring results, includingthe licences and permits issued by the Department of Environment.


13/23

IX. PUBLIC INVOLVEMENT

40. Formal and informal consultation exercises were undertaken as part of the EIAprocess with both statutory consultees and nongovernment organisations. Informal-consultationwas the preferred method employed to obtain the views of affected groups within the vicinity ofthe proposed site. The groups consulted included Government and nongovernment

organisations which included the Department of Environment, the Bangladesh Centre forAdvanced Studies and the International Union for Conservation of Nature. Other groupsconsulted included local villagers from Islampur, Ganga Nagar and Dhadghata. As noresettlement is likely, the main concerns were that local inhabitants should be adequatelycompensated for the loss of land. The possibility of benefiting from improved services such asfresh water connection was also discussed.

X. CONCLUSIONS

41. The installed capacity in Bangladesh is insufficient to meet the demand forpower once allowance is made for scheduled outages and failures. This situation is

characteristic of the region as a whole and without additional plant, the need for load sheddingis likely to increase if a balance is to be maintained between demand and generation capability.Without additional generation, the countrys export-led stable economic growth may fall asprevious development plans have attempted to increase private investment in industrialproduction and to encourage export growth and import substitution. Increased generationcapacity is pivotal to this policy and the Meghnaghat Project will form an integral part ofproviding additional electricity-generation capacity. A 450 MW plant based upon CCGTtechnology and located at the Meghnaghat site represents an optimum situation to provide thisadditional capacity as it combines high cycle efficiency, relatively low construction time,relatively low atmospheric emissions, and plant compactness. Meanwhile, the site itself scoreshighly in relation to site selection criteria, such as water availability, grid connection, fuel supply,and geotechnics. Thermal power plants invariably have potential environmental effects during

both the construction and operational phases with examples of the former including air quality,socioeconomic, acoustic, and water quality impacts. However, the significance of constructionimpacts will be limited through the adoption of mitigation measures, including trafficmanagement, appropriate timing and routing of materials delivery, and consultation with localpeople throughout all power station works. In addition to the above, the potential forenvironmental impacts is also associated with the operation of thermal power stations.However, gas-fired CCGTs are regarded as being more environmentally benign thancomparably sized conventional steam plant. For instance, they have significantly lower coolingwater requirements and the need for the disposal of large quantities of combustion wastes isabsent. In relation to other issues such as changes in air and water quality, the introduction ofthe proposed mitigatory measure should allow compliance with appropriate standards andconfine negative effects to within acceptable limits. No appreciable operational impacts are

expected in relation to factors such as visual amenity and ecology.


14/23

Table 1. Salient Meteorological Data for Dhaka compiled during the period 19

TemperatureoC Relative

Humidity

Month HighestRecorded

Average Daily LowestRecorded

12:00 Hours AverageMonthly

Max Min

JanuaryFebruaryMarch

313439

252833

121316

78

13

463738

183158

AprilMay

June

4242

36

3534

32

2325

26

1819

22

4259

72

103194

321

JulyAugustSeptember

343635

313131

262626

242323

727471

437305254

OctoberNovemberDecember

343129

312926

241813

17127

655350

169282


15/23

Table 2. Surface and Ground Water Quality

Typical surface water (Meghna River)

Upstream DownstreamParameter

May 96 June 96 May 96 June

PH 6.7-6.9 6.7-6.9 6.7-6.9 6.7-6

BOD - 0.6-1.81 - 0.8-0.

Heavy metals, total (mg/l) -


16/23

Table 3. Comparison and Evaluation of Baseline Air Quality(Unit: g/m3)

Ambient concentration

PollutantAverageperiod Study Area Dhaka 1993-4

(populatedSuburban)

Chittagong 1993-4(populatedSuburban)

BanglaStand

Annual 13-19 7.49-8.10 5.30 - 24 hour 112 - - - 8 hour 156 - - 80NO21 hour 285 - - -

Annual 24-36 - 2.29 -

24 hour 212 - - -

8 hour 295 - - 80

SO2

1 hour 540 - - -


17/23

Table 4. Result of Noise Monitoring Survey

Receptor Location Monitored sound pressure level

1. West of proposed site 52.4 dB(A)

2. West of site on river bank 54.7 dB(A) Piling and dr

3. Southwest of proposed site on riverbank

53.5 dB(A) Piling and dr

4. South of proposed site (SW corner) onriver bank

55 dB(A) Piling and dr

5. South of proposed site (SE corner) on

river bank on the edge of Islam purvillage

57.1 dB(A) Piling and dr

6. East of proposed site in Islampurvillage

57.6 dB(A)

For an industrial/commercial mixed use area:Bangladesh day time standard is 75-60 dB(A)World Bank day time noise guideline is 70 dB(A)

Bangladesh night time standard is 70-50 dB(A)

World Bank night time noise guideline is 60 dB(A)


18/23

Table 5. Maximum On-ground Concentration and Distance of Maximum On-groundWith reference Environmental Standards

(Unit: g/Nm3)

Maximum On-ground ConcentrationPhase I (450 MW) Item

GT CCSOx 1 hour value 52.0 374

24 hour value 30.9 222 NOx 1 hour value 12.7 93.5

24 hour value 12.7 55.5 Distance to Maximum On-groundConcentration Position

km 16 5


19/23

Table 6. Effluent Discharge Limits for Bangladesh, World Bank and RFP(mg/l unless otherwise indicated)

Parameter Bangladesh Limit World BankGuideline (1995)

EnvironmentalRequirement in RFP

pH 6-9 6-9 6-9BOD 50 - 50COD - - 50TSS 150 50 50PO4

2- - - 5SO4

2- - - 1000N-NH3 - - 50

Total N (kjeldah) - - 150NH3 - - 5C1 600 0.2 600

Residual chlorine - - 0.2

Detergents - - 10Oil and Grease - 10 10Cr (total) - 0.5 0.5

Cr (hexavalent) - 0.1 0.1Cu, Ni - 0.5 0.5

Fe - 1.0 1.0Zn, A1 - 0.5 (Zn) 1.0

Cd - - 0.05Pb - - 1.5Ag - - 0.5CN - - 1.0

Odour - - None

Colour - - lightest brownTemperature 40oC summer Less than or

equalthe edge of the primarydilution mixing zone by

more than 3oc

1) The effluent should result in a temperature increase of no more than 3 degrees Celsius atthe edge of the zone where initial mixing and dilution take place.


20/23

Table 7. Bangladesh, World Bank and ER in RFP Noise Limited

Bangladesh World Bank

Area Type Day time Night time Day time Night timeA 45 dB(A) 35 dB(A) - -B 50 dB(A) 40 dB(A) 55 dB(A) 45 dB(A)C 60 dB(A) 50 dB(A) 70 dB(A) 60 dB(A)D 70 dB(A) 60 dB(A) - -E 75 dB(A) 70 dB(A) 70 dB(A) 60 dB(A)

Note: Due to slight variations in definition of area type the limited may not be wholly equivalent.

A. Areas where quietness if specially required such as where there is a concentration of convalescentfacilities: hospitals, educational institutions.

B. Area which are used mainly for residential purposes.

C. Area which are used considerably for residential purposes and which are also for commercial andindustrial purposes.

D. Commercial area.E. Industrial area.

Environmental Requirement in RFPThe modeled contribution to sound pressure levels would need to be equal to or less than 42 dB(A) (dayor night) at any residential property on the edges Islampur and Ganga Nagar facing the power station.


21/23

Table 8. Proposed Emission and Limit Values

ParameterEmission from proposed CCGT plant World Bank

Emission

Phase 1 Phase 2 GuideA B A B

BangladeshEmission

Limit

SO2g/s 1.4 1.4 2.8 2.8ton/day 0.12 0.12 0.24 0.24 100 (94)ton/year1 38.5 38.5 77.1 77.1mg/nm3 0.9 0.9 0.9 0.9 120 2000 (95)2

ton/day/MW 0.0001 0.0001 0.0001 0.0001 0.10 (94)NOX

ppm 25 25 25 25 150 25g/s 78.6 80.2 157.2 160.0

mg/Nm

3

51.3 51.3 51.3 51.3 240 (95)

2

ng/J 46.1 46.1 46.1 46.1 65CO

g/s 153.2 156.2 306.4 312.4mg/Nm3 100 100 100 100 190

CO2ton/day 8,178 8,338 16,356 16,676g/kWh 841.9 858.4 841.9 858.4

Note: A) The Siemen combined cycle blockB) The ABB combined cycle block

1) Based on annual plant load factors of 88 percentat 6 percent oxygen by volume in dry flue gas2) No limit has been set


22/23

Table 9. Result of Noise Assessment

Receptor LocationMonitored

Soundpressure level

Modeled Contribution to soundpressure Level

Predicted Dpressure lev

moPhase I Phase I & II Phase I

1. West of proposed site 52.4 dB(A) 32.5 dB(A) 37.0 dB(A) 52.4 dB(A) 2. West of site on riverbank

54.7 dB(A) 33.3 dB(A) 38.1 dB(A) 54.7 dB(A)

3. Southwest of proposedsite on river bank

53.5 dB(A) 35.2 dB(A) 40.0 dB(A) 53.6 dB(A)

4. South of proposed site(SW corner) on river bank

55 dB(A) 42.1 dB(A) 44.8 dB(A) 55.2 dB(A)

5. South of proposed site(SE corner) on river bankon the edge of Islampurvillage

57.1 dB(A) 41.9 dB(A) 53.5 dB(A) 57.2 dB(A)

6. East of proposed site inIslampur village

57.6 dB(A) 41.5 dB(A) 42.9 dB(A) 57.7 dB(A)

For an industrial/commercial mixed use area:Bangladesh day time standard is 75-60 dB(A)World Bank day time noise guideline is 70 dB(A)Bangladesh night time standard is 70-50 d B(A)


23/23

Table 10. Chemical Composition of Gas in percent

Titas Bakhrabad

Methane (CH4) 97.33 94.20Ethane (C2H6) 1.72 3.65Propane (C3H8) 0.35 0.72Iso-butane (iC4) 0.08 0.20N-Butane 0.05 0.10C5

+ 0.06 0.24Nitrogen (N2) 0.30 0.42Carbon Dioxide (CO2) 0.11 0.47Calorific Value 1031.55 1057.73Gross (BTU/SCF)Specific Gravity 0.5720 0.5970

ban meghnaghat

Documents