Padma Multipurpose Bridge Project

associated or not) cannot be predicted with much reliability, and might be affected by externalprocesses like climate change.103. Based on the morphological study for structural intervention (Updated RTW Scheme Design,Annex C, Section 9.4, submitted on April 15, 2010), it is identified that for different types of channeldevelopment due to the construction of river training works, three locations (Figure 2-2) could bevulnerable to erosion and the extent and magnitude are considered indicative. There is no confirmedanalysis on these erosion predictions. Comparison is done on the boundaries based on naturalenvelope for the next 50 years and the maximum erosion extent for the structural interventions showsthat additional erosion for the structural interventions would be about 900 ha along the right bank,located at about 15 km downstream of the bridge crossing. Since, these changes are not immediate,a monitoring program for the downstream river (for example as part of the regular annual monitoringprogram ending at Chandpur) can be undertaken by BBA/BWDB under the Charland Managementand Monitoring Program and accordingly prepare mitigation plan.104. Any engineering work in the river is liable to be cited as a cause of subsequent erosion, but suchclaims are generally difficult to sustain for upstream changes.7.2.3.3 Approach Roads105. Uninterrupted and fast movement of road traffics including cars, buses, trucks, lorries andsimilar other heavy transports will result in both potential significant negative and positive impacts.Major Negative Impacts92. The major negative impacts are on; Air quality and Emission Noise quality106. Air Quality: Air quality will be deteriorated due to the increased traffic flow on the approach road.Air Quality Dispersion Model (CALINE 4) is used to predict PM and NO 2 concentration andCAL3QHCR for CO concentration. The modeling results are provided in Table 7-21.Table 7-21: Predicted pollutant concentrations (g/m 3 ) along the road alignment.ParameterPMCONO 2YearAveragingPeriodJanjira -Distance fromRoad, mMawa -Distance fromRoad, m25 100 25 1002014 24 hr 87 86 93 882025 24 hr 96 92 109 962036 24 hr 105 97 126 1052014 1 hr 12,228 11,999 13,371 12,4572025 1 hr 13,942 13,142 16,571 14,0572036 1 hr 15,657 14,285 19,885 15,6572014 Annual 7.5 7.5 8.8 8.22025 Annual 10.1 8.8 13.4 10.12036 Annual 12.1 10.8 17.9 12.1NationalStandards15040,000107. Air Emission: About 75,635 vehicles will use Padma Bridge daily in the year 2036. Theincreased road traffics will emit air pollutants, dusts in the air and deteriorate air quality along theroadside, which will increase with the increase of road traffics year after year. Emissions generatedfrom the future traffic during O/M stage of the Project is estimated and presented in Table 7-22.Estimated GHG emission is presented in Table 7-23. On the other hand, due to construction of bridgeand approach roads the ferry operation will stop which will improve ambient air quality.100Table 7-22: Predicted EmissionsProjection Emission of Air Pollutants (ton/year)Year TSP NO x PM CO HC7-29