Cumulative Air Quality Impacts from Twenty-Two Major Power Plants

Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developments at risk. This study assessed the cumulative impacts of air emissions from 22 major power plants in southeast Bangladesh planned to generate 21,550 MW of electricity. It also includes anticipated growth in small to medium size industries, brickfields, highway traffic, inland water transport, transhippers, jetty, and vessel transports used for transporting fuel resources for these power plants. A 50 km by 50 km airshed is considered for air quality modeling. Cumulative analysis indicates that predicted MGLCs (Maximum Ground Level Concentrations) of NO₂ and CO are complying with both Bangladesh NAAQS (National Ambient Air Quality Standards) and WBG (World Bank Group) Guidelines. The daily average MGLC of PM2.5 (62.45 µg/m³) from all sources complies with NAAQS, however, exceeds the WBG Guidelines. Annual PM2.5 concentration (15.45 µg/m³) exceeds NAAQS and WBG Guidelines. The PM10 concentration complies with the NAAQS for both 24-hour and annual averaging times. Annual average concentration (23.12 µg/m³) exceeds WBG Guidelines. Daily average SO₂ concentration (102.49 µg/m³) complies with the NAAQS however, it exceeds the WBG guideline values. High concentrations of PM2.5 and SO₂ are due to the contribution of transboundary emissions and secondary pollutants in the atmosphere. This dispersion modeling outcome can be used by the policymakers for the pollution reduction strategy.