Square meters of land required per of alumina produced 53.2 51.1 50.1 48.3 47.2 46.4 2015 BASELINE 2016 2017 2018 2019 2020 https://www.alcoa.com/sustainability/en/pdf/Alcoa-Global-Impoundment-Policy.pdf https://www.alcoa.com/sustainability/en/pdf/Alcoa-Global-Impoundment-Policy.pdf https://globaltailingsreview.org/global-industry-standard/ https://globaltailingsreview.org/global-industry-standard/ to full height before material is deposited.