Source: http://wwwsp.dotd.la.gov/Inside_LaDOTD/Divisions/Engineering/Environmental/Documents/H.004791%20%20LA%2023-%20BELLE%20CHASSE%20BRIDGE%20AND%20TUNNEL/H004791%20EA%20with%20FONSI%20Belle%20Chasse%20Bridge%20and%20Tunnel%20LA%2023.pdf