Many environmental groups in Melbourne's east and south-east objected to the project, due to a number of factors, including vehicle emissions and disruption of habitat (in places such as the Mullum Mullum Valley and Dandenong Valley Wetlands). However, the road was the subject of an extensive Environmental Effects Statement (June 1998), which was followed by an extensive public hearing process in April 1999 before the final Government decision to proceed. The statement predicted an 18.5per cent increase in carbon dioxide, impacts on groundwater and wetlands, high impacts on areas of conservation value and the potential to affect 38 species of rare or threatened fauna and flora if the freeway was built.