Because that proposal might impact on the Firth of Forth, which is a special protection area, the Parliament, as the competent authority, is required to undertake an appropriate assessment of the project's impact on the SPA and to find out whether any steps could or should be taken to negate or mitigate any impacts.Members will note that Scottish Natural Heritage has been liaising with the promoter over the bill's potential impact on the Firth of Forth and has asked the promoter to provide additional information, which is contained in the promoter's report entitled "Edinburgh Airport Rail Link: An Assessment of the Effects to the Firth of Forth Special Protection Area".