Hawkesbury leaders say they are pleased to see Richmond RAAF Base remain a Department of Defence facility.
In October last year, Tiger Air Australia expressed interest in operating commercial flights from the base.
Macquarie MP Louise Markus said she "had always held concerns about the viability of the former Labor government's proposal to use Richmond RAAF Base as a second Sydney airport".
"Should a decision be made regarding Badgerys Creek I would have questions regarding the environmental impact and would want to ensure the appropriate road infrastructure is implemented within the Macquarie electorate," she said.
Labor spokeswoman for Macquarie Susan Templeman said if this decision is made, there are massive implications for the environment and people of greater western Sydney, not just within the boundaries of Macquarie.
''We need to be clear what the noise impacts are where people live and work, how Sydney's major water supply will be protected, and what rail and road will be in place so traffic in the west doesn't get worse,'' she said.
''I don't think we can make assumptions about what it might mean for the ongoing viability of the Richmond RAAF Base. The question is, if Badgery's Creek goes ahead will the federal government ensure Defence stays in Richmond, and if not, what happens to the site and the jobs that it gives the local area?''
Londonderry MP Bart Bassett said he had never supported the RAAF base as Sydney's second international airport and welcomed the proposal at Badgerys Creek.
"I would be keen to sit down with local, state and federal colleagues to discuss plans for that airport and to seek assurance from the federal government about assurances of RAAF Richmond," he said.
Hawkesbury mayor Kim Ford, also in support of the Badgerys site, said the council supported the retention of Richmond RAAF Base for defence purposes.