A preliminary feasibility report compiled by the consultant, Louis Berger Consulting Private Limited, had been submitted to the Civil Aviation Ministry, who, in turn, sought further details in this regard, he told the state Assembly.
Both the techno-economic feasibility study and the environmental impact study of the airport project had been entrusted with the company.
''Steps are being taken to look into the matter in detail and give the reply...The government is planning to implement the project in a time-bound manner after including it in its priority list,'' Vijayan said.
Detailing the progress of the project, he said, the Kerala State Industrial Development Corporation had been appointed as the nodal agency for land acquisition and DPR preparation for the construction of the airport.
The greenfield airport was proposed in Pathanamthitta district for the convenience of Sabarimala pilgrims and considering various criteria, the Malayalam Plantation, also known as Cheruvally Estate, was selected for the project, he said, adding that an in-principle nod was given by the government for the same in 2017.
Devaswom Minister K Radhakrishnan read out the reply of the Chief Minister in the House in his absence.
According to sources, the DGCA had raised certain issues about the proposed site for the Sabarimala airport and had required modifications could be carried out to address the concerns last month.
They submitted the comments to the ministry of civil aviation on the site clearance approval for developing the airport after an inspection conducted by its officials.
The airport is planned to be developed in the more than 2,200-acre Cheruvally estate and would be about 48 kilometers away from the famed Sabarimala Lord Ayyappa Temple, a hill shrine visited by lakhs of pilgrims every year.
Noting that the proposed site is a hilly terrain, DGCA said the site topography is similar to the Calicut and Mangaluru airports, and that also needs to be kept in mind while considering the proposal.
In its submissions to the ministry, the watchdog said there may be a ''constraint in runway length and associated facilities'' and result in restriction on aircraft operation. Another aspect is that the proposed airport falls within 150 kilometers aerial distance of two existing international airports -- Cochin and Thiruvananthapuram.
Under the Union government's Greenfield Airports Policy, no greenfield aerodrome would be allowed within an aerial distance of 150 kilometers of an existing civilian airport.