The delivery of new sports fields and parkland at Greenhills will be delayed under plans to expand the operations of the Breen Resources landfill.
Breen Resources plans to build a large new resource recovery facility and increase the industrial and commercial waste capacity of the former sandmining site by two million tonnes.
A Sutherland Shire Council report said the proposal would delay the next stages of Marang Parklands, which are being developed under a voluntary planning agreement with the council.
The delay, for an unspecified period, would result from the site being re-contoured with higher levels of waste.
The report said this could potentially result in a better outcome.
So far, only stage one of Marang Parklands has been delivered, and includes a skate park, two hockey fields and a football field with amenities.
Further stages are due to provide seven more playing fields and parkland that will also provide a "green corridor" to the wetlands of Towra Point, Quibray Bay and Botany Bay.
Breen Resources initiated a State Significant Development Application by requesting SEARS (Secretary's Environmental Assessment Requirements) from the Department of Planning and Environment in December 2019.
The council has been engaged in preliminary discussions with the company, and will make a submission on the proposal.
Breen received approval in 1990 to undertake landfilling and restoration of its former sandmining site.
Limited recycling of building and demolition type materials has taken place from a facility at the western end of the site, which needs to be demolished to allow development of the sports fields and parkland.
The proposed new resource recovery facility would be built at the eastern end, with access from Lindum Road.
The voluntary planning agreement was entered into by Breen Property, Australand (since renamed Frasers Property Australia) and the council in 2010.
It allowed for the companies' former sand mining sites to be developed for the Greenhills Beach housing estates and the development of what is now known as Marang Parklands.
The agreement was for a staged transfer of 91 hectares of land to public ownership for the purpose of environmental conservation and public open space.
It would involve construction of regional recreation facilities, including 10 playing fields, a skate park, three amenities buildings, walking and cycling tracks, picnic facilities and associated parking for over 400 cars.
There would be rehabilitation and landscaping of degraded land previously dredged for sand mining to support an ecological "green corridor" stretching from the Towra Point Nature Reserve to the ocean at Wanda Beach.
The first stage, comprising Sporting Field No 1, two hockey fields, the skate park, car parking, and associated amenities and landscaping, was completed in 2018.