Boolaroo's Pasminco Cockle Creek Smelter and Incitec Fertiliser sites have lain unused since industrial activity stopped more than 10 years ago.

The sites were used heavily throughout the 20th century and the land was significantly contaminated.

In 2007, the NSW Planning Minister Frank Sartor approved remediation plans to clean up the sites.

The remediation plans included the recommendation that two containment cells be built to store hazardous waste from the sites, with one on each site.

In 2012, landowners proposed a more "efficient, co-ordinated" plan that suggested only one cell was needed on the smelter site.

The new minister Brad Hazzard amended the original plans and allowed this to proceed.

Last year, Lake Macquarie council received a request to rezone the land allocated for the containment cell on the fertiliser site to that of residential use.

A draft amendment to the plans was placed on public exhibition last November.

No submissions were received.

The matter returned to the council last week where councillors voted for the amendment unanimously.

The council advised Mr Hazzard to sign off on the amendment so that residential development of the site can proceed.