THE discovery of more than 900kg of bonded asbestos among landfill at the planned site for Clarence Valley Council's depot could add up to $2.5 million to the cost of the project.
It has also helped put the project three months behind schedule.
At this afternoon's council meeting, councillors will be given an update on the multi-million dollar project that outlines some of the difficulties that have emerged as the site is prepared for construction.
The contractor for the project, Hutchinson Builders, has been working at the site since August this year.
According to the minutes of a November 2 meeting between council senior staff, Clarence Valley mayor Jim Simmons and Ian Feek of Ridgemill Project Management, among the work that has been done is the demolition of the former sewage treatment plant and the sifting of stockpiles of "uncontrolled fill".
A spokesman for Clarence Valley Council described uncontrolled fill as "fill that is placed in an uncontrolled manner".
About 4000cum of uncontrolled fill has been sifted, with the large amount of bonded asbestos uncovered.
According to the minutes, all asbestos and contaminants have been managed in accordance with the Site Management Plans.
Other waste material in the fill included large pieces of concrete, tyres and car parts, chain wire fencing and road markers.
The type of fill uncovered could mean the planned construction of the foundations for the depot is unsuitable and other options are being considered.
The minutes state, "It was noted that the RAP (Remediation Action Plan) report and Technical specifications had not been completed in accordance with EPA requirements".
Solutions for the remediation of the site are being considered, and include decontamination of the land; suitability for the end use; cost and compliance with NSW Environment Protection Authority (EPA) requirements.
Ridgemill Project Management has "advised that there are likely to be significant costs association with the remediation of the site as a result of the issues encountered that were not adequately addressed in the RAP," the minutes state.
Preliminary indications are that finding a solution to the problems of uncontrolled fill and bio-solids that keeps most of the pollutants on the site will increase the cost of $1million to $1.4million.
However, this type of solution might not meet EPA's approval.
Potential costs for removing the uncontrolled fill and bio-solids could be $2million to $2.5million.
The asbestos discoveries have led to Hutchinson Builders installing air monitoring stations around the boundary of the site, some staff carrying air monitoring devices, increased watering and stockpiles being treated with a polymer spray.