The removal of the rail line, part of the $181 million rail

bypass project, was to be the catalyst for immediate redevelopment of the central business district.

But authorities now say soil and water testing will be needed to assess the level of contamination before the land is released.

They say it is not a matter of if the land is contaminated but to what degree.

A desktop report in 2002 identified areas of potential contamination but no actual testing was done.

Member for Benambra Bill Tilley says whatever the assessment, the clean-up must be rigorous and thorough.

Significant contamination near a former goods shed next to Lilydale train station in Melbourne has already delayed the extension of a car park for more than a year.

“So we need to look beyond the opportunity to expand the city’s CBD and examine the potential for the site to have been contaminated,” he said.

“We need to apply proper practice to our public lands.

“You can’t put a lid on it and find 50 years down the track that it carried significant environmental impacts.

“Experts need to go in there and tell us what needs to be done.”

VicTrack, the Victorian Government owned corporation that owns all railway and tram lines and associated lands in the state, says almost all railway land is contaminated from past use.

“VicTrack has commenced a project to assess the degree of contamination on land released by the new rail bypass,” spokesman Mac Henshall said.

“(It) will be done in stages throughout 2010 given the extent of the land involved.

“The nature and cost of any remediation will depend on the final results from the environmental testing and the nature of what is proposed for the land — commercial uses require lower standards of remediation than residential land, for example.”

Mr Henshall said only site testing would determine the way ahead.

“We did undertake an investigation of the entire railway precinct, however, this was only a desk top investigation which provided preliminary advice in relation to areas of potential contamination based on the historical information,” he said.

“We now need to conduct the detailed field testing to confirm the state of the land.”