A potential buyer entered into tentative contracts late last week to redevelop one of Madison’s largest and most developable vacant sites.

Ruedebusch Development and Construction Company is exploring the costs and benefits of restoring the 26-acre former Royster-Clark property at Cottage Grove and Dempsey, city planner Michael Waidelich said.

The property, which currently houses an old fertilizer plant, has nitrate damage that seeped into the soil, and will therefore be costly to renovate, Waidelich said.

A neighborhood planning team performed a cost analysis to determine what type of development could financially succeed on the property given the costs of renovation, said John Marten, vice planning chair.

The city plan for the area calls for high-density development on the corner of Dempsey and Cottage Grove roads and residential development further back on the property, Marten said.

He said Ruedebusch’s plan in its preliminary stages seems to line up with what the city delineated in the property plan.

“In this case, we knew what would work for a developer in terms of a financial set up, and now, if what the developer has in mind is close to what we were proposing, there won’t be a battle – the city should support it,” Marten said.

The city plan also emphasizes the need for environmental remediation in the redevelopment process, he added.

The property is considered one of the most developable and largest tracts of undeveloped land in Madison. However, Dane County Sup. Tom Stoebig, District 17 and a member of the planning team, said the land is affected by nitrate and phosphate, making the redevelopment complicated.

The city has seen two tentative proposals for the property fall through since the city’s plan for the area was approved by the City Council more than a year ago.

Stoebig said new developers should be more than aware of the challenges that can come with the property.

“There will be about a $1 million cost associated with simply the demolition of the existing infrastructure and an additional $1.6 million in remediation,” Stoebig said.

Stoebig said the costs will cover the price of removing the nitrate and phosphate contaminates found in the soil on the site.

There are a number of grants available for environmental brownfields, which Marten said should be a source of relief for the developer.

Stoebig said some of the available brownfield grants might be available to the city but not the developer.

He added the city should show cooperation and assistance in allowing the development to happen by “using all of its power” to make sure the site is ready for the process.

“This is a huge parcel of land – this will be the largest in-field development site in the city of Madison, and I think there are an awful lot of good, positive things that could come from the redevelopment of the site,” Stoebig said.

Waidelich said Ruedebusch is a strong candidate for the project, but the company still has more than six months to finalize the deal.