Kent Dvorak, center, of the De Soto the Economic Development Council, peers out the bus window along side De Soto City Council members Thursday during a tour of the Sunflower Army Ammunition Plant south of De Soto. Sunflower Redevelopment is cleaning the 9,000 acres, much of which is contaminated from chemicals used to make explosive material. Sunflower Redevelopment aims to complete the project by 2012.

A warning sign hangs on a barbed wire fence at a closed entrance to the Sunflower Redevelopment area Thursday south of De Soto. The old Army ammunition plant is being demolished and cleaned to one day be used as residential land.

Sunflower Army Ammunition Plant, as seen on a bus tour Thursday, is a place where lush greenery contrasts with acres of neglected World War II era buildings, pitted concrete and other scenes of industrial decay.

But from time to time, the tour came upon a third landscape, one at which the plant’s new owners have begun the process of transforming brownfield sites into future residential neighborhoods, commercial centers or park land.

Sunflower Redevelopment LLC acquired the 9,065-acre plant south of De Soto in August 2005. With the federal government’s transfer of the plant to the partnership of Kessinger Hunter of Kansas City, Mo., International Risk Group Inc. of Denver and Prairie Center Investors LLC of Overland Park came with a commitment to clean up a property polluted from a half century of production of rocket propellant that started in World War II.

Sunflower Redevelopment arranged Thursday’s tour to update De Soto city officials and business leaders on the status of the cleanup.

Clean-up in progress

Although the cleanup got off to a slow start, the partners are committed to completing the environmental remediation by the end of 2012, said Sunflower Redevelopment executive director Kise Randall, who led the tour.

“We’ve got the resources and the commitment on our side to make that happen,” she said.

Environmental regulators, led by the Kansas Department of Health and Environment, have to share that commitment to realize the 2012 completion date, Randall told De Soto City Administrator Pat Guilfoyle.

The first three years of the cleanup focused on ridding the plant of explosive residue contaminating structures and sewer lines.

When the plant was transferred to Sunflower Redevelopment, about 1,000 structures possibly contaminated with explosive residue remained. Those structures were burned after being stripped of asbestos, fluorescents and other hazards because of the risk of explosion to workers if razed in traditional ways.

Randall said that part of the cleanup was finished with the burning of more than 110 buildings and 1,489 foundations, sumps and drains. However, area residents still will see columns of smoke rising from the plant as the environmental team led by International Risk Group burns 36 miles of sewer line, possibly containing explosive residue, and pastures to restore the prairie environment.

Methods

Work is now under way to break up and stockpile concrete from the explosive-cleansed foundations and other concrete structures, Randall said.

“We’ll have 11 or 12 large hills of concrete on the property,” she said.

Those with traces of pesticide or other pollutants will be shipped off-site, while the rest will probably be used as base material for parking lots and other future development on the plant, Randall said.

With the burn program completed, 1,000 aging buildings still dot the plant. Randall said it was the developer’s responsibility to deal with those structures without state or federal regulation.

Although some soil cleanup has already been completed, that part of the cleanup will become more intense in the next two years, Randall said.

There are 100 sites spread throughout the plant where explosives, sulfates, nitrates, heavy metals, organic compounds and pesticides are known or thought to pollute the ground. Randall said an estimated 279,000 cubic yards would be dug up, treated and removed.

At each site, Sunflower Redevelopment’s environmental team must propose a cleanup and verification method to regulators led by the Kansas Department of Health and Environment, remove contaminated soil, fill in excavations and confirm over time that the remediation was successful. Only when all those steps are completed can the site be certified as clean and developed, Randall said.

‘It’s safe’

Generally, the plan is to clean from the plant’s exterior to its interior, in part because of the commitment to donate 2,000 acres along Sunflower’s eastern, southern and western boundary to the Johnson County Parks and Recreation District, Randall said.

Some sites on higher ground would be addressed earlier to prevent runoff from re-contaminating already cleaned ground, she said.

Among the areas scheduled for cleanup is the 200 acres to be transferred to Kansas University for a life science research park and an adjacent 250 acres that Sunflower Redevelopment is reserving for the same use.

All areas are to be cleaned to residential standards with the exception of landfills. In select places, that would dictate digging as deep as 18 feet to remove soil near the bottom of basement drains, Randall said.

“As the end owners of the property, there is no incentive for us to cut corners on the cleanup,” she said. “We want people to know it’s safe to live here.”