A 40-acre parcel along Interstate 35 in Arden Hills could be home to a corporate headquarters, life science campus, manufacturing or other commercial uses following a unanimous vote by the Ramsey County Board Tuesday to approve a purchase and sale agreement for $12.7 million.

The agreement with developer Ryan Companies is for "Outlot A" or the "Thumb Parcel," of Rice Creek Commons, part of the former Twin Cities Army Ammunition Plant (TCAAP) site.

Ramsey County purchased TCAAP in 2013 and has paid for cleanup at the former superfund site. Development has been delayed by disagreements between the city and county, which are jointly responsible for the site's development.

But last week, the Arden Hills City Council approved zoning changes to allow as many as 1,960 residences on the 390-acre lower portion of Rice Creek Commons, being redeveloped by Alatus.

Ryan Companies was selected from a pool of six developers that submitted proposals to develop the outlot.

Peter Fitzgerald, Ryan Companies' vice president of real estate development, said the company was attracted to the site because of its proximity to workers living in both Ramsey and Hennepin counties.

"We think that with the right corporate user on this site, it could bring really awesome jobs to the Arden Hills community and the northern part of Ramsey County," he said.

Ryan Companies has hired a firm to help market the site to prospective tenants. The company has not announced a construction start date.

At Tuesday's Ramsey County Board meeting, Commissioner Nicole Frethem, who represents Arden Hills, expressed excitement over the deal. She said the sale of the outlot will help fund development of the lower parcel.

The agreement with Ryan Companies includes a due diligence period that could last as long as 15 months.