The Minnesota Pollution Control Agency has partially removed the former Twin Cities Army Ammunition Plant (TCAAP), Ramsey County’s biggest development site, from the state’s Superfund list following a parallel action taken last fall by the U.S. Environmental Protection Agency.

But while the soil and surface water has been delisted, groundwater contamination associated with the 2,370-acre Arden Hills site remains on both the state and federal Superfund lists and will continue to be treated through an existing groundwater cleanup system.

Friday’s action is an important step for plans now underway to redevelop more than 400 acres of the former industrial site into homes and businesses.

“For 30 years, local, regional and state leaders have been working to clean up” TCAAP, said Minnesota Pollution Control Agency (MPCA) Commissioner Laura Bishop in a written statement. “This is a major milestone only made possible by strong partnerships and a relentless commitment to improve the environment and vitality of the north metro.”

The Environmental Protection Agency (EPA) delisted the site’s soil and surface water in September. Delisting occurs when “all cleanup goals have been achieved” and “no further cleanup is required to protect human health or the environment,” according to the EPA.

Some of the property, including a portion used by the Minnesota National Guard, is cleaned up to industrial standards. Other areas, including more than 400 acres owned by Ramsey County and slated for redevelopment, have been cleaned up for residential construction.

The site, long owned by the U.S. Army, was added to the state and federal Superfund lists in 1980s after decades of pollution tied to the manufacturing of ammunition dating back to World War II.

Federal and local agencies have spent millions in pollution remediation over decades at the TCAAP site. Ramsey County purchased 427 acres of the site in 2013 and continued to clean up the soil to residential standards, under the oversight of the MPCA. Total cost to the county was $30 million.

“The cleanup has been done for a few years. This is an administration action, but it represents the end of an era,” said Amy Hadiaris, supervisor in the MPCA’s Remediation Division.

“It’s a very public statement that we are done with the soil cleanup. It helps remove some barriers for reuse of the property. Having that Superfund label is a stigma that can be concerning in terms of reuse of the property.”

In 2016, Ramsey County, in partnership with Arden Hills, selected Alatus to oversee development of what is now called Rice Creek Commons. But the city-county partnership has since devolved into an ongoing lawsuit, with the city and county disagreeing about the number of homes to be built. The county wants as many as 2,500 housing units, while Arden Hills wants to build about 1,400 units.

Toni Carter, who chairs the Ramsey County Board, said in a written statement that the county is committed to moving forward with “a mix of affordable and market-rate housing with retail and commercial properties.” She added she was proud that what was once the state’s largest Superfund site “will always be safe for our residents to live, work and play.”