Contaminated soil at Soo Line Community Garden halts 2024 gardening season
Posted on 19 March, 2024Plan is being created to clean up the site, which will continue to operate as a community garden after contamination is addressed
An analysis of recent and past soil samples at the Soo Line Community Garden found several types of contaminants that may exceed Minnesota Pollution Control Agency (MPCA) thresholds, so the Minneapolis Park and Recreation Board (MPRB) is pausing all gardening activities there until the contamination is addressed.
Soo Line Community Garden is located at 2845 Garfield Ave. S, between Garfield Avenue South, Harriet Avenue South, and the Midtown Greenway. Before its use as a garden, the land was occupied by railroads and grain elevators, both of which used petroleum products and other hazardous substances. Contaminants found at the garden include diesel range organics (DRO) from petroleum and polycyclic aromatic hydrocarbons (PAH).
Garden History
The land became a community garden under Hennepin County’s jurisdiction in 1991 and it was transferred to the MPRB in 2010.
Soo Line Community Garden is considered a “legacy garden” that predates the MPRB Community Garden Policy, which was finalized in 2018. Legacy gardens operate under an annual permit issued by the MPRB that requires establishing a gardening lead, maintaining liability insurance, and performing soil testing, among other requirements. The Soo Line Community Garden permit has been issued to the Soo Line Community Garden group in past years.
Previous Environmental Investigation
Environmental investigations dating back to at least 1999 concluded gardening was a supported site use, despite some soil contamination. Soil samples were collected and analyzed by ThermoRetec in 1999 and Peer Environmental in 2001. A total of 14 locations were sampled throughout the garden, six in 1999 and eight in 2001.
Four of the six 1999 samples exceeded MPCA thresholds for DRO, some significantly exceeding the threshold value. The 2001 samples were two composites collected from various portions of the site; those composites exceeded both DRO and PAH thresholds. All samples showed those contaminants in the upper 3-4 feet of collected soils.
These early samples used a process of averaging to determine if MPCA thresholds were exceeded. Averaging allowed the site to be acceptable for its gardening use according to MPCA standards, however, that is no longer a common practice used by soil scientists interpreting data from contaminated sites.
Recent Environmental Investigation
Hennepin County proposed constructing an accessible pathway through Soo Line Community Garden to improve connection between the Midtown Greenway and surrounding neighborhoods. That process has been ongoing for nearly two years.
As a part of the due diligence process for the proposed pathway, Hennepin County commissioned a soil investigation from Landmark Environmental. Three of the six samples collected near the proposed pathway exceed MPCA thresholds for DRO and PAH.
The MPRB recently hired a consultant from Braun Intertec to conduct an independent desktop review of the materials from the county and other sources. The consultant recommended against gardening at the site until steps are taken to mitigate soil contamination.
Environmental Cleanup Process
The MPRB consultant also recommended steps the MPRB might take to resolve concerns related to soils, including a process of removing and replacing current soils on site to ensure separation from underlying contaminated soils and using raised garden beds.
It’s important to note these are preliminary recommendations and the MPRB is working with its consultant to formalize recommendations. The MPRB could potentially go through the MPCA Voluntary Investigation and Cleanup Program and seek cleanup funding through the Hennepin County Environmental Response Fund. The first action would be preparing a Response Action Plan with approval by the MPCA.
Next steps for the Soo Line Community Garden
Addressing the environmental findings will take priority. However, Resolution 2024-54 will come before the full MPRB Board of Commissioners on March 20, 2024. Whatever the outcome of that resolution, the safety of future gardening activities at Soo Line Community Garden is paramount.
The MPRB recognizes the garden’s value for both food production and as a social and recreational community hub. The MPRB is exploring potential temporary garden sites at nearby park properties as well as ways to address food insecurity with produce brought in from other park gardens.