The St. James Mine Pit (St. James) is located north of the city of Aurora in St. Louis County, Minnesota. Currently, the city of Aurora utilizes the pit water for the city’s municipal water supply.
Natural iron ore was mined from the St. James pit and shipped between 1916 and 1963.
The Mineland Reclamation Rules for ferrous mining were adopted in 1980 and require mining operations to plan for closure and reclamation at the onset of mining. However, because mining in the St. James ceased prior to the Mineland Reclamation Rules, no company is responsible for reclamation of the site, which may include water level management. The state assumed responsibility for St. James and management of the water level.
St. James water level management
Though water from the St. James pit is used for the city of Aurora’s water supply, the demand is less than inflows to the pit resulting in rising water level. The pit receives water from precipitation, surface water inflow, and groundwater inflow.
The St. James continues to gain water and will need an engineered outlet and route in the future to prevent flooding. To enable informed discussion with state leaders and legislators, a number of state agencies are collaboratively working to gather data. The initial data gathering will be to collect water quantity and water quality information from the pit as well as potential nearby surface waters which may be receiving waters in various designed outlet scenarios.
Future work may include but are not limited to continuation of water level monitoring, bathymetric surveying, installation of groundwater wells, surveying of outlet route, and construction of a groundwater model.
Once a preferred outlet location and route are chosen, future phases would include engineering a design and then construction. Future data gathering, engineering design, and construction would need to be funded before these phases of the project could move forward.
Water level monitoring
The DNR Division of Lands and Minerals is actively working to assist in monitoring the St. James water level to understand the rate of pit water level increase.
DNR Division of Lands & Minerals
St. Paul, MN