It’s common to find materials stockpiled outside including:

• Auto parts in salvage yards
• Appliances, electronics and drums at solid waste facilities
• Lumber at sawmills, flooring mills or wood-preserving facilities
• Sand or de-icing salt at building/road maintenance facilities
• Topsoil/soil/gravel from excavations at sand and gravel facilities

If your facility stockpiles these or similar raw materials, proper management is necessary to prevent stormwater from washing across the exposed stockpile, becoming contaminated and carrying particulates and contamination off the facility property.

Some of the easiest practices to implement can be the most effective in managing any type of raw material stockpile:

• Impermeable berms or channels located ‘upstream’ to route surface flows away from the stockpiled material
• Berming the stockpile on all sides with a ramp for truck and equipment access
• Curbing along the perimeter of the area to prevent the run-on of uncontaminated stormwater from adjacent areas as well as runoff of stormwater from the stockpile areas
• Covering small stockpiles at all times when work with the stockpiles is not occurring
• If the stockpiles are so large that they cannot feasibly be covered and contained, implement erosion control practices at the perimeter of your site and at any catch basins to prevent erosion of the stockpiled material off-site

For more information go to the Minnesota Pollution Control Agency’s Industrial Stormwater Program webpage or call the MPCA at 651-296-6300.