General principles for erosion prevention and sediment control at construction sites in Minnesota
Soil erosion and sediment runoff to waterways are significant problems in Minnesota. According to the Minnesota Pollution Control Agency (MPCA 2014), approximately 30 percent of the state’s rivers and streams are impaired by sediment. Poorly managed construction sites can be substantial sediment sources to these surface waters. Up to 100 tons of sediment per acre can be lost annually from unmanaged construction sites (EPA 1999). Regulations administered by the State of Minnesota through the construction stormwater permit program (MPCA 2013) seek to address these impacts by requiring
- carefully crafted sediment and erosion control plans designed to reduce polluted runoff;
- implementation and updating of the plan;
- operation and maintenance of runoff reduction measures until the site is stabilized; and
- significant penalties for negligence and willful violations.
This section provides general information on the process by which sediment is eroded from the land surface from rainfall events and the basic principles of erosion prevention and sediment control. Understanding this basic information and applying these principles in the field will reduce negative environmental impacts associated with erosion and sediment loss and help ensure compliance with Minnesota requirements and avoidance of violations and fines.
Construction site stormwater program compliance timeline
- Evaluate and assess the construction site
- Collect site information (size, slopes, soils, drainage patterns)
- Identify sensitive areas – waters, vegetation, slopes, etc.
- Produce map or drawing of the existing site
- Create the final project design map or drawing
- Characterize the sequence of major construction activities
- Calculate area, infiltration, runoff, and drainage system sizing
- Select site-specific erosion, sediment, and housekeeping controls
- Review local and state permit requirements
- Identify erosion prevention field practices and site locations
- Select sediment control practices and field locations
- Determine housekeeping and pollution prevention practices
- Indicate location of best management practices (BMPs)
- Prepare a plan for inspecting and maintaining BMPs
- Complete permitting and notification tasks
- Identify all contractors and subcontractors
- Develop stormwater pollution prevention plan (SWPPP)
- Submit Notice of Intent to MPCA
- Apply for and obtain other local/state/federal permits
- Familiarize contractors and others with SWPPP requirements
- Construction and SWPPP implementation
- Install stabilized exit and initial downgradient perimeter controls
- Install and stabilize initial drainage system, traps, and basins
- Proceed with phased clearing and grading work
- Implement phased erosion/sediment BMPs as needed
- Stabilize disturbed areas within 14 days or as required
- Inspect and maintain BMPs, document activities
- Final stabilization and permit termination
- Stabilize all disturbed areas, slopes, and drainage systems
- Remove waste and unused materials
- Remove all temporary BMPs, stabilize BMP locations
- File Notice of Termination and other required notices