Trail projects that disturb greater than one acre require a Storm Water Pollution Prevention Plan (SWPPP) with detailed best management practices to control water pollution caused by increased sediment during construction.
Potential sediment sources during construction include bare earth, soil stockpiles, dirty construction equipment and vehicles used during construction. Construction sites with steep slopes, uncompacted soils, and barren areas require detailed erosion control Best Management Practices (BMPs) included below. SWPPP compliance inspections are conducted at least weekly during construction activities to inspect proper installation, operation and maintenance of BMPs. Major elements include:
- Total area to be disturbed.
- Description of BMPs to be used including and methods and schedule for installation.
- Details of temporary or permanent non-structural and structural BMPs.
- Details of general site management BMPs.
- Conditions that allow removal of BMPs.
Erosion control and SWPPP practices are critical to the success of project. These measures not only help keep soils on-site and in place, but also aid in limiting the amount sedimentation being deposited onto neighboring properties or into nearby water bodies.
- BMPs are used to allow sediment to settle out of runoff prior to leaving construction sites and are applied at construction site entrances and haul roads, to protect inlets, and applied as perimeter controls.
- BMP applications include minimizing land disturbance, stabilization of barren areas with temporary seeding, and retaining runoff using various structural BMPs as sediment traps.
- Covering stockpiles and mulching barren areas are additional BMPs to reduce sediment loading of local water bodies.
- Non-structural BMPs include proper site planning, construction sequencing and contractor education program.
- Reference sediment control measures in the St. Louis County Sediment and Erosion Control Manual https://www.stlouisco.com/Portals/8/docs/Document%20Library/highways/Publications/Sediment_and_Erosion_Control_Manual_St_Louis_County.pdf