How to Install Erosion Controls
Installing silt fence, inlet protection, stabilized construction entrances, and sediment basins to comply with NPDES stormwater requirements.
Step-by-Step
- 1
Review the SWPPP
Your Stormwater Pollution Prevention Plan (SWPPP) is a legal document that specifies which BMPs (Best Management Practices) are required, where they go, and who is responsible. Read it before you install anything. Deviating from the plan without updating it is a permit violation.
- 2
Install construction entrance
Place the stabilized construction entrance at every point vehicles enter or exit the site. Lay 6-inch compacted gravel (AASHTO #2 or 3) over geotextile, minimum 50 feet long and 12 feet wide. This knocks mud off tires before they reach the public road.
- 3
Install silt fence at the perimeter
Install silt fence along the downhill perimeter of all disturbed areas. Drive stakes every 6 feet and attach fabric to the uphill side. The bottom 6 inches of fabric must be buried in a trench and backfilled — a fence that is just stapled to stakes will wash out in the first rain.
- 4
Protect all storm drain inlets
Install inlet protection at every storm drain on or immediately adjacent to the site. Use filter sock, gravel bag berms, or manufactured inlet inserts. Inspect and clean out sediment after every significant rain event.
- 5
Install erosion control blanket on slopes
On slopes steeper than 3:1 or disturbed areas near waterways, install erosion control blanket (ECB). Start at the top of the slope and unroll downhill. Staple at 1-foot intervals on the edges and at the manufacturer's specified pattern. Overlap seams 6 inches.
- 6
Seed and mulch bare areas
Stabilize any disturbed area not under active construction within 14 days (NPDES requirement in most states). Seed with a fast-germinating temporary cover crop (annual rye or oats) and apply straw mulch at 2 tons per acre.
- 7
Establish inspection routine
Inspect all erosion controls within 24 hours of every 0.5-inch rain event and every 7 days. Document inspections in the SWPPP inspection log — the form is part of the permit. Repair damaged controls within 24 hours.
Pro Tips
- → The most common NPDES violation: silt fence installed but bottom not trenched in. Inspectors know to look for this.
- → Keep extra silt fence and inlet protection on-site — you will need to repair or add controls after every major storm.
- → Document everything with photos and the SWPPP log. If you get inspected, your documentation is your defense.
Watch Out
- ! NPDES violations carry fines up to $25,000 per day per violation. Take stormwater controls seriously.
- ! Mud on a public road from a construction entrance that isn't maintained is a violation — sweep or wash down the road daily.