Hillandale CDP (part), Montgomery County, Maryland Environmental Rules: Erosion Control Rules (2026)

Montgomery County administers erosion and sediment control as a delegated authority under Maryland Environment Article Title 4, Subtitle 1. County Code Chapter 19, Article II governs erosion and sediment control requirements. Any earth disturbance of 5,000 square feet or more (including clearing, grading, excavation, and filling) requires an approved erosion and sediment control plan before work begins. Plans must conform to the 2011 Maryland Standards and Specifications for Soil Erosion and Sediment Control. Required best management practices (BMPs) include silt fences, sediment traps, sediment basins, stabilized construction entrances, temporary seed and mulch, and inlet protection. All disturbed areas must be stabilized within 14 calendar days of final grading or 7 days if within 100 feet of a waterway. The Department of Permitting Services (DPS) reviews and approves erosion and sediment control plans and conducts inspections during construction. Projects disturbing one acre or more also require a National Pollutant Discharge Elimination System (NPDES) General Permit for Construction Activity from MDE. Contractors must have a certified Responsible Personnel on-site during earth-disturbing activities. Montgomery County conducts frequent inspections, particularly during the wet season and near environmentally sensitive areas such as stream buffers and Special Protection Areas.