Before revision: They have been less effective in areas with: high groundwater levels, close to the infiltrating surface; compacted soils; high levels of sediment in stormwater; or high clay soil content.Water Environment Federation, Alexandria, VA; and American Society of Civil Engineers, Reston, VA. "Urban Runoff Quality Management."
After revision: They may be less effective in areas with: high groundwater levels, close to the infiltrating surface; compacted soils; high levels of sediment in stormwater; or high clay soil content.Water Environment Federation, Alexandria, VA; and American Society of Civil Engineers, Reston, VA. "Urban Runoff Quality Management."