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Post-Construction | Section 2: Storm Water Management | 365

SWPPP Cut Sheet:

PURPOSE & DESCRIPTION

Filtrexx ® Filter strips are a temporary or permanent vegetative fltration practice used to reduce the amount of sediment and soluble pollutants, such as nutrients, heavy metals, and petroleum hydrocarbons, in storm water runoff prior to leaving a site or entering a receiving water or wetland. The primary purpose of a Filter strip is to reduce sediment and pollutant loading of surface sheet fow runoff and subsurface fow (interfow) by:

• Reducing pollutant loads by reducing runoff volume,

• Reducing runoff volume through increased water holding capacity and infltration,

• Increasing infltration by reducing runoff velocity, • Trapping and settling of pathogens and sediment by reducing runoff velocity,

• Chemical adsorption of nutrients and metals to humus colloids in compost,

• Recycling of nutrients and metals by plant uptake and microbial decomposition and uptake.

Filter strips consist of a 1 to 2 in (25-50mm) deep layer (135 to 270 cubic yards/acre, 257 to 513 cubic meters/ha) of Filtrexx ® GrowingMedia tm blended with a specifed seed mix and applied to ground surfaces with pneumatic blower trucks. Planting of perennials such as shrubs and trees will also improve storm water infltration and fltration of pollutants in storm water.

APPLICATION

Filtrexx ® Filter strips are generally used for post construction applications where permanent vegetation is established to increase infltration of storm water and fltration of storm water pollutants. Locations where Filter strips may be required or recommended to flter storm runoff include:

• From highways, streets, and parking lots, • Prior to surface waters, riparian areas, and wetlands,

• Above stream bank or shoreline structural stabilization projects, • Prior to channels and ditches,

• Prior to bioretention ponds, rain gardens, and storm water detention ponds,

• Around site perimeters where land disturbing/ construction activities may occur,

• Prior to structural sediment control devices as a pretreatment practice,

• Around and prior to sediment detention ponds where land disturbing/construction activities may occur.

Filter strips can also be designed to reduce runoff velocity leaving or entering the locations described above. Reducing runoff velocity will increase infltration of storm runoff, thereby reducing runoff volume and pollutant loading. GrowingMedia tm in Filter strips will further reduce pollutant loading in storm water by reducing runoff volume and

Section 2: Storm Water Management – Post-Construction

Filtrexx ® Filter Strip

Sediment & Pollution Control Technology