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Construction Activities | Section 1: Erosion & Sediment Control | 331

SWPPP Cut Sheet:

Filtrexx ®

Check Dams

Sediment & Perimeter Control Technology

PURPOSE & DESCRIPTION

Filtrexx ® Check dams are a 3-D tubular check dam device used in storm water drainage ditches/small channels on/near land disturbing activities to: • slow concentrated directional fow velocity of storm runoff,

• reduce gully erosion in ditch bottoms, • remove sediment and soluble pollutants (such as phosphorus and petroleum hydrocarbons) present in storm water runoff

Filtrexx ® Check dams provide a porous physical barrier perpendicular to concentrated storm water fow designed to reduce and disperse runoff energy. They reduce erosion by slowing runoff velocity and dissipating concentrated storm runoff fow. They trap sediment and soluble pollutants by fltering storm water as it passes through the Check dam and by water temporarily ponding behind the Check dam, allowing deposition of suspended solids.

APPLICATION

Check dams are used in drainage ditches and small channels on and around land disturbing activities until fnal stabilization is complete. Check dams should be installed prior to excavating, flling, or grading of uphill areas. Check dams are only used in ditch grades equal to or less than 10% (grades greater than 10% should employ structural stabilization practices). Check dams should not be used in areas where the contributing drainage area is greater than 2 to 10 acres (0.8 ha to 4 ha), and should be placed in a manner to prevent sediment from entering receiving streams, rivers, lakes, or wetlands. Check dams should never be used in ephemeral, perennial,

or intermittent streams.

INSTALLATION

1. Check dams used for slowing runoff velocity in storm ditches and channels and used to reduce sediment and soluble pollutant loads leaving ditches and channels shall meet Filtrexx ® FilterSoxx tm Material Specifcations and use Certifed Filtrexx ® FilterMedia tm .

2. Contractor is required tobe aFiltrexx ® Certifed tm Installer as determined by Filtrexx ® International, LLC (440-926-2607 or visit website at Filtrexx.com). Certifcation shall be considered current if appropriate identifcation is shown during time of bid or at time of application (current list can be found at www.fltrexx.com). Look for the Filtrexx ® Certifed tm Installer Seal.

3. Filtrexx ® Check dams shall be placed at locations indicated on plans as

directed/specifed by the Engineer. Check dams should be installed in a pattern that reduces runoff velocity and ditch erosion, and allows for deposition of sediment and fltration of pollutants.

4. Check dams may be manufactured on-site at time of application or pre-manufactured and delivered to site for installation.

5. Installation of Filtrexx ® Check dams will ensure that the Check dams exceed the width of the normal ditch/channel fow line by at least 4 ft (1.2m) on both banks to ensure water fows though and over the device and not around it.

6. Center of Check dams shall be at least 6 in. (150mm) lower than the sides of the ditch/ channel.

Section 1: Erosion & Sediment Control – Construction Activities