Page 2 - Section4.2.1-SWPPPCutSheet-FiltrexxStormWaterBlanket

362 | Filtrexx ® Low Impact Design Manual | Version 8.0

5,400 gal (722 cubic ft, 20 cubic m) of water per acre inch (0.01 ha meter, 103 cubic m) of Storm water blanket, and 10,800 gal (1444 cubic ft, 41 cubic m) of water for a 2 in (50mm) Storm water blanket; An acre inch (0.01 ha meter) of Storm water blanket requires approximately 135 cubic yards (103 cubic meters) of material. Although most specifcation and design manuals include fertilizer recommendations or requirements for permanent vegetation

establishment, mineral nutrients from fertilizers may not be preferable where vegetation sustainability and water quality are a concern. Storm water blankets provide organic nutrients, which: are slow release, provide plant micronutrients, and are less likely to be transported in storm runoff to receiving waters – which can reduce pollution and eutrophication of waterways.

1. Storm water blankets used for storm runoff reduction and permanent vegetation establish ment shall meet Filtrexx ® Storm water blanket Specifcations and use Filtrexx ® GrowingMedia tm .

2. Contractor is required to be a Filtrexx ® Certi fed tm Installer as determined by Filtrexx ® International, LLC (440-926-2607 or visit website at www.fltrexx.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. Storm water blankets will be placed at locations indicated on plans as directed by the Engineer.

2. Land or soil surface shall be roughened prior to application of Storm water blankets.

4. Storm water blankets shall be applied to 100% of the land surface area where storm water reduction and permanent vegetation is required. No native soil shall be visible in or through the Storm water blanket.

5. Storm water blankets shall be applied at a minimum depth of 2 in (50mm) or at a rate of 270 cubic yards/ac (513 cubic m/ha).

6. Seed shall be thoroughly mixed with the GrowingMedia tm prior to application or surface applied to GrowingMedia tm at time of application.

7. Storm water blankets shall not be installed in areas of concentrated storm runoff fow, including channels and ditches.

8. Storm water blankets shall be installed > 10 ft (3m) over and beyond the slope shoulder and/ or into existing vegetation to ensure runoff

does not undercut blanket.

9. Storm water blankets installed on slopes: greater than or equal to 4:1 shall be tracked; greater than 2:1 shall be tracked and use other support practices.

INSPECTION and MAINTENANCE

Routine inspection should be conducted within 24 hrs of a runoff event or as designated by the regulating authority. If rilling occurs or vegetation does not establish, the area of application should be reapplied with a Storm water blanket. If failure continues, the use of runoff diversion devices, slope interruption devices, erosion control support practices, soil stabilizers, turf reinforcement mats, or hard armoring practices should be considered. Storm water blankets should be inspected until permanent vegetation is established. Permanent vegetation practices should always be inspected for noxious or invasive weeds.

1. The Contractor shall maintain the Storm water blanket in a functional condition and it shall be routinely inspected until vegetation is established.

2. Storm water blankets shall be maintained until a minimum of 70% uniform cover of the applied area has been vegetated or as required by the jurisdictional agency.

3. Storm water blankets may require regular irrigation during hot and dry weather, or arid and semi-arid climates to ensure permanent vegetation establishment.

4. Where a Storm water blanket fails, rilling occurs, or vegetation does not establish the Contractor will repair or provide an approved and functioning alternative.

5. If gullies form in Storm water blanket, the area shall be re-graded prior to reinstallation of Storm water blanket or approved alternative. 6. If Storm water blanket is damaged by runoff, installation of slope interruption devices across slope, or runoff diversion devices above Storm water blanket may be required.

7. No additional fertilizer or lime is required for vegetation establishment and maintenance.