Phoenix Sky Harbor International Airport – Aviation Environmental (TPD0804025)

Slide 3

Review of the AZPDES permit Changes

How has it changed?

• City must submit a general NOI to ADEQ
• Contractors must submit neighborhood or individual NOIs to ADEQ
• Contractors must provide temporary stabilization or initiate final stabilization within 14 days of the most recent land disturbance
• Contractors must submit NOTs within 30 days of
  • Final stabilization has been achievement
  • Another operator assumes control over the site

Slide 4

ADEQ’s approved forms of soil stabilization

How does the new permit define stabilization?

• A uniform perennial vegetative cover with a density of 70% of the native background (Virgin Desert) vegetative cover for the area is in place.  If 50% vegetative cover exists prior to construction activities then 70% of the 50% would be accepted.
• Equivalent permanent stabilization measures (such as the use of riprap, decomposed granite, gabions, or geotextiles) have been employed

Slide 5

Slide 6

Current VARS Soil Stabilization/Dust Mitigation Plan

• In order to meet county dust control requirements, VARS is applying a polymer based soil stabilizer to the ground surface.  This stabilizer is under warranty for one year and a maintenance plan is in place to resolve issues after that year as needed.
• The product we have been using is SOILTAC by Soilworks^®.  Soil stabilizers of these type are not currently approved as a form of final stabilization by the AZPDES permit.
• As a result we would like to present the following information about the polymer based soil stabilizer currently used by the VARS program to ADEQ for their consideration as a final stabilization measure

Slide 7

Soiltac^®Defined

• Synthetically Manufactured Vinyl Copolymer
  • Similar properties to liquid plastic adhesives
  • Prime material manufactured molecule by molecule, not a by-product
  • Ecologically and environmentally safe
  • Soil stabilizer engineered to solidify any soil or aggregate

Slide 8

How Soiltac Works

• Utilizes water as a carrying and compaction agent
• As water evaporates, Soiltac molecules coalesce, link and cross-link together
• Adhere & Bind Dust & Soil Particles
• Form a strong & tightly bound matrix
  • Topical Surface Stabilization
  • Mix-in/Processed Stabilization

Slide 9

Soiltac Uses and Rates

• Soil Stabilization
  • Heavy  Application Rates
  • Road Construction, Runways, Helipads, Sub-Bases, etc.
• Water Erosion Control
  • Medium Application Rates
  • Slopes, Berms, Golf Bunker Stabilization, Dikes, etc.
• Wind Erosion Control
  • Light Application Rates
  • PM10 Dust Stabilization/Air Quality, FOD Control, etc.

Slide 10

How does Soiltac stack up when compared to ADEQ approved forms of permanent soil stabilization?

Slide 11

Soiltac vs. Vegetative Cover

• Ease of application
• Conserves water resources
• Minimal maintenance
• Requires seeding
• Daily irrigation
• Continual maintenance
• Potential fire hazard

Slide 12

Soiltac vs Riprap

• Proven effectiveness with soils <0.075 mm
• Stabilization inhibits vegetative growth
• Preserves native background
• Typically used on shorelines
• Requires vegetative maintenance and Geotextile
• Extensive installation transportation and removal

Slide 13

Soiltac vs. Decomposed Granite

• Long term PM10 control
• Prevents storm water silt loading
• Water Resistant; will not wash away
• Eliminates Import/Export
• Possibility for Opacity still eminent without stabilization
• Storm water silt hazard
• Requires depth >2”
• Requires periodic maintenance or underlay

Slide 14

Soiltac vs. Gabions

• Engineered for use on level or sloped surfaces
• Increases wet and dry strength of any soil
• Used for retaining walls
• Designed for vertical applications
• Not reasonable for flat stabilization

Slide 15

Soiltac vs. Geotextiles

• Designed for surface and/or subterranean application
• Ultraviolet ray resistant
• Not designed for surface application
• Rapid deterioration with exposure to sunlight
• Continued vegetation management evident

Slide 16

Known Geotextiles Considerations

• Products deteriorate significantly with age
• Adverse weathering reaction in desert environment (Decomposition)
• Up to 70% reduction in strength at 500 of direct sunlight hrs per ASTM D-4355
• Most geotextile fabrics are ineffective after 60 days of sun exposure

Slide 17

Recent Final Stabilization Projects Utilizing Soiltac Soil Stabilizer

• ADOT Unpaved Road Stabilizer 11/05
• US Army Corp of Engineers – Helipad Stabilization 4/04 & 2/06
• Marine Corp Air Grounds Combat Center 7/07
• Khumani Mine 300 Ton Heavy Haul Roads – South Africa 3/07
• California Dept of Transportation 10/06
• New Mexico Dept of Transportation 6/07
• Nevada Dept of Transportation 11/04
• US Army Corps of Engineers – Rapid Airfield Construction 8/07
• U.A.E. Army – 600 km Saudi Arabian Border Patrol Roads 8/05
• US Army Corps of Engineers – Base Camp Operations 3/05 & 10/05

Slide 18

ADEQ Considerations for Final Stabilization with Soiltac

•           Engineered to solidify any soil or aggregate

•           Permanent with minimal maintenance

•           Ecologically and environmentally safe

•           Easy to apply

•           Conserves resources

•           Preserves native background

•           Long term PM10 control

•           Water and UV resistant

•           Prevents storm water silt loading

•           Designed for surface and subterranean use

•           Eliminates Import/Export

•           Increase wet and dry strength of any soil

• Already approved through Maricopa County as a Dust Suppressant

Slide 19

Assumed Cost Summary*