Frequently Asked Questions

1. Will the sand stay in place?
   The sand infill, combined with the Super Gripnet (SGN) lining’s transmissivity, is designed to handle four inches of rain per hour without erosion. The synthetic grass also works as a grid that “locks” the sand in place if water quantity exceeds the drainage layer’s allowable flow of four inches per hour.
2. How stable is it? What is the interface friction?
   The interface friction is 43 degrees. This equates to a safety factor (SF) of 3.0 for a typical cover system (Sub D closures usually have a 1.1 to 1.5 SF).
3. How is it anchored?
   It is only anchored to terminate ClosureTurf™ at the toe or on the outside of a perimeter swale (based on site-specific design). There is no need to anchor to resist pullout forces. Instead of anchoring, ClosureTurf™ relies on the high friction coefficient and ballast created by the infill.
4. What about wind?
   The ballast ranges from 8 to 10 lbs per sq.ft. This can provide an uplift resistance for wind in excess of 120 mph, calculated by analyzing a surface shape similar to a landfill.
5. Can you use equipment on it?
   Yes, most small rubber-tired vehicles and low ground pressure equipment can operate on the material without causing damage.
6. How long does it last? What is the UV degradation?
   An independent UV weathering study was performed for this latest generation of advanced synthetic turf. The test used exposures in the Southern Arizona desert and data from accelerated weathering tests. The results indicate longevity in excess of 50 years based on these extreme exposures. The excellent resistance to UV weathering comes from the use of HDPE yarns that have a high absorption factor of a proprietary UV stabilizer. Note that most synthetic turfs for sports fields are made from polypropylene, which does not appear to resist weathering as well as the polyethylene material we use.
7. Does it come in any other color?
   Yes, it can be made in any color you want.
8. Does the turf fade?
   ClosureTurf™ will not noticeably fade for more than 30 years, again due to the proprietary UV stabilizer.
9. Does wind erode the material?
   No, the grass strands prevent wind erosion.
10. How does ClosureTurf™ respond to gas build-up resulting from collection system shutdowns?
    Landfill gas may lift the turf in the event of a flare shutdown, but will not cause a failure that can happen with Sub D closures.
11. Is ClosureTurf™ being approved solely as a long-term interim cover?
    Several states are evaluating ClosureTurf™ as a final cover. The performance criteria have been met for 30+ years post-closure use in Louisiana and final cover approval is pending for other states. One state has contacted us to possibly use ClosureTurf™ for sites they have inherited from bankrupt companies. Some agencies recognize that ClosureTurf™ can dramatically reduce states’ long-term liability for post-closure care.
12. Eventually the system will require replacing, so what happens then?
    The synthetic grass component may need to be replaced 50 years in the future, but this is a very small financial obligation in the context of the financial assurance mechanism, and is greatly outweighed by post-closure savings. In contrast, soil cover owners can never fully “walk away” because of ongoing erosion issues and weather damage throughout and beyond 30 years of post closure.
13. What do you say to environmentalists that may not like a “fake” grass cover?
    It is more environmentally friendly than the current Subtitle D cap for the following reasons:
    • Does not destroy land for soil borrow as required for many soil closures.
    • Less silt runoff from cover and from borrow areas (the landfill cap basically changes from being a problematic siltation and erosion issue under the old method, to one large BMP providing very clear water to the ponds.
    • The material is 100% recyclable.
    • The geotextiles can be made from a soybean based fuel.
    • Lower water storage in soil and lower evapotranspiration returns more water to the environment.
    • Less fuel consumption and emissions during construction.
14. Are any chemicals used that may leach and cause a problem with water quality?
    This is the third generation of synthetic turfs, and the particular turf we use has proven to have greater durability without the use of any heavy metals in the pigment or any chemicals that could impact water quality. The turf can, and is, being used in the most sensitive environments.