South Hilo Landfill
County of Hawai’i Department of Environmental Management
In 2019, South Hilo Landfill reached its capacity. Having been established in the 1960s, the more than 50 year old landfill contained a total of 3,208,204 tons of refuse.
The closure of the landfill had been a long time coming. The last load of rubbish was deposited in the landfill in December 2019, but the contractors had been working to decommission the site since August of 2019.
Traditional landfills require large amounts of soil throughout their lifespan and are often lacking adequate soil to complete closure construction. Many of these landfills experience on-going erosion and sedimentation issues. Traditional covers are highly reliant on trucking soils, heavy civil construction, on-going maintenance and repairs in order to maintain their integrity.
There were a couple main difficulties facing the closure of this landfill:
- Erosion issues were a huge concern with this closure due to the high rate of rainfall in the area, the poor soil, and the steep slopes of the landfill.
- Sharp, angular, volcanic sand in the surrounding area made the easy acquisition of local soil an impossibility. The next logical solution would be to find borrow sources. However, being in a remote location made acquiring borrowed soil difficult and extremely expensive.
ClosureTurf handled these concerns flawlessly:
- Protection Against Erosion: ClosureTurf eliminates 99.9% of sediment runoff versus traditional practices. It also eliminates thick soil profiles over the geosynthetics to provide greater stability on steeper grades and reduces slope rebuilding.
- Soil Cover Savings: ClosureTurf eliminates the need for high maintenance vegetative soil covers and increases weather resistance. Since final cover soils are challenging to locate and expensive to place in the final stages of the landfill’s lifespan, the resulting savings can be significant.
- Steeper Waste Slopes: Since soil stability problems either through earthquake or gas pressure buildup is reduced, steeper waste slopes can be used.
- Weather Resistant: The components of the ClosureTurf system work in conjunction to seal the waste mass from the destructive forces of high rainfall intensities and hurricane force winds.
ClosureTurf®, an EPA, Subtitle D Compliant landfill closure solution that is specifically designed to address and solve soil erosion, slope integrity, gas emission, installation and maintenance cost control, EPA regulation compliance, and longevity of structure and appearance.
ClosureTurf is a patented, three component system comprised of a structured geomembrane, an engineered turf, and a specialized sand infill. The foundation of the system is an impermeable, highly transmissive structured geomembrane. It provides for the highest interface friction values available in the market. The engineered turf component gives the system its natural look and feel of grass while protecting the geomembrane from extreme weather conditions for the long term. The specialized sand infill component is placed between the blades of the engineered turf and allows the system to be trafficked while also providing additional protection from weathering. When required, ClosureTurf®’s patented surficial gas system is included with the system to vent landfill gas emissions. ClosureTurf® is fast and easy to install for an aesthetically pleasing, cost-effective landfill closure solution.