Fort Bragg is Home of the Airborne and Special Operations and is considered as the central military headquarters of the US Army. It is the first responder to armed force calls and is the headquarters of the U.S. Army Special Operations Command. With approximately 53,000 troops and 14,000 civilians working on the post and 260,000 military families, contractors, retirees and more living on site, Fort Bragg supports the largest US military installation in terms of population. Fort Bragg encompasses approximately 500 square miles and 163,000 acres.
In 2011, the Assistant Secretary of the Army for Installations, Energy and Environment (ASA-IEE) announced the Army Net Zero Installation Strategy (ASA-IEE 2011). The main goal of this strategy was to integrate sustainability practices at the installation level, which preserves the organization’s flexibility to operate in constrained circumstances, either economic or environmental.
In 2014, Fort Bragg purchased and installed the LFC-200 biodigester. Fort Bragg was so pleased with the performance of Power Knot’s LFC biodigester that they purchased 14 additional units and the US Army has purchased many more for other military bases.
Net Zero Goals
Army Net Zero Initiative is a collaborative strategy between the US Army and Environmental Protection Agency (EPA) for sustainability and energy security to ensure that the future generations will have the same access to energy, water, land, and resources as the Army of today. It focuses primarily on energy, water, and solid waste management at military installations.
The Net Zero approach consists of five steps: reduction, repurposing, recycling and composting, energy recovery, and disposal. The Army has identified 17 Net Zero pilot installations to determine best practices. In 2016, The U.S. Army Engineer Research and Development Center (ERDC) released a 67 page document entitled Organic Waste Diversion Guidance for U.S. Army Installations which detailed concepts, small and large scale.
Evaluating Options
The US Army evaluated a number of small scale technologies for diverting food waste from landfills, such as dehydrators, composters, and digesters to better understand which solution would best fit their needs. The US Army understood that each form of technology best fit different locations, price ranges, and came with its own unique benefits and concerns.
The US Army found that organic waste digesters were most feasible when:
- limited indoor space was available
- waste must be processed within a day of production
- low to moderate amounts of energy are available for food waste processing
In 2012, the US Army evaluated the ORCA Green Food Digester in Camp Wilson. While in use, the following issues were found:
- main shaft seal developed a leak
- screen at the bottom of the chamber became loose, allowing biochips and food waste to exit the machine
- machine stopped running during electrical power interruptions
- loading door hinges became loose
Ultimately, the ORCA system experienced system operations failure and was shut down after five months of testing.
Additionally, the ORCA system faced mechanical, odor, and personally-use problems at several US Army installations, resulting in cessation of digester use.
In 2014, Fort Bragg purchased and installed the LFC-200 biodigester. Fort Bragg did not experience any odor problems with the biodigester which was able to decompose most food waste within 24 hours. The biodigester is fully automated and monitors itself, sending diagnostics and reporting on a frequent basis. The LFC biodigesters are designed for a 15-25 year life cycle and come with a three year warranty. Once turned on, it does not need to be turned off. Fort Bragg was so pleased with the performance of Power Knot’s LFC biodigester that they planned on purchasing 14 additional units (pg 44).
ROI and the US Army’s Verdict
In Organic Waste Diversion Guidance for U.S. Army Installations (pg 64), it is estimated that one building produces 300 tons of food waste a year.
The estimated cost incurred from dumpster rental, containment, handling, and transportation, is estimated to be $208 per week. The landfill tipping fee is estimated to be an additional $65 per week. The yearly food waste management costs for one building is an estimated $14,742.
Power Knot’s recurring yearly costs are: powerchips substrate, enzymes, water, and electricity which collectively remain under 10% of the waste management costs. Fort Bragg decided to install the LFC biodigesters in buildings where biodigesters were feasible and made economic sense.
Power Knot has remained the premier choice in biodigesters in the military. During the 18 months after the report, Fort Bragg purchased 14 additional LFC biodigesters. Subsequently, other US military bases have continued to purchase LFC biodigesters.
