South San Francisco Scavenger Co., Inc. (Scavenger) is, in a curious way, aptly named. From the waste collected from San Francisco Bay Area’s municipalities including facilities at San Francisco International Airport, it has employed anaerobic digestion to capture and process biogas and use it as fuel for fleet operations. It is a highly effective closed loop system made possible with the cooperation of nation-wide natural gas station operator, Clean Energy Fuels.
Recycling Today reports each vehicle collects enough organic waste during just one route to fuel it for an entire day, creating a true closed-loop system and the first project of its kind in the United States. Based on current projections of the amount of fuel the dry-AD Facility produces for its CNG fleet, SSF Scavengers plans to achieve a 43 percent reduction in emissions from its entire fleet of vehicles.
The collected organic waste makes up to 500 DGE/day of RNG and connects with a Clean Energy fueling station nearby. What’s left over in the digester goes to a compost site for farming and other uses.
This makes Scavenger one of the few carbon negative fleets in the U.S. with a drastically small carbon footprint compared to its competitors. Scavenger has gained tremendous community support and a competitive advantage thanks to its commitment to fueling a cleaner, compressed natural gas (CNG)-fueled fleet.
Transition to Natural Gas
Scavenger transitioned part of its fleet to Compressed Natural Gas (CNG) when San Francisco International Airport (SFO) announced a requirement for taxis and buses to reduce their environmental impact. While the regulation did not extend to haulers, Scavenger proactively jumped on board to make a positive impact as part of the airport’s environmental solution.
Very quickly, the CNG-fueled trucks proved their reliability and operational cost-savings. The company began converting more trucks each year knowing that CNG would play a major role in their future fueling strategy.
In 2009 Scavenger, along with its partners, won a bid with the City of Livermore, making a bold and unprecedented commitment to convert to a 100% CNG-fueled fleet. Clean Energy Fuel was instrumental in enabling Scavenger to meet that commitment on time, delivering an operational natural gas fueling facility for day one of the new contract.
With the success of the Livermore project, Scavenger’s confidence in CNG strengthened. With over 40 trucks in their fleet, 22 are now CNG-fueled and all will be converted as the company’s diesel-fueled vehicles are retired.
Since 2009, the company has engaged with Clean Energy to build and maintain a total of five Redeem® renewable natural gas (RNG)-flowing stations with 165 overnight, time-fill dispensers in the Bay Area.
Carbon Negative Closed Loop System
Furthering its commitment to innovation and waste reduction, Scavenger set its sights on creating its own fuel from commercial and residential waste. With Clean Energy and other partners, the company developed the first dry anaerobic digestion (AD) center in the U.S.
“It’s an incredibly clean, closed-loop system,” says Scavenger President Doug Button. “For example, our trucks pick up a huge amount of food waste from the San Francisco Airport. That waste is converted in the digester and within days it fuels those same trucks back to service the airport again.”
As governments and businesses continue to be more cautious of their environmental impacts, fleets are realizing the benefits of switching to natural gas as a transportation fuel. It’s cleaner, produced in North America, and it offers the same performance as other fuels, creating a market differentiator that makes companies like Scavenger stand out above the rest.
(Source: Clean Energy Fuels – pioneers and experts in natural gas for transportation; an NGV Global Sponsor Member)