By Courtney Hayden
April 17, 2012
In Los Angeles, city engineers and policy makers are taking an innovative approach to treating waste and protecting water. In the past, the city relied exclusively on trucking waste to Kern County for treatment. Groundbreaking technology has moved Los Angeles away from traditional methods of waste storage and treatment. New methods are lowering green house gas emissions and reducing the risk of water contamination. How can the city affordably avoid the pitfalls of trucking waste long distances for treatment? The solution is surprising.
Currently, the city of Los Angeles is contracted with Terralog Technologies (TT). Terralog is using the power stored deep underground to process waste generated at the surface. To do this, TT is injecting waste directly into the deep subsurface of the earth.
Mike Bruno, president of Terralog Technologies, describes the process as functioning like a “high- tech septic system.” Sound like you need a PhD to really decipher this? Put simply, as a drill bores deeper into the earth, the surrounding area becomes progressively hotter. That heat has energy, and Terralog is using the energy to process waste. Tapping into this energy, called geothermal, negates use of surface technology which is heavily dependent on water and fossil fuels.
Over the course of the past 3.5 years Terralog has injected 150 million gallons of sewage. This level of injection has avoided 3,000 long distance trucking trips. In addition to managing biosolids, the project has the potential to produce clean energy!
To understand this potential, imagine a compost pile in your garden. It is a hot summer day and carbon dioxide and methane are wafting off the kitchen scraps. The same thing happens underground, except the carbon dioxide is under such immense pressure that it liquefies. With carbon dioxide in liquid form, methane is free to build up on its own. Underground, the gases surrounding buried sewage are 95% methane.
Once enough methane builds under the surface, it will become possible to use the gas for fuel. Terralog is not currently creating energy, but methane levels are being closely monitored in hopes of using this abundant source in the future.
According to Mike Bruno, injecting sewage is reducing trucking, water pollution and green house gas emissions.
“We cannot continue to do what we’ve been doing in the United States and elsewhere; it just isn’t sustainable,” he says.
For related article, see:
City-Wide Program Composts 1 Million Tons
© 2012 SCGH, LLC.