Roseville Explores Turning Waste into Energy

Roseville, Calif. – Work is underway right now to develop a project that would one day help power one of Environmental Utilities’ (EU) wastewater treatment plants or provide fleet vehicle fuel using Compressed Natural Gas (CNG). 

Energy generation in the wastewater treatment process comes from biosolids that remain after the treatment process is completed. Also known as sludge, the biosolids are placed into an anaerobic digester where they are converted to methane gas that can be used to fuel a generator or processed into CNG vehicle fuel. 

One of the other attractive pieces to this project is the ability to process post-consumer food waste and fats, oils and grease to generate energy by having these sources delivered directly to our wastewater facility where it’s then placed into the digester. Doing so will not only help meet newly adopted statewide requirements for organic waste, but this type of material creates even more methane without additional equipment.

The investment in this technology is necessary to make the wastewater treatment process more efficient. It will allow us to process more waste over time – a vital feature as the region grows and more waste needs processing. But recovering energy from wastewater treatment provides economic and environmental benefits by offsetting operating and capital costs, reducing carbon emissions, and meeting statewide organics recycling mandates.

We don’t know how we will use the infrastructure just yet – whether to create energy or process CNG – but either option holds considerable promise for our utility operations. Energy, for example, is one of the largest expenses for our wastewater treatment facilities.  If you can imagine, it takes a lot of electricity to treat wastewater all hours of the day.  And this project could offset up to 25 percent of energy consumed at the City’s Pleasant Grove Wastewater Treatment Facility.

This project is in its infancy and more work  is needed to see this effort become a reality.  But we’re hard at work behind the scenes to bring this project online within the next three to five years.