The neighborhood of Avondale-Glen Elder, located on the west side of Power Inn Road and just north of Florin Road in South Sacramento, lies above an old depleted reservoir of natural gas formed hundreds of millions of years ago. Known as the Florin Gas Field, the reservoir was mostly pumped out by Union Oil in the 1970s and 1980s. However, the geology of the gas field, in theory, makes it possible for reuse as a giant holding tank. The Sacramento News and Review provides a simple but useful description of the proposed storage site:

SNGS Subsurface View

(Image from SNGS wesite at:

“The reservoir isn’t a great hollow cave, but a layer of porous sandstone with billions of tinyspaces for the gas molecules to hide in. Think of it as a 380-acre natural-gas sponge. On top of the sponge is a hard, 150-foot-thick layer of shale capstone that keeps the gas from escaping. Above that capstone are a couple of thousand feet of shale and sand. Above that are the local groundwater aquifers. And finally, there are a few hundred feet of soil and clay near the surface that we’re most familiar with. And on top of all that, about 750 homes and businesses, one city park and a lot of people.” (See the article here)

The SNGS plans to drill a hole through this multi-layered geology and insert a seven-inch pipe that will fill the reservoir under Avondale/Glen Elder with natural gas obtained from a large network of natural gas pipelines that runs from the Canadian border across California. This network of pipelines provides natural gas to Sacramento and other cities across the state. The proposed project includes the existing underground natural gas storage reservoir, a wellhead site, a compressor station, a buried 16-inch interconnection pipeline between the wellhead and compressor site, and a buried 16-inch interconnection pipeline to transport natural gas from the compressor site to a larger natural gas pipeline (known as SMUD Line 700) for use by the Sacramento Municipal Utilities District for energy production.

On July 12, 2012, the California Public Utilities Commission (CPUC) in a three to two vote, declined the SNGS application for a Certificate of Public Convenience and Necessity (CPCN) to construct a natural gas storage facility. However, appeals to this decision are expected. (continue reading about safety concerns) (home)