Map Series Depicting Oil and Gas Production That Penetrates the Santa Maria Valley Groundwater Basin

The production of this series of six maps was prompted by proposals by three oil companies to drill 760+ new oil wells that will all penetrate the Santa Maria Valley Groundwater Basin, which provides drinking water for 200,000 people and irrigation water for the highly productive agricultural industry in the Santa Maria Valley. The wells are all proposed to use enhanced extraction techniques, which involve boiling water in steam generators and pumping the steam under high pressure in pipes through the groundwater and into the oil reservoir below. They are located in Cat Canyon near Garey and Sisquoc at the eastern end of the groundwater basin.


(Click on title above for more information and six maps.)

For several years, Santa Barbara County Action Network and other organizations have expressed concern about the potential for these proposed projects to contaminate our water. Our concerns increased in April 2017 when the “2016 Annual Report of Hydrogeologic Conditions, Water Requirements, Supplies and Disposition” for the Santa Maria Valley Management Area was published. It noted that there are as many as 60 active investigations of possible or confirmed petroleum-product contamination being conducted between Sisquoc and Guadalupe, under the requirements of the Central Coast Regional Water Quality Control Board.

SCS Tracer Environmental produced the maps under contract with SBCAN and with input from the Community Environmental Research Project and SBCAN volunteers. Data sources included several governmental sources as indicated on each of the maps.

The six maps are below. 

Map 1 

This map shows the extent of the Santa Maria Valley Groundwater Basin. The orange shading indicates the Basin according to an adjudication of water rights several years ago. The DWR boundary is a more recent definition by the Department of Water Resources. The difference has little bearing on the subject at hand.


Map 2

This map shows all oil and gas wells in the area, including abandoned, idle, and active wells. Obviously, there is a long history of oil and gas production in the area, mainly using conventional extraction techniques. The thinner, easier-to-pump oil has mostly been extracted and the industry is turning increasingly to injecting high-pressure steam to loosen up the remaining thicker crude oil.


Map 3

This map shows only idle and active wells. The abandoned wells are not shown. Most of the wells near Guadalupe and Santa Maria have been abandoned.


Map 4

This map shows only the abandoned wells. The idle and active wells are not shown.


Map 5

This is the key map in this series.  It shows only the active wells that are using enhanced-extraction techniques. Studies have shown these techniques to have higher-than-normal well-casing failure rates. It shows that as of late 2017, according to the State’s Department of Oil, Gas and Geothermal Resources, there were only about three-dozen active wells using these techniques within the Santa Maria Valley Groundwater Basin. Proposals by three companies propose to expand this number by more than 760 wells that would penetrate the groundwater basin, which greatly increases the probability of contamination of our water.


Map 6

In this area, each barrel of oil that is pumped up comes with about nine barrels of briny water. Some of this “produced water” is cleaned and used to produce steam; much of it is re-injected, again under pressure and passing through our groundwater. This map shows active, idle and plugged wastewater disposal wells. Many more would need to be provided to provide for disposal of the wastewater from the 760+ proposed wells.