Infographic: Wastewater in California’s Oil Fields

The oil industry’s relationship to water is governed by a surprising ratio.

The main product, by volume, from California’s oil fields is not oil — it’s water.

For every barrel of oil that is pumped from the ground, 15 barrels of water, on average, come to the surface. (A barrel is 42 gallons.)

Called “produced water,” the chemical- and salt-laced liquid waste is found in the same deep geologic zones that contain oil and natural gas. When wells are drilled to the depth of the hydrocarbon reserves, a torrent of produced water — typically millions of gallons — rushes up the borehole to the surface.

California’s oil industry generated 3.3 billion barrels (140 billion gallons) of produced water in 2014.

Where does it go? The infographic below shows how oil companies dispose of this wastewater.

For every barrel of oil pumped in California, roughly 15 barrels of water flow out of the well. Graphic © Kaye LaFond/Circle of Blue. Click image to enlarge.

This graphic was made to accompany the article Amid California Drought, Oil Industry Wastewater Attracts New Scrutiny by Circle of Blue reporter Brett Walton. Contact Brett Walton or by @waltonwater on Twitter.