Voters in Mendocino and San Benito counties approved bans on fracking, the controversial method of extracting natural gas via a high-pressure injection of water and chemicals.
The Huffington Post notes that oil and gas companies spent big, to the tune of $5.7 million, to defeat a similar measure in Santa Barbara County.
Petroleum companies are eyeing Mendocino and San Benito due to their location on the Monterey Shale, a giant rock formation that supposedly has as much as 15.4 billion barrels of oil, according to scientists.
Researchers have said the water supplies near fracking sites are prone to contamination. Timothy Krantz, a professor of environmental studies at the University of Redlands in Southern California, found "off the charts" levels of a particular chemical linked to leukemia in water wells near fracking sites, the Post reported.
A fracking ban also passed in Denton, Texas, the birthplace of fracking.