By Betsy Herbert

Santa Cruz Sentinel

Posted: 01/17/13, 12:00 AM PST

Fracking -- short for hydraulic fracturing, a controversial mining practice -- has been in the national news a lot lately, and its dark side has been illustrated by two recent films.

The practice of fracking blasts water, chemicals, and sand deep underground, shattering rock to extract oil and gas. When combined with horizontal drilling, fracking enables oil companies to exploit veins of rock that are too cumbersome to reach through conventional mining practices.

Fracking has proliferated nationwide, since the large volumes of fossil fuels that it can recover is expected to move the U.S. closer to energy independence. But as fracking increases, so have concerns about its potential impact on human health and the environment, especially with regard to drinking water sources. Though many chemicals used in fracking are toxic and have the potential to contaminate groundwater supplies, mining companies can legally claim fracking chemicals as proprietary information.

"Gasland," a popular 2010 documentary by Josh Fox, graphically illustrates some of the worst potential impacts of fracking. The film's most enduring image is a Colorado man nearly knocked off his feet as he strikes a match igniting the water flowing from his kitchen faucet.

"Promised Land," co-starring Matt Damon, is a fictional account of corporate salespeople trying to convince citizens in a small Midwestern community to sell drilling rights on their land for fracking of natural gas.

Recent controversy has focused on areas underlain by the Marcellus Shale formation in New York, Pennsylvania, Ohio and West Virginia. Fracking is currently under a moratorium in the state of New York, as regulators weigh environmental and public health issues against economic benefits.

In California, fracking is under way, particularly in Kern County. Industry disclosure of fracking sites is currently voluntary, but the Center for Biological Diversity estimates that more than 600 wells were fracked in California in 2011.

The U.S. Energy Information Administration reports that approximately 15 billion barrels of oil are recoverable by fracking in California's huge Monterey Shale formation, which underlies six counties. While Kern County is currently the most heavily fracked area, some parts of the Central Coast are also vulnerable.

In July 2012, residents of Aromas -- a community straddling Santa Cruz, Monterey and San Benito counties -- were alarmed when crews from an oil exploration company, Freedom Resources, began drilling test wells at nearby A.W. Wilson Quarry, owned by Watsonville-based Graniterock Co. Fearing that an oil discovery could lead to fracking, residents organized a group called Aromas Cares for our Environment, and are lobbying the San Benito County Board of Supervisors for stronger county ordinances regulating fracking.

Last month, the Bureau of Land Management auctioned off leases on nearly 18,000 acres of public land in southern Monterey County for oil and gas mining, despite a plea by Rep. Sam Farr to postpone the auction until the impacts of fracking are better understood. (Fracking is off limits on the Coast Dairies property around Davenport in Santa Cruz County, now owned by the BLM. The mineral rights were fully protected before title to the property was transferred).

The state Conservation Department recently issued draft regulations for fracking in California (www.conservation.ca.gov). On Jan. 8, the Santa Cruz County Board of Supervisors directed county staff to review the draft and return to the board on Feb. 12 with their recommendations.

"As the nation develops greater awareness of fracking technology, we have growing concerns about what's pumped into the ground, how it impacts water supplies, and how it undercuts our efforts to reduce greenhouse gas emissions," said county Supervisor John Leopold. "Add secrecy to the mix, and we have a real need for reasonable and effective regulation."