With one of its guns trained on the statenatural gas storage and delivery systems, the Environmental Defense Fund (EDF) this week aimed another one at oil and natural gas fields in California, targeting alleged public health problems for populations living in and around production areas in a state that has several urban-located drill sites.

Noting that “massive gas leaks” like the one at the Aliso Canyon underground gas storage field on the outskirts of suburban Los Angeles “aren’t the only cause for alarm,” EDF’s Irene Burga, a fellow in the organization’s oil and gas program, cited a series of separate reports that she thinks prove that “oil/gas emissions from across the entire supply chain can wreak havoc on our health.”

Emissions from the fields are often higher than anyone suspected, Burga wrote on a EDF blog on Monday, citing a report from the California Air Resource Board (CARB) that analyzed data from 39 different production facilities across the state.

“Once again, anti-oil activists are using politics and twisting the facts in their quest to threaten our nation’s energy independence,” said a spokesperson for the Sacramento-based California Independent Petroleum Association (CIPA). “EDF uses Aliso Canyon as an example of why oil production is dangerous, but that is a utility [Southern California Gas Co.] owned natural gas storage facility, which is not the same.”

CIPA’s assessment is that EDF’s criticisms are politically motivated using what it considers “wrong science” that if left to stand “will only increase our dependence on more oil from the Middle East.”

EDF’s Burga cited the CARB report’s identification of 211 different gas leaks with nearly half of them including cancer-causing chemical benzene. She noted that the Centers for Disease Control has established that chronic exposure to the toxic benzene can cause cancer.

“This is not solely a problem at production facilities,” Burga said. “A separate CARB study focused on emissions from the ponds where drillers store wastewater coming from oil extraction.”

Some of California’s wastewater ponds emit substantial levels of toxic air contaminants like benzene, toluene, ethylbenzene, and xylene, according to another CARB study cited by Burga.

CIPA’s spokesperson said EDF made a mistake about the injection of produced water alleging the aquifers are for drinking water; “this is simply false because the water has been co-mingled with oil/gas, and by definition, cannot be used for drinking water.”

CIPA also contends that regulators have confirmed “no evidence of harm to the environment” from the operators reinjecting naturally occurring produced water back to where it originated.”

The Western States Petroleum Association (WSPA) disagreed with EDF’s assessment. President Catherine Reheis-Boyd stressed that California’s oil producers are committed to “upholding and abiding” by stringent standards. She said total industry sector emissions, including oil production and storage, is 4% of the state’s methane emissions, and of that total, less than 1% is from oil production.

“WSPA members’ equipment are already under vapor recovery systems that capture 95% of the emissions, and members are already subject to mature ‘leak detection and repair’ programs through the San Joaquin Valley Air Pollution Control District,” Reheis-Boyd said.