RICHMOND -- Chevron's Richmond refinery has increased its flaring by 80 percent since 2005 when the Bay Area Air Quality Management District passed a new rule limiting harmful refinery flaring to emergencies, according to a report released Monday by an environmental justice organization.

The organization, Communities for a Better Environment, studied data from the five Bay Area refineries and found that Chevron's Richmond refinery and the ConocoPhillips refinery in Rodeo were each emitting 30 to 50 times more pollution than the Shell Refinery in Martinez, according to CBE Senior Scientist Greg Karras.

Since January 2004 the five Bay Area refineries combined have emitted a total of more than 3 million pounds of pollutants, according to the report. A single flaring episode can release as much as 10,000 to 100,000 pounds of pollutants into the air, according to the report.

While most refineries have decreased their flaring, Chevron is the only refinery that has actually dramatically increased its flaring, the report states. Shell has reduced flaring by 74 percent, Valero's Benicia refinery and Tesora Avon refinery have both reduced flaring by 64 percent and ConocoPhillips has reduced flaring by 15 percent, according to the CBE report.

Dennis Bolt, manager for Bay Area Refining with the Western States Petroleum Association, said that the air district accurately reported that the refineries have reduced flaring and emissions by two-thirds since the flare rule was adopted.

Bolt also said that comparing flare emissions in one refinery to flare emissions in another refinery year to year didn't give an accurate assessment of the progress each refinery has made in reducing emissions, since most flaring occurs during maintenance operations, which vary among refineries from year to year.

"We've made tremendous progress in reducing flaring emissions," Bolt said.

While CBE has claimed that it appears as if some refineries are using the flares in non-emergency situations, Bolt said that the air district monitors every flaring event at each refinery to make sure that it was done out of necessity. Flaring is used to quickly burn off gasses, which build up during the refining process, that could otherwise cause an explosion or be released uncombusted into the environment.

"That flare is like your teakettle," Bolt said. "When it gets too hot, you want it to whistle."

Carla Perez, northern California program director for CBE, has argued that Shell's progress in reducing flares shows that such reductions are technologically possible and should be required for all refineries.

"Unfortunately, they prioritize their profit margin over people's health," Perez said.

While there are no published scientific studies that have been able to measure the damage done to peoples' health after breathing in chemicals from refinery flaring, anecdotal evidence has suggested that the pollutants may cause lung disease, cancer and other health problems, according to the CBE report.

"We know flares emit certain chemicals," Perez said. "We know what health effects those chemicals tend to cause. And we know what symptoms people are experiencing."

People living downwind from the Chevron refinery, for example, frequently experience severe asthma attacks, dizziness, migraine headaches, and rashes during or immediately following a flaring event, Perez said.

One study showed that people living downwind from the Chevron refinery, particularly those people living in the 94801 and 94808 zip codes, have the highest rates of hospitalization due to asthma attacks in the state of California, Perez said.

Women living in west Contra Costa County also have some of the highest rates of breast cancer in the state and some of the worst breast cancer mortality rates, Perez said.

CBE has argued that Shell's efforts to reduce flaring have shown that the technology exists to essentially eliminate flares except in extreme emergencies.

Shell, which had no major flaring events between 2004 and 2006, has installed dedicated back-up compressors that capture the excess gasses that build up during the refining process and eventually re-route those gasses back into the system.

Rather than install dedicated backup compressors, Chevron regularly uses flaring to get rid of excess gasses, Perez said.

"Every 17 minutes Chevron makes enough money to install a dedicated compressor and the equipment to operate it," Perez said. "Unfortunately, they prioritize their profit margin over people's health."

Bolt, however, said that Chevron also uses a system of collecting the excess gasses and using them to power the refinery.

According to Karras, Shell also slows down the refining process when too much gas builds up, which gives the system the chance to deal with the gas internally rather than being forced to flare. Some of the other refineries, Chevron and ConocoPhillips in particular, continuously refine more oil than their facilities have capacity for, forcing them to flare more often. The flares enable them to quickly burn off excess gasses and keep going, according to Karras.

And finally, several of the refineries have increased the amount of cheap, so-called "dirty crude" oil they are refining, Karras said. Dirty crude, like it's name suggests, creates more excess gasses during the refining process, causing refineries to flare more often and causing flares to be more toxic.

"They cut corners, that's why they flare," Karras said.

A representative from Chevron's Richmond refinery was not available for comment.