The Mayflower, Arkansas oil spill continues to be the source of questions about the long-term health, environmental and financial consequences for residents in a town the state's attorney general described as a scene out of "The Walking Dead."

And even as Exxon was cleans up after its tar-sands oil spill in Mayflower, Arkansas on Wednesday -- and threatening to have reporters arrested -- it spilled an unknown amount of unknown chemicals, possibly hydrogen sulfide and cancer-causing benzene during an accident at the Chalmette refinery in Louisiana.

From The Times-Picayune:

ExxonMobil first reported releasing 100 pounds of hydrogen sulfide and 10 pounds of benzene, a volatile organic carbon compound known to cause cancer, because those amounts are the minimum required for reporting, [Coast Guard Petty Officer Jason] Screws said. But the company has since said it is unsure exactly what chemicals were involved or how much may have been released, he said. The spill occurred as a result of a break in a pipeline connecting a drum used to store “liquid flare condensate,” with a flare on the refinery site, Screws said. He said the company measured 160 parts per million of hydrogen sulfide and 2 parts per million of benzene in the air at the site of the spill, but has not seen similar readings at the plant’s fence line or in the neighboring community.

Area residents breathed in the chemicals caused by the spill for over a day, leading to reports of breathing difficulties and other ailments. But the Coast Guard told them not to worry because everything was just fine.

Reuters:

"We haven't told the refinery to shut down because we haven't any cause for a shutdown," Zeteza said. "We've no indication that this is dangerous."

The "safety" record of the Louisiana refinery sounds horrid and includes a 36-barrel spill in January, and 10 incidents in which it violated the pollution limits, including an outage caused by Hurricane Isaac during the last 6 months of 2012.

Not too surprising, but the size of the Exxon tar sands disaster in Arkansas grew by thousands of barrels on Friday.

From InsideClimate News:

Since ExxonMobil’s Pegasus pipeline ruptured and leaked Canadian oil across an Arkansas suburb a week ago, the company has maintained that only "a few thousand barrels" spilled at the site. "We've had no reason to change that at this stage," Exxon spokesman Charles Engelmann told InsideClimate News on Friday.

...

Reports posted online by the U.S. Environmental Protection Agency estimate the spill even higher—at 4,000 to 7,000 barrels—as much as 40 percent more. Austin Vela, the EPA spokesman at the spill site, said the agency stands by its 4,000 to 7,000 barrel estimate. When asked why those higher numbers aren't being included in the daily press releases issued by the joint command of the cleanup operation, Vela did not respond. The joint command includes five EPA employees as well as ExxonMobil officials.

An update to the article notes that after it was published, Exxon Mobil updated the joint command incident report for Friday, and it now states that approximately 5,000 barrels of oil spilled in Mayflower.

For some perspective on the size of this mess, the report notes that if the EPA's highest estimate of 7,000 barrels is correct, that would make this spill about one-third the size of the Enbridge spill in Michigan's 2010 dilbit disaster.

Exxon is still keeping tight control of the command center even though the EPA is the designated on-scene coordinator. An employee of the oil giant threatened to have InsideClimate News reporter Lisa Song with arrested after she went to the command center in an effort to contact the EPA and Pipeline and Hazardous Materials Safety Administration (PHMSA) employees who are working there.