Sunday, July 22, 2012

hydrogen sulfide levels

Residents reported flaring, flaring associated odors, and a larger than usual discharge plume from the FCC stack at the Meraux refinery around 10:30pm on Saturday night, July 21, 2012, and further observed the wind carried the discharge towards the north of Judge Perez Drive.  Shortly before 2am on Sunday, July 22, 2012 "in an abundance of caution" residents on Jacob Drive were told it would be in their best interest to leave the area due to a chemical leak and possible fire.

At 4:15am on July 22, 2012 Valero reported to the National Response Center:
....... CALLER STATES THAT THERE A WAS LEAKING EXCHANGER AT THE REFINERY THAT CAUGHT ON FIRE. IT IS BELIEVED THAT IT WAS LEAKING CRUDE OIL. THE FIRE WAS SAID TO BE "UNDER CONTROL" AT THE TIME OF THE CALL, BUT IT WAS NOT COMPLETELY EXTINGUISHED.
http://www.nrc.uscg.mil/reports/rwservlet?standard_web+inc_seq=1018545


Valero's ambient air monitor is dependent on wind direction.  Hydrogen sulfide readings on July 21-22, 2012 were:  at 9pm - 78 parts per billion H2S, at 10pm - 36 ppb H2S, at 1am 44 ppb H2S.  Daylight saving time is not reflected in the results.  EPA's recommended daily exposure to hydrogen sulfide is 1.4 ppb H2S. The State of Louisiana does not have an air quality standard for hydrogen sulfide. The State of California air quality standard for hydrogen sulfide is 30 ppb. .
http://oehha.ca.gov/air/pdf/oehhah2s.pdf

 Sulfur dioxide readings on July 22, 2012 were: at 2am 10 ppb SO2 and at 3am 15 ppb SO2.  Louisiana DEQ has stated sulfur dioxide levels at 12 ppb trigger headaches and other adverse quality of life effects. EPA's sulfur health standard is 75 ppb SO2.
Valero's ambient air monitor readings are accessible at this link after a 24 hour delay.  Valero's air samples for other chemicals can be accessed under Documents.

http://lena.providenceeng.com/hourly.aspx

Valero's air sample results for other chemicals can be accessed under Documents at the same link.

Some of the chemical sampling results from the June 29 2012 sample analyzed July 10 2012 and the June 13 2012 sample analyzed June 30 2012:

 

Acetone 10.7 ppbv / 25.4 ug/m3  and 4.3 ppbv / 10 ug/m3

Ethanol 7.6 ppbv / 14.0 ug/m3 and 6.8 ppbv / 13 ug/m3

Ethyl Acetate 1.4 ppbv / 5.0 ug/m3 and 1.8 ppbv / 6.5 ug/m3

Toluene 1.0 ppbv / 3.8 ug/m3 and 1.5 ppbv / 5.7 ug/m3

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