Presentation by: Wilma Subra, Technical Advisor to LEAN
P. O. Box 9813 New Iberia, LA 70562
In support of:
Center for Fair Housing, Inc.
P. O. Box 161202 Mobile, AL 36616
Mobile Gas Whistler Junction Gas Transfer Facility in Eight Mile
Mobile Gas (owned by Sempra Energy of California) operates the Whistler Junction Gas Transfer Facility in Eight Mile, Alabama. Mobile Gas purchases natural gas from Gulf South Pipeline Co. Gulf South Pipeline Co. owns the property on which Mobile Gas transfer facility is located. At the transfer facility Mobile Gas injects mercaptan (tert-butyl mercaptan and methyl ethyl sulfide) as an odorant into the natural gas purchased from the Gulf South Pipeline Co. Mobile Gas then distributes the odorized natural gas to its utility customers in the Mobile area. Federal regulations require the use of odorants as a safety precaution to identify leaks in the natural gas system.
Mobile Gas has a storage tank of mercaptan at the transfer facility for injection into the natural gas stream. Mercaptan is delivered to the Mobile Gas facility by tanker truck and transferred into the storage tank. From January to June 2008, the mercaptan in the storage tank leaked into the environment. On June 14 or 15, 2008, lightning struck the mercaptan 3/8 inch stainless steel underground injection line that feeds the pipeline system with odorant from the storage tank and mercaptan spilled into the soil in the area of the storage tank.
Between January and June 2008, an estimated 6,000 pounds of mercaptan disappeared from the mercaptan storage tank at the Mobile Gas facility. Mobile Gas loss the following quantities of mercaptan from the storage tank:
January 7-21, 2008 loss more than 1,300 pounds of mercaptan One week in February 2008, loss 900 pounds of mercaptan One week in March 2008, loss 1,600 pounds of mercaptan April 7-21, 2008, loss 1,500 pounds of mercaptan April 22-29, 2008, loss 1,200 pounds of mercaptan
On at least four occasions the mercaptan tank was completely empty and on numerous occasions, the mercaptan tank was nearly empty. On a yearly basis, Mobile Gas used 335 pounds (2004) to 636 pounds (2005) of mercaptan and yet they loss more than 6,000 pounds of mercaptan in a six month period.
Mobile Gas failed to notify the National Response Center of the release over the reportable quantity (mercaptan reportable quantity – 100 pounds). On June 16, 2008, Mobile Gas notified ADEM of the lightning strike and the leak in the mercaptan tank, but did not accurately notify ADEM of the severity of the release event. A cleanup company was hired and dug a hole three feet deep, two feet wide and 10 feet long and stopped digging when they hit groundwater. The contaminated soil (60 cubic feet) was removed and transferred to an offsite landfill. The remainder of the mercaptan contaminants in the environment were not addressed. The mercaptan contaminants remained in the soil and groundwater on the Mobile Gas site, which is owned by Gulf South Pipeline, and over time, migrated down slope onto the adjacent property, emerging in spring fed water and the beaver pond. In 2010, Mobile Gas replaced the mercaptan dosing system but still did not address the environmental contamination situation resulting from the mercaptan leak of 2008.
In October 2011, community members of Eight Mile began complaining of gas leaks and odor events. On November 7, 2011, Mobile Gas notified ADEM of odor complaints from Eight Mile. The community of Eight Mile complained of -foul and unbearable smells -odors making people sick with -breathing difficulties -hoarseness -sore throat -headaches -dizziness -confusion -nausea -irritation and burning of eyes, nose -irritability -weakness -loss of sleep
The odor events occurred on a frequent basis and were strongest at night and on cloudy days. It was later determined that the source of the odors were mercaptans and that sunlight degrades the mercaptans. Thus the strongest odor events occurred at night due to the absence of sunlight to degrade the mercaptans.
Areas were identified where the odors were strongest. These areas included springs, seeps, and the beaver pond on the property adjacent to the Mobile Gas facility. ADEM collected samples from the springs (groundwater seeps) and the beaver pond spring area on property adjacent to the Mobile Gas facility and identified concentrations of Butyl Mercaptan as high as 14,000 ppb in the water from the underground spring. The human nose can detect as little as 1 ppb of mercaptan. Butyl Mercaptan was one of the chemicals used as a odorant by Mobile Gas and released from the mercaptan storage tank on the Mobile Gas facility in 2008.
Odor and Symptom Survey Associated with Mercaptan Contamination at Eight Mile, Alabama
Developed and Evaluated by Subra Company, Distributed by the Center for Fair Housing
The individuals in the community of Eight Mile have been complaining of foul odors, pungent smells and stench in their community since October 2011. Butyl Mercaptan is used as an odorant in natural gas distribution systems to assist in identifying natural gas leaks and was and is the odorant agent used by Mobile Gas in their utility natural gas distributed from Whistler Junction Gas Transfer Facility in Eight Mile.
The Alabama Department of Environmental Management (ADEM) performed sampling of an underground spring that joins a beaver pond in Eight Mile in February 2012. ADEM detected up to 14,000 parts per billion (14 parts per million) Butyl Mercaptan in the underground spring water in Eight Mile.
Exposure to high concentrations of Butyl Mercaptan causes: Headaches, Confusion, Dizziness, Nausea, Weakness
Contact with Butyl Mercaptan can cause Irritation of skin and eyes, Skin rashes
Breathing Butyl Mercaptan can cause Irritation to nose, throat and lungs Bronchitis, Shortness of Breathe, Coughing, Wheezing
Health Symptoms Experienced as a Result of Exposure to the Odor Events
An Odor and Symptom Survey was performed on individuals living or working in the Eight Mile area. The individuals surveyed reported detecting foul odors, pungent smells, very strong gas odors and chemical odors.
|Health Symptoms||% of Individuals Surveyed|
|Shortness of Breath*||100|
|Loss of Sense of Smell||16|
*Health symptoms associated with breathing and contact exposure to Butyl Mercaptan
**Health symptoms associated with exposure to high concentrations of Butyl Mercaptan
The individuals surveyed reported they did not have health conditions before the odor events occurred. The most prevalent health impacts experienced by all individuals surveyed were associated with high concentration exposure to Butyl Mercaptan (headaches, dizziness) and breathing and contact exposure to Butyl Mercaptan (eye and throat irritation and wheezing). Fourteen of the 20 health symptoms reported by the individuals surveyed corresponded to the health impacts associated with exposure to Butyl Mercaptan. All individuals surveyed had health impacts associated with high concentrations of exposure to Butyl Mercaptan, as well as breathing and contact exposure to Butyl Mercaptan.
Alabama Department of Public Health and Center for Disease Control and Prevention (CDC) Health Effects Resulting from Community Exposure to Mecaptan
From September 12-14, 2012, the agencies performed a survey of 97 households within a one mile radius of the beaver pond spring (Zone 1) and 107 households within a two mile radius of the beaver pond spring (Zone 2). In Zone 1, 98% of those surveyed reported experiencing odors while in Zone 2, 78%, experienced odors.
Odors were more severe in Zone 1 than in Zone 2. The odors were worse outdoors, around their homes, and in the early morning and evening hours. The majority of respondents reported;14 out of the past 30 days being physically and mentally unhealthy. The health symptoms most reported and more prevalent in Zone 1 than Zone 2 included: nasal congestion shortness of breathe wheezing loss of appetite eye irritation headache dizziness agitated behavior difficulty concentrating worsening hypertension
Recommendations included having the Mobile County Health Department issue communication messages to the community -to minimize exposure by limiting outdoor activities and keeping windows closed in the evening and overnight hours (6 PM to 8 AM) -those with chronic respiratory (asthma) and cardiovascular (hypertension) conditions to have their medications readily available
Investigation of Nature and Source of Contaminants
An investigation of the nature and source of contaminants was performed from April through June 2012, at the site of the Mercaptan release on the property where Mobile Gas operates the Whistler Junction Gas Transfer facility (property owned by Gulf South Pipeline Co.) and down slope onto the adjacent property which is owned by the Reed family and is the location of the groundwater seeps, springs and beaver pond from which mercaptan odors are being released. Soil borings and groundwater wells were installed on the two pieces of property and samples of soil, groundwater and surface seep water were collected and analyzed for reduced sulfur compounds.
On the Gulf South Property, where Mobile Gas has their facility, 11 soil borings and six monitoring wells were installed. On the Reed property down slope from the Gulf South property, eight soil borings and eight monitoring wells were installed. The soil borings on the Gulf South property contained up to six reduced sulfur compounds (including tert-Butyl Mercaptan), in soil borings 2, 3, and 4, down to a depth of 48 feet. These contaminated soil clustered were at and down slope of the area of odorant release. The groundwater in five shallow wells and three deep wells contained reduced sulfur compounds (including tert-Butyl Mercaptan). The contaminated groundwater was down dip of the odorant release location. The deep aquifer flows from the Gulf South property to the east-southeast towards the Reed property where the groundwater seeps, springs and beaver pond are located. The groundwater is located two to 17 feet below ground surface on the Reed property.
On the Reed property, two soil samples, in the saturated zone down dip of the Gulf South property, contained up to five reduced sulfur compounds including tert-Butyl Mercaptan. The groundwater in five of the monitoring wells contained up to seven reduced sulfur compounds, including tert-Butyl Mercaptan, down dip of the Gulf South property. The water in the groundwater seep on the Reed property contained 7 reduced sulfur compounds including tert-Butyl Mercaptan at a concentration of 3.7 mg/l. The Reed property seep contents of tert-Butyl Mercaptan was the second highest concentration of tert-Butyl Mercaptan detected in groundwater. Monitoring well MW-13, on the Reed property, was the groundwater sample with the highest concentration of tert-Butyl Mercaptan, 8.5 mg/l.
Reduced Sulfur Compounds in Soil and Groundwater
|Mobile Gas Gulf South Property||Reed Property|
|Methyl Ethyl Sulfide||*||*||*||*|
On September 12, 2012, ADEM ordered Mobile Gas to install additional monitoring wells at locations farther from the spill/odor release area.
On September 27, 2012, ADEM demanded that Mobile Gas take action to mitigate and abate the irritating odors in the air within 14 days. By October 16, 2012, the ADEM deadline, Mobile Gas had not mitigated and abated the irritating odors as required by ADEM.
ADEM then cited Mobile Gas for failure to initiate the requested investigation and cleanup of the contaminants.
Mobile Gas eventually installed a tent over the natural spring and a carbon filter. The company then changed out the tent material to a canvas tent. The attempt to mitigate the Mercaptan odor failed to adequately address the problem. The community continues to suffer from extensive odors and associated health impacts. Mercaptans and reduced sulfur compounds continue to be present in the soils, aquifer, groundwater seeps, springs, ponds, and streams in the Eight Mile area.
Due to the extensive health symptoms being experienced by the individuals living and working in the Eight Mile area, as a result of exposure to tert-Butyl Mercaptan and other reduced sulfur compounds, there is a need to reduce the Butyl Mercaptan exposure.
Interruption of the air pathway of exposure is necessary to reduce community exposure and associated health symptoms. Determination of the extent of environmental contamination by Butyl Mercaptan and other reduced sulfur compounds in the soils, sediments, groundwater and surface water resources must be performed.
Remedial measures must be implemented to address contaminants in the groundwater and soil on both the Mobile Gas property and the Reed property.
Protection of the health of community members as a result of ongoing exposure, as well as during investigations and remedial activities, is of critical importance. Human exposure must cease.