Respondent is the owner and operator of the natural gas compressor stations. The Facilities receive natural gas from well sites, separate out liquids from the natural gas and route the natural gas liquids to aboveground storage tanks at the Facilities. The natural gas is compressed and then sent via pipeline to gas plants for further processing. Pipeline quality gas is discharged via pipeline to natural gas distributors.
Pursuant to Section 112(r)(1) of the CAA, 42 U.S.C. § 7412(r)(1), the owners and operators of stationary sources producing, processing, handling or storing substances listed pursuant to Section 112(r)(3) of the CAA, 42 U.S.C. § 7412(r)(3), or any other extremely hazardous substance, have a general duty, in the same manner and to the same extent as 29 U.S.C. § 654, to identify hazards which may result from accidental releases of such substances using appropriate hazard assessment techniques, to design and maintain a safe facility taking such steps as are necessary to prevent releases, and to minimize the consequences of accidental releases which do occur. Section 112(r)(l) is hereinafter referred to as the “General Duty Clause.” The General Duty Clause of Section 112(r) of the CAA, 42 U.S.C. § 7412(r)(1), applies to any stationary source producing, processing, handling, or storing regulated substances, as defined above, or other extremely hazardous substances (“EHS”). An EHS is any chemical which may, as a result of short-term exposures because of releases to the air, cause death, injury or property damage due to its toxicity, reactivity, flammability, volatility or corrosivity.
Section 112(r)(2)(C) of the CAA, 42 U.S.C. § 7412(r)(2)(C), defines “stationary source” as any buildings, structures, equipment, installations or substance emitting stationary activities which belong to the same industrial group, which are located on one or more contiguous properties, which are under the control of the same person (or persons under common control) and from which an accidental release may occur.
EPA conducted an inspection of 10 of the 14 Facilities on September 27-29, 2011, to assess Respondent’s compliance with Section 112(r)(1) of the CAA. At each of the inspected Facilities, EPA observed two and five condensate tanks (including mix tanks, produced water tanks, and condensate collection tanks) ranging in size from 400 barrels to 500 barrels located outside the compressor building. Respondent had natural gas condensate in at least one of the condensate tanks at each Inspected Facility. EPA observed 8″ thief hatches manufactured by ENARDO on each of the condensate tanks. According to the Material Safety Data Sheet (“MSDS”) for Respondent’s natural gas condensate, the natural gas condensate has constituents of approximately 20-70% propane (Chemical Abstracts Service (“CAS”) #74-98-6), 15-25% butane (CAS #106-97-8), 5-25% pentane (CAS #109-66-0) and 0-5% ethane (CAS #74-84-0). According to its MSDS, the mixture has a flammability rating of 4. Using data from MARPLOT and GoogleEarth, EPA has determined that the approximate population within one half-mile of each Inspected Facility ranges from 6 residences with an estimated 12 persons at one Compressor Station to 89 residences with 194 persons at another Compressor Station. The National Fire Protection Association 30, Flammable and Combustible Liquids Code (2008 Edition) (“NFP A 30”) applies to the storage, handling, and use of flammable and combustible liquids. Section 22.7.1.1 of NFPA 30 states that, “Every above ground storage tank shall have emergency relief venting in the form of construction or a device or devices that will relieve excessive internal pressure caused by exposure fire.”
The American Petroleum Institute Standard 12F, Specification/or Shop Welded Tanks for Storage of Production Liquids (12th edition, October 2008) (“API 12F”) covers material, design, fabrication, and testing requirements for shop-fabricated vertical, cylindrical, aboveground, closed top, welded steel storage tanks in various standard sizes and capacities for internal pressures approximately atmospheric.
a. Section 6.2 of API 12F states that “when storage tanks containing flammable liquids are exposed to fire, the venting rate may be in excess of that resulting from a combination of normal thermal effects and oil movement. Unless tanks are installed in remote locations, the purchaser shall provide, or cause to be provided, pressure relieving devices which will provide capacity in addition to normal venting to meet the requirements tabulated in Table C.l. The opening pressure of such devices shall not exceed the design pressure of the tank on which the devices are installed. The maximum internal pressure under normal relieving conditions should not exceed that tabulated in Table C.1. Column 6. Pressure relieving devices may take the form of larger or additional vent valves or additional thief hatches.”
b. According to Table C.1., the required emergency venting for 400-barrel 12′ x 20′ tanks without drainage should be 446,350 standard cubic feet per hour.
c. According to Table C.1., the required emergency venting for 500-barrel 12′ x 25′ tanks without drainage should be 507,000 standard cubic feet per hour.
ENARDO provides installation and maintenance instructions for its Spring Loaded Hatch Model 660 hatches to prevent the loss of vapors in a closed storage system and provide pressure and vacuum relief:
a. Section II, the maintenance instructions, states, “Scheduled maintenance should be performed every three (3) months and more frequently in
corrosive or dusty atmospheres. Normal maintenance requires the pressure gaskets and vacuum gaskets to be inspected. Under average operating conditions the pressure and vacuum gaskets should be replaced once a year. The base gasket need only be replaced when a leak is noticed at the bolting area or if the hatch is removed, breaking the seal. If the hatch is continually relieving, the user should be alerted that there is a problem; at that time a close inspection should be made to determine the cause.”
EPA’s inspection and communications with the facilities in the aftermath of the inspection revealed a number of safety concerns at the Inspected Facilities:
a. The condensate tanks at the Inspected Facilities had in-breathing/out-breathing ENARDO 8″ thief hatches but lacked pressure relieving devices such as emergency vents. ‘
b. API 12F, Annex C, Table C.2 indicates that at 12 ounces of venting pressure, the conservative calculated venting capacity of an 8″ thief hatch is 169,094 standard cubic feet per hour. Thus, the 8″ diameter thief hatches and other vent piping on the condensate tanks were inadequately sized to meet the emergency venting requirements ofNFP A 30 and API 12F, Annex C, Table C.l.
c. Using a Forward Looking Infrared (“FLIR”) camera, EPA observed continual visible releases of natural gas condensate vapors coming from some of the thief hatches on the condensate tanks.
d. Two vertical process units were not secured to their foundations at the Godwin Compressor Station.
e. Respondent did not inspect or maintain the thief hatches in accordance with the manufacturer’s recommendations.
EPA’s investigation indicates that, prior to Respondent’s compliance with the order, the company failed to satisfy the General Duty Clause requirement to design and maintain safe facilities. In particular:
a. Respondent failed to install pressure relieving such as emergency vents, to provide protection consistent with the requirements of API 12F and NFPA 30; and
b. Respondent failed to implement a maintenance program for its thief hatches in accordance with the manufacturer’s instructions to provide
protection consistent with the instructions.
CLICK HERE for the agreement