The EPA has issued an Interim Chemical Accident Prevention Advisory addressing concerns about the design and construction of liquid petroleum gas (LPG) installations at natural gas processing plants. This advisory has implications for facilities that store LPG and are regulated under the Clean Air Act's risk management program (RMP).
According to the advisory, the EPA has been informed and has verified through inspections that some installations have not been built according to the appropriate industry standards. The Agency says that inspectors frequently determine compliance with the implementing requirements of the CAA's RMP (40 CFR 68) by determining if facilities have been designed according to good engineering practices contained in applicable industry codes and standards.
The RMP is intended to prevent chemical accidents that may impact communities near a facility.
NFPA and API
The advisory states that some plants have been constructed in accordance with National Fire Protection Association 58 (NFPA 58), Liquefied Petroleum Gas Code. “While compliance with NFPA 58 is consistent with good engineering practices, we note that NFPA 58 does not apply to natural gas processing plants and more specific industry standards than NFPA 58 would apply,” says the EPA.
The Agency appears most concerned that this standard does not provide for the adequate spacing of equipment such as loading racks and storage tanks at natural gas processing plants.
The advisory indicates that criteria in the American Petroleum Institute’s (API) standard 2510 (Design and Construction of Liquefied Petroleum Gas [LPG] Installations) and its companion document, API 2510A (Fire Protection Considerations for the Design and Operation of LPG Storage Facilities), are directly applicable to LPG installations at natural gas processing plants and are more protective than NFPA 58 for several parameters, including spacing of LPG tanks from loading racks. API 2510 also requires adequate spacing of equipment at natural gas processing plants, parameters not addressed in NFPA 58.
Other standards
The advisory lists the following additional standards or guidance documents that may be applicable to LPG installations, natural gas processing plants, wells, and associated equipment:
- API Standards—6A, 12R1, 12F, 12J, 12K, 12GDU, 51R, 54, 74, 75L, 76, 500, 505, 510, 521, 570, 576, 650, 618, 653, 752, 753, 2000, 2003, 2510, 2510A, HF1, HF2, HF3
- NFPA Standards—15, 30, 70, 497
- American Society of Mechanical Engineers—A13.1, B31.3, B31.4, B31.8
- International Fire Code and Mechanical Code.
- International Organization for Standardization—13631
- Steel Tank Institute—SP001-00
NFPA 30 and API 2000 require sufficient venting, under normal and emergency conditions, for atmospheric aboveground storage tanks storing flammable liquids (such as condensate) to prevent tank overpressurizations from fire exposure at the applicable facilities, including those processing natural gas. Storage tanks containing flammable liquids may also require secondary containment in accordance with NFPA 30 and possibly the spill prevention, control, and countermeasure (SPCC) regulations at 40 CFR Part 112 and state or local regulations.
“The codes and standards discussed in this advisory are sources for establishing the level of design engineering protectiveness that is recognized and generally accepted in the industry,” concludes the advisory.
The EPA says it will accept comments on the advisory until July 31, 2014.
Interim Chemical Accident Prevention Advisory