OIL AND NATURAL GAS PRODUCTION NESHAP PROPOSAL

Chemical Engineering Progress, Sep 2005

REGULATORY UPDATE

On July 8,2005, the Environmental Protection Agency (EPA; Washington, DC; www.epa.gov) proposed a new rale supplementing a 1998 regulation issued under the Clean Air Act Amendments to control hazardous air pollutant (HAP) emissions from oil and natural gas production facilities. The proposal would reduce air toxics emissions from as many as 2,200 facilities (nationwide) to as few as 1,050 facilities (in urban counties only) that produce oil and natural gas. If implemented nationwide, EPA estimates that emissions of air toxics and volatile organic compounds (VOCs) would drop by 16,400 ton/yr and 31,400 ton/yr, respectively.

This supplemental plan would apply to "area sources" of HAP, or those that fall below the "major source" threshold. The latter pertains to sources that emit 10 ton/yr or more of a single HAP or 25 ton/yr or more of a combination of air toxics. The 1998 proposal specified that area-source triethylene glycol dehydration (TEG) units (which are used to remove excess water vapor from natural gas before it enters transmission pipelines) must reduce emissions in counties designated as urban areas.

The new proposition would require TEG units in any U.S. location to reduce emissions by implementing emission controls in the process vents of TEG units. These process vents will be required to do one of the following: vent emissions to a control device; make process changes to achieve emission reductions comparable to a control device; document that the unit's emissions are low enough that controls are not needed.

EPA estimates the cost to implement the rule on a national basis as $39.2 million, whereas the cost of implementation in urban counties alone would be $18.5 million. EPA will take final action on this rale by Dec. 30, 2006 (see the Federal Register, July 8, 2005, pp. 39,441-39,457).