New EPA Air Toxics Rule Afflects Facilities with TEG Dehydrators
By: Clare Bienvenu
On January 3, 2007, EPA promulgated a final rule amending 40 C.F.R. part 63, Subpart HH, “NESHAP (National Emission Standards for Hazardous Air Pollutants) for Source Categories from Oil and Natural Gas Production Facilities” to include the regulation of area sources. See 72 Fed.Reg. 26 (January 3, 2007). The final rule is posted here. Subpart HH has historically regulated various emissions points for major sources of air toxics in the oil and natural gas production industry. This amendment adds the regulation of benzene emissions from tetraethylene glycol (TEG) dehydration units at minor sources. The significance of this new rule is that all TEG dehydration units in the oil and gas production industry are now subject to Subpart HH unless they meet the exemption criteria provided in the regulations. While the amendment adds the regulation of area sources, it does not alter any of the major source standards. Accordingly, any TEG dehydration unit already regulated under Subpart HH’s major source standards must continue to comply with those requirements.
This article will first discuss control requirements for area source TEG dehydration units, which vary based on whether the unit is located within a high population density area, referred to as an “UA plus offset or UC.” The article will next discuss applicable compliance dates, which vary based on the date the TEG dehydration unit was constructed or modified and whether the unit is located in an “Urban 1 County” and/or a high population density area. Notably, this rule is immediately effective for any source constructed or modified on or after July 8, 2005 and for certain sources constructed or modified on or after February 6, 1998.
