In response to a December 2009 petition for reconsideration from the American Petroleum Institute (API), the EPA has issued technical amendments to its National Emissions Standards for Hazardous Air Pollutants (NESHAP) for petroleum refineries.  The amendments affect heat exchange systems, and three of those changes are significant, says the EPA.  The Agency adds that two of the three amendments will probably reduce compliance costs, and no change will reduce the level of environmental protection provided under the standards.

10 issues

Since 1995, the EPA has issued a series of NESHAPs affecting petroleum refineries.  The initial proposal to include heat exchange systems in the NESHAP was published in November 2007, and a final rule was issued in October 2009.  Subsequently, the API requested administrative reconsideration of 10 heat exchange issues in the NESHAP.  The Agency declined to reconsider six of those issues either because they became irrelevant in light of subsequent regulatory action or they had not been raised by the API at the appropriate time.  Of the remaining four issues addressed, one concerns the date new sources become subject to the NESHAP.

The remaining three changes are as follows:

• The definition of heat exchange system is revised to improve clarity regarding applicability of the monitoring and repair provisions for individual heat exchangers within the heat exchange system.  Specifically, the definition is revised to focus on heat exchangers (and not sample coolers) that are in organic HAP service and that are associated with a petroleum refinery process unit.
• An alternative monitoring option for heat exchange systems is provided to allow owners and operators at existing sources to monitor quarterly using a leak action level defined as a total strippable hydrocarbon concentration (as methane) in the stripping gas of 3.1 parts per million by volume (ppmv); the current regulations provide only one monitoring option, which requires monthly monitoring at a leak action level defined as a total strippable hydrocarbon concentration (as methane) in the stripping gas of 6.2 ppmv.  The Agency says it performed modeling of the monitoring alternative, which indicates that quarterly monitoring at the lower leak action level provides equivalent emissions reductions to monthly monitoring at the higher leak action level in the existing regulations.  These amendments also include specific recordkeeping and reporting requirements for owners and operators electing to use the alternative monitoring frequency.
• The monitoring requirements for once-through cooling systems are amended to allow monitoring at an aggregated location for once-through cooling water heat exchange systems, provided the combined cooling water flow rate at the monitoring location does not exceed 40,000 gallons per minute.

Uniform standards

The EPA notes that the current action does not address uniform standards for heat exchange systems the Agency proposed on January 6, 2012.  These standards are intended to apply across multiple industry categories.  The Agency says it is still evaluating comments on that proposal.

The final amendments to the petroleum refinery NESHAP were published in the June 20, 2013, FR.