On Jan. 14, 2013, the USEPA finalized revisions to MACT standards for reciprocating internal combustion engines, “RICE”. See: http://www.epa.gov/ttn/atw/rice/20130114amendments.pdf.
A controversy concerning the draft rule was whether facilities can use backup diesel generators during non-emergency, demand-response purposes without emission controls. According to the USEPA, there are over 1 million RICEs in the US, most of which used only for power in emergencies. Many are located in areas that may experience power shortages during the peak season. These, therefore, are seen as potential sources to provide a facility power during peak demand when there may be shortages or risk of one: greater operating flexibility for the facility and local power grid.

The vast majority of RICEs combust diesel oil, whose combustion by-products have been linked to asthma, lung cancer and, particularly, childhood respiratory problems. However, because many RICEs are located in sparsely populated areas (for example, for oil or gas production) or are used to power offshore vessels, some have argued that emission controls need not be as strict as for units commonly found in populated areas.

The USEPA had previously proposed to allow backup generators to run for up to 100 hours/year for demand-response purposes without being subject to emission limits. Both industry and environmental groups objected. In the final rule just announced, the USEPA provided these compromises:

• Emergency engines can operate for demand-response up to 100 hours/year

• More clearly defined the precise situations when backup generators may operate (what is an emergency)

• Backup generators must use ultra-low sulfur diesel fuel beginning in 2015.
Operators with subject RICE emergency engines must submit annual reports reporting the dates and lengths of times of operations to determine compliance.

While some groups are still dissatisfied and threaten to sue, a number of commentators believe that this represents reasonable public health protection and will survive in court.
The USEPA intends to modify the New Source Performance Standards (NSPS) for stationary compression-ignition and spark-ignition internal combustion engines (40 CFR Part 60, Subparts IIII and JJJJ, respectively) to ensure consistency with RICE MACT.

CCES has the experts and the experience to evaluate your engine generators for compliance with these and other federal and state air quality regulations, and advise you on technical options to comply and provide your operators with greater operating flexibility. Contact us today.