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10.10.2022 Legal News

EPA ENFORCEMENT ALERT: Emergency and Non-Emergency Stationary Sources Are the Focus of EPA

In a recent “Enforcement Alert,” EPA set out its intent to target owners and operators of stationary engines for compliance with Clean Air Act emissions requirements. According to the Enforcement Alert, “EPA has been finding numerous violations of the applicable Clean Air Act requirements” for stationary engines and have “assessed substantial penalties for facilities that have failed to comply.” The Enforcement Alert announces EPA’s intent to aggressively inspect and prosecute violators.

Scope of the Regulations

Most industries and some office complexes own and operate emergency power generators governed by EPA regulations. The regulated “RICE sources” include any “reciprocating internal combustion engine (RICE), which uses reciprocating motion to convert heat energy into mechanical work and which is not mobile.” They are typically used to provide backup electricity, produce primary power, or power pumps and compressors. They may also supply electricity in the event of emergencies such as fire or flood. Across the country, there are an estimated 37,000 RICE units according to EPA, and it is the normal practice for these emergency generators to burn fossil fuels (such as fuel oil or natural gas) and emit hazardous air pollutants (HAP) or criteria air pollutants.

Regulations Governing RICE Sources

EPA regulations govern most RICE sources under the national emissions standard for hazardous air pollutants (NESHAP) found at 40 CFR 63, Subpart ZZZZ. The 4Z subpart applies to all existing, new and reconstructed stationary reciprocating internal combustion engines at major and area sources of HAP. The primary HAP emitted from these stationary engines include formaldehyde, acrolein, acetaldehyde and methanol.

EPA also has established New Source Performance Standards (NSPS) for some stationary compression ignition sources at 40 CFR 60, Subpart IIII, and spark ignition sources at 40 CFR 60, Subpart JJJJ. These NSPS requirements limit emissions of criteria air pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs) and particulate matter (PM). 

Requirements under NESHAP or NSPS primarily include new recordkeeping, operational limitations, performance test, and maintenance requirements, and there may be a need to retrofit the unit to add pollution control technology depending on size and age of engine and potential emission of HAPs at the host facility. For non-emergency RICE systems, there are requirements for initial performance tests, ultra-low sulfur diesel (ULSD), crankcase emission controls, operating parameters (pressure drop and inlet temperature), fuel restrictions, and notifications/semi-annual reports. Larger non-emergency units must shut down at certain high temperatures and continuously monitor catalyst inlet temperature.

Existing smaller emergency RICE units are subject to a plethora of requirements:

  • Operate/maintain engine and control device per manufacturer’s instructions or owner-developed maintenance plan
  • May use oil analysis program instead of prescribed oil change frequency
  • Emergency engines must have hour meter and record hours of operation
  • Keep records of maintenance
  • Notifications not required
  • Reporting and ULSD for emergency engines used for local reliability


Larger emergency units must add initial and periodic performance tests to the list of requirements.

EPA Enforcement Initiative

The EPA Enforcement Alert is founded on concern over wide-spread non-compliance. In fact, the Enforcement Alert lists examples of recent enforcement actions for consideration of the reader.

The Enforcement Alert states, “EPA investigations have uncovered numerous violations. The most serious violations include failure to retrofit existing engines with necessary pollution controls. Depending on the age and size of the engine, and the type of source at which it is located, pollution controls may be required.” In addition, the Enforcement Alert notes “owners of emergency stationary engines sometimes participate in demand response programs run by electricity system operators, thus voiding the emergency status of the engines.” The Enforcement Alert also mentions RICE owners not performing testing required by the RICE regulations.

EPA used the Enforcement Alert to introduce examples of EPA’s recent enforcement activities involving RICE violations. On June 5, 2020, EPA Region 10 ratified a consent agreement and final order under Section 113 of the Clean Air Act against a sand and gravel plant for failure to operate diesel engines in compliance with emissions standards; the company agreed to pay a civil penalty of $123,553. In 2021, a Vermont power company agreed to pay a penalty of $28,800 for lack of compliant emissions monitoring equipment and failure to file required semi-annual reports. A Michigan metal company paid $166,571 in fines and penalties in 2019 for failure to comply with monitoring, testing, emissions limitations, operating specifications, and recordkeeping requirements under the RICE regulations.

Conclusion and Recommended Action

RICE requirements are easy to overlook. The benefits and value of these smaller systems cannot be overestimated for every business. However, EPA believes they pose a risk to human health and the environment if not operated in accordance with NESHAP and NSPS standards. The Environmental Alert is proof the Agency may be knocking on your door soon to see compliance records. 

To prepare for this risk, it is recommended companies operating emergency and non-emergency RICE units take the following steps:

Step No. 1: Review the NESHAP and NSPS regulations to determine if they apply to your facility.

Step No. 2: Determine whether the RICE regulations are being met, focusing on the need for pollution controls, certificate of conformity from the manufacturer (newer units), and compliance with operating limits, monitoring requirements, and recordkeeping. 

Step No. 3: In the event noncompliance is discovered, seek assistance from legal counsel on the need or ability to demonstrate voluntary disclosure requirements in the EPA Self-Policing Policy. 

“Enforcement Alert,” EPA Publication No. 310‐F‐22‐00140 CFR 63.6675 (August 2022); 40 CFR 60, Subpart IIII and Subpart JJJJ; and 40 CFR 63, Subpart ZZZZ.