For reciprocating engines there are MACT standards. There are also NSPS standards with new and existing units. The EPA recently sent out an enforcement alert indicating that there are a number of engines not reporting to EPA, primarily because they did not realize that their particular engine was covered by a regulation. Types of engine (IC or diesel), 2 stroke or 4 stroke, emergency or non-emergency, etc. all have different regulations. Emergency engines are not supposed to be operated in non-emergency situations. If the grid goes down, the emergency engine kicks in. As soon as the power is restored, any operating time counts as “non-emergency” time. There are limits on the amount of time to operate in non-emergency operation. There are around 100 different regulations on these engines. Storm mode operation is used to provide water supply either during or in anticipation of a power outage due to a storm. EPA has determined that anticipation of an outage is not an outage.

Citizens Thermal has 95 engines for their systems. These are both emergency and non-emergency units. Catalysts were installed in 2013. For emergency units, non- emergency operation for readiness, maintenance, and testing is limited to 100 hours. All other non-emergency operation is limited to 50 hours. Various tools were developed to help operations staff understand and follow compliance. Log books, stickers, fact sheets, and FAQ sheets were utilized. Compliance is a “team sport”. The various tools were updated and modified as operations personnel became more familiar with the requirements and related them to operations. Data visualization helps to monitor performance and alert operations staff. Engine maintenance was shifted to an annual basis based on ZZZZ requirements. The maintenance was moved to the 3^rd quarter to allow for full compliance checking by year end. An oil sampling program was developed. Oil has to be changed within 2 days of a non-compliance report. By correlating oil changes with use, oil change schedules for each engine were determined. Stack tests are required every 3 years for non-emergency engines. As a result, 5 non-emergency engines were re-classified to emergency engines.

Ann McIver and David Foster, Citizens Thermal