FORT WAYNE, Ind. (WOWO) — Google has submitted another application to modify its air permit as construction continues at its Fort Wayne data center.

The application was submitted to the Indiana Department of Environmental Management and involves plans to add 228 emergency generators at the facility, according to a Google spokesperson.

Google says the generators would serve as backup power for the data center and would not be used to supply electricity during normal operations.

The company says the generators would operate primarily during power outages and for required maintenance testing. Google anticipates each generator would be tested for fewer than 10 hours per year.

Google also says the generators would be subject to existing air-quality requirements and that the facility would remain below its permitted emissions limits. The company says non-resettable hour meters will be installed on the generators to track operating time.

According to Google, some of the generators will also have additional pollution controls designed to meet or exceed EPA Tier 4 emissions standards.

The company says the backup generators will use ultra-low sulfur diesel or renewable fuels such as hydrotreated vegetable oil, or HVO. Fuel will be stored in integrated, double-walled tanks, according to Google.

Google says the generator specifications and other information are included in the air permit application and that emissions and operating records will be maintained and reported to IDEM as required.

The latest application is part of the ongoing expansion of Google’s Fort Wayne data center. IDEM approved a previous air permit modification in April allowing more than 140 additional emergency generators at the site.

The latest application can be viewed through IDEM’s air permit database.