SAN JUAN, Puerto Rico -- Maintenance operations conducted as part of the U.S. Army Corps of Engineers temporary emergency power mission in Puerto Rico are keeping nearly 1,000 federal emergency power generators running at critical public facilities across the island.

The generators help power lifesaving facilities like fire stations and medical centers, as well as drinking water and wastewater treatment plants, until electricity from the grid is restored.

Working at a pier in San Juan, USACE personnel orchestrated a "repair shop" and staging area that is critical to the success of the mission. Here, USACE logistics and quality assurance specialists track all of the federal generators coming into Puerto Rico from the U.S. Virgin Islands and the mainland United States.

Once the generators arrive, contract crews check to make sure the generators are fully mission capable -- meaning they produce a reliable source of electricity at the levels they are designed to provide. The generators can then be added to the inventory of generators available for installation.

The pier also functions as a repair center for generators that exhibit problems after they have been installed at a facility. While USACE quality assurance specialists regularly check on installed generators and contract crews perform preventative maintenance, sometimes issues arise that are too complex to fix on site. In that case, the generator is uninstalled and sent back to the pier for repair. A functioning generator is sent from the inventory to be installed in its place.

Repairs run the gamut from exhaust systems to electrical breakers to fuel pumps, according to Jim Wade, a logistics specialist from the USACE Walla Walla District who coordinates operations at the pier. These repairs are the result of how hard the generators have been working -- in some cases, 24 hours a day, seven days a week for several months.

"It's normal wear and tear," Wade said. "It's like taking your car on cross-country trips back to back. It's the same types of issues."

The length of time it takes to repair a generator depends on how complicated the problem is, as well as if parts are available. Common parts are kept stocked at the pier, but some generators require parts that need to be manufactured, which adds to the repair time.

Once repairs are completed, contractors perform a load bank test to make sure the generator is fully functioning. The test employs a machine, called a load bank, that simulates different levels of load, which is the amount of electricity being made by the generator.

"It gradually builds the load up and shows you can operate the generator at capacity without any problems," said Wade. "It helps reduce the number of failures in the field."

Generators that pass the test are signed off as fully mission capable and returned to the inventory of generators available for installation -- another step in the USACE's nonstop efforts to bring back power to all of Puerto Rico.