SOUTH PORTLAND — Sprague Energy employees are pumping out and preparing to repair a large kerosene storage tank at the company’s waterfront facility off lower Main Street after the tank developed a leak early Saturday morning.

The company’s security system detected the leak around 2:30 a.m. Saturday and employees notified public safety agencies as required, including the Maine Department of Environmental Protection, said Deputy Chief Paul Salway of the South Portland Fire Department.

Salway said he anticipated no harm to the public or the environment because the leak was caught early and the tank is surrounded by a berm or moat that is designed to capture 110 percent of the tank’s total capacity.

“They’re in the process of pumping the tank out,” Salway said Saturday afternoon. “It’s safe. This is old hat to them. They’ve called us with updates. They’re taking care of it 100 percent.”

Salway said he didn’t know how much fuel was lost in the spill or the size of the tank, but it’s one of the smaller tanks at the company’s facility off lower Main Street.

The tank farm, like several others in the city, is surrounded by a security fence, so it’s not accessible to the public, Salway said. Sprague employees are expected to finish emptying the tank by early Sunday afternoon and begin making repairs, he said.

The leaky tank is one of more than 100 large storage tanks that serve seven fuel terminals along the city’s waterfront, according South Portland fire officials. Firefighters inspect all fuel tankers that dock at the terminals and undergo training to respond to potential spills or fires at the tanks.