According to a spokesperson, Exxon Mobil (XOM) has temporarily suspended operations at an oil pipeline system at California’s Port of Long Beach.

The energy giant says it took the action “in an abundance of caution” once an oil leak had been detected in the area. The affected pipeline — the THUMS system — carries up to 155,000 barrels of oil daily from Long Beach Harbor to Exxon’s refinery in Torrence, Dow Jones notes.

Exxon has filed documents with the California Emergency Management Agency indicating that the leak did not affect local waterways.

The company did not identify the source of the leak or say how much oil had been released, but it noted that the oil had been contained.

Earlier this year, a New Hampshire jury imposed a $236 million fine on Exxon Mobil for contaminating groundwater in the state.

Shares of Exxon Mobil fell almost 1% in Tuesday morning trading.