The MFSA plan was activated for a suspected stern tube leak at a vessel at berth. An MFSA ISRC and Clean Rivers Response Manager responded, mobilizing an OSRV. Clean Rivers completed initial assessment and found limited sheening. Per the ISRC the USCG and WA DOE requested containment booming until repairs could be made. Once it was identified that the heat exchanger was leaking and repaired, boom was removed the next day.