What actions must be taken after containing a HAZMAT spill?

After containing a HAZMAT spill, it is essential to notify the dispatcher and initiate cleanup operations. This action is crucial because the dispatcher needs to be informed of the situation to coordinate any necessary emergency response and ensure the safety of the crew and those nearby. Cleanup is a fundamental part of spill management, as it minimizes environmental impact and reduces potential hazards to the public and the surrounding area.

The other options do not align with the necessary protocols following a HAZMAT spill. Leaving the site would abandon the situation without ensuring the safety of the area or mitigating any further risks. Beginning an investigation into the cause may be important but should occur after proper notification and cleanup processes are initiated. Reporting to the nearest fire station could be useful in specific situations, but it is not a primary action immediately following the containment of a HAZMAT spill.