Investigate the T-105 high level alarm activation
You are a process safety engineer in Process Safety and Emergency Response.
What has happened
On 8 September a road tanker receipt of hydrochloric acid into tank T-105 reached 92 percent and activated the high level alarm before the operator stopped the transfer. The high high trip at 95 percent was not reached. The transfer register shows a planned receipt of 19.6 tonnes, the automatic gauge read 39 percent before the receipt and the weekly manual verification of the gauge was overdue. The tank data sheet gives the safe fill level and the receipt margin. The safety case lists the high level alarm and the high high trip as control measures for tank overfill. Declan Murphy wants a timeline, causes, an assessment of the safety case control measures and corrective actions for the process safety review on 23 September, and a view on whether the safety case needs to change.
Deliverables
- Evidence file and interview notes
- Timeline with reconciliation of quantity and level
- Cause analysis
- Control measure assessment against the safety case
- Investigation report with corrective actions and register update
Documents to use
Systems to use
Incident and Process Safety Event Register
Logs injuries, near misses, losses of containment, safety system activations, limit excursions and environmental events with tier, investigation and actions.
Bulk Transfer and Tank Inventory Register
Records every receipt, internal transfer and dispatch of bulk product with tank, quantity, gauging and reconciliation.
Management of Change Register
Tracks every management of change request from submission to close-out including temporary changes, overrides and their expiry dates.
Units of competency
Current on training.gov.au for the Chemical, Hydrocarbons and Refining as at 10 September 2026.
PMAWHS310Investigate incidentsPMAWHS502Contribute to safety casePMAOPS240Store fluids in bulkPMASUP420Minimise environmental impact of processPMAOPS402Respond to abnormal process situationsQualifications
PMA40116Certificate IV in Process Plant TechnologyPMA50116Diploma of Process Plant TechnologyWhat to look for
Evidence guide
Look for a timeline built from records rather than recollection, the gauge accuracy tested by reconciliation, underlying causes that address the system and not only the operator, an honest assessment of whether the alarm and trip met their performance standards, and corrective actions that prefer engineered controls. The safety case recommendation must be reasoned from the control measures identified.