My suggestion:
1. Tank basement was dirty
- Correction: Clean it immediately
- Corrective action: Establish a cleaning schedule, regular checking / audit / inspection etc.
2. Screw nut bolt were found in production area
- Correction: Remove it immediately from the area
- Corrective action: Establish a procedure, regular checking / audit / inspection, Warning (to the specific person if you know) etc
3. Uncover drain line was found
- Correction: Cover or seal it permanently
- Corrective action: Regular checking etc. (If permanently seal, then should be no corrective action)
4. Product line was found leaked.
- Correction: The repair immediately
- Corrective action: Establish the maintenance schedule, regular checking / audit / inspection etc.
5. Staff change room was found dirty and few lockers were found broken.
- Correction: Clean up immediately
- Corrective action: Establish cleaning schedule, awareness training, regular checking / audit / inspection, Warning (to the specific person if you know) etc