Multiple slow fixtures
One slow sink may be a local plumbing clog. Several fixtures changing at once deserves a broader system check.
Wet or lush ground
Unexpected saturation over the field can be a warning sign, especially with odour or surfacing effluent.
Alarms
Do not silence a pump or high-water alarm without finding the reason it activated.
Backups
Reduce water use and get qualified help quickly. Avoid opening a septic tank; confined-space gases and collapse hazards are serious.
Before you act
Keep the system location, approval records and service history together. For purchases, failures or renovations, use a qualified onsite professional appropriate to your province and the scope of work.