Common signs that your septic tank needs emptying include slow-draining sinks, showers, and toilets, foul odours coming from your drains or outside near the septic tank, and pooling water in your garden, particularly around the drain field. In severe cases, you might notice sewage backing up into your home. If you experience any of these symptoms, it’s crucial to contact a professional service immediately to inspect and empty your tank. Ignoring these signs can lead to significant health hazards, property damage, and costly repairs.