The answer to 'why is my septic tank' is that there are several common causes for issues with a septic tank, including a full or clogged tank, leaks, or a problem with the drain field. Symptoms can include slow draining sinks and toilets, gurgling noises, or sewage backing up into the home.
Some potential solutions include having the septic tank pumped and inspected, fixing any leaks, or addressing issues with the drain field. However, many septic tank problems require the expertise of a professional plumber or septic service technician, especially for more complex issues. It's generally best to call in a pro rather than attempting DIY septic tank repairs.