When a home isn’t connected to a municipal sewer system, it uses a septic tank system. Septic tank systems are self-contained units consisting of a septic tank and a drain field buried just below the lawn. Generally, they take care of themselves and require periodic draining, cleaning, and inspection by a certified professional at least once a year. When things go awry with your septic system, you can do a few things before calling in the pros. Learn how to troubleshoot common septic system issues.