Septic systems are designed to provide long-term, effective treatment of householdwaste when operated and maintained properly. However, most systems that fail prematurely are due to improper maintenance. Less serious problems are usually withplumbing (such as pipe blockages from tree roots growing into the pipe). Sometimes,the septic tank, although durable, can deteriorate or have other structural problems. The most serious problems are the result of a clogged drainfield. Unfortunately, this isthe most expensive to repair. Once the absorption field is clogged, it must be replaced and can cost thousands of dollars.