You need to have a regular septic pumping so that the sludge in your septic tank will be removed. If your septic tank is left uncleaned, some parts of the system will deteriorate and clog your leach field. It will lead to an expensive repair compared to the cost of having a regular septic tank maintenance.
One of the main problems why you need to repair your septic system is because of clogging. Septic tanks gradually fills up with solid wastes if not maintained properly. This in turn can clog the drains and toilets in your house. Having as a regular septic tank maintenance will save you of all that hassle.