For homeowners with septic systems, the U.S. Environmental Protection Agency has some tips to ensure your system can handle the extra usage during the holiday season. It’s important to have a well performing system, as a malfunctioning one can kill native plants and fish, as well as reduce property values and lead to legal liability. Tips include: don’t allow parking or driving on your system’s drainfield to reduce damage to buried pipes; and never pour fats, grease, or solids down the drain as it may clog your system, have your system inspected every three years and your tank pumped every three to five years.