Answers to your Questions Additives— Most household wastewater supplies bacteria for proper septic tank operation. Use of laundry detergents and small amounts of bleach will not harm the naturally occurring bacteria found in the tank. If you use excessive amounts of cleansers and detergents, you may want to consider using a biological enhancer. Accurate Waste Systems, Inc., provides a bacteria culture specifically designed to replace and enhance the bacteriological environment. Yeast— Case studies have determined yeast is not an effective additive for a septic tank. Garbage Disposals— If a garbage disposal is used in a home with a septic tank, the tank solids will accumulate more rapidly than homes without a disposal. This facilitates the need for annual septic pumping. Pump Tanks— Pump tanks are used when the elevation of the drainage area is higher than the outlet of the septic tank. Be sure to periodically inspect the pumps, floats and electrical connections. Knowing When to Pump Your Septic Tank— Residential septic tanks should be pumped every three years and more often if the household consists of more than four people. It is important to remember that it is the amount of sludge in the tank that determines the need for pumping.