These symptoms tell you that you have a serious problem:

• Sewage backup in your drains or toilets. This is often a black liquid with a disagreeable odor.
• Slow flushing of your toilets. Many of the drains in your house will drain much slower than usual, despite the use of plungers or drain cleaning products.
• Surface flow of wastewater. Sometimes you will notice liquid seeping along the surface of the ground near your septic system. It may or may not have an odor associated with it.
• Lush green grass over the absorption field, even during dry weather. Often, this indicates that an excessive amount of liquid from your system is moving up through the soil, instead of downward, as it should. While some upward movement of liquid from the absorption field is good, too much could indicate major problems.
• The presence of nitrates or bacteria in your drinking water well. This indicates that liquid from the system may be flowing into the well through the ground or over the surface. Water tests available from your local health department will indicate if you have this problem.
• Buildup of aquatic weeds or algae in lakes or ponds adjacent to your home. This may indicate that nutrient-rich septic system waste is leaching into the surface water. This may lead to both inconvenience and possible health problems.
• Unpleasant odors around your house. Often, an improperly vented plumbing system or a failing septic system causes a buildup of disagreeable odors around the house.
• Several products are marketed with the pledge that they can keep septic systems operating smoothly, correct system upsets, or do away with the need to pump the tank periodically. Chemical additives are strong acids or alkalis, or organic solvents. Biological additives are cultures of harmless bacteria, plus waste-digesting enzymes. These sometimes contain yeast cultures.
• Although some manufacturers of additives have test data showing how their products perform, there has been almost no independent testing of these products in full-sized septic systems. The information that exists does not show improved long-term performance in systems where additives have been used. If a system is not being misused by the homeowner, these products are unlikely to pose a benefit. The amount of material added with each dose of product is small compared to the biological material already present and working in the tank.
• Occasionally a system suffers an upset when the septic tank bacteria are harmed or destroyed. This can happen if the home is vacant for a long period and the tank receives no fresh wastewater, or if strong cleaning agents are flushed down the drain. After a few days of normal use, the biological system in the tank will re-establish itself. In this situation the biological additives may help speed the recovery of the septic tank.
• Every septic tank needs to be pumped periodically, because all wastewater contains inert matter that cannot be degraded in the tank. No additive can do away with this need.