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Medications are a part of daily life for many people. Have you thought about how your medications may affect your septic system and the treatment of wastewater? Normal use of many medications including over the counter drugs will not harm your septic system. However, antibiotics and certain strong medications such as those used in chemotherapy can affect the operation of your system.
High concentrations of antibiotics or chemicals can kill or retard the growth of the bacteria in your septic tank and soil treatment area (drainfield or mound). These bacteria are necessary for proper operation of your system because they digest some of the organic matter entering the tank. They reduce the amount of solids in the tank and reduce the biochemical oxygen demand (BOD) of the effluent—the water leaving the tank to the soil treatment area. If the tank bacteria are destroyed, solids accumulate in the tank much faster and can create problems in the soil treatment area.
If you expect to be taking medications on a long or short-term basis, there are some things you can do to protect your septic system and groundwater. The human body does not completely metabolize medications, so they enter septic systems unavoidably through our body wastes. Certain medications may cause premature failure of your septic system.
Do not flush leftover medications into your septic system. High concentrations of antibiotics will destroy the beneficial bacteria. There is also potential for medications to contaminate groundwater, as a septic system may not adequately remove them from the wastewater. Some pharmacists will dispose of the medication for you if you return it to them.
There are many possible solutions to deal with medication use and septic systems. They start with simple techniques, but get more sophisticated as the problem increases.