NYSDOH recommends that septic tanks should be pumped every two to three years or when the total depth of sludge and scum exceeds one-third of the liquid depth of the tank. However, a single person household may go longer between pumpings than a family of four.
Garbage disposals use should be avoided with a septic system, as they can produce large amounts of solids which bacteria are incapable of breaking down. Further, they can grind the food particles small enough that they pass through the septic tank into the leaching field, which can cause permanent damage. Regular use of a garbage disposal would shorten the time between pumpings to one year.
NYSDOH says, "Septic tank additvies are NOT recommended. Additives are unneccessary to the proper operation of the household systems and may cause the sludge and scum in the septic tank to be discharged into the absorption field, resulting in premature failure. Some additives may actually pollute groundwater."
Grease or cooking oil, latex paint pesticides hazardous chemicals, dental floss, feminine hygene products, condoms, diapers, coffee grounds, cat litter, caustic drain cleaners, paper towels, q-tips, baby wipes, medications, antibacterial soaps.