Sewage comes in several types: domestic sewage, commercial or industrial sewage, agricultural sewage, and storm sewage. Domestic sewage (also called wastewater) is the waste product from the used water from houses and apartments that comes from kitchen, bathroom, and laundry rooms: bath water, kitchen disposal, laundry tub drains, and toilets, for example. Domestic sewage contains more than just water. It contains anything that might go down the drains: soaps and cleaners, bits of food, hair, and anything else that might get flushed or drained down. The sewage also contains organic materials and plant nutrients that help it to rot along the way. Sewage treatment plants and septic tanks both neutralize and deactivate the chemicals found in wastewater, relying on bacteria that will eat away the nitrates and organic matter that is found in the wastewater.
But homeowners beware! Just because there is a drain doesn’t mean you should just pour anything down it! Paints and paint thinners, unused medications, grease or oils, pesticides, disinfectants, antifreeze, and gasoline can all affect the organisms that digest and treat the waste and can actually be toxic for a septic system. The same rule applies to toilets: if it is not urine, fecal matter or toilet paper, it should not be flushed. The toilet is not a garbage can! Cat litter, coffee grounds, baby wipes, feminine products, cigarette butts, and dental floss, for example, can all clog a septic system and potentially damage the system’s components if they become stuck. If it doesn't belong, bag it and dispose of it in the trash; and even better, if it’s organic, compost it!