Frequently Asked Questions

On Long Island, septic systems usually consist of two main parts; a septic tank and a cesspool, or drainage field. The septic tank is a watertight box, usually made of concrete or fiberglass with inlet and outlet pipes. Wastewater flows from the home to the septic tank through a pipeline. The septic tanks treat wastewater naturally by holding it in the tank long enough for solids and liquids to separate.

The wastewater forms three layers inside the tank. Solids that are lighter than water, such as greases and oils, will float to the top and form a layer of scum. Solids that are heavier than water will settle at the bottom of the tank to form a layer of sludge. This leaves a middle layer of partially clarified wastewater.

The layers of sludge and scum remain in the septic tank where bacteria occurring naturally in the wastewater work to break the solids down. Natural bacteria generated by the solid waste partially decompose the waste in the cesspool and septic tank and reduces the amount of solid material by as much as 60 percent.

The sludge and scum that cannot be broken down remain in the tank until being pumped out. The layer of clarified liquid flows from the septic tank to the cesspool. 

The cesspool, or overflow pool, has holes on the sides and bottom that allow the clarified liquid from the septic tank to leach out into the ground. This leach field allows wastewater to slowly trickle from the pipes down through the soil. The soil acts as a biological filter.

The most important thing you can do as a homeowner is having your septic tank pumped out regularly, every two to three years in most cases. There are a few other things to remember that will help you get the maximum efficiency out of your system:

1. Don't park heavy vehicles over your septic system. You may damage the components
2. Don't build structures over your septic tank or in any area that would cover the leach field or block access to the septic tank for servicing
3. Avoid septic tank additives. A properly maintained septic tank does not need additives to function efficiently. Chemical or biological additives may cause damage and are unnecessary
4. Think twice before installing a garbage disposal. The trade-off for the convenience of putting food waste down the drain will be a substantial increase in the volume of solids entering your septic tank, leading to the need for more frequent pumping
5. Don't plant a vegetable garden over your septic tank
6. Conserve water to extend the life of your system. Fix leaky toilet tank valves and drippy faucets. The more that goes in, the more often you'll need to pump
7. Plants grass and other shallow-rooted plants over your septic system. Deep-rooted shrubs and trees can grow into the pipes and clog the system

The label may say it's flushable, but don't believe it. Items that are not easily biodegradable will clog up your septic tank. Many common household chemicals can interfere with the biological process necessary to break down waste materials. Here's a partial list of items you should not flush. If you're not sure if something is flushable, assume it isn't!

DO NOT FLUSH:

• Paper towels
• Cotton swabs
• Personal hygiene products
• Medications
• Disposable diapers
• Coffee grounds
• Cat litter
• Cooking fats and oils
• Facial tissues
• Dental floss
• Cigarette butts
• Plastics
• Grease
• Bones
• Antibacterial products
• Drain cleaners
• Paint, solvents, or paint thinners
• Motor oil or antifreeze
• Pesticides