How Do Septic Tanks Work?
A septic tank system uses natural processes to treat and dispose of the wastewater generated in your home. It typically consists of a septic tank and a drain field, or soil absorption field. The septic tank provides the first step in treatment. As the wastewater flows into the tank, the heavier solids settle to the bottom to form a sludge layer, and the lighter solids, greases, and oils float to the top to form a scum layer. The liquid wastewater (effluent) from the tank flows into gravel-filled trenches in a typical drain field where it is distributed via perforated pipes and then treated by the natural soil system.
Septic System Operation – The septic tank provides some biological treatment of the sludge and scum layers that accumulate there. The majority of treatment occurs in the drain field where the effluent enters the soil and is treated as it percolates to the groundwater. The soil acts as a biological and physical filter to remove harmful substances, including disease-causing bacteria and viruses, toxic organics and other undesirable wastewater constituents remaining in the effluent.
Outlet filters or baffles are located in the tank and are designed to prevent the sludge and scum from flowing into the drain field. If the tank is not pumped regularly to remove the accumulated solids, the tank will fill with sludge and the solids will be washed out into the drain field, or clog the outlet filter. If solids reach the drain field or clog the outlet filter, they will quickly clog the soil and eventually lead to system failure.
5 Tips To Keeping Septic Tanks Working
A septic tank wastewater system can contaminate ground water, surface water and your yard with nutrients, bacteria and viruses if it isn’t maintained properly and pumped often enough. By following these, you can help ensure that your system continues to function properly, safely and without septic odors.
1. Inspect your septic system annually. Local septic pumpers can do this.
2. Pump out your septic tank regularly. Every three to five years is recommended by experts for a three-bedroom house with a 1,000-gallon tank. Smaller tanks should be pumped more often than that. This helps eliminate solids build-up that can clog your leach field.
3. Do not divert roof drains or basement sump pumps into septic systems. You want to drain as little water into them as possible.
4. Avoid or reduce the use of your garbage disposal. If you use a garbage disposal, have the tank pumped more frequently.
5. Don’t use your toilet as a garbage can! If you put lots of stuff down the toilet, you will need to have the septic tank pumped more often.
Why Does the Septic System Back Up During a Party?
Indeed it seems to be just the luck that we are living happily along not giving the septic tank a thought until we have a bunch of guests over for Thanksgiving, Chanukah, Christmas, or a graduation party. Why is it that at events we often see the septic system backing up?
The explanation is that a septic system that backs up during a party was already in trouble, but our usage was modest enough that we just weren’t noticing it. The surge of waste water entering the septic tank cannot flow into a flooded drainfield so sewage may back up into the home, usually at the lowest plumbing fixture. Sometimes it’s not the wastewater surge but someone flushing something down a toilet that blocks a drain – that’s a problem that can be cleared by a plumber using a plumbing snake or drain router. But often the problem is in the septic field itself.
Here are some simple tips for avoiding a septic backup during times of surges in use such as during a party:
1. Pump the septic tank before the party: When a septic system is otherwise in good working condition, the septic system stress created by having many people use the sinks, showers, and toilets over a short time is not so much the solid waste as the high wastewater volume in gallons. Very high water usage over a short time can flood a drain field or septic mound which in turn could cause a septic backup. Pump the septic tank right before the event, or the day before. This will give some extra capacity to absorbing this high use resulting in a sudden surge in wastewater volume.
2. Avoid using water unnecessarily after pump out. That means don’t leave running toilets un-repaired, don’t leave water running unnecessarily. See Water usage for a table of typical daily residential water usage under normal conditions.
3. Regular septic system maintenance, pumping on schedule, is the long term way to protect the system tank and drainfield from early failure and thus to protect from septic system backups.