How to Maintain Your Septic System

How to Maintain Your Septic System

...from the National Small Flows Clearinghouse at West Virginia University

Septic systems are a very simple way to treat household wastewater and are easy to operate and maintain. Although, homeowners must take a more active role in maintaining septic systems, once they learn how their systems work, it is easy for them to appreciate the importance of a few sound operation and maintenance practices.

How Septic Systems Work

There is two main parts to the basic septic system: the septic tank and the drain field. 

The Septic Tank

Household wastewater first flows into the septic tank where it should stay for at least a day. In the tank, heavy solids in the wastewater settle to the bottom forming a layer of sludge, and grease and light solids float to the top forming a layer of scum.

The sludge and scum remain in the tank where naturally occurring bacteria work to break them down. The bacteria cannot completely break down all of the sludge and scum, however, and this is why septic tanks need to be pumped periodically. 

The separated wastewater in the middle layer of the tank is pushed out into the drain field as more wastewater enters the septic tank from the house. If too much water is flushed into the septic tank in a short period of time, the wastewater flows out of the tank before it has had time to separate. This can happen on days when water use is unusually high (laundry day, for example), or more often if the septic tank is too small for the needs of the household.

The Drain field

When wastewater leaves a septic tank too soon, solids can be carried with it to the drain field. Drain fields provide additional treatment for the wastewater by allowing it to trickle from a series of perforated pipes, through a layer of gravel, and down through the soil. The soil acts as a natural filter and contains organisms that help treat the waste. Solids damage the drain field by clogging the small holes in the drain field pipes and the surrounding gravel, and excess water strains the system unnecessarily.

How To Care for Your System

Septic system maintenance is often compared to automobile maintenance because only a little effort on a regular basis can save a lot of money and significantly prolong the life of the system.

Sound septic system operation and maintenance practices include conserving water, being careful that nothing harmful is disposed of through the system, and having the system inspected annually and pumped regularly.

By educating everyone in your household about what is and what isn't good for septic systems, they can begin to develop good maintenance habits. 

Use Water Wisely

Water conservation is very important for septic systems because continual saturation of the soil in the drain field can affect the quality of the soil and its ability to naturally remove toxins, bacteria, viruses, and other pollutants from the wastewater.

The most effective way to conserve water around the house is to first take stock of how it is being wasted.  Look at your monthly water bill.  If more then 14,000 gallons of water (500gal. per day) are going down the drain monthly your using too much water. Immediately repair any leaking faucets or running toilets, and use washing machines and dishwashers only when full.

In a typical household, most of the water used indoors is used in the bathroom, and there are a lot of little things that can be done to conserve water there. For example, try to avoid letting water run while washing hands and brushing teeth. Avoid taking long showers and install water-saving features in faucets and shower heads. These devices can reduce water use by up to 50 percent. Low-flush toilets use one to two gallons per flush compared to the three to five gallons used by conventional toilets. Even using a toilet dam or putting a container filled with rocks in the toilet tank can reduce water use by 25 percent.

It is also important to avoid overtaxing your system by using a lot of water in a short time period, or by allowing too much outside water to reach the drain field. Try to space out activities requiring heavy water use (like laundry) over several days (If you routinely do multiple loads of laundry in one day you will blow your drain field). Also, divert roof drains, and surface water away from the drain field.

Know What Not To Flush

What you put into your septic system greatly affects its ability to do its job. As a general rule of thumb, do not dispose of anything in your septic system that can just as easily be put in the trash. Remember that your system is not designed to be a garbage disposal, and that solids build up in the septic tank and eventually need to be pumped out.

In the kitchen, avoid washing food scraps, coffee grinds, and other food items down the drain. Grease and cooking oils contribute to the layer of scum in the tank and also should not be put down the drain. Grease and other floating solids are prevented from flowing out of the tank by a baffle, filter, or screen located on the inside of the tank at the outlet end.  Another baffle is placed on the inlet side of the septic tank.  This forces the incoming waste down into the tank, which prevents short-circuiting across the tank. These baffles can deteriorate over time and must be checked at each tank servicing.  In theory, only liquid flows out of the septic tank and into the drain field, thereby recycling the household wastewater into the ground.  There are tank effluent filters available that can prevent larger suspended solids in wastewater from getting out of the septic tank, which may clog pumps, distribution pipes and soil.  These filters are commonly serviced with routine septic tank pumping.

The same common-sense approach used in the kitchen should be used in the bathroom. Don't use the toilet to dispose of plastics, paper towels, tampons, disposable diapers, condoms, kitty litter, etc. The only things that should be flushed down the toilet are wastewater and toilet paper. 

Antibacterial soaps are dangerous to the life of your drain field too.  The new soap kills the bacteria that break down the solids.  The solids clog your filter and eventually your drain field.  An annual inspection by a qualified septic company will help monitor the health of your system.  If your soap products are causing a problem your professional can help.

Avoid Hazardous Chemicals

To avoid disrupting or permanently damaging your septic system, do not use it to dispose of hazardous household chemicals. Even small amounts of paints, varnishes, thinners, waste oil, photographic solutions, pesticides, and other organic chemicals can destroy helpful bacteria and the biological digestion taking place within your system. These chemicals also pollute the groundwater.

Some septic system additives that claim to help or clean your system also contain hazardous chemicals and should be avoided. Household cleaners, such as bleach, disinfectants, and drain and toilet bowl cleaners should be used in moderation and only in accordance with product labels. Overuse of these products can harm your system. It makes sense to try to keep all toxic and hazardous chemicals out of your septic tank system when possible. 

To help prevent groundwater pollution, be sure to dispose of leftover hazardous chemicals by taking them to an approved hazardous waste collection center. For locations and more information, contact your local health department.

Pump Your Tank Regularly

Pumping your septic tank (every 3 years) is probably the single most important thing you can do to protect your system. If the buildup of solids in the tank becomes too high and solids move to the drain field, this could clog and strain the system to the point where a new drain field will be needed.

Outlet Filter/Screen

The outlet filter/screen of the primary treatment tank should be cleaned as necessary to ensure proper operation.  The filter cartridge must not be removed unless provisions are made to retain solids in the tank that may slough off the filter when removed from its enclosure.  Avoid letting hair go down the drain as it will clog up your filter, requiring more frequent service calls.

There are circumstances that shorten the life of a drain field:

Inspect Your System Annually

Inspecting your septic system annually is a good way to monitor your system's health. Inspections can reveal problems before they become serious, and by checking the levels of sludge and scum in your tank, you can get a more accurate idea of how often it should be pumped.

Protect Your System

Finally; it is important to protect your septic system from potential damage. Don't plant anything but grass near your septic system: roots from shrubs and trees can cause damage: and don't allow anyone to drive or operate heavy machinery over any part of the system. Also, don't build anything over the drain field. Grass is the most appropriate cover for the drain field.

Frequent Questions And Answers

Q Should I add anything to my septic tank?

A Biological and chemical additives are not needed to aid or accelerate decomposition. At this time, there is no conclusive data to support the effectiveness of enzymes or any chemical treatment to rejuvenate a failing drain field.  These products are approved by the State of Wisconsin only if they do not harm the septic system.

Q What are the warning signs of a failing septic system?

A These signs may be indicators that the drain field is failing: 

1.    Plumbing backups

2.    Grass in the yard growing faster and greener in the area of  the drain field

3.    Soft or mushy ground in the area of the drain field

4.    Sluggish toilet flushing

5.    Septic pump runs constantly

Q Can garbage disposals be used with a septic system?

A Yes, but try to avoid allowing grease or slowly biodegradable products such as coarse fruit, vegetable peelings and bones to get into the disposal.

Q Can I plant trees or shrubs over my drain field?

A Generally no.  Many tree species have roots that will attempt to grow into the drain field to seek out moisture and nutrients.  These may break sewer lines or disrupt the distribution of effluent.  There are some trees and shrubbery whose root systems cannot stand "wet feet" and are safe to plant over or near drain fields.  Your local landscape contractor or garden center is a good source of information.

Q What if liquid is observed in the drain field vent or observation tubes?

A Liquid observed in the drain field vent usually indicates that the soil absorption capability of the drain field is reduced and ponding is progressing.  Many systems begin ponding within the first few years.  The ponded state of a drain field is usually a slowly developing condition.  The estimated life of today's drain fields under normal usage is 15 to 25 years and sometimes much more.  The performance and life expectancy of a septic system must never be judged by age alone.  The drain field can be ponded to some degree for many years and still function normally.  A consistently rising level of ponding is a possible indicator as to the life expectancy of a drain field.  Sludge in a vent pipe or observation tube is an indicator of a more serious condition.  Many lending institutions and some inexperienced inspectors have been using the observance of any liquid in a vent or observation tube as the sole criteria for failing a septic system for a proposed sale or purchase of a home.  As noted above, this is an inaccurate conclusion.  Technical failure of a septic drain field is when the effluent is bleeding out onto the ground surface, wastewater backing up into the building (not due to plugged or broken sewer lines) or the existing drain field was installed less than 3 feet to a saturation zone, groundwater, bedrock or impervious soil.  Careful and accurate dye testing of the system by an experienced septic inspector is the only way to accurately access the remaining life expectancy of the drain field.  

Q What can I do to prolong the life of my drain field?

A There are a variety of things you can do:  Install water saving devices and be on-guard for leaky fixtures.  Water conservation reduces the amount of liquid going into the drain field.  Have the tank(s) pumped and inspected regularly.  Keep surface water away from the septic system area, including the septic and pump tanks.  Keep driveways, parked vehicles and buildings off the drain field area.  Soil compaction can cause premature failure by restricting the infiltrative and evaporative capability of the soil.  Installing an effluent filter to confine most of the suspended solids to the septic tank.  The use of pretreatment components has been shown to improve effluent quality and moderate or reduce ponding.  Understand what can and cannot be put into the septic tank.