In this Guide:
- Septic Tank System Basics
- Why Septic Tank Systems Need Attention and Maintenance
- Overview of Septic Tank System Upkeep
- How To Perform Septic Tank Inspections, Cleaning and Maintenance
- When Is It Time for Septic Inspection and Maintenance
- Warning Signs of Septic Tank Failure or Needed Maintenance
Septic Tank System Basics
First, understanding that a septic tank is part of a complete system as well as how it is designed and operates is key to properly caring for what is a miniature onsite wastewater treatment plant. As a whole, the conventional gravity-fed septic system is most often used and can be thought of in three parts:
- Plumbing, both incoming and outgoing
- Septic tank, for holding and breaking down sewage
- Drain field, also called soil absorption field, leach field, or septic lateral field
For more info, see our article on 5 types of septic tank system types.
Septic tanks are built with an inlet port and baffle that receives wastewater as blackwater and greywater influent from a property’s toilets, sinks, bathing facilities, and washing machines. A septic tank may be a single chamber or two, and it may be made of concrete or polyethylene plastic, which is increasing in popularity as a durable replacement option for concrete tanks.
Chambered septic tanks are joined by baffle plumbing, and the first chamber is where most biodegradation of waste material is intended to occur and accumulate. Many septic tanks have an outlet port baffle and filter that keeps solids in and discharges semi-treated water only, known as effluent, to the system’s final step in the treatment process: the drain field.
A properly working septic tank should always be full of water. If the water level is low, it can indicate a leak in the tank. As new water enters, some water will be discharged into the leach field for treatment by bacteria in the soil. Two important layers are also always present in an active septic tank: the sludge layer and the scum layer.
- The sludge layer is located at the bottom of the tank and is made up of the heavier waste solids being digested and broken down by anaerobic bacteria that are responsible for how the whole system works.
- The scum layer is located at the top of the water in the tank and is made up of the water-insoluble waste of fats, greases and light-weighted solids that may not get broken down by the bacteria in the septic tank.
- Over time, both layers will increase in size and will eventually need to be pumped out.
Why Septic Tank Systems Need Attention and Maintenance
The average American household will produce anywhere between 25,000 to 80,000 gallons of wastewater every year. Anywhere within these gallon ranges is a significant volume of water that needs to be managed. When a septic tank is neglected, it can overflow or clog with sludge and scum, which can, at its worst, lead to a costly system collapse. For this reason, you need to keep your septic tank in top working shape.
For properties and homes on septic systems, having a tank and drainfield that is regularly inspected, maintained and correctly cleaned is the answer to having a properly operating system and to many successful years in personal waste management.
By definition, septic tanks are not connected to municipal companies, sewers or waterworks; it’s your property, your responsibility. No one is going to clean or maintain that tank but you. Failure to do so is the leading cause of septic tank system failure. And failed systems can result in cleanup or repair costs from:
- Damages to your property or even a neighbor’s property
- Backup of sewage inside your property
- Replacements or repairs to the tank or leach field
- Polluted surface waters, which local authorities or health departments may not be overly pleased about, and fines can be issued for the improper management of personal wastes
Consider it another way for why the septic system should be a regular part of property upkeep. Do you want a septic tank system that results in high-cost fixes and/or recurring problems every few years? Or do you want one that will perform as intended with minimal to no issues for 10 to 25 years, the projected average working life of a standard septic system?
Overview of Septic Tank System Upkeep
The regular maintenance of the septic tank as a system does not need to be difficult, intimidating or an expensive process. Good septic tank upkeep can be broken down into four main points:
- Inspect and pump: as part of regular maintenance and preventive care
- Be water efficient and knowledgeable: concerning your water use and any heavy fluctuations
- Dispose of waste properly: if it’s not biodegradable or simply shouldn’t be in the septic tank, make sure it doesn’t end up there
- Maintain system leach field: to ensure it remains functioning optimally
How To Perform Septic Tank Inspections, Cleaning & Maintenance
To inspect and maintain a septic tank and system you will need to: (1) Locate the tank if unknown; (2) Optional: unearth and inspect tank and plumbing connections for cracks and leaks; (3) Open the tank lid or manhole(s); (4) Measure scum and sludge layers; (5) Clean the outlet baffle filter, and; (6) Have a company pump out wastes or perform any needed repairs. A professional septic tank company should be able to perform all of these steps.
1. Locate the Tank — All septic tanks are buried underground except for aboveground septic tanks. Underground septic tanks can have plumbing vents or risers that make locating them easier. If location is unknown, review property land records or system installation documents to determine septic tank location. If this fails and no other clues are present, a septic pumping company should be able to locate your tank for you at an extra cost.
Septic tanks have top access ports known as manways and are recommended with tank manhole risers that make tank location and maintenance much easier. Risers extend the tank’s reach up to ground level so the septic tank lid can be accessed without digging. If your tank does not have risers, they can often be installed as an add-on for future jobs.
2. Optional: Unearth Tank & Plumbing — For underground septic tanks, if external visual inspection is desired, the tank will need to be unearthed. This should be done carefully and with simple tools, not machinery, to avoid damage to the tank or system.
After unearthing, the tank and its connections can be inspected for annual wear, corrosive damage from soil effects, or cracks that can allow water infiltration or escape that affects total system performance. This optional step is more recommended for aged tanks and systems.
3. Open Tank Lids / Manways — If the inside of the tank needs to be inspected or the sludge and scum layer measured, this is recommended and best performed by a professional.
If self-inspection is preferred, never breathe in fumes from the tank, especially on first opening. The septic tank is an oxygen-less environment and high in methane gas, which over-exposure to can cause asphyxiation. Exercise caution at all times, even with looking into a septic tank. Falling into a functional septic tank can be fatal, especially if no one is around to help.
4. Measure Scum and Sludge Layers — These are two distinct, separate layers in a septic tank. The scum layer floats, while the sludge layer settles on the bottom. The results of measuring these layers will determine if it’s time to call a pumping company.
There are various ways to measure these layers, and in a two chamber septic tank, both chambers need to be measured. Common methods involve making measuring poles from PVC pipe that can be used to determine where the scum and sludge layers are and how thick they are.
For the Sludge Layer: Use an “L-shaped” pole. Lower it into the tank past the floating scum layer until point of resistance. Mark this point on the pole. Push the pole into the sludge layer until it reaches the bottom of the tank. Mark this point. The distance between your marks is the thickness of the sludge layer.
For the Scum Layer: Use a straight pole with a white, absorbent material or cloth at least 12 to 18 inches long attached to the end. Insert the scum pole into tank contents, remain in location and slowly agitate the pole to promote staining of the absorbent material by the scum layer. After 30 – 60 seconds, a discernible stain should be present on the scum pole which can serve as an indicator of the scum layer thickness.
(See “When Is It Time for Septic Inspection and Maintenance” below for individual measurement results that indicate when pumping is needed.)
5. Clean the Baffle Filter — In the second chamber and in the outlet baffle there is often a filter installed in the plumbing to keep solids out of the drain field. Most filters can be simply lifted out and rinsed with a hose jet to clean. Do not use cleaners or chemicals that can injure septic tank balance. Filters can be rinsed directly into the open septic tank.
6. Pump Wastes from the Tank — Pump removal of scum and sludge from a septic tank is best reserved for professionals. This is due to hazards associated with the wastes as well as disposal regulations in place by government.
The main idea behind septic tank cleaning is to ensure solid materials do not accumulate to the point of making it to the outlet plumbing or cause backup within the property. In septic systems, we never want solids to make it to the drain field. The drain field is not designed to accept solid materials but liquids only, i.e., septic effluent. If solids make it to the drain field, it can cause clogging and lead to system failure. This is one reason why regular pumping is important to prevent this from happening.
Note: Proper, correct cleaning of a septic tank and system does not involve the use of any chemicals, washing or scrubbing. Rather, septic cleaning is about regular inspections to ensure it is free of damages, that it is operating properly and determining if it is time for the tank to be pumped. Chemicals, cleaners and even septic-designated additives can do more harm than good, kill the necessary bacteria, and are, in general, not needed for a septic tank to work or continue working correctly. To best maintain your septic system, do your best to avoid having chemicals added to the tank through sinks, drains, or otherwise.
When Is It Time for Septic Inspection and Maintenance
In short, there is no catch-all answer because systems and usage volumes are often unique to the property. Inspection, cleaning, and pumping of a septic tank should be a calculated and carefully considered operation, one that is ideally tailored to the specific water use and waste production of the specific septic system. This will be based on tank size, household size of people and facilities contributing to wastewater generation, and the efficiency of the drainage field.
Systems should be cleaned often enough to avoid clogging or other types of system failure. But not too frequently that you incur unnecessary maintenance costs. While uncommon, local government and health departments may have standard requirements on when inspections and/or clean-outs must occur and on reporting results. If unknown, it is recommended to contact your local health department concerning the required, regular maintenance of your septic tank if any.
In General:
- Septic tank and plumbing are recommended to be unearthed and visually inspected for cracks, corrosion or other signs of failure every 2 to 5 years after 5 to 10 years of service. This may need to be done more frequently in concrete septic tanks vs polyethylene septic tanks as the chance is greater for problems to arise with concrete.
- Septic baffle filters are recommended to be inspected and/or cleaned annually or once every two years as a clogged filter can slow effluent release into the drainage field. Frequency is dependent on total tank cleanliness and operation and is often done when the septic tank is pumped.
- Pumping of septic tank contents should occur at regular intervals and is dependent on actual, personal water volume use, septic tank size, type of system and effectiveness of the drain field. Pumping will need to occur more regularly if the tank is small or smaller than recommended for the projected use and if the wastewater volume generated is large such as due to the amount of people it services.
On average, septic tank inspection and pumping is recommended to occur every 2 to 5 years and should be done when:
- Measured sludge layer is beyond one-third the level of the tank or is nearing the tank’s drain field outlet from about 12 inches;
- The scum layer is within 3 inches of the bottom of the tank’s drain field outlet plumbing, and/or when;
- The scum layer is 6 inches thick or greater.
We have included the following table adapted from higher educational research from the Pennsylvania State University. The table outlines approximate septic tank pumping schedules based on tank size and household size:
Warning Signs of Septic Tank Failure or Maintenance Needed
Knowing the signs of a poorly performing septic tank or, worst case, a failed tank is important as an individual owner and caretaker of a septic system. The following points can be indicators of tank failure or that it’s time for some necessary maintenance:
- Sudden changes in normal plumbing system operation such as gurgling or slow draining fixtures
- Odors of sewage inside the property or outdoors, especially after heavy rains then dry sunny days
- Sewage waste backups, such as returned flushing to drains and fixtures
- Water and/or waste accumulating on top the drain field
- Atypical or abundant plant growth on top of the septic tank
For #3 above, if toilet flushes are being returned to your other toilets or your shower, this is a serious indicator the septic tank is likely full or may not be functioning properly. In this case, call a septic tank pumping company to come out to clean and pump your septic tank. In the meantime, limit the total water use inside the property as much as possible.
Takeaway | Proper Cleaning and Caring for a Septic Tank
Cleaning and caring for your septic tank can be a complex job or a simple task. It can be complex when it involves unearthing the system to inspect plumbing connections and the septic tank’s structural integrity. Or maintenance can be more on the simple side when it involves cleaning the tank filter, measuring the sewage layers, and/or pumped by a professional. In either case, proper care of your personal septic tank system is vitally important to its continued operation and to ensuring a long service life without highly undesirable or costly septic tank problems.
For more information concerning septic tanks, systems, or other maintenance resources, review our knowledge base. If looking for polyethylene underground septic tanks, we provide North America’s top quality septic tanks rotationally molded by today’s industry-leading manufacturers. We offer the septic tank style, volume capacity, and options you are looking for. For questions or further assistance, we are America’s liquid tank experts, never hesitate to contact us today.