A residential septic system uses natural and technological processes to treat household wastewater from toilets, showers, sinks, and other water-using appliances. When a septic system fails, it can spread untreated wastewater into homes or nearby water resources. Untreated wastewater contains bacteria, viruses, and other pollutants. These pollutants can make water in the immediate and downstream areas unsafe for people and wildlife to drink, bathe, or swim. The best way residents can prevent septic system failure is to follow best practices.
Best practices have other benefits too. By following best practices, a septic system can last between 20 and 30 years before it needs replacing. Increasing the periods in between replacements can save residents significant amounts of money over time. For example, according to the EPA, “Regular maintenance fees of $250 to $500 every three to five years is a bargain compared to the cost of repairing or replacing a malfunctioning system, which can cost between $3,000 and $7,000 for a conventional system” (https://www.epa.gov/septic/why-maintain-your-septic-system). When a septic system begins to fail, it can decrease the value of the land and home. Therefore, following septic system best practices saves residents money, protects their property values, keeps their families and neighbors healthy, and protects the environment.
There are four main categories of septic system best practices:
- Proper maintenance
- Drainfield protection
- Efficient water use
- Proper waste disposal
Proper Maintenance Best Practices
Proper septic system maintenance involves regular system inspections and pump-outs. Residents can perform visual checks of the drainfield for signs of failure and the cleanout for signs of blockages or leaks. Annual or biannual inspection is recommended. If residents are using alternative septic tank systems with mechanical parts, the residents should inspect this system annually. Residents or property owners should not inspect their tank levels themselves. SCDHEC requires a licensed contractor to repair and pump out septic systems. Septic systems contain toxic fumes, small spaces, and hazardous conditions that septic system contractors have the training, equipment, and personal protective gear needed to do the job safely. You can find a licensed septic system professional in your area on SCDHEC’s website which is located in the resource section below.
For more information on locating your drainfield and signs of failure, please refer to HGIC 1895, Be Septic Safe: Considerations for New Septic System Users, Locating the System, & Basic Maintenance and HGIC 1897, Be Septic Safe: Septic Failures. Regularly inspecting septic systems can help detect issues early on. Early detection can keep repair costs down and potentially avoid expensive problems. If residents notice any signs of failure, a licensed professional needs to inspect and repair the system as soon as possible.
Septic systems also need regular pump-outs. The average system needs to be pumped out every three to five years, but the actual frequency may vary depending upon the size of the tank and the number of people using the system. The septic tank size determines how much solid material the system can hold at one time, and the number of people using the system determines how fast a tank will fill up. Contractors recommend pumping out the tank once it is one-third to one-half full of solid waste.
When it is time for a pump-out, a septic tank professional will locate the system, inspect its condition, and make recommendations for future maintenance along with pumping out solid waste from the tank. Keep a record of all septic system maintenance performed by contractors. Note the date, the activity performed, the name and contact info of the contractor, and any comments. You can find a downloadable form for this type of record-keeping on the EPA’s Tools about Septic Systems for Homeowners website, which can be found in the resource section below.
Residents may need to inspect or pump out septic systems more frequently if the system is older, it’s an engineered system, or in a unique situation like flooding and drought. For more information, please refer to HGIC 1898, Be Septic Safe: Unique Situations.
Drainfield Protection Best Practices
The drainfield is one of the essential features of a septic system. The drainfield is where all the liquid waste goes to be filtered and cleaned by the soil. When drainfields are not protected, they can cause the septic system to clog, back up, and pollute local waterways. The first step to protecting the drainfield is to know and mark its location. For more information on locating your drainfield, please refer to HGIC 1895, Be Septic Safe: New Users, Locating, & Basic Maintenance. Use these markings to prevent storing equipment, driving/parking vehicles, or installing structures over it. This will prevent soil compaction, which makes the drainfield less efficient. Fertilizers can also make the drainfield less efficient, so use the markings to maintain a fertilizer-free buffer around the drainfield. Residents should also avoid digging or planting trees or vegetables in the drainfield. Turfgrass is the most recommended plant to cover the drainfield. See HGIC 1726, Landscaping Over Septic Drainfields for other landscaping options.
Finally, residents should be aware that drainfields do not work well when saturated with rainwater. Avoid using washing machines, dishwashers, and other similar appliances during and directly after a rain event. Limit irrigation near or on the drainfield. Residents can use stormwater best management practices like rain gardens, rain barrels, and permeable pavers to increase the infiltration of rainwater in other areas to divert the water from the septic drainfield. See HGIC 1884, Water Management in the Home Landscape for more ideas on this subject.
Proper Waste Disposal Best Practices
In an ideal world, only wastewater and toilet paper would enter a septic system. However, that is not always the case with the typical uses of household plumbing. Therefore, residents need to be aware of precisely what they are putting down drains and flushing down toilets, particularly when it comes to solid matter. Too much solid matter in a septic system can result in more frequent pump-outs and clogs that could cause the system to back up into the home or fail altogether.
Do NOT let these items into your septic tank:
- biological additives
- cat litter
- cigarette butts
- coffee grounds
- dental floss
- fats, oils, or grease
- feminine hygiene products (pads, tampons, etc.)
- flushable wipes
- liquid/chemical drain openers
- non-septic-safe cleaning products
- paint thinner
- paper towels
- pool/hot tub water
- raw meat
- water softeners
Clogs form when solid materials are pushed out of the tank and into the drainfield. When solid materials block the drainfield, wastewater cannot flow freely through the area, which can cause system back-ups or failures. The only way to resolve a clog in the septic system is to call a professional to repair it. The best way to reduce clogs is to reduce the amount of solid material collected in the tank.
Garbage disposals can add up to an additional 50% of solid matter entering the septic systems. Kitchen scraps do not break down over time in septic systems and quickly form clogs, especially fats, oils, and greases (FOGs). FOGs should never be poured down the drain but poured into another container instead and then disposed of in household garbage or recycled. See HGIC 1878, FOG (Fats, Oils, and Grease) Pollution for more FOG disposal methods. Other sources of excess solids include “flushable” wipes and other similarly labeled products. Never flush these products as they do not break down over time and cause clogs both in pipes and septic systems.
Certain products and practices can harm the biological community needed for wastewater treatment. The associated microbes help to break down solids in septic systems. Household cleaners not labeled as “septic-safe” should not enter the system as they could kill necessary microbes. Similarly, residents should keep chemical drain openers, paint thinners, oils, and other household products out of the septic system to protect the biological community. Household cleaning products with the words “non-toxic”, “biodegradable”, and “septic safe” are typically safe to use while on a septic system.
There is never a need to use biological additives such as yeast, sugar, and raw meat in the septic system. Avoid products that advertise to reduce or eliminate the need for pump-outs in septic systems. All the microbes needed for decomposition and proper septic system functioning are already present in human waste. Residents do not need other materials or products to add microbes to the system.
Efficient Water Use Best Practices
Reducing the amount of water that enters the septic system will also reduce the likelihood of solids in the drainfield. When less water moves through the septic system, there is a lower chance water will carry clog-causing solids into the drainfield.
An easy way to reduce water use and ease the strain on septic systems is to install high-efficiency appliances and low-flow fixtures. There are also many ways to reduce water use without a trip to the store.
- Run dishwashers and washing machines only when there is a full load.
- Turn on only one water-using appliance at a time. For example, do not wash laundry and run the dishwasher at the same time.
- Reduce the daily number of times residents use each water-using appliance.
- Try not to run water-using machines during or just after a rainstorm. Rainwater will saturate the drainfield and cause it to be unable to absorb large amounts of wastewater.
- Turn off the tap while brushing teeth, shaving, or washing hands.
- Take shorter showers.
- Turn your toilet into a low-flow toilet.
- Scrape, but do not rinse dishes before washing them.
- If washing dishes by hand, use a basin.
- Thaw frozen foods in the refrigerator overnight instead of running them under the tap.
If you would like more information on other topics related to septic systems, check out HGIC 1895, Be Septic Safe: Considerations for New Septic System Users, Locating the System, & Basic Maintenance; HGIC 1897, Be Septic Safe: Septic Failures; and HGIC 1898, Be Septic Safe: Unique Situations; or Clemson’s Be Septic Safe website at https://www.clemson.edu/extension/water/be-septic-safe.html.
Originally published 05/22