6 Septic Tank Alternatives For Land That Won't Perk
In order for a septic to be installed on a property, you must have a successful perc test. If your land cannot be perked, this means the soil does not have the ability to absorb water. When it comes to a septic system, it is essentially a series of pipes under your property that wastewater drains into. If the soil isn’t moist enough to allow for drainage, the system simply will not work.
In this case, an alternative septic system will be required. Additionally, environmentally sensitive areas and waterfront properties may require an alternate method in order to protect water sources.
Alternatives to septic systems will cost you more to install because of their complexity and need for expert installation. In order to prevent any potential issues with them, they also require regular maintenance and monitoring.
There isn’t a one-size-fits-all solution for a land that won’t perk, as the design of a septic system is specific to the site conditions, usage levels, and soil type. However, when you have a soil that is either too shallow over bedrock, too dense, or a water table that is too high, a “mound” system is generally the first choice. It works very similar to your standard septic system, with a leach field that is positioned above the natural grade.
However, a mound system isn’t the only option you have for a septic system substitute. Let’s explore all of the possible septic system alternatives for land that won’t perk.
What is a Perc Test?
If you’ve just purchased or are planning on securing a piece of vacant land, you must understand the importance of having a perc test done. A Perc Test, also referred to as a “Perk Test,” and previously as a Percolation test, is an evaluation conducted on your soil to determine the rate at which water drains through it.
In most areas of the world, perc tests are required because the results provide all the necessary information for the design and installation of a septic system. They are initiated by digging or drilling a hole into the ground, pouring water in the hole, and observing the rate that it is absorbed into the soil.
Conducting a perc test will help you to determine the need for an alternative to a septic system if your soil turn out to not be suitable enough. Check out the cost to have a perc test completed.
Video: A Solid Aerobatic Septic System (with Plans)
1. Mound Systems
When a land will not perk, a mound system is often the first choice for an alternative system. They generally cost around two to three times more than traditional septic systems and will require additional maintenance and supervision.
With a mound system, a series of small distribution pipes are placed in a layer of gravel atop a deposit of sand. They are generally positioned about two to three feet deep and covered on all sides with topsoil. Unlike conventional septic systems, a mound system implements an additional component, a dosing chamber, for collecting the wastewater that exits the septic tank.
With a pump and float technique, the dosing chamber pumps sewage at a controlled rate and evenly distributes it into the drain field. Alarm systems, observation tubes, and monitoring wells are often put in place for monitoring and to alert the owner of any failure within the system.
The biggest expenses associated with a mound system are the earthwork, and additional materials and equipment needed for the construction of the mound itself. Overall, depending on the design and local cost for materials, installation of a mound system can cost more than $10,000 more than a traditional septic system. Additionally, the annual maintenance costs of frequent pumping and more extensive observation can cost you as much as $500.
2. Aerobic Septic Systems
Aerobic Septic Systems, also referred to as aeration systems, are used for situations where standard septic systems are not a feasible option. Aerobic systems are similar to septic in that they both use natural processes to treat wastewater. However, unlike septic treatment, the aerobic process requires oxygen.
These units use a device that injects and distributes air throughout the tank, effectively accelerating the treatment process. For this reason, aerobic septic systems require electricity to function and will cost more and require more frequent maintenance in order to continue operating as expected.
Aerobic units can be installed both above or below ground and will typically require additional excavation, electrical connections, installation of pretreatment components, and easy access for maintenance. When properly installed and preserved, aerobic systems can be a high quality, excellent wastewater treatment alternative to traditional septic. Check out this guide to learn more about the cost of an aerobic septic system.
3. Cesspool Systems
Simply put, a cesspool is a ditch in the ground, whose walls are lined with metal, stone, or cement. This lining contains holes and the entire system is then covered with a lid. This type of wastewater treatment used to be much more common and is still often found in some older homes.
Most of the time, the cesspool pit is connected, by way of an outer pipe, to another tank. This method lacks the ability to effectively filter waste, collecting it instead, and eventually contaminating the surrounding soil. While cesspool systems are still available in some areas, the associated problems are becoming more well-known and homeowners often elect for a different alternative.
4. Sand Filter
This method involves a large, sand-filled box that is generally between two and four feet deep and contains a watertight lining of PVC or concrete. The sand’s purpose is to pre-treat sewage through aerobic bacteria and filtration and then dispose of it in the leach field.
These boxes can be placed partially or fully underground, but can be installed above-grade when necessary. In most designs, a pump and controls are used to uniformly distribute the sewage over top of the filter, and then, after treatment, it is collected at the bottom.
The collected sewage is then gravity-fed or pumped into the leach field. In some cases, the sand filter recirculates the sewage multiple times before it is distributed into the drain field. For sand filters to be effective at either pre-treatment or primary treatment, they must be properly constructed and maintained.
5. Constructed Wetlands
If you consider yourself to be ecologically minded or want an active role in recycling your wastewater, constructed wetlands may be the alternative for you. This method can work in virtually any type of soil, making it a great choice for land that will not perk.
This system implements a man-made shallow pond that is lined and packed with rock, tire clippings, or other related materials. These materials provide an environment for special plants that can treat wastewater, while also creating a pleasant setting.
The wastewater from your septic tank is led through a perforated pipe and distributed across this bed of materials. Bacteria, plant roots, and other microorganisms will work to break down the pollutants from your wastewater. Then, an additional pipe at the back of the wetland will collect the treated water.
With this wastewater treatment system, you can expect to spend a considerable amount of time planting, trimming, weeding, and engaging in general maintenance of the wetlands area.
6. Drip Irrigation
The final alternative to traditional septic systems is known as drip irrigation, or distribution. This system uses a pump to deliver sewage through a filtering device and then to a series of shallow drip tubes that extend over a large space. In this case, a pretreatment component is generally needed in order to deliver relatively clean water to the system. Drip irrigation systems can be used with shallow soils, clays, and on property with steep sloping.
For more information on septic systems, check out: “ Can A Homeowner Install A Septic System?” and “ What Is The Difference Between A Septic Tank And A Cesspool?“
Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.
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