Many new log homes are built in rural areas where municipal sewer treatment is not an option. As a result, log home owners may have their first exposure to their own private wastewater system or septic system. To get you started on the right foot, we’ve explored septic systems and identified some of the new alternative systems available.
Elements of Septic Systems
Private wastewater systems or septic systems haven’t changed much over the past few years. They involve four elements: a collection pipe that transfers liquid waste away from your home, a septic tank, a drain field and the soil in which the drain field empties. In some systems that cannot be designed to move the waste by gravity, an electric pump, filtration devices or other mechanical elements can be added. Click here for more information basic on the Environmental Protection Agency website.
If you’ve been looking at land or have already purchased it, you’ll be familiar with the “perk” test that is required by many municipalities before a home and its accompanying septic system can be constructed. The perk test merely identifies whether the soil is a type that can allow the liquid waste to drain away into the leach or drain field. If it cannot, then the septic contractor may need to construct a septic system that is more complicated to compensate for the inability of the soil to accept liquid waste at a rate that is safe. There are alternative septic designs to accommodate domestic wastewater if soils do not permit a conventional system.
Maintenance is Key
Septic systems do require regular maintenance. Many homeowners are not schooled on the maintenance of their septic systems and as a result may have problems if not monitored. There are some basics for septic systems, which include pumping the septic tank at least every 3 years. If the system has any mechanical elements or filters, maintenance may require more frequent inspections. If your system has a pump or float alarm, you’ll need to ensure that the pump is properly electrified, as sometimes the septic system is built long before the electrician appears to wire the home. You’ll also want to consider an alarm to avoid problems should something malfunction or back up.
Alternative Leach Fields
The increased use of private wastewater systems has developed an array of options to handle the waste where soils are not suitable for a traditional design. Some of these also enable the homeowner to designate a smaller area for the leach field, which can be useful when dealing with a restricted building envelope. One good source for detailed schematics and costs associated with alternative systems is Toolbase Services’ Technology Inventory website.
- Mounding—When high water tables or poor leaching soils exist on site, elevated soil absorption beds can be constructed. The absorption beds are constructed of gravel or other aggregate materials. Mounds will require more maintenance, as they often require electric pumps to disperse the effluent. The upside is that mound systems generally require less square footage to comply with codes.
- Pressurized Dosing— In this method, the effluent is delivered to the leach field in small or large doses, oftentimes under pressure. Dosing has several benefits and can be used in some situations to rehabilitate a failed leach field. Because the application occurs on a dosing-then-resting cycle—about every 4-6 hours for the average home— there can be a positive effect on the maintenance of the bacteria which help to break down the waste. Also because dosing distributes the effluent evenly, it reduces the extent of soil saturation and can improve leach field performance.
- Substitute Aggregate Leach Field— This method uses alternative substances for or in addition to gravel in the leach field. They avoid some of the issues associated with stone aggregate in the leach field such as compaction of the soil or clogging the leachate with additional dirt/sand present in the gravel. Some systems involve piping surrounded by plastic beads held in place by netting, others use recycled glass or tire rubber to provide extra surface area in the leach field.
- Plastic Chamber Leach Field— This is another solution where some municipalities will allow a small area for the leach field. The system uses pre-formed plastic arches to create voids where effluent flows. Aggregates such as gravel are used to fill the voids in the arches.
- Drip Irrigation Leach Field— In areas where water may be in limited supply, this recycles treated effluent to water landscape areas. The septic system includes an additional tank where the effluent is further filtered and treated to be safe for drip irrigation systems in the lawn. Once it passes through the second filtration phase the water is pumped through flexible plastic tubing installed close to the surface to reach roots of grass or other vegetation. The plant life acts as a further natural treatment for the materials from the septic system.
- Gravelless Pipe Leach Field — This system uses either large diameter piping covered in filter fabric or arrays of narrower gauge piping to distribute effluent through the leach field. Depending upon design, these can gain some efficiency. These are believed to promote growth of aerobic material, which collect on the fabric and pipe surfaces. The application of these systems is fairly widespread, but regulation and sizing is heavily reliant on local regulations, and may require extra monitoring stations.
- Evapotranspiration Effluent Disposal — Instead of leaching down to stratus below the pipes, effluent moves upward from perforated pipes. The pies are laid under inverted-v shaped beds of sand to maximize the contact between the sand and covering soil. This system can be effective when groundwater contamination may be a factor, when the piping is laid on a waterproof covering.
There are several benefits to a non-traditional septic system; one key bonus is the ability to reduce the size of the system. Many of these alternative systems require no stone added to the field, eliminating the need for heavy transport truck to the site. Many systems fail because of high levels of nitrogen released into surrounding streams and wetlands. Many alternative systems reduce or eliminate nitrogen runoff.
When working with your contractor, you may want to explore the options that are available for wastewater systems. Some contractors who have worked with one septic provider will install a traditional system without investigating alternatives that may better suit your site and circumstances.