As part of this ongoing series looking at infrastructure surrounding rural undeveloped sites, we examine septic systems. In most instances, rural building sites require private sewage disposal in the form of a septic disposal system. When reviewing property, one question to ask is whether a percolation or “perk test” has been conducted on the site. This test will indicate the type of soils on the parcel and whether a traditional septic system consisting of a holding tank, pump and drain field is possible. If the site does not have the type of soils to allow a simple septic system, or has a high water table or too much ledge, then alternative septic waste disposal systems must be explored.
Mound Systems
Mound systems overcome poor septic soils by adding a supply of gravel and sand to process the liquid effluent. Mound systems have an extra chamber, called a dosing chamber, that collects liquid and when a certain amount is accumulated, a pump distributes it over the gravel and sand media in the leaching field in the mound for filtering. The dosing chamber requires venting, and mound systems in general need some monitoring to ensure proper functioning. Depending on the size of the home —many municipalities size septic systems based on number of bedrooms— a mound system can be considerably more expensive and can also become a large feature on a small parcel. Sand, gravel and sometimes topsoil will need to be trucked in to build a mound system, so costs will be subject to local variables.
While the mound system can be costly, a number of newer septic designs have been developed that are more compact and easier to incorporate into an overall site infrastructure. Below are some of the current options available and will vary in costs and area requirements.
Plastic Chamber Leach Field— These plastic pipes provide a void that eliminates the need for gravel and distributes the liquids more effectively than a traditional field. These can often support a traffic load when buried under 12 inches of soil, making them good choices for small lots. The additional investment in plastic components is somewhat offset by the reduced amount of sand and gravel required.
Pressurized Dosing— This method uses a holding tank and pump to pressurize and distribute the liquid waste more efficiently in the leach field. Many times these are paired with a drip irrigation system.
Drip Irrigation System— This uses a pump to distribute the liquids through a filtering agent, sometimes a fabric or combination of fabric and sand to perforated tubes to irrigate landscaping or lawns.
Recirculating Sand Filter — When a high water table is the challenge, a recirculating sand filter system may be the answer. This system also uses two tanks, and creates a chamber filled with sand and fabric filters to filter waste water, which is then pumped into a more traditional leach field. This pre-treats waste water before it reaches the ground and protects the ground water from contamination in a traditional leach septic system.
Composting Alternative Options
All of these septic systems require electric pumps to achieve safe wastewater treatment. But what if you want to go off-grid? A combination of solar panels and batteries can certainly power a septic disposal system. But many homeowners seeking an alternative turn to a manufacturer of composting toilet systems, Clivus Multrim Inc. This company has developed advanced composting and graywater systems that have domestic household applications. Their Foam-Flush toilets (left) use minimal amounts of water and specialized soap to flush a toilet in a similar effect to regular household plumbing. These composting toilet systems are paired with graywater systems for all other household water—showers, sinks, appliances— that collects and then distributes this water to landscaping and gardens that completes the recycling process. Composting toilets and graywater systems do require a more informed approach to household tasks, and may not suit everyone.
As with any major expenditure in infrastructure, it’s a good idea to enlist the advice of a professional septic company, and review your building site with a septic pro to understand the potential costs, challenges and solutions.