The Coyote and the Effluent
Several years ago, on a lovely spring morning, we looked out our window to see a coyote rolling in the snow runoff in our driveway. Unfortunately, the runoff wasn’t just snow-water. Our septic field was essentially leaking semi-processed sewage onto our driveway! We take good care of our septic and our system is generally very healthy, so what was going on?
Basically, our leach field was waterlogged. The spring snowmelt had saturated the soil in our septic field and the effluent (water leaving the system) from our septic had nowhere to go other than to flow downhill to our driveway, where the coyote thought that smelly water would make a good perfume.
Normally, standing water in your septic field is the leading sign of field failure and truthfully, we had experienced a version of leach field failure. However, we knew not to panic and that the issues were due to the massive seasonal amount of water from the snow melt. After a few sunny days and some serious evaporation, our field was back to its normal, dry self.
In this post, I want to briefly explore the percolation of a septic field, what factors affect percolation rates and
Percolation and Various Soil Types
Percolation is one of the most important and deciding factors of a leach field’s efficiency. Dictionary.cambridge.org defines percolation as “the process of liquid moving slowly through a substance that has very small holes in it.” In the case of a leach field, the substance is the soil and the very small holes is the space between the soil particles. One of the major causes for differing percolation rates in soil is the actual soil type which is in turn dictated by particle size. We will outline a couple of soil types below that represent the extremes of percolation.
Sandy soil percolates extremely well. The larger grains in this soil type means there is consistently space between the solid material through which the water can move. Good percolation means water flows through rapidly, which also means more volume of water can move through sandy soil in a given timeframe.
Clay type soils typically exhibit poor percolation because the smaller particulate size means there is less space between the particles through which the water can flow. Clay types soils are often what drive engineers to plan system types other than a typical septic system, just because the field won’t handle the flow of a typical system. For more info on types of onsite treatment systems, click here.
When it comes to a leach field, hardpan is the ultimate enemy in soil form. Hardpan is soil that is so fine or so compacted that it is virtually impervious to water. Typically, hardpan would be identified when installing a septic tank and workarounds would be made, but we have heard of one system that had to be dug up and hardpan was identified just below the level of the leach field laterals.
Percolation Issues in a Septic
Septic field issues often come down to percolation problems. Standing water in a septic field means the field isn’t percolating as it should. Other symptoms could include slow or stopped drains throughout your home.
These percolation issues can be caused by a few different issues. One of the issues is that your field could have an overabundance of biomat. Biomat is a bacteria and protein jelly that surrounds the laterals in your field. This biomat is a very important part of the water purification process. The bacteria feed on the nutrients in the water that is leaving the laterals thus purifying it. If the biomat gets too thick however, it impedes the flow of water into the soil, slowing your percolation and causing issues. Our Septic Field Rejuvenator will help bring biomat back to healthy levels and thus will aid in proper percolation.
Another issue that can arise and that will cause percolation issues is water saturation. This is what we experienced when the coyote was rolling in our effluent. Our field, which typically has fairly good percolation, was waterlogged. Because the snow was melting in such great volume, the water couldn’t percolate fast enough. When the water is seasonal and a bit of above ground water is your worst symptom, there is little to fear. Avoid contact with the effluent as it likely contaminated with unsafe bacteria. Once the soil drains enough, your field will dry up and be back to normal.
During times of water saturation, it is important to take good care of your septic. Keep using a high-quality septic treatment like Septic System Digester and be mindful of water usage. Doing many loads of laundry at a time when your field has standing water will be counterproductive and could even result in backups into the house.
If you are frequently encountering standing water due to over-saturation, your field could have some issues. This is when you might need to investigate a means to help your system drain more consistently or find ways to reduce outside water getting to your field. Both options could potentially be costly, but if your field was properly located when installed, there should be little issue. Before taking any costly measures with your leach field, we do recommend trying Septic Field Rejuvenator, as many field issues are solved with a bottle or two of “SFR”.
Moral of the story, if you are experiencing heavy rains or spring melts and your leach field develops standing water, don’t panic. Give the soil a couple days to dry out, take care of your septic and I will bet that in most cases, your field will be back to normal and no worse for the wear.