The septic system drainfield typically contains pipes buried from 12 inches to 36 inches (depending on your system) below the ground. This does not leave much room for root growth.
Generally speaking, septic drain lines are buried between 18 and 36 inches underground, and the pipes are surrounded by gravel and sand to aid in the filtration and water treatment process.
Typically, the drainfield consists of three to five trenches that are 18 to 24 inches deep, up to 100 ft long, with a perforated pipe in 12 to 18 inches deep gravel covered by 12 inches of soil.
So how do tree roots get in a septic drain field, to begin with? There are a few ways this can happen. One is obvious – you planted them there. The takeaway of this entire article should be this – you should never plant trees near or in leach fields.
The best plants you can put on top of a septic drain or leach field are shallow-rooted herbaceous plants. These include perennials, bulbs, turf-grass, weeds, groundcovers, and more. A few examples are holly shrubs, boxwood shrubs, azalea shrubs, hollyhocks, wild violets, and spring bulbs.
Put plastic sheets, bark, gravel or other fill over the drainfield. Reshape or fill the ground surface over the drainfield and reserve area. However, just adding topsoil is generally OK if it isn't more than a couple of inches.
Grass provides ideal year-round cover for drainfields. Ornamental grasses can be planted, as well as maintaining a traditional lawn.
In addition to the potential contamination from pathogens, crops grown above your drainfield may also be exposed to household chemicals that are still present in effluent before it filters through the drainfield. Many of these are not safe for your septic system, let alone safe for human consumption.
Minimize traffic on the mound, both human and animal, to avoid soil compaction. Do not exercise pets or stake pets on septic mounds. Never drive a car or other vehicle across the mound or mow when the soil is wet.
In general: Your septic tank and leach field should be 100% within your property line, so putting a fence on the outside edge of your property won't be a problem as you won't hit either the leach field or the septic tank. If you want to run a fence through the leach field, beware!
One of the most valuable tools for finding a septic tank is a soil probe—a thin piece of metal that pierces through the soil to quickly locate anything that might be buried underground. Insert your soil probe every two feet starting from the location where your sewer line leaves your home and follow it straight out.
For instance, residential sewer line depth ranges from 18 to 30 inches. However, city sewer line depths are different. Your city's sewer lines must always be deeper than the deepest residential pipe to allow waste to flow downhill. As such, these lines can go as deep as needed.
If you see dead grass and the ground is wet or soggy, especially when it hasn't rained, that's not good either. This usually means the wastewater isn't being absorbed and filtered through the soil properly, making the surface too wet – it's a sign your septic system might be leaking.
A typical septic drain field (see Figure 1), also known as a leach field, is a series of perforated pipes that are set in trenches and buried with aggregates (½- to 2½-inch gravel or ½- to 4-inch rubber chips) and soil. These drain lines are at a minimum depth of 6 inches and are typically 18 to 36 inches wide.
Typically, septic tanks are installed below ground level within 10-25 feet from the house, but they must be a certain distance away from any creeks, rivers, ponds, wells, paved surfaces, trees, and structures such as homes, patios, and decks.
The average lifespan of a septic system is 15 to 40 years, but it can last longer if properly maintained! Think at the sink. Consider what you put into your toilet and sink and the impact it may have on your system. Many common household items can either clog your system or kill the microbes that treat the wastewater.
To prevent compaction, do not allow any vehicles or heavy equipment on the mound. When mowing the lawn, use a hand mower, rather than a riding mower. In general, try to reduce the amount of foot traffic and other activity on the mound. This will also help protect the mound from losing soil to erosion.
While many professionals believe that a leach field could bear about 10,000 pounds of weight for a short period of time, it's often not worth the risk. While you can safely walk on your leach field, parking, driving, and building on the area above should be avoided.
In order to keep your septic system running properly, you should avoid building on or near your leach field.
Large animals also cause compaction. If you choose to allow animals to graze the drainfield area, you risk decreasing the effectiveness of you septic drainfield. Animals should never be allowed to graze the drainfield during the wet season and should be removed before grazing results in bare soil.
You can plant grasses and other shallow-rooted flowers and plants directly on top of a septic field. Keep trees away from a septic tank and field. The tree's height in feet indicates how far the tree should be from the system.
However, if you are careful, you can put trees with non-invasive, shallow roots in the area around your drain field and septic tank. Some examples include crabapples and white oaks. It's best to skip the Japanese maple, as these are extremely well-known for their pipe clogging abilities.
The septic tank, drain field and reserve area should remain clear of sprinkler lines, decks, patios, storage sheds, sand boxes, swing sets, paved or dirt driveways, parking areas and walkways. Adequate access to the components of the septic system is also critical for maintenance and pumping.
Put plastic sheets, bark, gravel or other fill over the drainfield. Reshape or fill the ground surface over the drainfield and reserve area. However, just adding topsoil is generally OK if it isn't more than a couple of inches.