Mulch and Your Septic System

Mulch around Septic Tank
Mulch around Septic Tank

Spring and early summer is the prime time of year for cleaning up around your yard – readying flower beds, planting new foliage, gardening. When your green thumb grows this spring and summer, make sure you are using caution when it comes to the gardening and yardwork you do around your septic system. We cannot emphasize enough the importance of planting only shallow-rooted vegetation around your septic system and covering the septic yard with nothing more than grass indigenous to our Northeast Ohio climate, but we also need to take note concerning any mulch you may be using around your septic system.

Mulch on or around the Septic Drainfield

Second to deep-rooted vegetation (including certain shrubs and trees), mulch is the least septic friendly item you can find in and around your yard. One primary reason to avoid mulching on your drainfield is because it inhibits the oxygen exchange within your secondary treatment system that is integral to the proper filtration of effluent leaving your septic tank. Without proper oxygen exchange, the bacteria working within your septic system cannot efficiently break down the remaining solids being filtered out in your drainfield.

Additionally, it is important to understand that mulch is very often used around the foundation of homes to absorb runoff during rainstorms, an effective method for controlling the moisture around the foundation and keeping water away from the base of the foundation (and out of your basement). However, overtop a drainfield, this mulch would retain extra moisture, and in so doing, add to the moisture strain on your septic system. Rather than allowing any rainwater to run off, mulch would force this rainwater to be essentially filtered through your septic’s drainfield, increasing the strain and effectively shortening the life of your system.

Mulch on or around the Septic Tank

Another significant issue mulch creates for your septic system is seen when mulch is used around the septic tank itself, often piled around the tank’s openings to make them look prettier. Unfortunately, during necessary routine maintenance of the septic tank, pieces of mulch will often fall into the tank, causing any number of potentially catastrophic problems for your system, including damage to your system’s pumps and aerators. As with the moisture retention we discussed with mulch on the drainfield, excess moisture around your septic tank will create similar problems, straining the system and potentially shortening its life.

Keep your septic beautiful this year by following our guidelines on what to plant around your system. Our technicians will be happy to answer any questions you may have during your routine maintenance visit. Schedule yours today!