Septic systems offer an on-property way to manage household waste, and they can easily rival the performance of a municipal sewer system when properly installed. At the heart of every septic system lies the septic tank. The tank acts as a receptacle for solid waste, while allowing liquid waste to percolate out into the drain field through a special outlet pipe.
Traditionally, most septic systems contained tanks made out of concrete. Today, however, more and more homeowners opt for plastic septic tanks instead. If you would like to learn more about the relative merits of these two options, keep reading. This article takes a closer look at three key advantages of plastic septic tanks.
1. Less Expensive
The most immediate advantage of a plastic septic tank has to do with its relative cost compared to a concrete tank. Depending on its size, a plastic septic tank may cost anywhere between $500 and $1,500. The equivalent size of concrete tank may cost between $1,300 and $5,000 - a considerable amount more.
This difference only accounts for the actual materials costs involved in creating the tank. The price difference balloons even farther when considering transportation and installation costs. Plastic septic tanks weigh a mere fraction of a pre-cast concrete tank, thus lowering the amount of energy required to transport them to the job site.
Cast-in-place concrete septic tanks also carry higher installation costs than plastic tanks. Such tanks require a team of skilled concrete workers to erect the forms and pour the fresh concrete into place. This process takes much longer - and hence costs much more - than simply excavating the ground and popping a plastic tank into place.
2. Immune to Corrosion
Concrete tanks face a significant threat in the form of corrosion. Such corrosion happens naturally in the presence of hydrogen sulfide gas, a common by-product of the bacteria that process waste inside the tank. When this gas escapes into the air space of a septic tank, a different species of bacteria turns it into the potent acid known as hydrosulfuric acid.
Hydrosulfuric acid has a highly destructive effect on concrete, eating away at the bonds that hold it together. Such corrosion can ultimately chew right through the walls of a concrete septic tank, allowing dangerous sewage to escape into the surrounding ground. Other factors such as water chemistry and the make-up of the concrete mix may also exacerbate concrete tank corrosion.
Hydrosulfuric acid has no effect on polyethylene, meaning those who opt for plastic septic tanks can rest easy regarding their tank's long-term health.
3. Easier Repairs
Although a plastic septic tank cannot suffer corrosion, it may still develop structural problems as time goes on. The walls of a plastic septic tank may crack if subjected to excessive amounts of stress. For instance, accidentally driving over a plastic septic tank can compress the soil enough to crack the tank wall.
Fortunately, a septic professional can repair a plastic tank provided the damage remains within certain limitations. Better yet, the repair process involves fewer steps and much less work than repairing a concrete tank.
In either case, workers must first pump all of the waste out of the damaged tank. Then the tank must be partially excavated to expose the damaged portion. At this point, the contractor simply has to use a plastic welding gun to close up the crack in the tank wall. A concrete tank, by contrast, requires workers to mix up repair mortar, allow it to fully cure, and then apply a sealant.
Plastic septic tanks have become a popular option among homeowners, thanks to their low price point and excellent longevity. For more information about the best type of septic tank for your needs, please contact the pros at Pete's Outflow Technicians.