Plastic vs. Concrete Septic Tanks: Main Advantages and Disadvantages

When it comes time to choose a septic tank for your home, there are many factors you should take into consideration. What size do you need? What shape will be the best to use? And one of the most important factors — what material do you want to use for your septic tank? 

All of these are great questions, and understanding the available options and their details will help you make the best decision for your home. 

In this article, we'll discuss the main advantages and disadvantages of plastic vs. concrete septic tanks. Ultimately, the choice between a plastic or concrete septic tank comes down to personal preference, but it's important to be informed about the pros and cons of each type of tank before making a decision.

Plastic Septic Tanks

Plastic septic tanks are generally made from polyethylene and have been around since the 1980s. They came into existence because of the frequent failures of concrete and steel tanks that were previously installed. These modern alternatives offer substantial advantages over concrete systems, and if they are allowed in your area, may be a better choice than tanks of the past.

Plastic septic tanks are lighter and easier to install than concrete tanks. They are less susceptible to water damage and corrosion from acidic soil, and they are also less prone to cracking because they are more malleable than concrete.

Plastic septic tanks are often the preferred choice for new construction and replacement projects. However, it is important to note that plastic septic tanks may not be the best choice for every situation. 

For example, if your property is located in an area with high groundwater levels, a concrete tank may be a better option because it’s naturally heavier. A plastic tank however will hold less effluent and could try to float out of position. Plastic septic tanks may not be approved for use in your area, in which case an alternative will be ideal.

Installation and Maintenance

Pros and Cons

Installing and maintaining a plastic septic tank will be less expensive than the concrete option for many reasons:

1. They don't require heavy machinery to move them around.
2. They can be transported on a regular truck.
3. Due to their light weight, a plastic tank can be installed using fewer people.
4. Lower labor requirements make the installation less expensive.
5. Plastic is more hygienic and easier to keep clean.
6. When it is time to replace the tank, plastic is easier to remove and dispose of than concrete.

However, plastic tanks have a lifespan of 30+ years, compared to 40+ years for concrete. Care must be taken when determining the location of the tank. For instance, if heavy vehicle traffic travels over the tank, it may cause damage.

The decision on which type of tank to install should be made by a qualified professional and needs to follow all local building code guidelines.

Concrete Septic Tanks

Concrete tanks have been around since the late 19th century, and until the 1980s they were the primary, if not only, septic tank system in use. This changed when lighter, less expensive options were created. While concrete septic tanks are more expensive than plastic septic tanks, they offer many advantages.

Concrete septic tanks are much more durable than plastic tanks and can last for decades — with a lifespan of approximately 40 years — with proper care. Because of their durability, they are not as susceptible to damage from ground movement, which can cause serious damage to your septic system. They are also less likely to float out of the ground during heavy rains, which can lead to flooding and property damage.

They also can hold a larger quantity of effluent than a plastic tank, which means fewer pumping operations are required. Plus, concrete septic tanks offer better protection from root intrusion, which can clog and damage your septic system. 

Installation and Maintenance

Before choosing a concrete tank, consider the following:

1. Concrete tanks weigh a few tons and require special equipment to transport and install.
2. They also require more labor at the job site, which adds to the installation cost. If the tank gets damaged, it is more difficult to repair than a plastic model.
3. Another concern is damage due to groundwater contact. If the tank was not properly constructed, the concrete could start to crumble and fall apart.

Plastic Tank Options

Since their conception, manufacturers of plastic tanks have provided numerous options to the market. While most tanks are oblong and dome-shaped, there are also low-profile models and sphere-shaped models, depending on your need. Some tanks are portable, providing options for campers, RVs and temporary construction site use.

Sphere Shaped: These are available in 200- to 500-gallon models and can be used for storage of wastewater and effluent. 

Dome Shaped: The more common types of tanks, these can be purchased as single or double compartments, from 1000 to 1500 gallons. They are priced from $2,100 to over $3,000. If you need something even heftier for your septic needs, investing in a heavy-duty option will give you that extra durability and space.

Low Profile: Low profile tanks are needed when you are limited to how deep you can go in the earth. Single-compartment tanks start at 500-gallon capacities and go up to 1500 gallons, while double compartments start at 750 gallons.

Tank Depot is Your Best Resource for Plastic Septic Tanks

If you're looking for a quality and affordable plastic septic tank, look no further than Tank Depot. We carry a wide variety of tanks in all shapes and sizes to meet your needs. Our experts can help you choose the right tank for your home or business and answer your questions about recommended methods of installation. 
Contact us today for more information.