Septic Tanks
Plastic septic tanks are more common than concrete septic tanks. A number of benefits exist for having a plastic tank instead of a concrete one, including price and ease of installation. A few disadvantages do exist as well, mostly based on what the consumer is looking for in their tank.
Plastic Septic Tanks
Price: A plastic septic tank costs less than a concrete one.
Cost-Effectiveness: Plastic is better at insulating which helps keep the water warm throughout the winter months, allowing it to work daily without any problems. Concrete would need to be heated if this were an option due to its limited insulation capabilities. No Expansion/Contraction: All materials expand and contract over time with exposure to weather conditions; the plastic tank does not because it is one solid piece. Ease of Installation: The plastic septic tank is light and takes less time to install than a concrete septic tank.
Disadvantages of Plastic Septic Tanks
Size: Plastic tanks are smaller than concrete ones, so this should be taken into consideration if having additional people in the household or water-heavy appliances such as a washing machine. Ejection Holes: Concrete tanks have many small holes that allow trapped air inside to escape instead of forming condensation on the interior plates, which can cause bacteria to build up over time even with proper care and maintenance. In addition, these holes allow liquids to flow easily through the tank when being pumped out. If there were no ejection holes on the concrete tank, it would need to be filled with water before it could be pumped out. This is more of a hassle for the person pumping out the septic system compared to the plastic tank where this step can be skipped if desired. Odor: Plastic tanks are known for trapping bad odors inside more than concrete ones due to their single-piece design and lack of air circulation.
Recommendation
Based on price, ease of installation, no expansion/contraction, being lightweight, and not needing heating during colder months, plastic septic tanks are ideal for households with fewer people or that have limited need for hot water or larger appliances that would require them to have a larger septic tank. If having large families, heavy water use, or including a washing machine in the home, a concrete septic tank would be recommended.
Concrete Septic Tanks
Price: Concrete septic tanks cost more than plastic ones.
Cost-Effectiveness: Concrete is not very good at insulating so it needs to be heated in colder climates if having additional households use hot water. This heating process could lead to condensation build-up on the plates inside of the tank over time, which can create bacteria and foul odors unless pumped out regularly. No Expansion/Contraction: All materials expand and contract with exposure to weather conditions; concrete will crack if not repaired when this occurs due to its brittle nature compared to plastic tanks which do not need any attention when expanding or contracting. Easy Installation: The concrete septic tank may be difficult to install compared to the plastic one.
Disadvantages of Concrete Septic Tanks
Size: Concrete tanks are larger than plastic ones, so this should be taken into consideration if having limited space in the yard for it. Ejection Holes: Concrete tanks have many small holes that allow trapped air inside to escape instead of forming condensation on the interior plates, which can cause bacteria to build up over time even with proper care and maintenance. In addition, these holes allow liquids to flow easily through the tank when being pumped out. If there were no ejection holes on the concrete tank, it would need to be filled with water before it could be pumped out. This is more of a hassle for the person pumping out the septic system compared to the plastic tank where this step can be skipped if desired. Odor: Concrete tanks are known for trapping bad odors inside more than plastic ones due to their single-piece design and lack of air circulation.
Recommendation
Based on the size, ease of installation, Ejection Holes, being brittle, and having condensation build-up traps bacteria inside it over time that needs regular removal complete with proper care and maintenance, concrete septic tanks are ideal for houses with large families or water-heavy appliances such as a washing machine. If only needing hot water in one area of the home, not heating it would reduce condensation buildup which leads to foul odors and possible bacterial growth. If having a small family or not expecting to expand it, a plastic septic tank would be ideal. Some of the disadvantages of concrete tanks can be reduced by having a new, insulated one installed compared to an older unit that hasn’t been maintained properly.