Home > Septic Services Blog > Comparing ATUs to Traditional Septic Systems: Which is Best for You?

When it comes to managing wastewater in areas not served by municipal sewage systems, homeowners have several options. Among the most common are traditional septic systems and Aerobic Treatment Units (ATUs). Both systems serve the same fundamental purpose—treating and disposing of wastewater—but they operate in different ways and offer distinct advantages. Understanding these differences can help you decide which system is best for your property.

Traditional Septic Systems

Comparing ATUs to Septic Systems

How They Work

Traditional septic systems have two main parts – a septic tank and a drain field. Wastewater from your home travels into the septic tank and is separated into three layers. Solids settle at the bottom and become sludge, oils and grease float to the top and become scum, and the liquid waste stays in the middle. From there, the liquid waste flows out to the drain field, where it soaks into the soil, which works as a natural filter.


Simplicity and Reliability: Traditional septic systems have been around for decades and are known for their simplicity and reliability. They require less maintenance compared to ATUs and have fewer mechanical parts that can fail.

Lower Initial Cost: The initial cost of installing a traditional septic system is generally lower than that of an ATU. This makes it an attractive option for homeowners looking to minimize upfront expenses.

Energy Efficiency: Traditional septic systems do not require electricity to operate, making them more energy-efficient and less costly to run over time.

Soil Dependence: The effectiveness of a traditional septic system depends on the soil’s ability to absorb and filter the waste. In areas with poor soil conditions or high groundwater levels, these systems may not be suitable.

Environmental Impact: Traditional systems may pose a greater risk of groundwater contamination if not properly maintained or if the drain field is not functioning correctly.

Aerobic Treatment Units (ATUs)

How They Work

ATUs operate similarly to municipal sewage treatment plants but on a smaller scale. They use oxygen to break down organic matter more efficiently than traditional systems. Wastewater enters the ATU, where it is exposed to air through a mechanical aeration process, promoting the growth of aerobic bacteria that digest the waste. The treated waste is then either discharged directly into the soil or further treated before disposal.


Enhanced Treatment: ATUs provide a higher level of treatment compared to traditional septic systems. They can effectively reduce the levels of pathogens, nutrients, and organic matter in the effluent, resulting in cleaner discharge.

Versatility: ATUs are suitable for areas with poor soil conditions, high groundwater levels, or other environmental constraints that make traditional systems impractical.

Environmental Benefits: Due to their superior treatment capabilities, ATUs are less likely to contaminate groundwater and can be used in environmentally sensitive areas.


Higher Initial and Maintenance Costs: The advanced technology and additional components involved in ATUs result in higher initial installation costs and more frequent maintenance requirements.

Energy Consumption: ATUs require a constant supply of electricity to operate the aeration system, leading to ongoing energy costs.

Complexity: The mechanical components and more complex treatment process mean there is a higher likelihood of mechanical failure and a need for professional servicing.

Which is Best for You?

Choosing between a traditional septic system and an ATU depends on several factors, including your property’s soil conditions, local regulations, environmental considerations, and budget.

Here are some key points to consider:

Soil and Site Conditions: If your property has soil that drains well and sufficient space for a drain field, a traditional septic system might be the most cost-effective and low-maintenance option. However, if you have poor soil conditions or a high water table, an ATU may be necessary to ensure proper treatment and disposal of wastewater.

Environmental Sensitivity: If protecting local water quality is a high priority, or if you live in an area with stringent environmental regulations, an ATU’s advanced treatment capabilities can offer significant benefits.

Budget: While traditional septic systems are generally less expensive to install and maintain, the long-term benefits and environmental advantages of an ATU can justify the higher initial investment for many homeowners.

At Quality Septic, Inc., we understand that every property and homeowner’s needs are unique. Our team of experts is here to help you assess your options and choose the septic system that best suits your situation. Contact us today for a consultation and let us guide you through the process of selecting and installing the perfect wastewater treatment solution for your home.