How Much Do Aerobic and Anaerobic Septic Systems Cost?

Last Updated on September 20, 2024
Written by CPA Alec Pow | Content Reviewed by CFA Alexander Popinker

For homeowners not connected to municipal sewer lines, installing an effective septic system is a major yet necessary investment. But what exactly is the true cost of aerobic and anaerobic septic systems – the two main onsite residential wastewater treatment options?

In this guide, we’ll thoroughly break down the installation, maintenance, repair, and replacement costs for both aerobic and anaerobic septic systems. You’ll understand the full price range based on factors like system size, soil conditions, permit requirements, and energy usage.

Whether you’re pricing a septic system for a new construction home or replacing an existing failing drain field, the significant costs involved make evaluating both aerobic and anaerobic systems crucial. By understanding the full range of expenses, you can make the smartest decision balancing upfront costs with long-term maintenance. 

How Much Do Aerobic and Anaerobic Septic Systems Cost?

Aerobic and anaerobic septic systems typically range in cost from $7,000 to $30,000+ depending on several factors like system size and site conditions. Proper ongoing maintenance and eventual replacement of failed systems also represent major septic system expenses that homeowners must account for.

Typical Aerobic System Pricing

• Permitting – $200 to $500
• Excavation – $2,000 to $6,000
• Tank – $2,000 to $5,000
• Treatment system – $3,000 to $7,000
• Air compressor – $1,500 to $3,000
• Control panel – $500 to $1,500
• Drain field – $3,000 to $10,000
• Landscaping – $500 to $2,000
• Total Cost – $12,000 to $30,000+

Typical Anaerobic System Pricing

• Permitting – $200 to $500
• Excavation – $1,500 to $4,000
• Tank – $2,000 to $5,000
• Drain field – $3,000 to $8,000
• Landscaping – $500 to $2,000
• Total Cost – $7,000 to $18,000+

As you can see, aerobic systems involve greater complexity and upfront investment, but provide thorough treatment. Anaerobic systems are simpler and more affordable initially, but require diligent maintenance.

According to Aero-Stream, the average cost of an aerobic septic system ranges from $10,000 to $20,000. This includes various components such as permits, which typically cost between $200 and $400, and the overall installation process. In contrast, anaerobic septic systems are generally less expensive, with costs starting around $7,500 for the complete system including labor.

A detailed comparison on Countryside Construction indicates that while anaerobic systems might be cheaper initially, they require more frequent maintenance and have a shorter lifespan compared to aerobic systems.

The Engineering Choice also notes that aerobic systems can incur additional costs over time due to maintenance needs. The average cost for maintaining an aerobic septic system is about $200 for inspections every one to three years. Additionally, parts like motors and timers may need replacing, costing around $500 to $600 for motors and $100 for timers.

According to a report from NexGen Septics, homeowners can expect to pay between $15,000 and $35,000 for aerobic systems depending on soil conditions and other factors. They emphasize that the total cost can be influenced by additional elements such as leach fields and specific local regulations.

Lastly, a summary on U.S. News states that installing a new septic system averages around $6,000, but costs can range from $3,000 to $20,000 depending on whether it is an aerobic or anaerobic system. This wide range reflects variations in installation complexity and local market conditions.

Overview of Septic System Types

First, a quick look at the two septic system varieties:

Aerobic Treatment Systems

• Use oxygen to break down waste via aerobic bacteria
• Require electricity to power air compressor
• More complex components

Anaerobic Treatment Systems

• Rely on anaerobic bacteria that work without oxygen
• No electrical components
• Simple gravity-flow drain field

Both effectively process household wastewater when properly maintained. Now let’s compare the costs.

Factors That Affect Septic System Costs

Many factors influence the total costs:

System Capacity – More bedrooms/bathrooms need bigger tanks and drain fields

Soil Conditions and Topography – Poor drainage, shallow bedrock, or high-water table require more complex installs

Level of Treatment Required – Sensitive lakeside locations may mandate advanced treatment

Electric and Plumbing Hookups – Longer connections to power and house lines cost more in labor and materials

Landscaping Needs After Install – Replacing removed trees/plants and redo extensive landscaping boosts price

Local Permitting and Septic Codes – Stricter regulations require pricier equipment and licensed contractors

Careful planning and quote comparisons keep project costs in check.

Long-Term Septic System Costs

You might also like our articles about the cost to replace a toilet wax ring, to install a toilet or the costs of the Roto-Rooter plumbing services.

Aerobic System Ongoing Costs

• Electricity – $30 to $200 monthly
• Annual inspections – $150 to $300
• Pumping every 2-3 years – $250 to $500
• Occasional repairs – $200 to $2,000

Anaerobic System Ongoing Costs

• Annual inspections – $150 to $300
• Pumping every 3-5 years – $250 to $500
• Occasional repairs – $200 to $2,000

The aerobic system’s electrical costs are the primary distinguishing maintenance factor long-term.

Aerobic Septic System Cost Breakdown

For a detailed look at pricing, here is an overview of aerobic septic system costs per major component:

Permitting and Fees

• County health department approval – $150 to $350
• System permitting – $50 to $150

Site Evaluation and Excavation

• Initial site assessment – $0 to $500
• Land surveying – $300 to $1,000
• Soil analysis and testing – $500 to $1,500
• Excavating equipment rental – $1,000 to $3,000
• Labor for excavation – $1,000 to $3,000

Treatment System Equipment

• Treatment tank – $1,500 to $3,500
• Air compressor – $1,000 to $2,500
• Control panel – $500 to $1,500
• Wiring and electrical – $500 to $1,500

Drain Field

• Piping – $500 to $1,500
• Gravel or alternative material – $1,500 to $5,000
• Observation ports – $50 to $200 each
• Labor for installation – $1,000 to $3,000

Final Grading and Landscaping

• Fill dirt or topsoil – $500 to $1,500
• Finish grading – $500 to $1,500
• Reseeding or sod – $500 to $1,500

Total System Cost – $12,000 to $30,000+

System Costs By Location

To give location-specific price examples:

New England Area

• Permitting – $300
• Excavation – $4,000
• Tank – $3,000
• Treatment System – $5,000
• Drain Field – $8,000
• Total Cost – $20,000

Midwest Region

• Permitting – $250
• Excavation – $3,000
• Tank – $2,500
• Treatment System – $4,000
• Drain Field – $5,000
• Total Cost – $15,000

West Coast Area

• Permitting – $400
• Excavation – $5,000
• Tank – $4,000
• Treatment System – $6,000
• Drain Field – $10,000
• Total Cost – $25,000

Actual pricing depends on specific site conditions and system size required.

When Does it Need Replacement?

Septic systems typically last 20-30 years. Signs it’s time to replace the entire system:

• Frequent clogs or backups
• Groundwater contamination
• Foul sewage odors
• System flood damage
• Drain field failure
• Inability to handle household usage
• Age exceeding design lifespan

Partial repairs can potentially extend the system lifespan further.

Replacing a Failed Septic System

When an old septic system has reached the end of its lifespan, replacement costs typically run:

Aerobic System Replacement Cost

• Drain field replacement – $5,000 to $15,000
• Treatment system update – $3,000 to $10,000
• Total replacement cost – $10,000 to $20,000+

Anaerobic System Replacement Cost

• New drain field – $5,000 to $10,000
• New tank – $3,000 to $6,000
• Total replacement cost – $8,000 to $15,000+

While not inexpensive, replacing a failed septic system protects your property value and health.

Saving on Septic System Costs

Smart ways to save on septic system costs:

• Compare multiple contractor quotes for best pricing
• Choose appropriate size system for your household needs
• Utilize gravity drain field if soil permits versus pressurized
• Consider a basic anaerobic system if usage is low
• Research any state or county rebate programs
• Avoid complex landscaping that increases restoration costs
• DIY install where codes allow but have insured pro start system

Being an informed buyer is crucial to realize savings on this major investment.

Final Words

While requiring significant upfront investment, properly functioning septic systems protect home values, health, and the environment. Aerobic systems provide thorough treatment starting around $15,000 but have higher maintenance costs long-term.

Anaerobic systems are simpler and more affordable to install at around $8,000 but require diligent pumping and care. Review all price considerations and plan septic system costs into your overall budget when building or replacing this vital home system.

Answers to Common Questions

What is the most expensive part of a septic system?

The drain field is often the most expensive septic system component, costing anywhere from $1,500 to as high as $10,000 depending on the size, soil conditions, location, and if alternative materials like gravelless chambers are used. Larger households require larger drain fields, significantly affecting overall system costs.

How do I know when to pump my aerobic septic system?

Experts recommend pumping aerobic septic systems annually since they process waste more thoroughly. Annual cleanouts prevent bio-mat buildup and ensure proper operation. Anaerobic systems may only need pumping every 2-3 years since solids separate and breakdown slower.

How much space does an aerobic septic system need?

A typical aerobic septic system requires a land area of approximately 150 linear feet by 100 linear feet, allowing space for the main treatment tank, air compressor, control panel, and adequate drain field run. The size may need to be larger if the soil conditions are poor or the household’s daily wastewater volume is higher.