How Much Does an Engineered Septic System Cost? [2024 Data]

Engineered Septic System Cost Breakdown

The cost of engineered septic systems is primarily—50% through 70%—from labor costs.

Labor

When you hire a licensed, insured, and bonded plumber, you’ll pay $45 to $200 per hour in labor cost. When plumbers install an engineered septic system, you’re typically paying for the time it takes to excavate your yard, prep the site, build the drain field, get permits, and install the system.

However, depending on your contractor or septic tank company, you could pay a flat fee for some or all of those services. Here are the prices you can expect:

• Land prep: $1,600–$8,000

• Excavation: $1,200–$4,500

• Perc test: $750–$1,850

Ask your contractor to provide a line-by-line written estimate to avoid any surprise bills.  

Drain or Leach Field

A drain field, also known as a leach field, is a major component of your entire septic system responsible for dispersing your filtered wastewater into the soil. The cost to build a drain field is $3,000 to $15,000.  

Engineer Fees

When you need an engineered septic system, it’s not a plumber that’ll design your new septic system but a civil engineer or soil scientist. And because they’ll need to design and potentially oversee your system’s design, expect to pay $500 to $1,000 or 5% to 15% of the project’s design budget. 

Material 

Each engineered system will be structured differently to fit your individual septic needs. But the materials commonly used for them include a septic and pump tank and piping. Some systems such as mounds and sand filters also require sand that costs $15 to $20 per cubic yard and gravel that costs $15 to $75 per yard. 

Permit

Installing an engineered septic tank will require a permit to ensure it complies with your local and state building code requirements. The cost of getting a permit is $400 to $2,000; however, the actual cost varies by city and state.

Engineered Septic System Cost Near You

Labor costs play a significant role in how much you’ll spend on an engineered septic system. Because engineered septic systems require a different installation process than conventional ones, you’ll pay more for the time, experience, and skills required for a proper installation. 

So, if you stay in an area where the ground is too permeable, isn’t permeable enough, or your home resides on a hill, it’ll take longer to install with labor fees of  $45 to $200 per hour.

Engineered Septic System Cost by Type

The most common engineered septic systems are mound, recirculating sand filter, and aerobic. Below, we’ll cover each one and the actual cost of these types.

Mound System

A mound system is one of the most common engineered septic systems for areas with high water tables, shallow solid depths, or shallow bedrocks. It uses an elevated mound of sand as the drain field. The septic tank pumps the effluent into the drain field in doses. From there, it’s filtered through the sand and dispersed into the native topsoil. Because of the labor, material such as sand and gravel, and pump tank required to install this system, homeowners pay $10,000 to $20,000 on average. 

Recirculating Sand Filter System

Sand filter septic systems are essentially a large PVC-line or concrete box filled with sand. A pump pushes the effluent through the top layer of sand, where the system treats and filters the wastewater. After treatment, the system disperses the wastewater through the drain field. The pump tank, excavation, installation work needed, and material used cause this system to run $7,000 to $18,000. 

Aerobic System

The oxygen inside the Aerobic Treatment Unit (ATU) accelerates the bacteria activity, allowing the waste to break down efficiently. Aerobic systems might also require pre- and post-treatment tanks to kill bacteria further before it’s dispersed into the drain field. The equipment and labor necessary for it bump the cost $10,000 to $20,000.

DIY vs. Hiring a Pro

Installing an engineered septic system is a complex and highly regulated process that requires professional expertise. Local regulations, soil assessments, and specific engineering requirements must be considered.

Attempting a DIY installation without the necessary knowledge and permits can result in costly mistakes, environmental damage, and legal issues. You should hire a licensed septic tank company near you with experience in designing and installing engineered septic systems to ensure compliance with regulations and the proper functioning of your septic system.

Cost of Common Add-Ons

While the prospect of DIY septic system installation may not be feasible for properties that need engineered septic systems, we still have several cost-saving tips for you to undertake independently. After partnering with a reputable installation company, collaborate with them to pinpoint which of the following tasks you can tackle yourself:

Soil Testing

You can take charge of arranging soil tests for your property to save some cash. By handling this aspect, you can ensure that the soil's composition is analyzed accurately and aligns with your septic system's requirements. 

Obtain Building Permits Yourself

While ensuring your chosen installer is in agreement, you can get the necessary building permits on your own. This streamlines the process, saves money, and ensures compliance with local codes and regulations.

Do Some Landscaping Preparation

To make room for your new septic system and save on engineered septic system costs, consider taking on the responsibility of removing existing landscaping features, such as trees and shrubs. This saves you on labor costs through the septic tank company.

Perform Excavation Work Beforehand

According to the installation plans provided by your installer, you can dig the required holes and trenches. By adhering to their specifications, this DIY task can both save some cash and ensure precise placement of the system components.

Purchase Your Materials Separately

Procuring materials like gravel and other essentials can be a task you handle independently. This ensures that the required supplies are readily available for the installation process and can potentially lead to cost savings if you sniff out some deals.

Ongoing Costs

Managing septic tank maintenance expenses is vital, as it can range from $280 to $550 on average per year and can be over $1,000 for larger systems. To ensure you minimize these costs and keep your septic system running smoothly, consider the following guidelines:

Annual Inspections 

A septic system inspection costs between $200 and $250 and is recommended every year for a healthy, functional system. These inspections help identify issues early and prevent costly repairs down the road.

Septic Tank Pumping

Schedule septic tank pumping every three to five years. This routine maintenance task ensures that solids and sludge do not accumulate excessively in your tank, which can lead to system failures. Septic tank pumping costs between $250 and $550.

Bacterium Additives

Use bacterium additives as part of your monthly maintenance regimen. These additives cost roughly $40 for a year’s supply and aid in breaking down unnatural materials in the septic tank, enhancing its efficiency and longevity. 

Effluent Filter 

Consider installing an effluent filter in your septic system to keep your system in good health. This filter captures solid particles from wastewater, preventing them from clogging the drain field and improving overall system efficiency and longevity. Cleaning and replacing an effluent filter costs $150, while installing one on an existing system ranges from $275 to $850.

Bry'Ana Arvie contributed to this piece.