Types of Septic Systems: Which One Is Right for Your Property?

Not all septic systems are created equal. The right system for your Green Bay property depends on soil conditions, lot size, water table depth, and local regulations. Here's an overview of the most common types of septic systems used in Wisconsin.

1. Conventional Gravity System

Best for: Properties with deep, well-draining soil and adequate slope.

A conventional gravity system is the most common and most affordable type. Wastewater flows by gravity from the house to the septic tank, then to the drain field. No pumps or electricity required. Cost: $4,000 - $8,000.

2. Pressure Distribution System

Best for: Flat lots or properties with shallow soil.

This system uses a pump to distribute effluent evenly across the drain field. The pump ensures uniform distribution, which helps prevent overloading any one area. Cost: $5,000 - $10,000.

3. Mound System

Best for: Properties with high water tables, shallow soil, or poor drainage.

A mound system builds a sand mound above ground level to provide additional treatment before the effluent reaches the natural soil. These are common in areas of Brown County with clay soil or high groundwater. Cost: $8,000 - $15,000.

4. Aerobic Treatment System

Best for: Properties with sensitive environments or where higher treatment levels are required.

Aerobic systems use oxygen to promote bacterial activity, producing cleaner effluent than conventional systems. They require electricity and more maintenance but provide the highest level of treatment. Cost: $10,000 - $20,000.

5. Drip Distribution System

Best for: Shallow soil or steep slopes.

This system uses a pump to drip effluent slowly into the soil through a network of small tubes. The slow, even distribution allows for effective treatment in challenging conditions.

Types of Septic Fields (Drain Fields)

The septic field, also called a drain field or leach field, is where treated wastewater is absorbed into the soil. Different types of septic fields work better in different conditions.

Conventional Trench System

Best for: Properties with adequate space and well-draining soil.

Wastewater flows from the septic tank into perforated pipes laid in gravel-filled trenches. The effluent trickles through the gravel and into the soil for final treatment. This is the most common and affordable drain field type.

Requirements: At least 4 feet of suitable soil below the trench, minimum 10-foot separation from groundwater.

Chamber System

Best for: Areas with high groundwater or limited gravel availability.

Plastic chambers replace the gravel and pipe system. Effluent flows into the chambers and slowly seeps into the surrounding soil. Chamber systems are easier to install and require less gravel.

Advantages: Lighter weight, easier installation, better for areas with limited gravel access.

Gravelless System

Best for: Environmentally sensitive areas.

Similar to chamber systems but uses bundles of plastic pipes or other materials instead of gravel. These systems have a smaller footprint and are less disruptive to install.

Mound System Drain Field

Best for: High water tables, shallow soil, or poor drainage.

A sand mound is constructed above the natural soil, and effluent is pumped into the mound for treatment. The mound provides additional treatment area when natural soil conditions are inadequate.

Requirements: Regular pumping of the lift pump, more maintenance than conventional systems.

Sand Filter System

Best for: Properties with poor soil conditions or environmental sensitivity.

Effluent is pumped through a sand filter before reaching the drain field. The sand provides additional treatment, making this suitable for areas with challenging soil conditions.

Cost: $8,000 - $15,000

Evapotranspiration System

Best for: Arid climates with low rainfall (less common in Wisconsin).

These systems rely on evaporation and plant transpiration to dispose of effluent. They require specific climate conditions and are rarely used in Green Bay due to our rainfall levels.

Constructed Wetland System

Best for: Large properties with space for a wetland area.

Effluent flows through a constructed wetland where plants and microorganisms treat the wastewater. These systems provide excellent treatment but require significant space.

Low-Pressure Dose System

Best for: Properties with uneven terrain or shallow soil.

Effluent is pumped in controlled doses to the drain field, allowing for even distribution and better absorption. This prevents overloading any one area of the field.

Septic System Types by Region

You may notice different septic system preferences in different regions. Here's why:

Types of Septic Systems in Alberta

Alberta's cold climate and varying soil conditions favor certain system types:

• Conventional systems: Common in areas with good soil drainage
• Mound systems: Frequently used due to clay soil and high water tables
• Holding tanks: More common in very remote or challenging areas
• Treatment plants: Used where higher treatment levels are required

Types of Septic Systems in Ontario

Ontario has strict regulations under the Ontario Building Code:

• Conventional trench systems: Most common where soil permits
• Filter bed systems: Used for properties with marginal soil
• Shallow buried trench systems: For areas with high bedrock
• Treatment units: Required for sensitive environmental areas

Wisconsin Septic System Requirements

In Brown County and throughout Wisconsin, septic systems must comply with Chapter 38 of the Wisconsin Administrative Code:

• All new systems require a permit from the local health department
• Soil evaluation and site assessment are mandatory
• Minimum setbacks from wells, property lines, and water bodies
• Regular inspections and pumping required
• Existing non-conforming systems may need upgrades upon sale or major renovation

How to Choose the Right System

The best way to determine the right system for your property is to have a professional site evaluation. This includes soil testing, percolation tests, and an assessment of your lot's characteristics.

Factors that determine your system type:

• Soil type: Sandy soil drains faster than clay
• Soil depth: Distance to bedrock or groundwater
• Slope: Steep slopes may require special design
• Lot size: Larger lots can accommodate conventional systems
• Water table: High groundwater limits options
• Local regulations: Brown County health department requirements
• Budget: Some systems cost 2-3x more than others

Contact Septic Green Bay to connect with licensed contractors who can evaluate your property and recommend the best system.