How To Install A Septic System

Installing a septic system is a crucial undertaking that requires careful planning and execution. Whether you’re building a new home or replacing an existing system, the process can be daunting, but by following a systematic approach, you can ensure a successful and trouble-free installation.

Firstly, the site selection is paramount. The area where the septic system will be placed must meet specific criteria, such as having a sufficient slope for drainage, being away from water sources, and having suitable soil conditions. A percolation test is typically conducted to determine the soil’s ability to absorb and disperse wastewater. If the soil fails the test, an alternative design or location may be necessary.

Furthermore, the design of the septic system is critical. The size and type of system will depend on the number of bedrooms in the house, the daily water usage, and the characteristics of the soil. There are two main types of septic systems: conventional and alternative. Conventional systems consist of a septic tank and a drain field, while alternative systems utilize different technologies, such as sand filters or aerobic units, to treat wastewater. The choice of system will be based on factors such as cost, site constraints, and environmental regulations.

Site Selection and Evaluation

Site Suitability Assessment

A comprehensive evaluation of the site is crucial to ensure a properly functioning septic system. Here are key factors to consider:

1. Soil Characteristics:

Soil Depth: Minimum depth of 24 inches (60 cm) is required below the bottom of the leach field.
Soil Permeability: Soil must allow water to percolate at a rate suitable for septic system discharge. This can be determined through a soil percolation test.
Soil Structure: Soil should be stable and not prone to settling or erosion. Avoid soils with excessive sand, clay, or rocks.
Groundwater Level: Septic systems should be located at least 12 inches (30 cm) above the highest expected groundwater level.
Bedrock Depth: Bedrock should be at least 6 inches (15 cm) below the bottom of the leach field.
Soil pH: Soil pH should be between 6.0 and 7.5 for optimal bacterial activity.

Site Topography

Slope: The site should have a slope of no more than 10%. Steeper slopes may require additional measures to prevent erosion.
Drainage: The site should have good surface drainage to prevent ponding of water.
Distance to Surface Water: Septic systems should be located at least 100 feet (30 m) from any surface water body, such as lakes, rivers, or streams.

Other Site Requirements

Access: The site should be easily accessible for maintenance and pumping.
Setbacks: Adequate setbacks from property lines, wells, and dwellings are required to meet local regulations.
Zoning: Verify that the proposed septic system is permitted in the zoning district for the property.

Designing the Septic System

Planning and Research

Before embarking on your septic system installation, it’s crucial to gather essential information and consult with local authorities. Determine the size and type of system required based on household size, soil conditions, and drainage patterns. Research local regulations, permitting requirements, and health codes to ensure compliance.

Engineering and Layout

This phase involves creating a detailed design plan that specifies the system’s layout and components. The septic tank, drainfield, and potential effluent filters or pumps are all carefully engineered to meet specific requirements. The design should consider factors such as soil permeability, slope, and distance to water sources to ensure optimal performance and prevent contamination.

Component	Function
Septic Tank	Primary treatment unit that separates and settles waste solids
Drainfield	Subsurface network that distributes treated wastewater into the soil for final disposal
Effluent Filter	Optional device that further treats wastewater before entering the drainfield
Pump	Used to move wastewater uphill or when gravity flow is insufficient

Excavating the System

Once the design of your septic system has been finalized and approved by the local authorities, it’s time to begin the excavation process. This phase involves digging the trenches and holes necessary for the installation of the septic tank and the drain field.

The excavation process can be carried out manually or with the use of heavy machinery. The method chosen will depend on the size and complexity of your system, as well as the nature of the terrain. If the excavation is extensive or the soil conditions are challenging, it’s advisable to hire professional contractors with the appropriate equipment and expertise.

Here are the specific steps involved in excavating the system:

1. Trenching

The first step is to excavate the trenches for the drain field. The trenches should be dug parallel to each other and at the specified depth and width as per the design. The length of the trenches will depend on the size of the drain field and the expected flow rate.

2. Tank Excavation

Next, the hole for the septic tank is excavated. The hole should be large enough to accommodate the tank and provide sufficient clearance for maintenance and repairs. The depth of the hole will depend on the size of the tank and the depth required for proper drainage.

3. Inspection and Preparation

Once the trenches and tank hole have been dug, it’s essential to thoroughly inspect the excavation work. Ensure that the trenches and hole are dug to the correct specifications and that the soil conditions are suitable for the installation. If necessary, make any necessary adjustments or corrections before proceeding with the installation.

Excavation Step	Description
Trenching	Digging parallel trenches for the drain field.
Tank Excavation	Creating a hole for the septic tank.
Inspection and Preparation	Checking the excavation work, making adjustments, and preparing the site for installation.

Installing the Septic Tank

1. Dig a large enough hole to accommodate the septic tank. The hole should be at least 12 inches wider and longer than the tank, and it should be deep enough so that the top of the tank is at least 6 inches underground.

2. Place the septic tank in the hole and level it. Use a level to make sure that the tank is level from side to side and from front to back.

3. Connect the inlet and outlet pipes to the septic tank. The inlet pipe is the pipe that carries wastewater from the house to the septic tank. The outlet pipe is the pipe that carries wastewater from the septic tank to the drain field.

4. Backfill the hole around the septic tank with dirt. Compact the dirt firmly around the tank to prevent it from moving. The soil should be firmly compacted around the tank, but avoid using a vibrating compactor, such as a jumping jack, near the septic tank.

5. Install the lid on the septic tank. The lid should be secured tightly to prevent water from entering the tank.

6. Install a cleanout pipe on the lid of the septic tank. The cleanout pipe will allow you to inspect the tank and remove any solids that may accumulate over time.

7. Cover the septic tank with a layer of topsoil. The topsoil will help to protect the tank from damage and will allow grass to grow over the tank.

Connecting the Leach Field

The leach field is where the wastewater from your septic tank is distributed and treated by the soil. It’s typically made up of a series of perforated pipes laid in trenches that are filled with gravel or other coarse material. The wastewater flows out of the septic tank and into the pipes, where it gradually seeps into the surrounding soil. The soil bacteria then break down the organic matter in the wastewater, purifying it before it reaches groundwater.

To connect the leach field to your septic tank, you’ll need to:

1. Dig trenches around the perimeter of the leach field. The trenches should be deep enough to accommodate the pipes and gravel, and they should be spaced far enough apart to allow the wastewater to spread out evenly.

2. Lay the perforated pipes in the trenches. The pipes should be connected end-to-end, and they should be sloped slightly so that the wastewater flows downhill.

3. Fill the trenches around the pipes with gravel. The gravel will help to distribute the wastewater and provide support for the pipes.

4. Connect the leach field to the septic tank. The connection should be made using a pipe that is large enough to handle the flow of wastewater.

5. Cover the leach field with soil. The soil will help to protect the pipes and gravel from damage, and it will also help to absorb the wastewater.

Backfilling and Grading

Once the trench and seepage bed have been installed, it’s important to properly backfill and grade the area to ensure the septic system functions correctly and lasts for many years to come.

Backfilling

The trench and seepage bed should be backfilled with a mixture of native soil and sand. The soil should be compacted in layers to prevent settling and create a stable base for the system. Avoid using large rocks or debris that could damage the system.

Grading

After backfilling, the area around the septic system should be graded to promote proper drainage. The soil should be sloped away from the system to prevent water from pooling and infiltrating the components.

Grading Requirements

The following table outlines the minimum grading requirements for septic systems:

Distance from Septic System	Slope
0-10 feet	1%
10-25 feet	0.5%
Over 25 feet	0.25%

Connecting the Plumbing

7. Connecting the Septic Tank to the Drainfield

This step involves connecting the outlet pipe from the septic tank to the distribution box, which distributes the wastewater evenly throughout the drainfield. Here’s a detailed overview of the process:

a. Installing the Distribution Box

* Dig a hole large enough to accommodate the distribution box.
* Place a layer of gravel in the bottom of the hole for drainage.
* Set the distribution box in place and level it.
* Cover the distribution box with another layer of gravel.

b. Connecting the Outlet Pipe to the Distribution Box

* Cut the outlet pipe from the septic tank to the appropriate length.
* Fit a reducer coupling on the end of the outlet pipe to connect it to the distribution box.
* Connect the pipe to the distribution box and secure it with a hose clamp.

c. Connecting the Drainfield Lines

* Cut and prepare the drainfield lines according to the manufacturer’s instructions.
* Firmly insert one end of each drainfield line into one of the distribution box outlets.
* Secure the lines with hose clamps.

d. Backfilling the Lines

* Cover the distribution box and drainfield lines with a layer of gravel or crushed stone.
* Fill the remaining space around the lines with topsoil.
* Compact the soil to create a stable base for the drainfield.

Inspecting and Testing the System

1. Inspecting the Tank

Thoroughly inspect the septic tank for any leaks or damage. Make sure the lids are securely fastened, and check the inlet and outlet pipes for any obstructions.

2. Testing the Drain Field

The drain field is where the treated wastewater from the septic tank is discharged into the soil. Test the drain field by pouring water into the distribution box and observing the flow. If the water drains away quickly, the drain field is functioning properly.

3. Inspecting the Absorption Area

The absorption area is the area around the drain field where the wastewater is absorbed into the soil. Inspect the area for any signs of surface ponding or odors. If any problems are found, the absorption area may need to be repaired or replaced.

4. Checking the Effluent Filter

If your septic system has an effluent filter, check it regularly for any clogs or debris. A clogged filter can restrict the flow of wastewater out of the septic tank.

5. Monitoring the Scum and Sludge Levels

Monitor the scum and sludge levels in the septic tank. If the levels become too high, the tank may need to be pumped.

6. Testing the Water Quality

Test the water quality in the absorption area to ensure that the system is treating the wastewater properly. This can be done by collecting a sample of water from the absorption area and sending it to a laboratory for testing.

7. Maintaining a Septic System Log

Keep a log of all inspections, tests, and maintenance performed on the septic system. This log will help you track the performance of the system and identify any potential problems early.

8. Hiring a Professional

If you notice any problems with your septic system, it is best to hire a professional to inspect the system and make the necessary repairs. A professional will have the knowledge and experience to identify and fix any problems with your septic system.

Maintaining the Septic System

Maintaining a septic system is crucial for its longevity and effectiveness. Here are some essential maintenance practices to follow:

1. Regular Inspections

Schedule regular inspections by a qualified professional to identify any potential issues and address them promptly.

2. Pumping

Pump the septic tank every 3-5 years to remove sludge that can clog the system and reduce its efficiency.

3. Keep Away Chemicals

Avoid pouring harsh chemicals, such as bleach or drain cleaners, into the septic system, as they can damage beneficial bacteria.

4. Minimize Water Usage

Conserve water to reduce the load on the septic system, particularly during peak usage times.

5. Plant Selection

Choose plants that do not have aggressive root systems nearby the septic system to prevent damage to pipes.

6. Avoid Driving

Keep vehicles and heavy equipment away from the drain field, as it can compact the soil and impair drainage.

7. Repair Leaks

Fix any leaks in toilets, faucets, or pipes promptly to prevent excessive water from entering the septic system.

8. Use Septic-Safe Products

Opt for septic-safe cleaning products and toilet paper to avoid harming beneficial bacteria in the tank.

9. Garbage Disposal Usage

Minimize the use of garbage disposals, as they can add excessive organic matter to the septic tank, leading to faster sludge accumulation. Consider composting biodegradable waste instead.

Frequency	Task
Monthly	Check for leaks and odors around the tank
Quarterly	Inspect the drain field for any signs of pooling or surface water
Annually	Schedule a professional inspection and pumping

Troubleshooting Common Issues

1. Slow Drainage

Possible Causes:
– Clogged drain pipes
– Overloaded septic tank
– Failed drain field

Solutions:
– Clear drain pipes
– Pump septic tank
– Repair or replace drain field

2. Foul Odors

Possible Causes:
– Overloaded septic tank
– Leaking septic tank
– Deteriorated drain lines

Solutions:
– Pump septic tank
– Repair septic tank leaks
– Replace deteriorated drain lines

3. Sewage Backups

Possible Causes:
– Clogged sewer line
– Overloaded septic tank
– Failed septic field

Solutions:
– Clear sewer line
– Pump septic tank
– Repair or replace septic field

4. Standing Water Near Drain Field

Possible Causes:
– Saturated drain field
– Failed drain field
– Obstructed drain pipes

Solutions:
– Aerate drain field
– Repair or replace drain field
– Clear drain pipes

5. Soil Pollution

Possible Causes:
– Leaking septic system
– Overloaded septic tank
– Deteriorated drain field

Solutions:
– Repair septic system leaks
– Pump septic tank
– Replace deteriorated drain field

6. Algae Growth Near Drain Field

Possible Causes:
– Discharge of untreated sewage
– Leaking septic system
– Poorly designed drain field

Solutions:
– Inspect septic system for leaks
– Redirect discharge
– Redesign drain field

7. Green Grass Near Drain Field

Possible Causes:
– High nutrient levels in soil
– Discharge of untreated sewage
– Leaking septic system

Solutions:
– Test soil for nutrient levels
– Inspect septic system for leaks
– Redirect discharge

8. Sinkholes Near Drain Field

Possible Causes:
– Collapse of drain field
– Leaking septic tank
– Erosion of soil

Solutions:
– Repair or replace drain field
– Repair septic tank leaks
– Stabilize soil

9. Electrical Problems

Possible Causes:
– Faulty septic pump
– Damaged electrical wiring
– Power outage

Solutions:
– Replace septic pump
– Repair electrical wiring
– Restore power

10. Septic System Maintenance

Regular Maintenance

Benefits:
– Extends the life of the septic system
– Prevents costly repairs
– Protects the environment

Recommended Maintenance Schedule:
– Pump septic tank every 3-5 years
– Inspect septic system annually
– Clear drain lines regularly