100-Gallon Portable Septic Tank: What You Need to Know

Two green septic tanks sitting perpendicular to each other with black manholes on top.

Septic tank systems are a common way to dispose of wastewater for homes that are not connected to a public sewer system. The septic tank is the first step in the process, and it is important to understand how it works in order to keep your system running smoothly. 

This article will describe how a typical septic tank system works, from the wastewater entering the tank to the final discharge of treated wastewater.

What is a Septic Tank System and How Does it Work?

A septic tank is a self-contained, watertight chamber typically buried underground. Septic tanks are used to treat and dispose of household sewage and wastewater. They are most commonly used in rural areas where there is no centralized sewer system. Septic tanks are typically made of concrete, fiberglass or plastic and range in size from 200 to 1,500 gallons.

Septic tanks work by allowing all wastewater from the home to flow into the tank through a pipe. The wastewater then settles into three layers: solid, scum, and effluent. The solid layer consists of heavy particles that settle to the bottom of the tank. The scum layer consists of lighter particles that float to the top of the tank. The effluent layer is the liquid that remains between the solid and scum layers.

As the effluent flows out of the septic tank, it enters a drain field. The drain field is a series of trenches filled with gravel or other porous materials. This allows the effluent to slowly seep into the ground, where bacteria treats it before it enters the groundwater.

An alternative to the standard trench drain field is a sand filter. These drain fields are used when there is a high groundwater table or the soils won’t pass a perc (percolation) test.

The Different Parts of a Septic Tank System

A septic system is composed of four or five main elements and each is absolutely necessary for the proper function of the system

1. Inlet Baffle

The inlet is where the wastewater enters the tank. The inlet pipe should be large enough to allow the wastewater to flow into the tank quickly, without any restrictions. The inlet baffle is where the septic tank and main sewer line from the house intersect. 

Its purpose is to help wastewater flow quickly and smoothly into the tank by keeping undigested scum on top of the water while it moves down, then across, then up inside the tank. This allows more time for separation than if it just flowed straight across.

2. Tank (One or Two Compartments)

The tank is where the wastewater is stored and where the solids are allowed to decompose. The size of the tank depends on how many people use the system and how much wastewater they produce.

There are single-compartment and double-compartment tanks. So, what’s the difference between them?

  • A single-compartment septic tank: This system has one chamber where wastewater is treated. These types of tanks are not as efficient and require pumping every three to five years, as the separation between liquids and solids all occurs within the same space with no option for an overflow location.
  • Double-compartment tanks: The first chamber treats the wastewater by breaking it down into its three components: sludge on the bottom, wastewater in the middle and the scum layer that floats on the surface. The second chamber provides an overflow, which allows the treated water to further settle before it flows into the drain field.

3. Two Tank Systems

One tank is for storing blackwater and the other greywater. Blackwater includes urine, feces and water from flushing toilets, while greywater is liquid (but not contaminated) coming from showers or sinks. This reduces the pressure on one septic tank and prevents it from becoming overloaded.

There are several benefits to having a dual tank septic system, the main being that it stores and releases waste better than a single tank system. With two tanks, you won’t have to pay to pump as often, because they can hold more wastewater. Furthermore, it’s less likely to overflow and break pipes due to strain, since there is less pressure on the system overall. In other words, you’ll save money on repairs compared to a standard septic system.

4. Outlet Baffle

An outlet baffle with an effluent filter is the most successful at keeping solids from reaching the drain field. If you don’t have one, contact your septic contractor to see about getting one installed. It will need to be replaced periodically, but that’s a small price compared to replacing your drain field.

5. Drain Field/Leach Field

A drain field, also known as a leach field, is an important part of a septic system. It is a network of perforated pipes and gravel-filled trenches, which allows treated effluent to slowly seep into the soil. The drain field must be located in an area with good drainage and should be at least 10 feet away from any buildings or other potential sources of contamination. 

The effluent is evenly distributed throughout the drain field by the perforated pipes, and the soil filters out any remaining impurities before the water eventually enters the groundwater. A properly designed and maintained drain field can provide many years of trouble-free operation.

Tank Depot Has the Best Price on Single and Double Compartment Septic Tanks

A large blue, medium yellow, and small round black septic tank with black manholes on top.

Are you looking for a quality septic tank at an affordable price? Look no further than Tank Depot! We have the best selection of single- and double-compartment tanks available, and our prices are unbeatable. We also carry a vast selection of water storage tanks

So don’t wait any longer, contact us today for more information or to locate a dealer near you!