Septic Tanks – a brief introduction

Typical septic tank system layout - septic tank connected to a percolation area

Septic Tanks and Wastewater treatment systems- a brief introduction

Septic tanks, a brief summary to help you better understand what’s behind the process hidden in your garden and the difference in wastewater systems and process provided by a septic tank systems.  The full article can be read here…..

Septic Tanks Explained – Your home, your waste and the septic tank inspections

Septic tanks are a type of wastewater management system commonly used in rural areas. Septic tanks are usually found underground in close proximity to the premises. They manage all waste emitted from a household (wastewater from bathrooms, kitchens and appliances). Septic tanks are not connected to any sewer system; they are very commonly used in rural areas. This is due to the lack of alternatives to household waste management. If a property were to be developed on a quiet countryside road, it would most like have a septic system

Houses outside towns and villages that are likely on septic tank waste management

Like every waste management system, Septic tanks have their own pros and cons. A consumer should be well versed in both before further inquiry. Compared to the alternative of sewers septic tanks are much more eco friendly. Although, septic systems place the responsibility for proper installation, maintenance and use on the owner of the septic system.

The full detail of post 1 in this series of articles about drains, septic tanks and proper waste water management can be viewed at link mentioned here:

The maintenance of drains & Septic tanks – The Do’s & Don’ts ! 

For assistance with Ground works and percolation testing and no obligation quotations on the condition of your wastewater septic tank system contact either – Sean Ansboro by clicking here:  Alpha septic systems Ireland or phone to discuss any queries or questions you may have that are septic tank and off mains wastewater systems- 087-7817953

Or for help, advice and sales / service and replacement septic tank systems and commercial wastewater system repair, maintenance or installation of mechanical or biological septic systems across the counties in Leinster and the Midlands including: Kildare, Meath, Offaly, Westmeath, Wicklow & county Dublin – Contact for all your septic tank needs and drain cleaning, drain jetting, sewer relining, CCTV drain surveys and basically all wastewater system requirements – ( Phone:  085-1276288   ). For post 2 and in this article I will summarize the difference between a ‘septic tank‘ and ‘wastewater treatment’ system. 

Some properties(both homes and commercial businesses) have septic tanks while others will have a type of wastewater treatment system they basically are Both the same systems with similar function. I.e. to breakdown and dispose of waste effectively, efficiently and safely from your property in compliance with Local authority and EPA guidance on septic tank wastewater systems.

What are the differences between a septic tank and a wastewater treatment system?

The key difference for a septic tank system & a wastewater treatment systems is based around how they break down and dispose of the waste.

Which system should you choose?

This depends on a number of factors including location (space on your property or site), number inhabitants or occupants, site restrictions and of course cost or budget. To assist with information on the key basic differences and provide a better understanding of how to choose your septic tank a summary of the manner and process of how a septic tank breaks down sewerage and how a wastewater system processes the effluent from a home or building is detailed below.

Septic tank systems & Wastewater treatment systems breakdown Procedure
How the wastewater and waste matter breakdown process carried out by a system is the biggest difference between them.

A septic tank, when wastewater enters the tank and the solids sink to the bottom and any matter that floats will rise to form a scum layer at the top of the septic tank. Between the bottom solids layer and scum top layer is a fairly clear body of water that contains bacteria and chemicals. The majority of this waste is broken down through a natural biological process provided by the bacteria.
A benefit of this gravity fed natural septic tank function is there is usually no need for maintenance (when set up and used correctly).

Septic tank | gravity fed biological break down of waste

A wastewater treatment system, the wastewater and waste matter is broken down utilizing a mechanical process usually using a set of rotating discs that are designed to activate aerobic bacterial breakdown of the waste. This process produces a non-damaging effluent that can be generally released without the need for further treatment. These systems do have a number of mechanical components from the rotating discs to pumps and control panel systems which do require regular maintenance to ensure the system is functioning effectively and in overall good condition

Wastewater treatment through a mechanical process


A septic tank using self-forming bacteria will break down the solids that are disposed of producing an effluent that is only about 70% clean. A percolation area normally provides the further treatment before it can be released into the environment.

A wastewater system, by the aerobic breakdown of the solid being more complex, and as a result the wastewater system effluent is 95% clean allowing direct discharge into the environment to soak away in most cases.

Emptying septic tanks and wastewater systems

Emptying after prolonged use, the layer of solids at the bottom of a septic tank will increase to such an extent that the tank will have to be emptied. How often will depend on its level of usage, but in general, a septic tank should be emptied at least once a year.
wastewater treatment system will require emptying less often through the aerobic breakdown of solids is much faster and therefore blockages are infrequent, however again a lot depends on the level of usage of a system or if either a septic tank or wastewater mechanical system is undersized for the number of inhabitants or occupants of a property this can lead to frequent emptying and damage to overworked systems. It is vital to have your system correctly sized and site assessment carried out before choosing the best system for you.