Septic tanks have been around for many years, and most people living on rural properties will be familiar with how they function. But residential wastewater treatment systems are relatively new to the market. A residential wastewater treatment system works more like the large sewage treatment plants that accommodate local council areas (the one your home is too far away to connect to!) but on a much smaller scale. The most popular and effective residential wastewater treatment systems use an aeration process, where a pump will oxygenate the wastewater, creating the ideal conditions for the breakdown of organic matter. The main difference between a septic system and a wastewater treatment system is the quality of the effluent once processed. But there are many differences which might affect your decision when choosing which is most suitable for your property. In this blog, we outline these variations to assist you in making the most informed choice.
Quality of effluent
The effluent discharged from a wastewater treatment system is much cleaner than that dispelled from a septic tank. Septic tank effluent needs further processing once it has left the tank. It will run from a pipe to a soakaway, where the soil will assist in removing bacteria from the effluent. This soakaway cannot be used for anything else; the area of land is expressly for the final treatment of your wastewater, and the soil needs to be kept in good health so that this is possible.
The effluent produced by a wastewater treatment system, however, can be used on your garden (but not your vegetable garden). Many homes will still choose to have it transported to a soakaway after treatment, but it’s often clean enough to use for irrigation. It’s recommended that you carefully consider what plants can handle the nutrient-rich soil that the effluent from the wastewater treatment system produces. But if you do a little research, your garden can really thrive, growing in the soil that’s nurtured by aerobically treated wastewater.
Capacity and efficiency
Wastewater treatment systems work much more efficiently than septic tanks because the aeration system is powered by a pump, assisting in the flow of oxygen to decompose organic compounds. Septic tanks rely on the natural separation of solids from liquids which takes more time. As such, a wastewater treatment system can handle heavier loads of sewage and is much more ideal for larger households. A wastewater treatment system is also better equipped to deal with ‘shock loads,’ for example, when you host a party or have extra family come to stay for Christmas. A 6000L wastewater treatment system, as a guide, will accommodate a household of approximately 11 people with the ability to handle shock loads. A 3000L septic tank will usually only cater for a household of up to four (and if you have a large party, you’d better get the phone number for the local porta-potty company).
Maintenance and servicing
A wastewater treatment system is much less prone to blockages then a septic tank. The pump facilitates the constant movement of organic matter, meaning that services to rectify blockages are rare. However, its mechanical components do require servicing and replacing more frequently. You should regularly check that your pump and blower are in good working order; an easy task if they are readily accessible at the top of your tank.
When it comes to emptying your tanks, a septic tank will need to be de-sludged more often than the chambers in a wastewater treatment system. A 6000L wastewater treatment system with a filter will need to be pumped out once every ten years, whereas a 4500L septic tank without a filter will need to be pumped out once every three years.
If only two people are living in your home at any given time, a septic tank may work well for your property. However, if you have a large household, or you frequently host large events with a constant stream of visitors coming and going, a wastewater treatment system may be more efficient for you. Often the decision comes down to budget. While a wastewater treatment system is more costly to purchase outright, it can save you a lot of money in the long run, with less need for emptying, and a decreased risk of blockage. The added bonus of being able to use the treated wastewater on the garden also appeals to many homeowners.