Blackwater recycling: the basics

Whilst greywater covers most of the waste water from our homes (water from sinks, washing machines, showers, dishwashers and baths), blackwater is the nasty stuff – the toilet waste.

A blackwater recycling system will collect all the dirty water from your home, filter it, treat it, and re-use it in the garden for irrigation.

The Garden Master Elite is a home sewerage treatment tank that is installed underground in the garden.

“The system relies on anaerobic bacteria, which is produced by your solids,” explained Peter. When waste water enters the system it goes through five stages:

• Septic tank: Anaerobic bacteria builds by the billions and the waste turns mud-like.
• Secondary tank: The waste water is treated with air, via an air blower that sits on top of the tank and mulches the water like a spa bath.
• Filter: The aerated water is filtered and clarified.
• Sterilisation: Chlorine is added to the water to kill bacteria.
• Irrigation chamber: The treated water is used to irrigate the garden.

The irrigation is then either above ground or underground, to a specific area in the garden dedicated to receiving the irrigated water. Shrubs and trees will extract the remaining nutrients from the water.

“There is no smell at all,” said Peter. “The only way it will smell is if the customer puts bacteria killers like Napisan, hospital cleaner or hair dye into it. As long as they don’t do this, the system will be crystal clear with no problems or smells.”

Unfortunately, it’s not simply a case of deciding you want to be super self-sufficient and start treating your sewage at home.

It all depends on where you live. Basically, metropolitan areas are out, rural areas are in.

“If you live in a metropolitan area, you have to hook up to the sewerage system – that’s a mandatory requirement,” explained Peter. “But in Australia there are so many areas that are rural and not connected to metropolitan sewage systems, you only have to get a few kilometres out of the cities – there are already 2-300,000 black water recycling systems out there.”

There are also requirements that need to be met – set by the local council – to ensure systems are safe.

“We visit the customer and look at the house plans or site plan, then draw everything up for the council, making sure all the health requirements and planning requirements are met,” added Peter.

A fully installed Garden Master Elite will costs in the region of $11,000.

Garden Master also supplies a greywater recycling system – the ultraGTS.

“The hardest thing with greywater recycling is getting rid of lint, but our system uses a membrane to filter it out,” said Peter.

The ultraGTS, which comes with water tanks, the filtration unit itself and pressure pumps, costs about $15,000.