Holiday shacks wastewater gets special treatment

An isolated, scenic spot in Southern Tasmania had a waste problem. Located on crown land, the community of numerous separate holiday shacks was too remote to access a municipal sewer main.

The Tasmanian government realised the problem could have serious implications for the local environment and determined the wastewater requirements that the site needed to meet.

When Kelair was brought in, it looked at the requirements and offered a system to suit – the Kelair-Blivet all-in-one, ‘plug and play’ wastewater treatment plant.

A tailored wastewater solution
The location required onsite wastewater treatment facilities to replace a series of old septic tanks.

The government owned the land, with individuals occupying the separate dwellings.

Kelair Sales Engineer for Tasmania Peter Doran said, “You can imagine a little community with small, fairly basic houses - each with its own bathroom.

“The setup, with the septic tanks, was an environmental risk. The government decided they needed to do something to improve the situation.

“So they employed a consulting engineering firm to work out how to get a better environmental outcome for the site. Based on those criteria we selected an appropriate treatment system.”

Kelair provided a Kelair-Blivet BL1500 packaged wastewater treatment plant along with a separate inlet pump station, a treated effluent discharge pump station, a disinfection system, and a wastewater feed pump station for each shack site.

The Kelair-Blivet is an all-encompassing wastewater treatment plant that comes ready-to-go and can be quickly and easily installed.

Wastewater enters the Blivet through the primary settlement zone, then rises through a set of parallel plates, passes through the Aerobic Treatment Unit (Aerotor Biozone) and into the final settlement zone before moving up through another set of parallel plates and out of the Blivet. From there, the effluent can receive further treatment if required – such as filtration and / or disinfection – before being transferred to the disposal point.

The treatment package at this particular site produces a disinfected effluent with a Biochemical Oxygen Demand (BOD) of 10mg/L and Suspended Solids (SS) of 15mg/L that is suitable for sub-surface disposal or for limited reuse.

Mr Doran said, “Each lot has its own little pumping station. So basically, when you flush your toilet or use the sink or shower, it goes out through the waste pipe to a tank outside the house.

“There’s a pump in each one of those tanks that pumps the wastewater through a pipe that goes all the way along to the inlet pump station near the Blivet itself. The inlet pumps – in duty or standby configuration – then feed the wastewater into the Blivet.”

Mr Doran said the plant then discharged the water into a tank, and from there it passes through disinfection equipment.

The disinfection system, separate from the main plant, can consist of UV disinfection, chlorine disinfection, or both. Chlorine disinfection in the form of tablets was used at the holiday shack site.

The effluent was then transferred via a pipe to the soakage trenches.

Mr Doran said, “The final product was dispersed subsurface and allowed to filter through the ground naturally.”

While the soakage trenches are fairly typical discharge systems, effluent from the Blivet can be used for drip, or even sprayed, irrigation – depending upon the location and regulatory requirements.

Kelair can assist with disposal options, although typically a contractor will install the system.

The Blivet BL1500 was able to provide for a maximum capacity of 150 people, though the population of the community was generally much smaller.

“It was sized slightly conservatively to allow for any peak periods where they had more people visiting.”

The Kelair treatment
At the South Tasmanian site, Kelair helped the contractor throughout the installation process and provided support when needed.

“We were able to assist with any technical enquiries that they weren’t sure about. We were also involved with commissioning the units and just making sure everything worked and was set up correctly.”

As the only supplier of the Blivet in Australia, Kelair has 20 years of experience supplying and maintaining the systems.

Mr Doran said the Kelair-Blivet was a great solution for sites that were unable to access a sewer main and required onsite wastewater treatment.

“The Kelair-Blivet is compact, does not require constant manning, is simple to operate and maintain, has low operating costs and is a practical and economical wastewater treatment option.

“Effective wastewater treatment is essential for every community in order to protect the environment and also look after the health of the general public.”