A solar-powered treatment solution

Wastewater treatment in national park

Wattamolla lagoon and surf beach is a picturesque and popular swimming spot, nestled amongst rugged cliffs. Less than an hour south of Sydney, and also part of the network of bushwalks through the Royal National Park, the picnic area is heavily used in the summer.

The old wastewater treatment system and land application area had seen better days and it was time to upgrade. The key criteria selection for a system was:

• a low-energy system to run on solar;
• a system that can handle the seasonality; and
• a low-maintenance, hassle-free system.

“The system has to be robust enough to cope with low to no flows in the winter through to peaks of 8000 litres a day for up to six weeks in summer,” said Damien Dubrowin, National Parks and Wildlife.

Strategic Environmental & Engineering Consulting (SEEC) designed a system using Orenco’s AdvanTex recirculating textile filter. It is an attached growth technology using low power and achieving high levels of treatment. Once treated the effluent is stored in an effluent storage tank and then pumped to absorption trenches in non-trafficable areas.

The other low-energy option considered was a sand filter - also a recirculating media filter. It was discounted due to the space it required - 130 m² versus the textile filters which require 6.6 m² of treatment area.

The AdvanTex was also selected due to its low odour/noise, given the pristine setting and, in particular, its close proximity to a kiosk.

“The system was a breeze to install, and I was amazed how fast the treatment kicked in, with extremely clear effluent visible after only days,” said Kerry Flanagan, Project Manager.

Initially, the maintenance program will see a four-monthly service technician visit, but it is expected the length between services will extend, especially when the actual performance of the system is measured.