As a remote coral cay in the middle of the ocean, Lady Elliot Island isn’t connected to any mainland sewerage system—we have to manage all our wastewater on site. To protect the surrounding Great Barrier Reef, we treat every drop of used water to a strict environmental standard. Using natural processes, the system breaks down waste with the help of beneficial microbes before it’s irrigated back onto the island.

Our custom-built Wastewater Treatment Plant (WWTP) is intricately designed to avoid adverse impact on the Great Barrier Reef Marine Park. This carefully managed process ensures that treated water irrigated on the airstrip exceeds environmental standards, protecting the fragile coral cay ecosystem. 

The system involves several key stages: primary treatment to remove solids, secondary treatment to break down organic matter using microbes, and tertiary treatment for additional purification, including UV sterilisation via sunlight – achieving high water quality at no additional cost.

Primary Treatment: The first stage combines natural and physical processes. Solids settle to the bottom of enclosed tanks, while anaerobic microorganisms break down organic matter in the absence of oxygen.

Secondary Treatment: In this stage, oxygen is introduced (aerobic treatment) to support aerobic microorganisms that “polish” the waste-water by further breaking down organic material, effectively removing contaminants and nutrients.  

Recirculation: Treated water is then recirculated through the system, to optimise biological treatment and ensure water quality.Disinfection: Chlorine is added to kill off any remaining microorganisms and bacteria, ensuring the water is safe for re-use.

UV Treatment: The final stage before irrigation uses natural UV light from the sun to break down residual chlorine – achieving clean, safe water at no additional cost.

Groundwater
Ongoing monitoring of treated effluent, soil, groundwater and vegetation ensures that our waste-water meets strict environmental standards and is not adversely affecting the groundwater reliant ecosystem. 

Studies show that the amount of nutrients added from the effluent is 1.5% of the input added by birds

Did you know that we don’t use any harsh chemicals in the resort?
To ensure that our WWTP operates at the highest standard, every chemical that is used on the island – from dishwashing, to body wash, must be approved to ensure no harsh chemicals are used

What Goes Down, Comes Around
All drains lead to the ocean. What you wash down the sink or flush away doesn’t just disappear. The Great Barrier Reef catchment spans over 420,000 square kilometres—that’s two-thirds of Queensland! So even if you live far from the coast, your choices still flow downstream.