Community and Environmental Benefits
We continue to improve how we treat sewage at the Eastern Treatment Plant. Currently we are completing a major upgrade which will:
- reduce the impact on the marine environment at Boags Rocks, where treated water is discharged
- produce better quality recycled water which can be used for a variety of purposes
We are also increasing the amount of renewable energy we produce and use at the plant.
Improve effluent quality
Ammonia from the Eastern Treatment Plant has an impact on the marine environment at Boags Rocks, where treated effluent is released.
We have been working since the mid-1990s to reduce these ammonia levels in the treated effluent. For example, we have:
- upgraded six existing aeration tanks in our secondary treatment process to achieve an 85% reduction in the annual ammonia amount released
- built four additional aeration tanks to further reduce ammonia levels
- improved water recycling to limit amount of water discharged at Boags Rocks
We are also collaborating with South East Water to improve the quality of treated effluent at Boags Rocks. Treated effluent from its Mount Martha, Boneo and Somers plants is also discharged there.
Water recycling
In 2010/2011, we supplied 16,740 million litres of recycled water which was then used as part of the sewage treatment process and to maintain grounds.
Our recycled water was also used offsite by nearby customers for activities such as irrigation of market gardens and golf courses and some residential supplies.
The upgrade of the Eastern Treatment Plant will allow the plant will produce recycled water of a higher quality from the end of 2012. The recycled water will be of a class A standard, suitable for:
- toilet flushing
- garden watering
- car washing
- growing crops that are eaten raw
- fire fighting
Renewable energy
Since opening in 1975, the Eastern Treatment Plant has used renewable energy produced from the methane gas emitted from sewage.
The gas is used to run seven generators which are able to provide around 40% of the plant’s electricity needs.