Agri-Ash is a sterile by-product of the sewerage treatment process, which is used as a soil conditioner for agricultural purposes. The Lower Molonglo Water Quality Control Centre produces around 16 tonnes of Agri-Ash a day.

What makes Agri-Ash important?

There are no waste products from the Lower Molonglo treatment process because all solids are recycled into Agri-Ash. Our sophisticated and holistic treatment process is of particular interest to other countries and communities who are also located inland and have limited waste disposal options. In the future, Agri-Ash may increase in importance to agricultural communities as the world’s supply of phosphorus — vital for intensive agriculture — runs out. Phosphorus cannot be synthesised. Agri-Ash is rich in phosphorus and calcium which are excellent for acidic soils. It is also an economical alternative for farmers.

The Lower Molonglo treatment process explains how Agri-Ash is produced.

Chemical composition of Agri-Ash

Agri-Ash is approximately 60% calcium-based compounds, including calcium carbonate, calcium oxide and tricalcium phosphate. These calcium compounds neutralise soil acidity. The phosphorus content of Agri-Ash is around 6%. The Agri-Ash also contains traces of heavy metals such as zinc, copper, nickel, lead, cobalt and cadmium. Nearly all the metals are locked up in insoluble forms and will not harm pastures or livestock. Agri-Ash meets the supply and quality requirements set by the NSW Environment Protection Authority Resource Recovery Order (Agri-Ash) 2020, as per Part 9, Clause 93 of the Protection of the Environment Operations (Waste) Regulation 2014. 

Component Value  Standard 
 Phosphorus  6.6%  >2% total phosphorus
 Cadmium  9.1  <300mg cadmium per kilogram of phosphorus
 Lead  28.0  <100mg lead per kilogram of the fertiliser
 Mercury  <0.10  <5mg mercury per kilogram of the fertiliser

More information

If you would like more information about Agri-Ash, please email us.

Please note: Icon Water does not sell Agri-Ash directly to consumers. If you are a farmer who would like to enquire about purchasing Agri-Ash, please ring the distributor Fertspread on 1800 500 184 (free call).