[en] Full text: Engineering company GHD has implemented an innovative multi- barrier storm water treatment system for a major milling company at the Port of Townsville. The technology economically filters stormwater and is effective for a broad range of contaminants including oil, grease, soluble nutrients and heavy metals. GHD's industrial water and coal seam gas business development leader, Kostas Athanasiadis, created StormDMT, a configuration of inexpensive filter media in a cartridge that cost-effectively removes heavy metals and other dissolved contaminants. He said there was growing recognition of the need to protect receiving waterways and to address water scarcity through measures such as stormwater harvesting. “However, there are few stormwater treatment technologies currently available to effectively and economically remove these contaminants both in particulate and soluble forms, to desirable levels,” he said. GHD carried out a trial at the site in collaboration with the client's engineering, environmental and operational teams. The filter exceeded anticipated performance and the client has adopted a site-wide solution based on the technology. The StormDMT stormwater filter system design incorporates a filtering system (cartridge or other types of filtering configurations) that contains a combination of filter media, including polypropylene flakes to remove oil and grease and particulate-bound contaminants. It also features a zeolite named clinoptilolite to remove positive charged dissolved contaminants such as heavy metals and ammonium nitrogen. Clinoptilolite has been chemically conditioned to maximise its operational ion exchange capacity. Finally, laterite removes negative charged contaminants such as phosphate, nitrate and arsenic as well as heavy metals that have broken through the clinotpilolite layer. One of the key advantages of the StormDMT technology is the low discharge levels it is capable of achieving or dissolved nutrients and heavy metals, the system also has the flexibility to target contaminants specific to site requirements, meeting a range of permit licences. or a typical cartridge configuration, the system has the ability to treat flow rates ranging from six litres per second up to 100L/s. In addition, the technology is installed underground, saving space.