Water quality treatment is neccesary for developments that trigger criteria of the State Planning Policy. The State Planning Policy can be viewed at http://www.dilgp.qld.gov.au/resources/policy/state-planning/state-planning-policy-jul-2014.pdf. Water Quality Objectives are set by the governing council. Some of the water quality treatment devices that make up a treatment train are presented below.
A bio-retention basin is vegetated area with various underlying soil types. Runoff directed to the bio-retention basin ponds on the surface, gradually filteriing through the underlying soil, removing key pollutants. Bio-retention basins are capable of achieving water quality objectives without the need for pre-treatment of runoff. An example of a bio-retention basin is presented below.
A StormFilter system is a tertiary treatment device. The StormFilter works by filtering runoff through the filter inert and ion exchange media to remove key pollutants. A StormFilter system typically comprises a below ground chamber with access through manholes. StormFilters can also be incorporated into larger detention tank style systems to have the Water Quality and Quantity in the same excavation. The StormFilter typically utilises either pre-treatment via EnviroPods or rainwater tanks to achieve the required pollutant reductions and is most efficient when used in the approved StormFilter EnviroPod treatment train. Stormwater360 also have a new media named Phosphosorb (PSorb) which operates at a significantly higher pollutant removal efficiency which reduces the need for pre-treatment. This new PSorb media has just been approved by the Gold Coast City Council's new protocol and can achieve the required reduction targets as a standalone system in some applicatio ns. The Stormfilter filter device is pictured below.
A Jellyfish filter is a tertiary stormwater treatment device. The Jellyfish system works by filtering runoff through membranes which removes key pollutants. The Jellyfish device is located underground with access through a manhole. The Jellyfish device is capable of achieving water quality objectives without the need for pre-treatment of runoff. The Jellyfish filter device is pictured below.
A SpelFilter is a tertiary stormwater treatment device. The SpelFilter works by filtering runoff through a spiral wrapped media to remove key pollutants. The SpelFilter device is located underground with access through a manhole. The SpelFilter is capable of achieving water quality objectives without the need for pre-treatment of runoff. The Spelfilter device is pictured below.
A swale is a vegetated channel that conveys runoff. Whilst swales do not achieve water quality objectives by themselves, they are an important part of a treatment train. Swales are able to be incorporated into car parks, green spaces, walkways, roads, parks and landscape areas which makes them an excellent method of treating stormwater without losing development area. An example of a swale is presented below.
A trash bag is a bag made from a fine mesh. The trash bag is placed in gully pits and are used to capture gross pollutants. Whilst trash bags do not achieve water quality objectives by themselves, they are an important part of a treatment train. An example of a trash bag (SPEL's Storm Sack) is presented below.