Bio Retention

Southern Pacific Sands is a market leading supplier for providing the highest quality and industry approved bioretention filter media for the construction of bioretention basins and systems throughout Brisbane and South-East Queensland (SEQ).

Bio Retention Photo - Courtesy of Jack Mullaly

Since the development and implementation of the FAWB guidelines and bioretention basins for the treatment of stormwater in Australia, Southern Pacific Sands has been at the forefront of establishing best practices and producing the most suitable bioretention filter and drainage media.

All filtration media is tested through our own internal stringent quality and control processes and up to date external NATA laboratory testing, as set out by the FAWB and Water by Design Construction Guidelines (WSUD, Healthy Waterways).

Supplying over 300,000 tonnes of bioretention filtration media to the construction industry, Southern Pacific Sands has the experience and industry knowledge to meet the requirements for your next bioretention construction.

With our diverse product range, Southern Pacific Sands is able to provide all the required layers of filtration media required for the installation of a bioretention basin. These layers consist of:

Filter Media

Typically 400-700mm deep or as specified in the engineering design, below is a description of the two types of bio-retention filtration media that Southern Pacific Sands produce.

  • Bioret Plus: Bioretention filter media blended with an organic amendment to increase the water holding capacity and meet the FAWB and WSUD organic requirements, Bio Plus is tested and compliant to the June 2009 v3.01 FAWB guidelines for filter media in biofiltration systems.
  • Bioret: Engineered filter media tested and compliant to the June 2009 v3.01 FAWB guidelines for filter media in biofiltration systems as per section 3 Engineered Filter Media typically requiring amendments to the top 100mm as per section 3, table 1 of the FAWB guidelines.

Transition Layer

Typically 100-150mm deep or as specified in the engineering design. A clean well graded sand material containing less than 2% fines. The transition layer is used to avoid the migration of the filter media into the drainage layer.

  • Our Transition Layer sand meets the FAWB bridging criteria. D15 (transition layer) ≤ 5 x d85 (filter media) when used with our Bioret plus or Bioret filtration media.

Drainage Layer

50-150mm cover over the drainage pipe or as specified.

  • Typically 5-7mm grading or as specified in the engineering design, a clean fine gravel that collects treated water at the bottom of the bioretention system and convey treated water to the underdrain pipes.

Healthy Waterways Limited Bio Retention Diagram

For further information on bioretention basins and swales, please follow the links,