Dulwa & Nengi Bamir - Lake Ginninderra

Source Information

Environment Protection (EP) monitors freshwater recreational sites for blue-green algae (Cyanobacteria). Health Protection Services (HPS) monitors sites for bacteria by testing for intestinal enterococci, a faecal indicator organism used to assess water quality. Sampling and analysis is carried out in accordance with the ACT Guidelines for Recreational Water Quality. Blue-green algae (Cyanobacteria) and Bacteria (intestinal enterococci, a faecal indicator) are monitored to evaluate water quality for recreational purposes. Bacteria water quality criteria only applies to primary contact activities e.g. swimming, water-skiing, diving etc. Blue- green algae water quality criteria applies to both primary and secondary contact activities e.g. sailing, rowing, kayaking etc. Blue-green algae is tested all year-round on a weekly basis. Faecal indicators are tested weekly during the recreation season (September/ October to April). Samples are typically collected on Mondays (or Tuesdays if Monday is a public holiday). Secondary resampling if required occurs on the following day. Water quality results are posted on the Transport Canberra and City Services (TCCS) website, Water Quality in Our Lakes, Ponds and Rivers. Water quality advisory signs are located at all recreational areas where sampling occurs and as required are changed to reflect the status of a designated site. Microbial results are entered into a spreadsheet which is sent out to designated stakeholders. From October 2017 the microbial results may be available from the data act website. Certificates of analysis are sent to Environmental Health at the HPS. Advisories are issued when water quality exceeds either cyanobacteria and cyanotoxin criteria or when enterococci levels exceed public health risk criteria. Beaches are given a green (pass) status if their most recent sample results meet both of the following protective criteria : Enterococci: 200 cfu/100mL Cyanobacteria: less than 20,000 Indicative Microcystis aeruginosa algae cells/ml Beaches are given a red (fail) if they exceed either of the following protective criteria: Enterococci: 200 cfu/100mL Cyanobacteria: 20,000 Indicative Microcystis aeruginosa algae cells/ml (Medium alert) Additional warnings are issued when cyanobacteria level reach high (≥50,000 cells/ml) or extreme ( ≥125,000 cells/ml) levels.