Algal Alerts in the Lachlan Catchment

Algal Alerts in the Lachlan Catchment

Algal Alerts in the Lachlan Catchment

3rd September2015

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This blue-green algal alert report is based on routine monitoring undertaken by the Cowra, Forbes and Lachlan Shire Councils; State Water Corporation and the NSW Office of Water.

These alert levels apply to non consumptive or recreational contact. Drinking water safety thresholds are much more stringent.

Table 1: LachlanSampling Sites - Counts of potentially toxic blue-green algae (cells/mL total species and biovolume equivalent BVEq of total blue green algae and potentially toxic blue green algae).Bold = new result from previous report
Sampled Date/Alert / Sampling Site / Total BGA cells
mL / BVEq total BGA
mL / BVEq potentially toxic BGA / Previous Alert / Dominant species
* Potentially toxic
20 May 2014
No alert / Lake Wyangala Dam Wall
Stn 1 (41210001) / 0 C/mL
mm3/L BVEq
mm3/L BVEq / Nil
10 Aug 2015
No alert / Lake Wyangalaat Grabine
Stn 2 (41210002) / 34C/mL
0.04 mm3/L BVEq
0.04 mm3/L BVEq / Amber
10 Aug 2015
No alert / Lake Wyangala Lachlan Arm
Stn 3 (41210003) / 104 C/mL
0.04 mm3/L BVEq
0.04 mm3/L BVEq / Nil
10 Aug 2015
No alert / Lake Wyangala Lachlan Arm
Stn 4 (41210004) / 106C/mL
<0.04 mm3/L BVEq
0.04 mm3/L BVEq / Green
10 Aug 2015
No alert / Lake Wyangala Abercrombie Arm Stn 5 (41210005) / 282 C/mL
<0.04 mm3/L BVEq
0.04 mm3/L BVEq / Nil
10 Aug 2015
No alert / Lake Wyangala State Park
Stn 7 (41210007) / 120C/mL
0.04mm3/L BVEq
<0.040mm3/L BVEq / Amber
10 Aug 2015
No alert / Lachlan River D/S Wyangala Dam (412067) / 220 C/mL
<0.04 mm3/L BVEq
0 mm3/L BVEq / Nil
14 Jan 2015Amber / Carcoar Dam Stn 1
(4120021) / 22,400 C/mL
0.61 mm3/L BVEq
0.61 mm3/L BVEq / Nil
10 Apr 2013
Amber / Carcoar Dam Rec Area
(41210191) / 111502 C/mL
2.45 mm3/L BVEq
2.45 mm3/L BVEq / Amber / * Microcystis flos-aquae
14 Jan 2015 No Alert / Belubula River D/S Carcoar Dam
(41210106) / 98 C/mL
0.0 mm3/L BVEq / Nil
Lachlan River @ Cowra / C/mL
mm3/L BVEq
Sampled Date/Alert / Sampling Site / Total BGA cells
mL / BVEqtotal BGA
mL / BVEq potentially toxic BGA / Previous Alert / Dominant species
* Potentially toxic
11 March 2015
No alert / Lachlan River @ Forbes
Cottons Weir (412004) / 0 C/mL
0 mm3/L BVEq
mm3/L BVEq / Nil
11 March 2015
Amber / Lake Forbes
/ 2033 C/mL
0.48mm3/L BVEq
0mm3/L BVEq / Nil
24 June 2015
No Alert / Goobank Creek@Goobang Weir / 0 C/mL
0. mm3/L BVEq
0 mm3/L BVEq / Nil
24 June 2015
No Alert / Lachlan River @ Condobolin Bridge (412006) / 0 C/mL
mm3/L BVEq
mm3/L BVEq / Nil
3 Mar 2015
No Alert / Lachlan River
@ Condobolin Weir (412034) / 0 C/mL
mm3/L BVEq
mm3/L BVEq / Nil
13 Aug 2015
No Alert / Lake Cargelligo Intake D/S Curlew Water (41210155) / 0C/mL
0 mm3/L BVEq
0 mm3/L BVEq / Amber
14 Aug 2015
No Alert / Lake Cargelligo TWS Site 2
(41210042) / 0 C/mL
0 mm3/L BVEq
0 mm3/L BVEq / Red
17 June 2014
No Alert / Lake Cargelligo Site 3 Main Swimming Area (41210043) / 6,098 C/mL
0.01 mm3/L BVEq
0.01 mm3/L BVEq / Green / *Cylindrospermopsis raciborskii
13 Aug 2015
No Alert / Lachlan River at
Lake Cargelligo Weir (412011) / 44 C/mL
0.04 mm3/L BVEq
0.04 mm3/L BVEq / Nil
14 Aug 2015
No Alert /
Lake Cargelligo Boat Shed (4121543) / 0 C/mL
0 mm3/L BVEq
0mm3/L BVEq / Red
13 Aug 2015
No Alert / Lake Creek @ Lake Cargelligo Outlet (412008) / 0 C/mL
0.0 mm3/L BVEq
0 mm3/L BVEq / Nil
14 May 2014
No Alert / Lachlan River
at Lake Brewster Weir (412048) / 0 C/mL
0 mm3/L BVEq
0 mm3/L BVEq / Amber / *Anabaena
14 Aug 2015
No Alert / Lake Brewster Intake
(412102) / 0 C/mL
0.0 mm3/L BVEq
0.0 mm3/L BVEq / Green
Sampled Date/Alert / Sampling Site / Total BGA cells
mL / BVEq total BGA
mL / BVEq potentially toxic BGA / Previous Alert / Dominant species
* Potentially toxic
19 Nov 2013
Amber / Lake Brewster
Main Storage at Regulator
(41210197) / 978,.282 C/mL
1.09 mm3/L BVEq
0 mm3/L BVEq / Nil / Cyanocatena
11 Mar 2013
No alert / Lake Brewster Outlet Channel D/S Regulator C (41210196) / 0 C/mL
0 mm3/L BVEq
0 mm3/L BVEq / Nil
19 Nov 2013
Green / Lake Brewster Inflow Wetland
U/S Spillway (41210195) / 170,293 C/mL
0.31 mm3/L BVEq
mm3/L BVEq / Nil / Cyanocatena
14 Aug 2015
No Alert / Lake Brewster Storage Gauge
(412108) / 0C/mL
0.0 mm3/L BVEq
0.0 mm3/L BVEq / Nil
23June 2014
No Alert / Lake Brewster Outlet
@ Bensons Drop Weir
(412047) / 2346 C/mL
0mm3/L BVEq
08 mm3/L BVEq / Green / Microcystis aeruginosa
23June 2014
No alert / Lachlan River at Willandra Weir (412038) / 0C/mL
mm3/L BVEq
mm3/L BVEq / Nil
11 Aug 2015
Nil / Lachlan River at
Hillston Weir
(412039) / 0 C/mL
0mm3/L BVEq
mm3/L BVEq / Nil
11 Aug 2015
Nil / Lachlan River at Booligal Weir
412005 / 0 C/mL
0mm3/L BVEq
0mm3/L BVEq / Amber
11 Aug 2015
Nil / Lachlan River at Corrong
(412045) / 0 C/mL
0 mm3/L BVEq
0 mm3/L BVEq / Amber
3 Feb 14
Amber / Cadiangullong Dam / 9,930
mm3/L BVEq
2.76 mm3/L BVEq / Amber / * Dolchiospermum, Aphanizomenon
24Jun 2015
Green / Gum Bend Lake / 705 C/mL
0.07 mm3/L BVEq
0 mm3/L BVEq / Amber

The bio-volume equivalent (BVEq)calculated for all contributing cyanobacteria species is used to determine alert thresholds. The total observed cyanobacteria genera that contribute to the current alert level are also presented.

It is recommend that water treatment and stock management responses should not be altered according to the observed cyanobacteria genera but that the BVEq Alert framework be applied. All cyanobacteria should be considered as potentially harmful to human and animal health when present in blooms.

River users and landholders are advised to avoid waters in areas subject to RED (High) alert levels or with visible algae scums. They should also consider either alternative sources of water for stock. NSW Health advises that any domestic use of surface water without treatment is dangerous and should be avoided. Note, boiling water contaminated with blue green algae does not remove toxins

Alert Definitions are as specified in The National Health and Medical Research Council (NHMRC) Guidelines for Managing Risks in Recreational Water 2008

The use of these guidelines is endorsed by the Scientific Subcommittee of the State Algal Advisory Group

Key to alerts for recreational waters
Blue-Green Algal Level /
Alert Definition
GREEN
>500 – <5,000 cells/mL Microcystis aeruginosaOR biovolume equivalent of >0.04 to <0.4 mm3/L for the combined total of all cyanobacteria / GREEN ALERT
  • Low levels of detected –base crop of blue green algae may be on the increase
ACTION
Continue/increase routine sampling to measure cyanobacteria levels
AMBER
≥5,000 – <50,000 cells/mL Microcystis aeruginosaOR biovolume equivalent of >0.4 to < 4.0 mm3/L for the combined total of all cyanobacteria where a known toxin producer is dominantOR ≥0.4 to <10 mm3/L for the combined total of all cyanobacteria where known toxin producers are not present. / AMBER ALERT
  • Indicates blue-green algae are multiplying
  • Water may have a green tinge and musty taste and odour
ACTION
  • Water supply authorities to commence filtering with activated carbon
  • Investigations into the causes of the elevated levels and increased sampling to enable the risks to recreational users to be more accurately assessed

RED
>50,000 cells/mL Microcystis aeruginosa OR biovolume equivalent of ≥ 4 mm3/L for the combined total of all cyanobacteria where a known toxin producer is dominant
Or
The total biovolume of all cyanobacterial material exceeds 10 mm3/L where known toxin producers are not present
Or
Cyanobacterial blooms are consistently present / RED ALERT
  • High levels detected
  • Indicates “bloom” conditions
  • Toxicity should be presumed
  • Water will appear green or brownish and may have a strong musty taste and odour
  • Surface scums could occur
  • Extreme care should be exercised, and contact with the water should be avoided
ACTION
  • Issue Media Release
  • Water supply authorities to increase filtering with activated carbon as appropriate
Local authority and health authorities to warn the public that the water body is considered to be unsuitable for primary contact recreation.

For media enquiries contact Public Relations Officer on 02 6701 9662.
For further information contact the Water Quality Officer at the NSW Office of Water, on (02) 8838 7517.

For toll free information on blue-green algae outbreaks contact the Algal Information Hotline - 1 800 999 457Page 1