Expert Opinion (Brett Neilan, UNSW)
I refer to the reports EB1100382 and EB1101592 sent to me by Mark Solomons
(Brisbane Courier Mail). I refer in particular to the section reporting the
Enterococci, E. coli and Faecal Coliforms of three water samples collected from
Brisbane River on two different dates, 10/01/2011 (EB1100381) and
31/01/2001 (EB1101592).
Summary
Based on the values provided by the reports EB1100382 and EB1101592 the
ANZECC Guidelines for recreational water quality (see below), all microbial
values reported for samples processed on 10/01/2001 (EB1100382) are higher
than the maximum values recommended for recreational waters (for both
primary and secondary contact).
For samples processed on 31/01/2001 (EB1101492), Enterococcus
contamination was only within acceptable limits for the REGATTA sample.
Feacal coliform contamination was only within acceptable limits for secondary
contact for the JINDALEE and borderline acceptable for the REGATTA sample.
The ANZECC Guideline
The Australian and New Zealand Environmental Conservation Council (ANZECC)
has published the Australian and New Zealand Guidelines for Fresh and Marine
Water Quality in 2000. This guideline is used by the NSW Department of
Environment, Climate Change, and Conservation (DECC) to provide water quality
guidelines to community groups and other water management organisations.
The ANZECC guidelines are also referred to in the Queensland Water Quality
Guidelines 2009, published by the QLD Department of Environment and Resource
Management.
The above guidelines can be freely downloaded from the Internet
ANZECC Guidelines:
http://www.mincos.gov.au/publications/australian_and_new_zealand_guideline
s_for_fresh_and_marine_water_quality
NSW DECC Guide to using ANZECC Guidelines:
http://www.environment.nsw.gov.au/water/usinganzeccandwqos.htm
QLD Water Quality Guidelines 2009:
http://www.derm.qld.gov.au/environmental_management/water/queensland_
water_quality_guidelines/index.html
Guideline Values
Chapter 5 of the ANZECC guidelines stipulates the following values for
recreational water use (see report for definition of primary and secondary
contact)
Primary contact
The median bacterial content in samples of fresh or marine waters taken
over the bathing season should not exceed:
• 150 faecal coliform organisms/100 mL (minimum of five samples taken
at regular intervals not exceeding one month, with four out of five
samples containing less than 600 organisms/100 mL);
• 35 enterococci organisms/100 mL (maximum number in any one sample:
60–100 organisms/100 mL).
Pathogenic free-living protozoans should be absent from bodies of fresh
water. (It is not necessary to analyse water for these pathogens unless the
temperature is greater than 24°C.)
Secondary contact
The median bacterial content in fresh and marine waters should not exceed:
• 1000 faecal coliform organisms/100 mL (minimum of five samples taken
at regular intervals not exceeding one month, with four out of five
samples containing less than 4000 organisms/100 mL);
• 230 enterococci organisms/100 mL (maximum number in any one
sample: 450–700 organisms/100 mL).
Microbiological values reported the reports and Conclusions
Organism
Unit
JINDALEE
INDOOROPILLY
REGATTA
Sample Date
--
10/01/
11
31/01
/11
10/01/
11
31/01/
11
10/01
/11
31/01/
11
Enterococci
Faecal Coliforms
Escherichia coli
CFU/100mL
CFU/100mL
CFU/100mL
1400
~200
2400
~500
11000
<10
3600
~600
3600
1800
5100
1000
2400
~200
2600
730
2600
1000
All microbial values reported for samples processed on 10/01/2001
(EB1100382) are higher than the maximum values recommended for
recreational waters (for both primary and secondary contact).
For samples processed on 31/01/2001 (EB1101492), Enterococcus
contamination was only within acceptable limits for the REGATTA sample.
Feacal coliform contamination was only within acceptable limits for secondary
contact for the JINDALEE and borderline acceptable for the REGATTA sample.