WATERWATCH VICTORIA
QA/QC WEEK 2011
REPORT ON STATE-WIDE RESULTS FOR
PHYSICOCHEMICAL PARAMETERS AND
MACROINVERTEBRATES
November 2011
1.0 Background
Waterwatch Victoria is a state-wide community based water quality monitoring
organisation that aims to increase local community understanding and ownership
of waterway and catchment issues. Community volunteers and Waterwatch coordinators are involved in the monitoring of waterway health, including water
quality and macroinvertebrate indicators.
Waterwatch Victoria’s QA/QC Week program is an annual event co-ordinated at
a state-wide level. It involves the testing of laboratory prepared standard
samples by monitors and coordinators to ensure that their equipment and
monitoring techniques are accurate. For more information on Waterwatch
Victoria’s Data Confidence Framework, guidelines and data confidence plans,
visit www.vic.waterwatch.org.au
This report provides a simple summary of the state-wide data provided by both
co-ordinators and monitors during QA/QC Week 2011. It follows on from similar
programs that have been conducted annually since 1998. Further detail can be
found within the eight regional reports that have been distributed to the
Waterwatch coordinators.
2.0 Methods
2.1 Physico-chemical Parameters
Stable ‘Mystery’ reference water samples were prepared for pH, electrical
conductivity (EC), turbidity and orthophosphate by Australian Chemical Reagents
(Roach Analysts), QLD. Each parameter was further divided into a low range
sample (A) and a high range sample (B) giving a total of 8 unique samples. A
subset of these samples (approximately 10%) was tested by a NATA accredited
laboratory to check for sample homogeneity and stability.
Physicochemical ‘mystery’ solutions were prepared to specifications
recommended by the state Waterwatch Victoria office. Values listed in Table 1
are the averaged solution concentrations of the subset measured during QA/QC
Week.
Individual parameter solutions were provided to all regions in separate bottles
with labelled instructions for sample preservation and use. Acceptable upper and
lower quality control limits for each parameter were set according to the
standards outlined in the Waterwatch Victoria Data Confidence Framework.
These quality control limits are sensitive to the wide array of equipment used by
Waterwatch coordinators and monitors.
As with previous years there was again an issue relating to the measurement of
orthophosphate samples using the colour comparators. In light of this issue, the
Waterwatch Victoria QA/QC Week 2011
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acceptable range for the low range parameter was maintained at 40% as was
the case in 2010.
Table 1. True values and acceptable limits for phys-chem parameters.
Parameter
pH (pH units)
EC (µS/cm)
Turbidity Meter
(NTU)
Turbidity Tube
(NTU)
Orthophosphate
mg/L
Sample
Acceptable
Range
True Value
Lower
Limit
Upper
Limit
A
± 0.3
6.2
5.9
6.5
B
8.8
8.5
9.1
A
± 0.3
± 10%
440
396
484
B
± 10%
6200
5580
6820
A
± 20%
18
14
22
B
± 20%
55
44
66
A
± 25%
18
14
23
B
± 25%
55
41
69
A
± 40%
0.04
0.024
0.056
B
± 20%
0.4
0.32
0.48
A total of 1368 phys-chem samples were sent out across the state for QA/QC
Week 2011. Two hundred and sixty one participants took part in the event
including 21 coordinators and 240 monitors. Please note that not every
participant attempted all eight samples as regional co-ordinators decided which
samples they, and their monitors, would assess prior to QA/QC Week 2011. The
minimum number of samples assessed by any one participant was two, with the
majority assessing between four and seven. All participants were provided with
event codes to allow their results to be included in the state-wide analysis
anonymously.
The Victorian Waterwatch Data Confidence Framework sets out minimum
requirements for equipment to be used by monitors and co-ordinators to conduct
water quality analysis. A summary of the requirements for monitoring
Standards 3 and 4 is provided in Table 2 below.
Table 2. Minimum requirements outlined in the Data Confidence Framework.
Parameter
Standard 3
Standard 4
EC
Low range = minimum
resolution of 0.10 mS/cm
High Range = minimum
resolution of 10 mS/cm
Low range = min resolution
of 0.10 mS/cm
High Range = minimum
resolution of 10 mS/cm
pH
pH meters (not strips)
pH meters (not strips)
Turbidity
Turbidity tubes
Turbidity meter
P04
Comparator
Colorimeter
Waterwatch Victoria QA/QC Week 2011
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2.2 Macroinvertebrates
A total of 70 ‘Mystery’ macroinvertebrate samples of known taxonomic
composition were prepared by Instream Solutions. These samples were provided
to test the co-ordinators and monitors identification skills at variable taxonomic
resolutions. The ‘mystery’ samples consisted of six macroinvertebrates that are
naturally found in the majority of Victorian bioregions so not to disadvantage
participants (Table 3). Coordinators and monitors were asked to identify the
macroinvertebrates at the Order, Family and common name level.
Table 3. Macroinvertebrate “Mystery Sample” taxa list.
Order
Family
Common Name
Trichoptera
Calamocertidae
Sleeping Bag
Caddis
Trichoptera
Leptoceridae
Walking Stick
Caddis
Coleoptera
Psephenidae
Water Penny
Coleoptera
Elmidae
Riffle Beetle
Ephemeroptera
Leptophlebiidae
Odonata
Gomphidae
Mudeyes,
Dragonfly larve
Waterwatch Victoria QA/QC Week 2011
Found in Victorian
Bioregions
Highlands, Forest A,
Forest B, Cleared Hills
and Coastal plains
Highlands, Forest A,
Forest B, Cleared Hills
and Coastal plains
Highlands, Forest A,
Forest B, Cleared Hills
and Coastal plains
Highlands, Forest A,
Forest B, Cleared Hills
and Coastal plains
Highlands, Forest A,
Forest B, Cleared Hills
and Coastal plains
Highlands, Forest A,
Forest B, Cleared Hills
and Coastal plains
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3.0
Results
3.1 Physicochemical
The following table summarises the co-ordinators results across all of the eight
regions. A 100 percent pass rate was achieved for the high range (sample B)
electrical conductivity sample and for both turbidity samples.
Table 4. Co-ordinator pass rates for physicochemical parameters.
Parameter
Sample
pH (pH units)
EC (µS/cm)
Turbidity (NTU)
Orthophosphate
mg/L
A
B
A
B
A
B
A
B
Number of
results (n)
17
15
17
12
19
12
18
10
Pass
Rate %
88
93
94
100
100
100
66
70
2010 Pass
Rate %
100
100
100
100
88
100
100
100
As can be seen in Figure 1 the coordinator results in 2011 were slightly lower
than those recorded in 2010 and were in fact very similar to the results from
2009.
Figure 1. Comparison of Co-ordinator pass rates between 2010 and 2011.
Coordinator Comparison 2010 - 2011
120
% Pass Rate
100
80
2011
60
2010
40
20
0
pH A
pH B
EC A
EC B
Turb A
Turb B
Waterwatch Victoria QA/QC Week 2011
PO4 A
PO4 B
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State-wide results for the monitors are summarised in Table 5 below.
Table 5. Monitor pass rates for physicochemical parameters.
Parameter
Sample
pH (pH units)
EC (µS/cm)
Turbidity (NTU)
Orthophosphate
mg/L
A
B
A
B
A
B
A
B
Number of
results (n)
174
121
201
101
207
111
176
53
Pass
Rate %
95
87
92
88
80
75
71
70
2010 Pass
Rate %
92
87
86
85
86
88
71
62
A comparison between pass rates in 2010 and 2011 suggests that monitors
accuracy slightly increased for the pH A and Electrical Conductivity parameters.
A small decrease in pass rates was observed for both turbidity parameters.
Figure 2. Comparison of monitor pass rates between 2010 and 2011.
Monitor Comparison 2010 - 2011
100
90
80
% Pass Rate
70
60
50
2011
40
2010
30
20
10
0
pH A
pH B
EC A
EC B
Turb A
Turb B
Waterwatch Victoria QA/QC Week 2011
PO4 A
PO4 B
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A comparison between the performance of the co-ordinators and that of the
monitors, in 2011, is provided in figures 3 and 4 below. For the low range
samples the monitors had surprisingly higher pass rates for both the pH and
ortho-phosphate samples.
Figure 3. 2011 Pass rates for coordinators and monitors – Low Range
Low Range Sample A
120
% Pass Rate
100
80
Coordinators
60
Monitors
40
20
0
pH A
EC A
Turb A
PO4 A
Results for the high range parameters were more in line with expectations and
coordinators pass rates were consistently higher when compared with the
monitors’ results.
Figure 4. 2011 Pass rates for coordinators and monitors – High Range
High Range Sample B
120
% Pass Rate
100
80
Coordinators
60
Monitors
40
20
0
pH B
EC B
Turb B
Waterwatch Victoria QA/QC Week 2011
PO4 B
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3.2 Macroinvertebrates
Twelve coordinators and twenty eight monitors attempted to identify the
macroinvertebrate ‘Mystery samples’. Bugs were identified by eye, hand lens or
microscope, using a variety of macroinvertebrate keys and picture books. The
majority of co-ordinators and approximately half of the monitors attempted to
identify the bugs at family level. Pass rates were generally quite good, with the
co-ordinators having a slightly higher overall pass rate than the monitors.
As with last year there were several macroinvertebrates included in the vials that
can be difficult to identify. The features used to distinguish Calamocertidae,
Leptoceridae and Elmidae from other families are typically small and best
observed under a microscope.
A list of common misidentifications made by participants in QA/QC week 2011
are outlined in the table below.
Table 7. Common misidentifications at family level
Macroinvertebrate
Common Mistakes
Calamoceratidae
Ecnomidae, Hydropsychidae
Leptoceridae
Philopotamidae
Psephenidae
Elmidae
Hydrophilidae, Hydraenidae
Leptophlebiidae
Baetidae
Gomphidae
Aeshnidae, Telephlebiidae
Identification of macroinvertebrates at family level can be difficult. There are a
number of ways individual regions can improve their identification accuracy if
they wish to, including; purchasing stereo microscopes, obtaining appropriate
family level keys and participating in macroinvertebrate training seminars.
Waterwatch Victoria QA/QC Week 2011
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5.0 Conclusion
The annual QA/QC Week, which is conducted across the state, is just one quality
control check provided by Waterwatch Victoria to support volunteer monitors
and co-ordinators. This year over 260 data sheets for phys-chem and 52 data
sheets for macroinvertebrates were received for analysis. Pass rates for samples
were generally high with the exception again being the orthophosphate results.
A comparison between the 2011 and 2010 results revealed that overall the pass
rates for both monitors and co-ordinators are relatively stable.
As was the case with previous years, several issues relating to the use of
equipment were discovered when processing the data from QA/QC Week 2011..
Many level 4 co-ordinators and monitors are still using turbidity tubes and colour
comparators when according to the Data Framework they should be using
turbidity meters and colorimeters. It is suggested that if these participants were
to use the appropriate equipment (which is more accurate when used correctly)
many of their pass rates would improve. On a positive note the number of level
3 and 4 participants using pH strips instead of pH meters has declined
considerably.
Appendix 1: Data
Raw data from QA/QC Week 2011 can be accessed in excel spreadsheet format
upon request from Waterwatch Victoria.
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