1 October to 31 December 2015
Your water
This summary of the Quarterly drinking water quality report
1 October to 31 December 2015 includes both quarterly updates and
a table that shows water quality test results over the past 12 months.
Drinking water
management
We supply you with highquality, safe drinking water
– managed under quality
systems. Our water is among
the world’s best!
WaterNSW manages
Sydney’s catchments to
provide the best quality water
for us to treat. We treat your
water by first filtering it,
then disinfecting it. This is
called the ‘multiple-barrier’
approach. We continuously
monitor these steps to
ensure our systems are
working as expected.
During October to
December 2015, our monitoring
confirmed that the drinking
water we delivered to you was
of high quality and safe.
What is tested? Testing for water quality
Your water is tested for up to
70 different characteristics
including taste, colour, odour,
micro-organisms and chemical
content. This report summarises a
selection of health characteristics
chosen in consultation with
NSW Health and also key
aesthetic characteristics.
Our aim is to provide you with
high quality, safe drinking water
treated to meet the Australian
Drinking Water Guidelines.
We take water samples from the
catchments, at the inlet and outlet
of water filtration plants, from
the reservoirs and from about
650 customers’ front garden taps.
The table on the next page
summarises the water quality test
results for samples we collected
from customers’ taps over the
past 12 months.
Laboratories certified to
international standards do all our
testing. NSW Health reviews the
results of these tests.
Water quality test results
1 January to 31 December 2015
Microbiological
E. coli
1
Physical/Chemical
Fluoride
2
Chlorine
Trihalomethanes
Turbidity
True
colour
Iron
Australian Drinking Water Guidelines (ADWG).
ADWG performance criteria
(for assessment over
12 month period)
At least 98% of
results contain
no
E. coli
At least
95% of
results 0.9
to 1.5 mg/L
95th percentile less
than 5 mg/L
95th percentile less
than 0.25 mg/L
Average
result less
than 5 NTU
Health – (H), Aesthetic – (A)
(H)
(H)
(H)
(H)
(A)
Average
Average
result less
result
than 15 HU less than
0.3 mg/L
(A)
(A)
Actual test results for 12 months from 1 January to 31 December 2015 as per the agreed compliance schedule
Customer supply
system
All parameters
comply
% of results
meeting criteria
% of results
meeting
criteria
Percentile meets
criterion
Percentile meets
criterion
Average
result (NTU)
Average
result (HU)
Average
result
(mg/L)
North Richmond
P
P
P
P
P
P
P
P
P
P
P
P
P
100
100
<2
0.023
100
0.11
<2
<0.010
100
100
0.15
3
0.018
100
100
0.13
2
0.022
100
100
0.13
3
0.017
99.9
100
0.17
3
0.023
100
100
0.14
3
0.019
100
100
0.11
<2
0.010
100
100
0.14
<2
0.016
100
100
0.13
<2
0.020
100
100
0.13
<2
0.011
100
100
0.12
<2
0.016
100
100
P
P
P
P
P
P
P
P
P
P
P
P
P
0.16
100
P
P
P
P
P
P
P
P
P
P
P
P
P
0.13
<2
0.014
Orchard Hills
Prospect South
Prospect North
Prospect East
Ryde
Potts Hill
Warragamba
Nepean
Macarthur
Illawarra
Woronora
Cascade
Note: 1. A
s agreed with NSW Health, based on compliance samples only
2. A
lthough the ADWG specifies a guideline
value for fluoride of 1.5 mg/L, the NSW
Code of Practice for Fluoridation of Public
Water Supplies requires that, over a year,
greater than 95% of all routine samples fall
within the range 0.90 to 1.50 mg/L.
Storage behaviour and catchment rainfall
1 October to 31 December 2015
The total available water in WaterNSW’s storages was approximately 2.40 million megalitres at
the end of the quarter or 92.9% of total operating storage. The total available water decreased
by 4.7% over the quarter.
Approximately 144 millimetres of rainfall was recorded on the Warragamba catchment during
the quarter; 36% below the long term median for the same time of year.
Understanding your water
Escherichia coli (E. coli)
Chlorine
Turbidity
E. coli is used as a scientific
indicator of the quality of drinking
water and of the possible presence
of micro-organisms that cause
disease. E. coli is measured
as organisms per 100 millilitres
(Organisms/100 mL).
To ensure good quality drinking
water, chlorine is added to kill
bacteria that may cause disease.
We test for the residual level of
chlorine that must be present to
make sure that water is disinfected
all the way to your tap.
Turbidity is a measure of suspended
material in water and may
cause water to look muddy or
discoloured. Turbidity is measured in
Nephelometric Turbidity Units (NTU).
Fluoride
Some systems use ‘free’ chlorine
and others use monochloramines.
Water should be virtually colourless.
It is measured in Hazen Units (HU).
Trihalomethanes (THMs)
Iron
THMs are formed in water when
chlorine reacts with small amounts
of naturally occurring organic matter.
THMs are measured in mg/L.
Iron can be present at low levels in
the water and may be responsible
for some taste and staining
problems. It is measured in mg/L.
Small amounts of fluoride are
added for dental health reasons as
legislation requires. It is measured
in milligrams per litre (mg/L).
True colour
Visit sydneywater.com.au for the full quarterly drinking
water quality report
Our drinking water is treated
to meet the Australian
Drinking Water Guidelines
SW191 01/16