february 2 0 0 5

1
Water Quality
Sampling Team
2
What we do

• The sampling team is responsible for taking a
  range of representative samples related to every
  water production asset supplying our customers.
• That is 600 samples per week from
• 30 Treatment Works
• 208 Service Reservoirs
• 125 Customer House Taps (via cold calling)
• In an area stretching from the south of Scotland
  to North
• Yorkshire, and from Kielder reservoir to the
  coast (including Hartlepool Water).
• With a team of 16 samplers on 12 designated
  programmed rounds

3
Sampling

• What is sampled, the analysis required and how
  often is determined by the DWI and pre-planned in
  a sampling schedule
• Each individual sampling event consists of taking
  between 1 and 25 different bottles of varying
  type depending on the analysis required
• On-site tests such as chlorine, temperature ,
  taste and odour are also taken
• To do this each member of the team is trained in
  5 methods
• L1 Chemical and Micro Sampling
• L7 Determination of the Temperature of a Liquid
• L16 Qualitative Taste and Odour
• L13 Total and Free Chlorine
• L17 Cryptosporidium Sampling
• Once a year everyone is audited internally onsite
  to check they are complying with each method.
  Everyone is also subject to random spot check
  audits.

4
Sampling
L1 Chemical and Micro Sampling
5
Sampling L1

• Split into 2 parts
• Chemical Sampling
• Microbiological Sampling

6
Sampling L1
Chemical Sampling
YES
Is lead sample required? If so take sample.
Is a tap swab required? If so swab tap.
Is the tap constantly running?
Carry out any on-site tests
Take any chemical samples
Flush tap for a minimum of 2 mins or as indicated
at the sample point.
NO
7
Microbiological Sampling
Flame sterilisation
Take pre-sterilisation samples
Take Sample
Take post sterilisation swab if required.
Sterilise sample point
Chemical sterilisation
Check background chlorine (L13)
8
Chlorine
L13 Total and Free Chlorine
9
Chlorine L13

• Equipment
• Pocket Colorimeter
• 4 x 10ml glass cells
• Set of 3 DPD reagents (A,B C)

• Free Chlorine

Add 3 Drops of DPD Reagent A
Add 3 Drops of DPD Reagent B
RINSE the Free Chlorine Cell
BLANK
READ
Fill to the 10ml Line

• Total Chlorine

RINSE the Total Chlorine Cell
BLANK
READ
Add 1 Drops of DPD Reagent C
Add contents of Free Chlorine Cell
Wait 2 Minutes
10
Documentation

• Every part of the process is noted down on the
  samplers run sheet including
• Date time of sample
• Location if different from target (including
  reasons why)
• Equipment and methods used as part of the
  sampling process
• This ensures we have complete traceability over
  each sample for audit purposes.
• Each sample is also labelled with a pre-printed
  bar coded label so it can be clearly identified
  through the administration and analysis process

11
Storage Transportation

• It can take several hours between samples being
  taken and arriving back at the laboratory.
• To ensure the most accurate representation of the
  waters quality, samples need to be stored at a
  constant temperature between 2C and 8C
• Each sampler has a refrigerated van set to these
  parameters.
• Van temperature is monitored daily throughout
  each samplers shift with a calibrated fridge
  thermometer.

12
Calibration

• To ensure any results we produce for on-site
  tests are accurate, a strict calibration process
  is employed.
• The following are examples of everyday equipment
  requiring calibration that every sampler carries
• Colorimeters used to measure Free and Total
  Chlorine levels, these are calibrated annually.
  However they are also subject to a daily gel
  standard check and are used as part of the
  internal external PT schemes on a monthly and
  quarterly basis.
• Stick Thermometers Used to determine the
  temperature of the water we sample. Calibrated
  quarterly at three different temperatures.
• Van Thermometers Used to ensure sampler van
  fridges are running at the appropriate
  temperature. Calibrated annually