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• 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

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• 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 SamplingOnce a year everyone is audited internally onsite to check they are complying

with each method. Everyone is also subject to random spot check audits.

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L1 – Chemical and Micro Sampling

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Split into 2 parts

1.Chemical Sampling2.Microbiological Sampling

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Is lead sample

required?

If so take sample.

Is lead sample

required?

If so take sample.

Is a tap swab required?

If so swab tap.

Is a tap swab required?

If so swab tap.

Carry out any on-site

tests

Take any chemical samples

Take any chemical samples

Is the tap constantly running?

Is the tap constantly running?

YES

NO

Flush tap for a minimum of 2

mins or as indicated at the sample point.

Flush tap for a minimum of 2

mins or as indicated at the sample point.

Chemical Sampling

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Take pre-sterilisation

samples

Take pre-sterilisation

samples

Sterilise sample point Chemical

sterilisation

Chemical sterilisatio

n

Flame sterilisatio

n

Flame sterilisatio

n

Check background

chlorine (L13)

Take SampleTake

Sample

Take post sterilisation

swab if required.

Take post sterilisation

swab if required.

Microbiological Sampling

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L13 – Total and Free Chlorine

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

& C)

RINSE the Free

Chlorine Cell

BLANK READ

Add 3 Drops of

DPD Reagent A

Add 3 Drops of

DPD Reagent B

Fill to the 10ml Line

RINSE the Total

Chlorine Cell

BLANK READ

Add 1 Drops of

DPD Reagent C

Add contents of Free Chlorine

Cell

Wait 2 Minutes

•Free Chlorine

•Total Chlorine

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• 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

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• It can take several hours between samples being taken and arriving back at the laboratory.

• To ensure the most accurate representation of the water’s quality, samples need to be stored at a constant temperature between 2°C and 8°C

• Each sampler has a refrigerated van set to these parameters.

• Van temperature is monitored daily throughout each samplers shift with a calibrated fridge thermometer.

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• 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