24899 version 1
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Describe the management of drinking-water treatment filtration
processes
Level
5
Credits
10
Purpose
People credited with this unit standard are able to describe: sand filtration
processes; mechanical filtration processes; membrane filtration processes;
and diatomaceous earth filtration processes; and identify critical points,
hazards, preventive actions, and corrective actions of treatment filtration
processes.
Subfield
Water Industry
Domain
Drinking-Water
Status
Registered
Status date
19 September 2008
Date version published
19 September 2008
Planned review date
31 December 2013
Entry information
Open.
Replacement information
This unit standard replaced unit standard 18452.
Accreditation
Evaluation of documentation and visit by NZQA, industry
and teaching professional in the same field from another
provider.
Standard setting body (SSB)
Primary Industry Training Organisation
Accreditation and Moderation Action Plan (AMAP) reference
0179
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Special notes
Definitions
Critical points – points in a process or in equipment where failure to function correctly can
lead to a public health hazard.
Optimisation – adjusting plant input variables to make the process as effective as possible
in order to achieve the desired output, taking into account the constraints of cost, human
input, water quality, and water demand.
 New Zealand Qualifications Authority 2016
24899 version 1
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Organisational procedures – instructions to staff, and procedures which are documented in
memo or manual format and are available in the workplace. These requirements include
but are not limited to – site specific requirements, manufacturers’ specifications, product
quality specifications, and legislative or regulatory requirements.
Elements and performance criteria
Element 1
Describe sand filtration processes.
Range
includes but is not limited to – Granulated Activated Carbon (GAC), open,
pressure, Automatic Valveless Gravity (AVG), slow.
Performance criteria
1.1
Sand filtration processes are described in terms of their design features.
Range
1.2
filtration rates, inlet control, containment and flow paths, media
type and depth, nozzles, outlet flow control.
Sand filtration processes are described in terms of their operation, and the
organisational procedures for optimisation, and performance monitoring.
Range
operation – backwashing or cleaning, flow and level control,
effluent disposal.
Element 2
Describe mechanical filtration processes.
Range
includes but is not limited to – cartridge, bag, strainers.
Performance criteria
2.1
Mechanical filtration processes are described in terms of their design features.
Range
2.2
flow capacity, inlet control, containment and flow paths, filter
material, outlet flow control.
Mechanical filtration processes are described in terms of their operation, and
the organisational procedures for optimisation, and performance monitoring.
Range
operation – backwashing or cleaning, cleaning regime and
sequence, troubleshooting and maintenance, flow and head loss,
pressure control, filter disposal.
 New Zealand Qualifications Authority 2016
24899 version 1
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Element 3
Describe membrane filtration processes.
Range
includes but is not limited to – micro, ultra, nano, reverse osmosis, pressure,
vacuum.
Performance criteria
3.1
Membrane filtration processes are described in terms of their design features.
Range
3.2
filtration rates, inlet control, containment and flow paths,
membrane material, configuration, outlet flow control.
Membrane filtration processes are described in terms of their operation and the
organisational procedures for optimisation, and performance monitoring.
Range
operation – backwashing or cleaning, flow and level control,
effluent disposal membrane material condition, cleaning regime
and sequencing, troubleshooting and maintenance.
Element 4
Describe diatomaceous earth filtration processes.
Range
includes but is not limited to – pressure, vacuum.
Performance criteria
4.1
Diatomaceous earth filtration processes are described in terms of their design
features.
Range
4.2
filtration rates, inlet control, containment and flow paths, media
type and thickness, outlet flow control.
Diatomaceous earth filtration processes are described in terms of their
operation, and the organisational procedures for optimisation, and performance
monitoring.
Range
operation – backwashing or cleaning, flow and level control,
effluent disposal, media selection, media condition, cleaning
regime and sequencing, troubleshooting and maintenance.
 New Zealand Qualifications Authority 2016
24899 version 1
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Element 5
Identify critical points, hazards, preventive actions, and corrective actions of treatment
filtration processes.
Range
filtration processes – rapid sand, mechanical, membrane, diatomaceous earth.
Performance criteria
5.1
The critical points in the various processes are identified in accordance with
organisational procedures.
5.2
The hazards at each critical point are identified in terms of the causes of the
events leading to their appearance, and the risk factors.
5.3
The preventive and corrective actions for events related to each hazard are
identified.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP also includes useful information about special requirements for organisations
wishing to develop education and training programmes, such as minimum qualifications for
tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact the Primary Industry Training Organisation standards@primaryito.ac.nz if
you wish to suggest changes to the content of this unit standard.
 New Zealand Qualifications Authority 2016