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Title / 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 actionsof treatment filtration processes.
Classification / Water Industry > Drinking-Water
Available grade / Achieved
Explanatory 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.
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.
Outcomes and evidence requirements
Outcome 1
Describe sand filtration processes.
Rangeincludes but is not limited to – Granulated Activated Carbon (GAC), open, pressure, Automatic Valveless Gravity (AVG), slow.
Evidence requirements
1.1Sand filtration processes are described in terms of their design features.
Rangefiltration rates, inlet control, containment and flow paths, media type and depth, nozzles, outlet flow control.
1.2Sand filtration processes are described in terms of their operation, and the organisational procedures for optimisation, and performance monitoring.
Rangeoperation – backwashing or cleaning, flow and level control, effluent disposal.
Outcome 2
Describe mechanical filtration processes.
Rangeincludes but is not limited to – cartridge, bag, strainers.
Evidence requirements
2.1Mechanical filtration processes are described in terms of their design features.
Rangeflow capacity, inlet control, containment and flow paths, filter material, outlet flow control.
2.2Mechanical filtration processes are described in terms of their operation, and the organisational procedures for optimisation, and performance monitoring.
Rangeoperation – backwashing or cleaning, cleaning regime and sequence, troubleshooting and maintenance, flow and head loss, pressure control, filter disposal.
Outcome 3
Describe membrane filtration processes.
Rangeincludes but is not limited to – micro, ultra, nano, reverse osmosis, pressure, vacuum.
Evidence requirements
3.1Membrane filtration processes are described in terms of their design features.
Rangefiltration rates, inlet control, containment and flow paths, membrane material, configuration, outlet flow control.
3.2Membrane filtration processes are described in terms of their operation and the organisational procedures for optimisation, and performance monitoring.
Rangeoperation – backwashing or cleaning, flow and level control, effluent disposal membrane material condition, cleaning regime and sequencing, troubleshooting and maintenance.
Outcome 4
Describe diatomaceous earth filtration processes.
Rangeincludes but is not limited to – pressure, vacuum.
Evidence requirements
4.1Diatomaceous earth filtration processes are described in terms of their design features.
Rangefiltration rates, inlet control, containment and flow paths, media type and thickness, outlet flow control.
4.2Diatomaceous earth filtration processes are described in terms of their operation, and the organisational procedures for optimisation, and performance monitoring.
Rangeoperation – backwashing or cleaning, flow and level control, effluent disposal, media selection, media condition, cleaning regime and sequencing, troubleshooting and maintenance.
Outcome 5
Identify critical points, hazards, preventive actions, and corrective actions of treatment filtration processes.
Rangefiltration processes – rapid sand, mechanical, membrane, diatomaceous earth.
Evidence requirements
5.1The critical points in the various processes are identified in accordance with organisational procedures.
5.2The hazards at each critical point are identified in terms of the causes of the events leading to their appearance, and the risk factors.
5.3The preventive and corrective actions for events related to each hazard are identified.
This unit standard is expiring. Assessment against the standard must take place by the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process / Version / Date / Last Date for AssessmentRegistration / 1 / 19 September 2008 / 31 December 2018
Review / 2 / 16 March 2017 / 31 December 2018
Consent and Moderation Requirements (CMR) reference / 0101
This CMR can be accessed at
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and which are assessing against unit standards must engage with the moderation system that applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies to this standard are outlined in the Consent and Moderation Requirements (CMR). The CMR 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.
Infrastructure ITOSSB Code 101813 / New Zealand Qualifications Authority 2018 / / New Zealand Qualifications Aut