NZQA Expiring unit standard / 24972 version 2
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Title / Optimise and manage ultraviolet (UV) disinfection processes for drinking-water treatment
Level / 5 / Credits / 8
Purpose / People credited with this unit standard are able to: optimise and manage UV disinfection processes, variables which determine their effectiveness, design features, the equipment used for generation of UV, safety considerations, operating issues associated with UV disinfection; and identify critical points, hazards, and preventive and corrective actions in UV disinfection processes.
Classification / Water Industry > Water Treatment
Available grade / Achieved

Explanatory notes

1 References

Legislation relevant to this unit standard includes but is not limited to the Health Act 1956, and Resource Management Act 1991.

Ministry of Health Water Safety Plan Guides for Drinking-Water Supplies (WSPGs):

P7.4, Ultra-violet irradiation disinfection;

Drinking-Water Standards for New Zealand, 2005 (Revised 2008), Ministry of Health, Wellington.

2 Definitions

Critical points – points in a process or in equipment where failure to function correctly can lead to a public health hazard.

Optimise – 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.

Drinking-water supply – the supply catchment, treatment plant, and distribution. The drinking-water supplier has responsibility for managing the public health risks of the drinking-water supply.

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

Optimise and manage UV disinfection processes, variables which determine their effectiveness, and design features.

Evidence requirements

1.1 The mechanisms by which UV inactivates micro-organisms are optimised and managed in relation to UV disinfection processes.

1.2 The variables which determine the effectiveness of the process are optimised and managed in relation to UV disinfection.

Range includes but is not limited to – transmittance, contact time, temperature, turbidity, organic and inorganic loading, intensity.

1.3 Design features are optimised and managed in relation to UV disinfection processes.

Range sizes, configurations.

Outcome 2

Optimise and manage the equipment used for generation of UV, and safety considerations.

Evidence requirements

2.1 The equipment used for generation is optimised and managed in relation to UV disinfection processes.

Range reactor, lamp, ballasts, intensity sensor, transmittance meter, turbidity meter.

2.2 Monitoring equipment is optimised and managed in relation to UV disinfection processes.

Range process control, alarms.

2.3 The delivery mechanisms of UV light which can contribute to under or over dosing are optimised and managed in relation to UV disinfection processes.

2.4 Personal safety considerations are optimised and managed in relation to UV disinfection processes.

Outcome 3

Optimise and manage operating issues associated with UV disinfection.

Evidence requirements

3.1 Operating issues are optimised and managed in relation to UV disinfection processes.

Range flow rates, continuity of disposables and power supply, dose rate control, alarm response, drinking-water standard transgression, equipment failure, safety of public, equipment calibration and servicing, record keeping.

Outcome 4

Identify critical points, hazards, and preventive and corrective actions in UV disinfection processes.

Evidence requirements

4.1 The critical points in the disinfection processes are identified in accordance with organisational procedures.

4.2 The hazards at each critical point are identified in terms of the causes of the events leading to their occurrence, and the risk factors.

4.3 The preventive and corrective actions for events related to each hazard are identified.

Replacement information / This unit standard and unit standard 24902 were replaced by unit standard 29968.

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 Assessment /
Registration / 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 http://www.nzqa.govt.nz/framework/search/index.do.

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 ITO
SSB Code 101813 / Ó New Zealand Qualifications Authority 2017 / / New Zealand Qualifications Aut