24901 version 1
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Describe the management of ozone disinfection processes
Level
5
Credits
5
Purpose
People credited with this unit standard are able to describe: ozone
disinfection, variables which determine effectiveness, design features; the
methods of on-site generation of ozone, monitoring equipment, and safety
considerations; operating issues associated with ozone disinfection; and
identify critical points, hazards, preventive actions, and corrective actions of
ozone disinfection 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, unit standard 24900, and unit
standard 24902 replaced unit standard 18453.
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
1
References
Ministry of Health Public Health Risk Management Plan Guides for Drinking-Water
Supplies (PHRMPGs):
P7.3, Ozone disinfection.
Drinking-Water Standards for New Zealand, Ministry of Health, Wellington, 2000 and
2005.
 New Zealand Qualifications Authority 2016
24901 version 1
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2
Definitions
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.
Critical points – points in a process or in equipment where failure to function correctly
can lead to a public health hazard.
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 ozone disinfection, variables which determine their effectiveness, and design
features.
Performance criteria
1.1
Ozone disinfection is described in terms of the mechanisms by which ozone
inactivates micro-organisms.
1.2
Ozone disinfection is described in terms of the variables which determine the
effectiveness of the process.
Range
1.3
includes but is not limited to – ozone residual, contact time,
temperature, turbidity, organic loading.
Ozone disinfection is described in terms of its design features.
Range
typical sizes, configurations.
Element 2
Describe the methods of on-site generation of ozone, monitoring equipment, and safety
considerations.
Performance criteria
2.1
Ozone is described in terms of the process of on-site generation.
2.2
Ozone disinfection is described in terms of monitoring equipment.
Range
2.3
process control, alarms.
Ozone disinfection is described in terms of delivery mechanisms of ozone which
can contribute to under or over dosing.
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24901 version 1
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2.4
Ozone disinfection is described in terms of safety considerations when
handling.
2.5
Ozone is described in terms of the process by which ozone vapour destruction
occurs.
Element 3
Describe operating issues associated with ozone disinfection.
Performance criteria
3.1
Ozone disinfection is described in terms of operating issues.
Range
impact of contact time, continuity of power and chemical supply,
dose rate adjustment and control, alarm response, drinking-water
standard transgression, disinfection by-product formation,
equipment failure, safety of public, equipment calibration and
servicing, record keeping.
Element 4
Identify critical points, hazards, preventive actions, and corrective actions of ozone
disinfection processes.
Performance criteria
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 appearance, and the risk factors.
4.3
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.
 New Zealand Qualifications Authority 2016
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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