17900 version 2
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Describe organic compounds including taste and odour control in water
treatment processes
Level
4
Credits
4
Purpose
People credited with this unit standard are able to describe: the common
organic compounds, in generating tastes and odours that occur in drinking
water; and control processes used in water treatment to limit poor taste and
odours.
Subfield
Water Industry
Domain
Water Treatment
Status
Registered
Status date
19 September 2008
Date version published
19 September 2008
Planned review date
31 December 2013
Entry information
Open.
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
Legislation relevant to this unit standard includes but is not limited to the Health and
Safety in Employment Act 1992, and Hazardous Substances and New Organisms
(HSNO) Act 1996.
Drinking-Water Standards for New Zealand, Ministry of Health, Wellington, 2000 and
2005.
2
Definition
Cracking – breaking long chain hydrocarbons.
 New Zealand Qualifications Authority 2016
17900 version 2
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3
A person is required to have approved handler certification if handling substances
being transferred under the HSNO Act. Information on approved handler procedures
can be obtained from http://www.erma.govt.nz.
Elements and performance criteria
Element 1
Describe the common organic compounds, in generating tastes and odours that occur in
drinking water.
Performance criteria
1.1
The causes of tastes and odours in treated water are identified and described in
terms of organic compounds in raw water.
Range
includes but is not limited to – algae, geosmin, 2-MIB,
actinomycetes, cyanobacteria.
1.2
Guideline values for aesthetic determinands are described in terms of the
Drinking-water standards for New Zealand.
1.3
The chlorination of water supplies is described in terms of its effects in
generating tastes and odours.
Range
chloramines (mono, di, tri), water stagnation, chlorinated organics.
Element 2
Describe control processes used in water treatment to limit poor taste and odours.
Performance criteria
2.1
The use of intake depth variations and infiltration galleries are described in
terms of minimising turbidity and organic matter in a raw water supply.
2.2
The use of powdered activated carbon addition is described in terms of process
mechanisms, dosing equipment, methods, and procedures.
Range
2.3
includes but is not limited to –
equipment – dry powder feeders, slurry tank, dosing pumps;
methods – carry water, adsorption process;
procedures – dosing, flow control.
Granular activated carbon filtration is described in terms of plant design and
process mechanisms.
Range
plant design – location, components;
mechanisms – carbon surface structure and adsorption, activation
life, biological filtration.
 New Zealand Qualifications Authority 2016
17900 version 2
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2.4
Ozonation and chlorination of drinking water for taste and odour control is
described in terms of plant design and process mechanisms.
Range
2.5
Alternative methods of filtration are described in terms of process mechanisms.
Range
2.6
oxidation of organics, ammonia removal, breakpoint chlorination,
cracking, flocculation;
plant design – location, components.
biological filtration without carbon, magnetic ion exchange.
The storage, handling, and preparation of chemicals are described in terms of
the Health and Safety in Employment Act 1992, HSNO Act 1996 and
regulations.
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