17894 version 2
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Demonstrate knowledge of surface water and groundwater sources and
pre-treatment
Level
3
Credits
7
Purpose
People credited with this unit standard are able to demonstrate knowledge of:
the environmental factors affecting surface water sources; abstraction and
pre-treatment processes for surface water sources; groundflow principles,
well hydraulics, and well construction; and water quality parameters and
treatment of groundwater.
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 by NZQA and industry.
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
Definition
Water quality – the suitability of water for use as potable water, with or without water
treatment.
 New Zealand Qualifications Authority 2016
17894 version 2
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Elements and performance criteria
Element 1
Demonstrate knowledge of the environmental factors affecting surface water sources.
Performance criteria
1.1
Surface water environments are described in terms of their suitability as sources
for water supply.
Range
1.2
lakes, dams, stratification, eutrophication, upland rivers and
streams, lowland rivers and streams, off-river storage.
Surface water abstractions are identified and described in terms of the
constraints.
Range
river/stream topography and hydrology, water quality, stream bed
movement, resource consents, catchment land use, recreational
use, intake security, water level hydraulics, aquatic life.
Element 2
Demonstrate knowledge of abstraction and pre-treatment processes for surface water
sources.
Performance criteria
2.1
Pre-treatment processes are described in terms of their purpose and raw water
quality.
Range
2.2
Design features of hardware for surface water abstractions are identified in
terms of their function.
Range
2.3
removal of – pathogens, pollutants, suspended matter, turbidity,
algae, taste and odour, carbon dioxide, iron and manganese.
evidence is required for at least six of – river intake types, weirs,
pumps and wet wells, mechanical and fixed screens, infiltration
galleries, rough filtration, intake towers, sedimentation, spillways,
aerators.
Variations in water quality from surface water sources are outlined in terms of
operational factors which can be implemented to mitigate their effects.
Range
operational factors – flow control, water quality monitoring,
consent limits, retention time, depth selection, stratification,
chemical dosing and mixing, circulation.
 New Zealand Qualifications Authority 2016
17894 version 2
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Element 3
Demonstrate knowledge of groundflow principles, well hydraulics, and well construction.
Performance criteria
3.1
Groundwater flow principles are described in terms of the permeability of
aquifers, and aquicludes.
Range
infiltration zones, recharge areas, springs, piezometric head,
artesian systems, confined and unconfined aquifers, secure
groundwater.
3.2
Well hydraulics is described in terms of drawdown, cone of depression, and
different flow rates.
3.3
Well construction is described in terms of physical structures and processes.
Range
physical structures – screen types, pump placing and cooling,
power cables, pipework, check valves, well head;
processes – developing, surging, drawdown measurement.
Element 4
Demonstrate knowledge of water quality parameters and treatment of groundwater.
Performance criteria
4.1
Factors that affect the quality of groundwater are described in terms of the
decay of organics and pathogens.
Range
4.2
carbon dioxide, ammonia, hydrogen sulphide, pH shifts,
microbiological filtration and die-off;
parameters – organics, minerals, hardness.
Methods of groundwater treatment are described in terms of iron and
manganese removal.
Range
pH, carbon dioxide, iron and manganese solubility;
methods – pH control using alkalis, aeration, oxidation,
precipitation, filtration.
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.
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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