19349 version 2
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Optimise and manage coagulation and flocculation processes for
drinking-water treatment
Level
5
Credits
6
Purpose
People credited with this unit standard are able to: optimise the process of
coagulation as used in drinking-water treatment; optimise and manage the
process of flocculation as used in drinking-water treatment; and identify
critical points and hazards, and identify and manage preventive and
corrective actions, in coagulation and flocculation processes.
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 Act
1956, and Resource Management Act 1991;
Ministry of Health Public Health Risk Management Plan Guides for Drinking-Water
Supplies (PHRMPGs):
P5.1, Conventional coagulation /flocculation /sedimentation.
2
Definitions
Critical points – points in a process or in equipment where failure to function correctly
can lead to a public health hazard.
 New Zealand Qualifications Authority 2016
19349 version 2
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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.
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
Optimise the process of coagulation as used in drinking-water treatment.
Performance criteria
1.1
The coagulation process is optimised in terms of the impact of pH and alkalinity
in a drinking-water treatment process.
1.2
Coagulants are evaluated and described in terms of their effectiveness and
cost.
Range
1.3
Coagulant mixing is optimised and calculated in terms of the velocity gradient.
Range
1.4
may include but is not limited to – aluminium sulphate, ferric
chloride, poly-aluminium chloride, ferric sulphate, polyelectrolytes,
aluminium chloral hydrate;
evidence is required for at least two.
one of – flash mixers, drop structures, pumps, hydraulic mixers;
temperature, coagulant dispersion, chemical reaction times.
Coagulant dosing control methods and pH and alkalinity control for coagulant
dosing are optimised in terms of dose level assessment and control.
Range
pH meters, turbidity and colour loading;
two of – jar test, streaming current meters, coagulant residuals;
control methods – dilution, filter performance, separation
performance.
Element 2
Optimise and manage the process of flocculation as used in drinking-water treatment.
Performance criteria
2.1
Flocculation is optimised in terms of its relationship to coagulation.
Range
includes but is not limited to – contact zones, floc recycling, low
turbidity use, adsorption.
 New Zealand Qualifications Authority 2016
19349 version 2
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2.2
Optimal floc formation is managed in terms of particle contact.
Range
2.3
Polyelectrolytes are evaluated in terms of use as flocculant aids.
Range
2.4
time, temperature, flocculator types.
may include but is not limited to – anionic, cationic, non-ionic, high
and low molecular weights, dose levels, material quality standards.
The storage, handling and mixing of raw material is managed to optimise
treatment efficiencies for flocculation.
Element 3
Identify critical points and hazards, and identify and manage preventive and corrective
actions in coagulation and flocculation process.
Performance criteria
3.1
The critical points in the coagulation and flocculation processes are identified in
accordance with organisational procedures.
3.2
The hazards at each critical point are identified in terms of the causes of the
events leading to their appearance, and the risk factors.
3.3
The preventive and corrective actions for events related to each hazard are
identified and managed.
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