Elements and Performance Criteria

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.
Organisational or legislative requirements may include:
organisational performance quality standards
standard operating procedures
quality assurance guidelines
federal, state and local environmental and water quality legislation
occupational health and safety requirements
water quality standards and guidelines
Incoming water quality may include:
turbidity
colour
presence of algae
temperature
Processes may include:
sludge blanket clarifiers
conventional clarifiers
tube settlers
high rate plate settlers
recirculating contact clarifiers
pulsator clarifiers
ballasted sedimentation
Testing may include:
turbidity
true colour
float solids content
Plant components may include:
valves
sludge pumps
impellers
sludge collection cones
sludge rake
tube and plate settlers
weirs or launders
dosing points
Manufacturers' and plant designers' specifications may include:
surface loading rate
upflow velocity
detention time
weir loading rate
slurry recirculation rate
intended plant configuration
Potential changes to operational processes may include:
flow rate
polymer addition
slurry recirculation rate
sludge wasting rate
sludge blanket concentration and depth

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.
Critical aspects for assessment and evidence required to demonstrate competency in this unit
The candidate should demonstrate the ability to evaluate system performance and investigate and report on optimisation of sedimentation and clarification processes including:
reviewing existing sedimentation and clarification process performance with reference to historical data, differences in incoming water quality and plant configuration
identifying data deficiencies and organising additional data collection through appropriate sampling and testing
assessing fault reports and investigating the current operational status of sedimentation and clarification plant components
investigating current and potential chemical addition practices
planning trials to test the performance of the determined sedimentation and clarification optimisation options and compiling reports making recommendations
Context of and specific resources for assessment
Access to the workplace and resources, including:
documentation that should normally be available in a water industry organisation
relevant codes, standards and government regulations
Where applicable, physical resources should include equipment modified for people with disabilities.
Access must be provided to appropriate learning and assessment support when required.
Assessment processes and techniques must be culturally appropriate, and appropriate to the language and literacy capacity of the candidate and the work being performed.
Validity and sufficiency of evidence requires that:
competency will need to be demonstrated over a period of time reflecting the scope of the role and the practical requirements of the workplace
where the assessment is part of a structured learning experience the evidence collected must relate to a number of performances assessed at different points in time and separated by further learning and practice
a decision of competence only taken at the point when the assessor has complete confidence in the person's competence over time and in various contexts
all assessment that is part of a structured learning experience must include a combination of direct, indirect and supplementary evidence
where assessment is for the purpose of recognition (RCC/RPL), the evidence provided will need to be authenticated and show that it represents competency demonstrated over a period of time
assessment can be through simulated project-based activity and must include evidence relating to each of the elements in this unit
In all cases where practical assessment is used it will be combined with targeted questioning to assess the underpinning knowledge. Questioning will be undertaken in a manner appropriate to the skill levels of the operator and cultural issues that may affect responses to the questions, and will reflect the requirements of the competency and the work being performed.