Unit of competency details

Elements describe the essential outcomes of a unit of competency.

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold italicised  text is used, further information is detailed in the range statement. Assessment of performance is to be consistent with the evidence guide.

ELEMENT 

PERFORMANCE CRITERIA 

1 Evaluate dissolved air flotation process performance .

1.1 Review existing process performance data against relevant organisational or legislative requirements .

1.2 Review existing operational processes  with reference to manufacturers' or plant designers' specifications .

1.3 Identify the impact of incoming water quality  on dissolved air flotation processes as required.

1.4 Identify and coordinate any additional sampling and testing  required for valid evaluation of current process performance.

2 Investigate dissolved air flotation asset operation .

2.1 Review existing fault reports and other relevant plant asset information.

2.2 Evaluate the operational status of plant components  against manufacturers' and plant designers' specifications.

3 Investigate options for process optimisation .

3.1 Review relevant fault and incident reports and take remedial actions.

3.2 Investigate potential changes to operational processes  to identify possible optimisation strategies.

4 Plan process optimisation .

4.1 Determine plant configuration and revised operational processes for process optimisation.

4.2 Plan a trial to test the performance of the determined optimisation options.

4.3 Compile a report making recommendations on optimisation options.

This section describes the skills and knowledge required for this unit.

Required skills :

• conduct treatment system investigations and report on operational or control system problems
• coordinate DAF inspection, sampling and testing
• perform calculations to provide data for the analysis and development of options and solutions, such as hydraulic and solids loading rates, recycle ratios and air loading
• operate control and communication systems
• use safety and personal protective equipment
• communicate with colleagues, consultants and suppliers using clear and direct communication to identify and confirm requirements and concepts
• produce optimisation reports
• interpret a range of complex and technical documents, including relevant:

• regulatory, legislative, licensing and organisational requirements
• codes and standards
• specifications
• organisational policies

• articulate complex ideas clearly
• use mathematical calculations to analyse options and solutions
• work collaboratively with relevant stakeholders
• analyse problems and recommend appropriate remedial solutions
• identify risks and hazards
• identify opportunities for improved water management
• participate in the provision of appropriate information to inform workplace processes
• manage work priorities
• use information effectively to improve work performance
• prepare and apply chemical dosing

Required knowledge :

• principles that form the basis of dissolved air flotation processes
• types of dissolved air flotation processes
• polymers
• principles of DAF system maintenance
• system layout
• pumping and valving systems
• relevant historical records
• range of appropriate measuring and testing procedures
• investigation procedures
• risk management principles related to dissolved air flotation processes
• relevant legislation, standards and workplace policies and procedures.
• chemicals used for coagulation and flocculation or thickening
• chemical dosing processes

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 dissolved air flotation (DAF) processes including:

• reviewing existing DAF 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 DAF plant components
• investigating potential changes to DAF operational processes to identify possible optimisation strategies
• planning trials to test the performance of the determined DAF 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.

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

Processes  may include:

• dissolved air flotation
• dissolved air flotation filtration (DAFF)
• dissolved air flotation sludge thickening

Manufacturers' and plant designers' specifications  may include:

• hydraulic loading rate
• air loading
• recycle flow rates
• saturated pressure
• detention time
• float removal frequency
• intended plant configuration

Incoming water quality  may include:

• turbidity
• colour
• presence of algae
• temperature

Testing  may include:

• turbidity
• true colour
• float solids content

Plant components  may include:

• valves
• recycle pumps
• compressor
• saturator
• float removal mechanism
• dispersion valves
• cutting sprays

Potential changes to operational processes  may include:

• saturator pressure
• recycle ratio
• flow rate
• polymer addition
• float removal frequency