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 standards
standard operating procedures
quality assurance
federal, state and local environmental and water quality legislation
Processes may include:
activated sludge treatment processes, such as:
conventional or extended aeration
contact stabilization
high rate
membrane bioreactor (MBR)
intermittently decanted extended aeration (IDEA)
sequencing batch reactor (SBR)
Biological nutrient removal processes:
Modified Ludzac-Ettinger (MLE)
Bardenpho
University of Cape Town
Manufacturers' and plant designers' specifications may include:
food to micro-organism ratio (F:M)
mean cell residence time (MCRT)
detention time
mixed liquor suspended solids (MLSS)
Biological Oxygen Demand or Chemical Oxygen Demand removal
nitrogen or phosphorus removal
suspended solids removal
intended plant configuration
Influent quality may include:
Biological Oxygen Demand or Chemical Oxygen Demand
pH and alkalinity
nutrients
total and suspended solids
inhibitory compounds, such as heavy metals
temperature
Testing may include:
Biological Oxygen Demand or Chemical Oxygen Demand
temperature
nitrogen, such as total nitrogen, ammonia, nitrate and nitrite
phosphorus, such as orthophosphate and total phosphorus
settling tests
pH and alkalinity
microscopic observation
oxygen uptake rates
respiration rates
dissolved oxygen
redox potential
suspended solids, such as total and volatile
Plant components may include:
valves
return and wasting pumps
aeration equipment
chemical and nutrient dosing equipment
decanters
sedimentation tanks
on-line analysers
Potential changes to operational processes may include:
Food:Microorganism (F:M) ratio
Mean Cell Residues Time (MCRT)
Mixed Liquor Suspended Solids (MLSS)
return and waste activated sludge rates
chemical and nutrient addition
pre-treatment to remove inhibitory or toxic substances
alkalinity and pH correction
mixed liquor recycle rates
phase timing in intermittent or batch 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 activated sludge treatment processes in maintaining water quality including:
reviewing existing activated sludge or BNR treatment process performance with reference to historical data, differences in raw 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 activated sludge or BNR treatment process plant components
investigating current and potential chemical addition practices
planning trials to test the performance of the determined activated sludge or BNR treatment process optimisation options
preparing 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.