NWP404A
Apply principles of chemistry to water systems and processes

This unit of competency describes the knowledge required to identify and apply the principles of chemistry to water systems and processes, and to select the relevant and effective chemicals required for specific processes.

Application

This unit is relevant to a wide range of job roles within the water industry and is fundamental to all quality monitoring and treatment processes.


Prerequisites

Not applicable.


Elements and Performance Criteria

ELEMENT

PERFORMANCE CRITERIA

1Apply chemistry to water processes.

1.1 Identify and apply concepts of chemistry to the performance of water processes according to relevant legislation and workplace policies and procedures.

1.2 Identify and explain chemical reactions specific to water processes.

2Identify the use of chemicals in water industry processes.

2.1 Assess the functions of the range of industry chemicals in relation to their use in water processes.

2.2 Identify and explain factors influencing the effectiveness of chemical use.

2.3 Store, handle and prepare chemicals according to workplace policies and procedures and manufacturers' specifications.

3Select chemicals for specific water industry processes.

3.1 Identify the range of chemicals available for specific water industry processes.

3.2 Evaluate the factors affecting the selection of chemicals for particular water industry applications.

3.3 Select suitable chemicals and calculate correct usage for a range of specific water industry processes.

Required Skills

Required skills:

interpret a range of complex and technical documents including relevant:

regulatory, legislative, licensing and organisational requirements

codes and standards

specifications

organisational policies

communicate effectively with a range of relevant parties

articulate complex ideas clearly

analyse and evaluate reports and reference materials

work collaboratively with relevant stakeholders

analyse problems and apply effective remedial solutions

perform various calculations to provide data for the analysis and development of options and solutions

identify risks and hazards

identify opportunities for improved water management

participate in the provision of information to inform workplace processes

manage work priorities

use information effectively to improve work performance.

Required knowledge:

standards and workplace policies and procedures determining the use and management of chemical processes

chemical concepts relevant to water industry processes

chemical reactions

the range and characteristics of chemicals used in various water industry processes

the functions of various chemicals in water industry processes

factors influencing the effectiveness of chemicals

the factors affecting the selection of chemicals.

Evidence Required

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.

Overview of assessment

The candidate should:

perform each task outlined in the elements consistently and in a representative range of contexts required by the enterprise and worksite

meet the performance criteria associated with each element by employing the techniques, procedures, information and resources available in the workplace from those listed in the range statement

demonstrate an understanding of the underpinning knowledge and the application of skills as described in the required skills and knowledge section.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

The candidate should demonstrate the ability to:

understand and apply a knowledge of chemical concepts and reactions relevant to water industry processes

describe the range, characteristics and functions of chemicals used in various water industry processes

identify and evaluate the factors influencing the effectiveness of chemicals in specific water industry processes

select appropriate chemicals for specific water industry processes.

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.


Range Statement

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.

Concepts of chemistry may include:

atoms, ions, molecules and compounds

chemical bonding

chemical reactions

acids and bases

oxidation reduction potential (ORP).

Workplace policies and procedures may include:

organisational policies

standard operating procedures

communication and reporting protocols

quality assurance.

Relevant legislation may include:

federal, state and local environmental and water quality legislation

occupational health and safety legislation

hazardous chemicals and dangerous goods legislation.

Chemical reactions may include:

neutralization and pH buffering

pH correction

calcium carbonate precipitation

coagulation

chemical P removal

iron and manganese removal

sequestering.

Functions may include:

disinfectant

oxidant

reductant

sequestering agent

pH correction and buffering

coagulant

flocculant

surfactant

adsorbent

precipitant

catalyst.

Chemicals used in the water industry may include:

chlorine

ozone

sodium thiosulphate

sodium hexametaphosphate

activated carbon

hydrated lime

aluminium and iron salts

potassium permanganate

sulphuric acid.

Factors influencing the effectiveness of chemical use may include:

pH

ageing

mixing

temperature

concentration.

Factors affecting the selection of chemicals may include:

cost

purity

availability

by-product generation

storage and handling requirements

safety requirements

efficiency and effectiveness.


Sectors

Not applicable.


Competency Field

Treatment


Employability Skills

This unit contains employability skills.


Licensing Information

Not applicable.