Produce an engineering design for a sewerage reticulation scheme


Unit Descriptor

This unit of competency sets out the knowledge and skills required to apply principles of design for an engineering sewerage reticulation scheme using appropriate design standards.

The units includes conducting an on-site reconnaissance, data collection and analysis, application of hydrology principles, sewerage reticulation design procedures and use of relevant charts from drainage design manual.

No licensing, legislative, regulatory or certification requirements apply to this unit at the time of publication.


Employability Skills

This unit contains employability skills.


Application of the Unit

This unit of competency applies to a person working at paraprofessional level in a civil engineering environment responsible for the development sewerage reticulation design solutions.




Elements describe the essential outcomes of a unit of competency. Elements describe actions or outcomes that are demonstrable and assessable.


Performance criteria describe the required performance needed  to demonstrate achievement of the element – they identify the standard for the element. Where bold / italicized text is used, further information or explanation is detailed in the required skills and knowledge and/or the range statement.

Assessment of performance is to be consistent with the evidence guide.

1. Identify sewerage reticulation scheme to be designed

  • Occupational Health and Safety/Workplace Health and Safety (OHS/WHS) requirements and environmental requirements for a given work area are determined
  • Established OHS/WHS requirements and risk control measures and procedures are followed in preparation of the work
  • Safety hazards which have not previously been identified are documented and risk control measures devised and implemented in consultation with appropriate
  • Design is identified from documentation, job brief or discussions with appropriate
  • Appropriate personnel are consulted to ensure the work is co-ordinated effectively with others involved at the work site.
  • Resources and equipment needed for the task are obtained in accordance with enterprise procedures and checked for correct operation and

2. Plan design approach

  • OHS/WHS requirements for carrying out the work are followed.
  • On site reconnaissance to gather surveying data, measurements, photographs and other required information for the design project is carried
  • Design references are consulted and required documentation is gathered to complete the design task in accordance with enterprise
  • Design and drafting system (CAD) is set up according to operating
  • Decisions for dealing with unexpected situations are made from discussions with appropriate personnel, job specifications and enterprise
  • Methods for dealing with unexpected situations are selected on the basis of safety and specified work outcomes.

3. Complete the design

  • OHS/WHS requirements for carrying out the work are followed.
  • Design solution is prepared to conform to relevant standards and regulations in accordance with enterprise procedures.
  • Unexpected situations are deal with in accordance with work plan and discussions with appropriate
  • Completed design is reviewed with appropriate personnel and amended as required to provide optimum

4. Compile, document and present results

  • Design solution is presented and discussed with appropriate
  • Design references and equipment are maintained and stored in accordance with enterprise
  • Work completion is notified to appropriate personnel and required documentation completed accordance with workplace procedures



This describes the essential skills and knowledge and their level required for this unit.


Required Skills:

    • communicating and working with other team members
    • reading skills to interpret task related documentation, relevant data, job instructions, drawings and OHS/WHS procedures
    • carrying on site reconnaissance to obtain relevant data, such as survey measurements and site photographs and other required information in preparation for sewerage reticulation scheme

    • making computations and recording the results
    • assembling gathered information and data and preparing a design solution
    • setting up and using design aids
    • reviewing design in consultation with others and finalising the proposal
    • completing required workplace documentation

Required knowledge:

  • instrumentalities:
    • list of Authorities including agencies
    • sewerage reticulation
    • sewerage treatment
    • roles, jurisdiction and statutory powers of the above
  • job brief:
    • data required for design and specification
    • topographic detail
    • soil conditions
    • underground services
    • easements
    • obstructions
  • horizontal alignment:
    • standard practice and factors affecting location of sewers
    • along streets/rear of properties
    • along easements
    • other services
    • curved sewers
    • access
  • sewerage authority drawings:
    • existing mains
    • existing sewerage pipes
    • standard symbols for all features
  • vertical alignment:
    • allotment categories
    • allotment controls
    • area to be controlled
    • control surface level
    • minimum depths
    • minimum grades
    • boundary trap


  • fixing of vertical alignment:
    • minimum depth and clearance from other services
    • fixture controls
    • property branch sewers
    • IL of end fitting
    • access chambers, inspection shafts, pipeline ends
    • final invert levels, grades surface levels, chainages, type of pipes
  • working
    • plan and longitudinal
    • use of standard
  • testing:
    • initial test (air test)
    • acceptance test
    • visual inspection
    • exfiltration test
    • maintenance tests
    • TV inspection
    • infiltration
  • septic
    • principles of treatment methods
    • components of a septic tank
    • design according to the Septic Tank Code
  • package
    • role of the package treatment plant
    • permanent facility
    • temporary element in a larger scheme
    • principle of operation
    • commercial availability
    • sizes v. community population
  • small treatment
    • the need for treatment
    • function of the elements
    • design for 500 people
    • loading rates
    • disinfection
    • sludge disposal
    • location/security
    • sketch of layout



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 in the Performance Criteria is detailed below.


OHS/WHS requirements may include but not limited to:

  • legislation
  • protective equipment
  • material safety management systems
  • hazardous substances and dangerous goods code
  • local safe operation procedures
  • awards provisions


Environmental requirements may include but not limited to:

  • liquid waste
  • solid waste
  • gas, fume, vapour, smoke emissions, including fugitive emissions
  • excessive energy and water use
  • excessive noise

Appropriate personnel may include:


  • supervisor
  • leading hand
  • foreman
  • manager
  • site engineer
  • trainer
  • mentor
  • teacher
  • team member

Resources and equipment may include but not limited to:


  • specifications
  • appropriate manuals
  • standards
  • catalogues
  • stationary
  • calculators

Enterprise procedures may include but not limited to:


  • the use of tools and equipment
  • instructions, including job sheets, cutting lists, plans, drawings and designs
  • reporting and communication
  • manufacturers' specifications and operational procedures





The evidence guide provides advice on assessment and must be read in conjunction with the Elements, Performance Criteria, Required Skills and Knowledge, the Range Statement and the Assessment section in Section B of the Accreditation Submission.

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

  • Assessors must be satisfied that the candidate can competently and consistently perform all elements of the unit as specified by the associated performance criteria, including required skills and knowledge. Specifically they must be able to demonstrate the ability to:
    • implement OHS/WHS procedures and practices including the use of risk control measures as specified in the performance criteria
    • carry out an on-site reconnaissance and gather required data and information for a proposed sewerage reticulation scheme
    • apply principles of design for an engineering sewerage reticulation scheme in accordance appropriate design standards and design brief on at least one

Context of and specific resources for assessment

  • This unit may be assessed on the job, off the job or a combination of both on and off the job. Where assessment occurs off the job, that is the candidate is not in productive work, then an appropriate simulation must be used where the range of conditions reflects realistic workplace situations. The competencies covered by this unit would be demonstrated by an individual working alone or as part of a team. The assessment environment should not disadvantage the candidate
  • Resources required for assessment include:
    • OHS/WHS policy and work procedures and
    • access to workplace or simulated work facility and off site environments
    • access to relevant design aids and equipment, materials and consumables
    • access to relevant plans, drawings and instructions and manufacturer’s specifications/manuals



Methods of assessment

  • For valid and reliable assessment of this unit, evidence should be gathered through a range of methods to indicate consistent performance.
  • Evidence must involve demonstration of practical skills and may also include:
    • observation of processes and procedures
    • oral and/or written questioning on required knowledge and skills
    • testimony from supervisors, colleagues, clients and/or other appropriate persons
    • inspection of the final design solutions or outcomes
    • portfolio of documented
  • Where performance is not directly observed any evidence should be authenticated by colleagues, workplace supervisors or other appropriate


Software/Hardware Used