SAQA All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.
SOUTH AFRICAN QUALIFICATIONS AUTHORITY 
REGISTERED UNIT STANDARD THAT HAS PASSED THE END DATE: 

Operate a rapid gravity filtration process 
SAQA US ID UNIT STANDARD TITLE
246446  Operate a rapid gravity filtration process 
ORIGINATOR
SGB Water Sector 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 12 - Physical Planning and Construction Civil Engineering Construction 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 3  NQF Level 03  5 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Passed the End Date -
Status was "Reregistered" 		 2018-07-01  2023-06-30  SAQA 06120/18 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2026-06-30   2029-06-30  

In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise.  

This unit standard replaces: 
US ID Unit Standard Title Pre-2009 NQF Level NQF Level Credits Replacement Status
12070  Operate a rapid gravity filtration process  Level 4  NQF Level 04  5   

PURPOSE OF THE UNIT STANDARD 
The qualifying learner achieving this unit standard in combination with context expertise standard(s) will be able to operate and maintain a rapid gravity filter. This competence will contribute towards the water and wastewater treatment process by ensuring that the filter is maintained in good working order at all times. This competence will also equip the qualifying learner with an enhanced skills base thereby improving the qualifying learner`s motivation and employability in the water sector. This will contribute to the quality of potable water to communities.

Learners credited with this unit standard are capable of:
  • Operating sludge withdrawal process.
  • Maintaining the filter media.
  • Maintaining the filter structure.
  • Conducting an inspection of compressors, blowers and backwash pumps.
  • Reading and interpreting flow indicators.
  • Collating data for filtration process. 
    		•

    LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
    It is assumed that learners are already competent in the following:
  • Communication at NQF Level 2.
  • Mathematical literacy at NQF Level 2.
  • Apply personal safety practices at NQF Level 2.
  • Operate a sand filter at NQF Level 1. 
    		•

    UNIT STANDARD RANGE 
    1. Run-time:
  • Production time since last backwash.

    2. Filter media:
  • Sand, anthracite, gravel.

    3. Deficiencies:
  • Friability, cracks and funnelling in filter bed, mud-balling, bed expansion, media, loss, biological infestation and low filtration rates.

    4. Corrective action:
  • Chemical treatments, turn over medium, medium grading, representative, sampling, structure maintenance, addition and mixing of media, media loss, measurement. Different backwashing scenarios (e.g air and water separate versus air and water simultenously).

    5. Structural problems:
  • Sagging of medium bed over joints, funnelling of medium bed over nozzles, leaks and cracks on concrete structure, corrosion and/or erosion of overflow weir, diminished flow rate, conditions in the viewing chamber, operation of level controller and indicators, general structural damage (displaced tiles, etc.) and stuck actuators and valves as well as broken/blown-out nozzles.

    6. Preventative maintenance:
  • Drain accumulated moisture from pressure vessel, lubricating oil levels on compressors and blowers are checked and topped up to specifications, pressure lines are visually inspected for leaks and external damage, water traps on pressure lines are drained, oil levels in oil-pots on pressure lines are checked and topped-up to specifications and V-belts/couplings are checked.

    7. Weekly chart maintenance:
  • Completed chart is removed and annotated with date and time, new chart is annotated with date and time and installed. Pen is checked for damage and ink levels, and refilled or replaced if necessary. 
    		•

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Identify and explain the principles of rapid gravity filtration. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The purpose of a load calculation is explained to determine when to perform a backwash. 
    ASSESSMENT CRITERION RANGE 
    Load calculation refers but is not limited to:
  • Area of the filter, suspended solids from the clarified water and the flow to the relevant individual filter.
     
    		•

    ASSESSMENT CRITERION 2 
    The factors influencing filter production (run-time) are identified and explained in order to estimate the daily production of filtered water. 
    ASSESSMENT CRITERION RANGE 
    Factors include but are not limited to filtration rate, suspended solids and the condition of the filter media.
     

    ASSESSMENT CRITERION 3 
    The turbidity of the water into the filter is determined in terms of the standard operating procedures for compliance. 

    ASSESSMENT CRITERION 4 
    The turbidity of filtered water is maintained according to SANS 241 for domestic/potable/drinking purposes. 

    ASSESSMENT CRITERION 5 
    Head loss is monitored and compared to design specifications in order to take corrective action. 

    ASSESSMENT CRITERION 6 
    Inflow rate is monitored and compared to design specifications in order to take corrective action. 

    ASSESSMENT CRITERION 7 
    Situations that may adversely affect filtration and the quality of filtered water are identified and explained to determine remedial action. 
    ASSESSMENT CRITERION RANGE 
    Situations refer but are not limited to insects, algae, airlocks, sagging and mudballs.
     

    ASSESSMENT CRITERION 8 
    Information regarding the operation of filters is collated for record keeping purposes. 

    SPECIFIC OUTCOME 2 
    Maintain the filter media. 
    OUTCOME RANGE 
    Filter media refers to but is not limited to anthracite, sand, gravel and stones. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Different filter media are identified and explained in terms of their functions. 

    ASSESSMENT CRITERION 2 
    Media conditions are monitored in order to record deficiencies for corrective action. 
    ASSESSMENT CRITERION RANGE 
    Media conditions refer but are not limited to bed expansion, sand size distribution (uniformity coefficient and effective size i.e. d10 and d60).
     

    SPECIFIC OUTCOME 3 
    Maintain the filter structure. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The importance of monitoring a filter structure and its components is explained in terms of work policies and procedures. 

    ASSESSMENT CRITERION 2 
    The filter structure is inspected to determine structural damages to take corrective action. 
    ASSESSMENT CRITERION RANGE 
    Structural damages refer to but are not limited to cracks, leaks, and corrosion.
     

    SPECIFIC OUTCOME 4 
    Conduct an inspection of compressors, blowers and backwash pumps and compare with design parameters. 
    OUTCOME RANGE 
    Inspection refers to the inspection of driving belts, bearing noise, vibration levels, air filters, water traps, amps and oil leakages. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The inspection sheet is described in terms of its features and use. 

    ASSESSMENT CRITERION 2 
    Preventative maintenance procedures are identified and described to determine a course of action. 

    ASSESSMENT CRITERION 3 
    Safe working conditions of compressors, blowers and backwash pumps are identified and explained for the purposes of safety. 
    ASSESSMENT CRITERION RANGE 
    Safe working conditions include but are not limited to machinery guards, electrical panels/boxes, mounting bolts and general housekeeping.
     

    ASSESSMENT CRITERION 4 
    Inspection report is collated with recommendations for corrective action. 

    SPECIFIC OUTCOME 5 
    Read and interpret flow indicators. 
    OUTCOME RANGE 
    Flow indicators refer but are not limited to:
  • Paper chart recorder and paperless recorders. 
    		•

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Different systems for recording and saving flow measurements are identified and explained in terms of their use. 

    ASSESSMENT CRITERION 2 
    Knowledge of the units of volume, pressure and flow is demonstrated in order to interpret flow indicators. 
    ASSESSMENT CRITERION RANGE 
    Different systems include but are not limited to:
  • Scada, adroit programme (e.g 4 series), digital and chart recorder.
     
    		•

    ASSESSMENT CRITERION 3 
    Flow indicators are identified and explained in terms of their application. 

    ASSESSMENT CRITERION 4 
    A flow recorder is updated in accordance with standard operating procedures. 
    ASSESSMENT CRITERION RANGE 
    Update refers to updating of information of flows on daily, weekly and monthly basis.
     

    ASSESSMENT CRITERION 5 
    Knowledge of operating parameters for the filter is demonstrated to adjust the flows. 

    SPECIFIC OUTCOME 6 
    Collate data for filtration process. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Logsheets are completed in accordance with work policies and procedures. 

    ASSESSMENT CRITERION 2 
    The importance of handover and takeover is explained in the context of the filtration process. 


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
  • Anyone assessing a learner or moderating the assessment of a learner against this Unit Standard must be registered as an assessor with the relevant ETQA.
  • Any institution offering learning that will enable the achievement of this unit standard must be accredited as a provider with the relevant ETQA.
  • Assessment and moderation of assessment will be overseen by the relevant ETQA according to the ETQA`s policies and guidelines for assessment and moderation.
  • Moderation must include both internal and external moderation of assessments at exit points of the qualification, unless ETQA policies specify otherwise. Moderation should also encompass achievement of the competence described both in individual unit standards as well as the integrated competence described in the qualification. 
    		•

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    Learners should have a knowledge and understanding of:
  • Backwash procedures, sand grades, characteristics of different types of media, concept of filter ripening.
  • Head loss and flow rate.
  • The importance of frequent and regular monitoring of filter media and filter structures.
  • The purpose of different media used in rapid gravity filters.
  • The purpose of weekly maintenance of chart recorders.
  • Safety procedures when maintaining filter media.
  • Safety procedures when maintaining filter structure.
  • The importance of maintaining compressors and blowers in good working order.
  • The importance of accurate records.
  • Comparison of turbidity on inflow and final water. 
    		•

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems in which responses display that responsible decisions using critical and creative thinking have been made by monitoring the flow rate and report findings for corrective action. 

    UNIT STANDARD CCFO WORKING 
    Work effectively with others as a member of a team members for smooth shit hand over. 

    UNIT STANDARD CCFO ORGANISING 
    Plan, organise and manage oneself and one`s activities responsibly and effectively by identifying and obtaining relevant personal protective clothing and follow safety procedures in carrying out work. 

    UNIT STANDARD CCFO COLLECTING 
    Collect, analyse, organise and critically evaluate information relating to water quality. 

    UNIT STANDARD CCFO COMMUNICATING 
    Communicate effectively using visual, mathematical and/or language skills in the form of oral and/or written presentation to the plant supervisor relating to problems identified in the plant. 

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically, showing responsibility towards the environment and health of others by applying safety and preventative measures when carrying out work. 

    UNIT STANDARD CCFO DEMONSTRATING 
    Demonstrate an understanding of the world as a set of related systems by recognising that problem-solving contexts do not exists in isolation relating to working with filters. 

    UNIT STANDARD ASSESSOR CRITERIA 
    N/A 

    REREGISTRATION HISTORY 
    As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. 

    UNIT STANDARD NOTES 
    This unit standard replaces unit standard 12070, which is "Operate a rapid gravity filtration process", Level 4, 5 credits.

    Integrated assessment:

    When conducting assessments, assessors must ensure that they are familiar with the full text of the unit standards being assessed. Assessors must ensure that the assessment covers the specific outcomes, critical cross-field outcomes and essential embedded knowledge by developing assessment activities and tools, which are appropriate to the contexts in which the learners are working. These activities and tools may include self-assessment, peer assessment, formative and summative assessment. It may be more effective and efficient to assess a number of unit standards together in an integrated way, thus reducing the overall number of assessments and ensuring that commonalities that exist between a number of unit standards are captured in a way that makes sense for assessment.

    Assessment option:

    Learners could be assessed using the following methods:
  • Observation.
  • Verbal and written questions. 
    		•

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Core  60190   National Certificate: Water and Wastewater Process Control  Level 3  NQF Level 03  Passed the End Date -
    Status was "Reregistered"     		 2023-06-30  EWSETA 
    Elective  58951   National Certificate: Water and Wastewater Treatment Process Operations  Level 2  NQF Level 02  Passed the End Date -
    Status was "Reregistered"     		 2023-06-30  EWSETA 


    PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: 
    This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here.
     
    1. ATTI NELSPRUIT (PTY) LTD 
    2. CHILUTSI TRADING ENTERPRISE 
    3. DR HE MAEPA INSTITUTE 
    4. ERGO MAPHELONG INSTITUTE (PTY) LTD 
    5. HAZYVIEW WATER SKILLS ACADEMY 
    6. K-BONENG CONSULTING SERVICES (PTY) LTD 
    7. Kelvin Power (Pty) Ltd 
    8. NTANDOKAZI HOLDINGS (PTY) LTD 
    9. SEANEGO INTERGRATED NATURAL RESOURCES MANAGEMENT 
    10. URSIVOX (PTY) LTD 


    All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.