Enhancing Water Services Quality through Urban Construction Practices

1. Water Services Trust Fund The Urban Projects Concept (UPC) Implementation Workshop Quality of Works

2. Why Emphasise Quality? • To promote use of water in a hygienic environment • For sustainability and durability • For returns on investment • Image of the WSP among the public

3. Lessons from the WSTF Pilot Projects Quality of construction works was largely affected by: Weak supervision Lack of adherence to technical specifications Sloppy and incompetent Contractors Theft of materials Varying site conditions

4. Quality of works: Examples of “Don'ts” • Poor finishing • Evidence of poor concrete mix • Neglect of the water kiosk • Evidence that drawings • were not followed • No angle bars

5. Examples of “Don'ts” (cont’d) • Incomplete work • Poorly done soak pit • Gulley trap is uncovered • Accumulation of solid waste • Unkempt surroundings • Uncovered; posing a hazard

6. Examples of “Don'ts” (cont’d) • Poor concreting (ELDOWASS) • Short kicker bars (NZOWASCO)

7. Examples of “Don'ts” (cont’d) • Unacceptable poor quality of columns (NZOWASCO) • Unacceptable result of using poor materials (NZOWASCO)

8. Examples of “Don'ts” (cont’d) • Leakage • Wrong material usage • Poor quality improvising

9. 0 Examples of “Don'ts (cont’d) • Poor plumbing • Prone to rain water • Lack of repair works

10. Examples of “Don'ts” (cont’d) • Poor drainage around kiosk • Effect of leaking tank on roof slab

11. How Do We Ensure Quality? • Following construction guidelines and the Toolkit • Drawings and specifications • Routine inspections • Testing and approval of materials • Ensuring safe and healthy environment

12. Technical Specifications • Materials • Rejection of substandard materials • Examination of all materials arriving on site- should fit the specifications • Handling and storing materials with care • Codes of practice • Reference to be made to relevant codes of practice: (BS 8110, BS 5950, BS 6399, BS 4466 etc.)

13. Technical Specifications (cont’d) • Drawings • All technical drawings to be accurately adhered to • A set of the drawings must be provided on site at all times • Setting Out • Works shall be set out accurately • WSP to establish and locate all benchmarks, lines, boundaries and/ or levels on the ground • The Site • Accessible; with secure storage for materials and plant • The works should not adversely interfere with the environment

14. Technical Specifications (cont’d) • Concrete • Mix concrete in specified ratios at the site • Approved mechanical means of handling concrete are encouraged • Concrete should be placed in single operation to the full thickness of slabs and beams and similar members • Concrete in columns should be carefully placed and well vibrated • Work cube tests recommended

15. Technical Specifications (cont’d) • Curing of Concrete • Protect concrete from premature drying by protection from wind, sun or rain by sheeting, or other approved means • Wet the concrete continuously for 14 days • Reinforcement • Fabrication, bending and fixing of reinforcement should be in accordance with standards • Shall be free from rust, grease or any substance likely to reduce the bond between steel and concrete

16. Technical Specifications…cont’d • Finishes • Painting and other finishes to be carried out on clean surfaces • According to specifications • Fittings • High quality plumbing parts required; especially gate valves, bends and taps • Right class of pipes should be used

17. Supervision of Labour • Competence • Workers on site should be experienced • Removal of incompetent labour • encouraged • Approval • Work done shall be subject • to approval by Engineer • Engineer to ensure that works • are complete before payment

18. Supervision of Labour (cont’d) • Drawings • Workers should be able to • interpret all drawings • Safety & Health • Safety and health needs of • workers should be addressed

19. Thank you!