Sewer Acceptance Testing Specification

Transcription

1 Sewer Acceptance Testing Specification Sewer Acceptance Testing Specification August 2012

2 Document details Document History Issue Revision Date Approved Change A 1 Dec 2010 First edition A 2 May 2010 Reviewed Document A 3 Aug 2012 Reformat and minor corrections Document Details Document Name Document Issue Sever Acceptance Testing Specification A Document Revision No. 3 Document Owner Prepared by Manager, Standards and Design Robert Jagger Date Approved Aug 2012 Approved by TAG Next Scheduled Review Date Aug 2013 Document Path H:\Standards & Design\02 - Standards\13 - Specifications\Construction Specifications\CWW Sewer Acceptance Testing Specification_A2.doc Glossary CWW MRWA TAG WSAA CCTV OH&S QA City West Water Melbourne Retail Water Agencies Technical Advisory Group Water Services Association of Australia Closed Circuit Television Occupational Health & Safety Quality Assurance Sewer Acceptance Testing Specification August of 10

3 Contents 1 Purpose 4 2 Introduction 4 3 Related publications 4 4 Test requirements 4 5 Responsibilities and the Acceptance Testing Process 5 6 Testing Specifications CCTV Certification of CCTV Operators Data Capture Acceptable CCTV Results Ovality Testing Proving Tool Laser Light Profiling Vacuum testing 8 Sewer Acceptance Testing Specification August of 10

4 1 Purpose This paper has been prepared to provide instruction to consultants, contractors and CWW staff involved in the construction and acceptance testing of newly constructed CWW sewers. CWW is committed to introducing new acceptance testing methods as technology advances to ensure that sewer installation quality represents best practice. 2 Introduction As accepted in the CWW TAG meetings of February 2010 and then December 2010, sewer asset acceptance testing is to be undertaken on all new sewers as described in this specification. The requirement for electronic ovality testing and CCTV inspection survey will apply to all CWW sewerage asset creation contracts and land development deeds, in accordance with Section 4, but excludes the following assets: < DN 300 where depth is less than 5m or Property branches or Sewer lining systems. A revised MRWA WSAA Sewerage and Conduit Inspection codes are currently in development. These will impact on the use of this specification once the new revisions are released. At this time the new MRWA WSAA Sewerage and Conduit Inspection Codes will take precedence over this document where there is any discrepancy. 3 Related publications Melbourne Retail Water Agencies (MRWA) editions of the Sewerage Code of Australia (WSA 02). Conduit Inspection Reporting Code of Australia (WSA 05). Training Unit NWP331B- Inspect conduit and report on condition and features Training Unit NWP440A- Supervise conduit inspection and reporting 4 Test requirements Testing shall be undertaken as per Table 1 below: Table 1: Sewer Testing Requirements DN CCTV Vacuum Testing Deflection Testing Flexible Pipes (Proving Tool) Rigid Pipes (i.e: DI) Proving Tool Electronic Ovality Test >DN300 N/A N/A <DN300 where depth >5m N/A N/A <DN300 On request from CWW On request from CWW N/A Sewer Acceptance Testing Specification August of 10

5 5 Responsibilities and the Acceptance Testing Process Compliance to this specification is the responsibility of the Responsible Party, which is defined as: The land developer s consultant in the case of Land Development or shared assets built through a Deed of works by a developer, The contractor s Project Manager undertaking the construction works (or the Project Manager s representative) in the case of Capital Works or other construction activity managed by CWW. Sewer acceptance testing shall occur as per the following process and the responsible party shall: 1. Specify in all relevant contract documents or sub contractor conditions of work that compliance to this specification is required as part of all sewer construction activity, 2. Specify and stipulate competency requirements for those undertaking the field testing. Ensure that properly experienced and qualified practitioners of the various tests carry out the testing as per this specification. Where such practitioners require Accreditation with CWW, the responsible party shall ensure that CWW s Accreditation conditions are complied with. 3. Ensure that OH&S and environmental requirements are met at all times, 4. Ensure that sewers and maintenance structures are constructed in stages and tested (vacuum, ovality and CCTV if required) after each stage is completed, 5. Using CWW s form FOR 140, provide CWW with two working days notice of pending acceptance testing, so as to enable CWW representatives an opportunity to attend the site and witness testing. CWW is entitled to postpone the test for an additional two days if it is not able to attend the requested timeframe. 6. For each designated stage, ensure that tests are carried out while being witnessed by a CWW representative. Where such a representative cannot witness the tests, the Contractor may proceed with the tests provided that notification has been provided and the responsible party witnesses the tests. CWW reserves the right to request a copy of the Contractor s or Consultant s ITP's, procedures, work methods statements prior to or after the testing is conducted. 7. Ensure that all equipment used is regularly serviced (with maintenance records available), in good working order and can satisfy this specification Supervise all acceptance testing field activity, 8. For each designated stage, collect the data and reports from the field, 9. Review the acceptance testing data and reports to determine if they are acceptable (as defined within this specification), 10. Complete CWW form FOR211 with a signed statement that the acceptance testing was carried out in full as per this specification. 11. Report any results defined as unacceptable directly and immediately (within 2 days) to the relevant CWW representative (Project Manager in the case of Capital Works or the Land Development Officer in the case of Land Development works) and the CWW Supervisor QA, 12. Work constructively with CWW to help determine the Root Cause of any issues, identify further corrective or preventative actions required, identify who is responsible for implementing these actions and determine who shall bear the cost, 13. Implement any monitoring, corrective or preventative actions nominated by CWW (which may be at the responsible party s cost), or 14. Supervise any such actions which are assigned to a third party, 15. Retest or ensure that retests are completed on any assets which have been altered and report all results as described above, 16. Provide all final data and reports to CWW representative for downloading into the appropriate CWW database, Sewer Acceptance Testing Specification August of 10

6 The CWW representative (Land Development Officer in the case of developer built assets or Project Manager on the case of Capital Works built assets) shall: Provide the responsible party with contact details of any of the parties nominated above, Ensure that test results outside of acceptable tolerance are passed to Standards & Design for consideration. NSIRs (Notification of System Improvement Request) shall be raised (maybe either an observation or non conformance) by CWW to document each breach of standards, Ensure that final CCTV and Electronic Ovality Testing data is passed to the CWW representative. Acceptance of Works (in the case of developer built assets) or Practical Completion only when sewer assets meet the criteria contained within this document unless otherwise approved by CWW. 6 Testing Specifications 6.1 CCTV In stage 2, sewers >= DN300 and sewers < DN 300 with depth <5m shall have CCTV inspections completed unless otherwise specified by CWW. CCTV inspection surveys are to be undertaken in accordance with: MRWA Edition of the Sewerage Code of Australia WSA 02, and The Conduit Inspection Reporting Code of Australia WSA 05. Additionally, any pools of water which are observed which may indicate reverse graded (back fall) segments of sewer must be reported with the estimated depth and length of the pool. Surveys shall comply with the following requirements; The sewer shall be cleaned sufficiently to remove all construction debris, silt and loose material prior to the CCTV inspection, Designers will need to designate identification numbers of sewer maintenance structures on their design drawings in accordance with the MRWA s numbering system. These identification numbers are to be used on the CCTV reports and video to uniquely identify pipes between maintenance structures. The Superintendent is to ensure that this information is supplied to the Contractor, Appendix F of the latest version of the WSAA Conduit Inspection Reporting Code of Australia WSA 05. This includes all requirements outlined in Section 2 of the WSA 05 in relation to CCTV operator qualification, CCTV camera equipment and accuracy, camera operation, data display on recorded images and the inspection report., and The CCTV contractor shall have met the qualification criteria for CCTV contractors e.g. OH&S system, ISO 9000 accredited Certification of CCTV Operators National qualifications for CCTV Operators and Supervisors shall be acquired by participants successfully demonstrating their competency against National Water Training Package NWP331B Inspect conduit and report on condition and features (for operators) and NWP440A - Supervise conduit inspection and reporting (for supervisors and managers). The CCTV survey of the sewers is to be undertaken by a suitably qualified contractor or his appointed subcontractor (approved by the Superintendent), prior to handover in accordance with Clause 22.7 of the Code Data Capture CCTV Electronic reports, pictures and CCTV footage is to be submitted to the Superintendent as per Conduit Inspection Reporting Code of Australia WSA 05 as follows. Video: Digital Photographs: MPEG 4 or AVI format, JPEG format Sewer Acceptance Testing Specification August of 10

7 Defects report: As per Appendix F of WSA 05 Defect Coding: WinCan format These digital formats may be superseded in future editions of the WSA 05 standard. All of this data and reporting is to be submitted on CD, DVD media or portable hard disc to the Superintendent with a summary outlining which results are below the threshold described in section Acceptable CCTV Results The acceptance criteria for CCTV of sewers shall be in accordance with Conduit Inspection Reporting Code of Australia WSA 05, where any defect which has a score of 20 or greater must be immediately reported to CWW. Any sewer which exhibits any ponding of liquid must also be immediately reported to CWW. CWW will then determine an appropriate course of action depending on the risk and problem(s) identified. 6.2 Ovality Testing In sewerage asset creation, deflection testing of flexible sewer pipelines is used as a quantitative measure of quality of installation. It s a check to ensure that deformation induced shortly after installation does not lead to a limited service life of the asset. The Code requires that all flexible sewer pipelines be tested for ovality (i.e. UPVC, Polyethylene, Polypropylene and GRP) Proving Tool The MRWA has for some time now required that all flexible sewer pipelines be tested for ovality using an ovality proving tool (refer to section of the Sewerage Code). Such deflection testing is now required on sewers which are both <300 DN and < 5m deep. This test is to be performed by passing a proving tool through the sewer. The proving tool is to have an outside diameter as described by section , with the ball preferably being constructed of plastic (wooden balls can swell and be subject to wear). Proving balls shall be inspected by the contractor prior to each testing event to ensure that it has the correct shape, dimensions and is not overly worn, swollen or distorted. Deflections must conform to Table 22.7 of the Code. For example, for a newly constructed UPVC sewer pipeline the maximum allowable short-term vertical pipe deflection at 14 days is 4.8%. Where different time intervals are used to monitor deflection, the allowable deflection is given in Table 22.7 of the Code. Where deflection is unacceptable using this test, a laser light profile of the sewer shall be completed Laser Light Profiling Stage 2 of sewer acceptance testing requires that laser light profiling be undertaken on all >=DN300 or >5m deep sewers. The use of a laser light ring projected onto the inside of sewer pipe to measure deflection of the pipe is permitted in the Code. Typically, CCTV footage is undertaken in one direction, with Laser Light profiling equipment then being fitted to the CCTV tractor for the return journey allowing Laser Light Profiling data to be recorded without an additional pass of the sewer. The Laser Light profiler, when mounted on the CCTV tractor, must be capable of being inserted into sewers via access points from the surface i.e. personnel should not need to access the sewer. Some access points chases, however, are curved making placing of the tractor from above difficult, in which case Confined Space person entry may be required. The recording of sewer grade against chainage is required to verify that the sewer has been graded as per the design. It is accepted that CCTV tractors have some margin of error in measuring grade and this should be taken into account when assessing the acceptability of grade results. Sewer Acceptance Testing Specification August of 10

8 Certification of Laser Light Profiling As Laser Light profiling is a relatively recent technology there is no recognised training for operators. Those contractors accredited as CCTV operators must demonstrate to the Water Agencies satisfaction that they have undergone training in the use of the Laser Light profiler and are competent in its use. The Laser Light profiling equipment should be regularly serviced and certified to WRc standards by a reputable certification scheme (eg: SAI Global Watermark) Data Capture The ovality report shall be presented in continuous graph format with chainage plotted against % ovality. The graph shall include access point numbers and be generated automatically by the Laser Light profiler. It should not require input from the operator. Laser Profiling Results are to be submitted in the following formats: Video: Ovality Profile: Long section chart (grade): MPEG 4 or AVI format Excel Plot, CSV, JPEG or PDF file Excel Plot, CSV, JPEG or PDF file These digital formats may be superseded in future editions of the WSA 05 standard. All of this data and reporting is to be submitted on CD, DVD media or portable hard disc to the CWW representative with a written summary outlining which results are below the threshold described in section Acceptable Laser Profiling Results There are practical considerations in using a Laser Light profiler to determine acceptable pipe ovality. When this technology is used the passing of deflection tests will occur when a suitably qualified person has viewed the outputs (e.g. written report with images, a DVD) and signs off that the deflections are within permitted limits. The viewing and analysis of outputs shall be completed in the field or office by a consultants representative and a recommendation made to the CWW representative. For the purposes of explaining acceptable deformation of a pipe, assume that a pipe has been deformed from a circle (of internal diameter D ) to an ellipse (with a major diameter- Dmax which is equal to the longest internal measurement and a minor diameter- Dmin which is equal to the shortest internal measurement). Ovality % shall be calculated as: (Dmax-Dmin) / D x 100. Ovality % must conform to Table 22.7 of the Code. For example, for a newly constructed UPVC sewer pipeline the maximum allowable short-term vertical pipe deflection at 14 days is 4.8%. Grade sensing devices shall be fitted to the CCTV tractor and a grade vs chainage plot provided. The error margin of a tractor can be significant and should be determined through trials of the tractor on rough surfaces of known grade (this shall be known as % error ). Acceptable grade results shall be as per section of the code, taking the % error into account. 6.3 Vacuum testing All sewers are to be vacuum tested as per section and section of the MRWA version of the Sewer Code. Sewer lengths and manholes / maintenance shafts are to be tested as one item to ensure that all components of the sewer are vacuum tested. Pressure testing is not acceptable. Any sections of sewers which fail may be divided into smaller sections to identify the defect locations. Defects must be corrected before being retested. Sewer Acceptance Testing Specification August of 10

9 All manholes greater than 2m in depth cannot be entered without fall protection being applied. All personal entering manholes greater than 2m deep must wear an appropriate harness and be connected to a fall protection device. Sewer Acceptance Testing Specification August of 10

10 City West Water St Albans Road Locked Bag 350 DX Sunshine VIC 3020 Australia T F E accreditation@citywestwater.com.au citywestwater.com.au Sewer Acceptance Testing Specification August of 10