It was recognised in the 1990s within the UK geomembrane industry that there was a great deal of variation in the quality of welding personnel on landfill sites. Some companies had very good in-house training schemes, while others provided very little formal training or guidance. For this reason, the British Geomembrane Association (BGA) began talks with the TWI, to develop a comprehensive geomembrane welding scheme to be incorporated into their TWI CSWIP certification scheme.
The CSWIP scheme, which follows the British Standard BS EN 13067, requires that a welder must have at least two years industrial experience in the relevant welding technique(s) before they can take the examination. The examination package is run over two days, and the examination itself, which takes place on the second day, is divided into theoretical and practical tests. The candidate must pass both to be awarded a certificate, achieving at least 80% in a 20 multiple-choice paper and producing a welded test piece with minimum required properties.
One of the major concerns within the UK Geomembrane industry was the shortage of experienced welders. In response to this, in 2003 TWI set up a new Entry Level certification scheme for geomembrane welders, which does not require previous welding experience. The Entry Level examination tests the practical skill of the welder, and successful candidates are awarded a CSWIP Entry Level certificate. After two years industrial experience, they then become eligible to take the full examination, in accordance with BS EN 13067.
The Environment Agency agreed to specify that, from April 2004, on all landfill sites in the UK, at least two crew members must be accredited to BS EN 13067 and all other crew members (except for a maximum of one trainee) must be accredited to the CSWIP Entry Level.
Although it took the TWI and the BGA many hundreds of man-hours, over four years, to develop the CSWIP certification scheme for geomembrane welders, the owners of all landfill sites in the UK can now be totally confident that the welding carried out on their sites is of a consistently high quality.
Company Accreditation Scheme
After the success of the geomembrane welding scheme, the UK Geomembrane Industry became concerned about the professionalism of the companies that were working on landfill sites. So with the assistance of the TWI and backing from the Environment Agency, a comprehensive Company Accreditation Scheme was developed by the British Geomembrane Association to provide an auditable system of accreditation for installers of geomembrane liners for environmental protection. The scheme covers all environmental protection projects using geosynthetic liners, including geomembranes and Geosynthetic clay liners.
The Environment Agency insists that companies carrying out containment works where geomembranes are used must be accredited, or be working towards being accredited, to the British Geomembrane Accreditation scheme for geomembrane installers.
Responding to concerns about the professionalism of the companies designing and installing gas membrane systems, the British Geomembrane Association has also developed, with the TWI, an auditable system of accreditation for gas membrane installer companies that replicates the successful company accreditation scheme for the landfill sector.
The principal objectives of this accreditation scheme are:
- to provide an auditable system of accreditation for installers of geomembrane liners for environmental protection
- to raise standards in the industry.
To achieve these objectives, the accreditation scheme has the following aims:
- to set minimum standards to ensure environmental protection
- to provide guidance on best practice to installers and other industry stakeholders
- to assure consistent high standards of workmanship through accreditation
- to measure and implement continuous improvement