UNDERWOOD WATER SERVICES
Your local IAGI-certified specialist for
geomembrane consulting, inspection & repair support.
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Kaleb Walding is the owner and operator of Underwood Water Services, a South Australian business built on genuine skill, reliability, and pride in workmanship. An IAGI Certified Welding Technician (CWT), Kaleb brings years of field experience and technical precision to every project — delivering clean, compliant, and durable HDPE liner installations and repairs.
Having worked across mining, civil, municipal, and sustainable infrastructure projects throughout every Australian state and territory except Tasmania, Kaleb has developed a deep understanding of both the practical and compliance sides of liner construction. He’s delivered successful outcomes for a wide range of major clients including Rio Tinto, BHP, FMG, Santos, Senex, Glencore, MRL, Water Corporation, SA Water, Wakefield Regional Council, CM Costa Farms, Albany Water Catchment, SO4 Potash, Kalium Lakes, Bunbury Council, Gold Coast Council, Moreton Bay Council, McCosker Civil, WBHO, CBSP, McArthur River Mine, City of Ipswich, Kalgoorlie City Gold Mine, Norton Goldfields, CRE Civil, and Cast Civil.
Kaleb’s work has ranged from solo technician roles through to leading crews on complex containment builds, coordinating site QA, and driving fast-turnaround repair programs. His focus on precision, safety, and transparency has earned him a strong reputation as a dependable specialist who takes pride in doing things right — not just fast.
Alongside field work, Kaleb designed and developed LINR, a Construction Quality Assurance (CQA) logging tool for anyone involved in lining projects — from councils and developers to main contractors. LINR makes project documentation straightforward, providing clear access to panel layouts, weld logs, and repair records, giving clients confidence and traceability throughout construction.
Underwood Water Services operates on three simple values: integrity, accountability, and workmanship that stands the test of time. Every project is managed directly by Kaleb, ensuring consistent quality and honest communication from start to finish.
Kaleb continues to build UWS with one principle at its core: if it’s worth doing, it’s worth doing properly
LINR — Clarity for Every Lining Project
LINR is a Construction Quality Assurance (CQA) logging tool developed by Kaleb Walding of Underwood Water Services. It was built to make liner project documentation simple, transparent, and accessible — not just for contractors and supervisors, but for anyone involved in a lining job.
Whether you’re a client, council, project manager, or local contractor, LINR gives you the tools to understand what’s happening on site without needing to be an expert. Need a weld log? A repair record? A panel placement map? LINR keeps it all organised and ready to share, so everyone’s working from the same page.
Designed from years of hands-on field experience, LINR cuts through the confusion that often surrounds liner QA. It’s everything you need to document and deliver a compliant, well-built project — leaving the engineering specs and ITPs where they belong, while making the rest simple, clear, and foolproof.
Built for the industry, but made for everyone — LINR brings confidence and transparency to every lining project.
Our
Services
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IAGI CWT specialist services
Specialist inspection, fault diagnosis, and repair planning for HDPE liner systems — carried out by an IAGI Certified Welding Technician (CWT #22121). Whether it’s ageing seams, surface damage, or unknown leakage, I provide certified technical assessments and recommendations that stand up to audit and regulatory review.
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PRE-POST asset construction consulation
Independent, practical advice for containment assets at any stage — before construction, during commissioning, or once operational. I help councils, contractors, and asset owners identify design risks, verify construction quality, and plan long-term maintenance strategies based on real field experience
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Inspection and asset integrity report
Detailed, on-site inspections and reports covering liner condition, performance, and compliance. Each assessment includes photographic evidence, risk grading, and actionable repair or monitoring recommendations — tailored to environmental, wastewater, or storage applications. Ideal for council audits, EPA reporting, or insurance records
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Residential services and poly tank repairs
On-site and workshop repairs for domestic and small commercial assets — including HDPE tanks, liners, sumps, and irrigation containment. Whether you’ve got a cracked tank or a leaking pond, I offer straightforward, durable repairs and clear advice on how to prevent repeat failures
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Technician hire
Need support or an extra set of skilled hands on your current or upcoming project? crews tied up with up with other work? we offer temp contractor hire for onsite project installation or small repair works.
IAGI Certified Welding Technician (CWT) Program
What Is IAGI Certification?
The International Association of Geosynthetic Installers (IAGI) offers the Certified Welding Technician (CWT) program to formally recognize a geomembrane welder’s expertise. This globally recognized certification verifies that a technician has the knowledge, experience, and skill to weld geosynthetic liners to a high standard. A CWT designation signifies that a welder meets industry benchmarks for quality—ensuring consistent, high-integrity welds on HDPE, LLDPE, and other liner installations. It is a mark of professionalism in the field of geosynthetic installation, demonstrating that the certified individual has proven their competence through rigorous testing and meets established standards.
Certification Process
Becoming a CWT is a multi-step process that ensures only experienced and capable welders are certified. Candidates must first meet prerequisites—including documented field experience (at least one million square feet of installed polyethylene geomembrane). Then, the technician undergoes a two-part exam: a written test and a practical hands-on welding test.
The written exam tests knowledge of geomembrane welding, equipment, safety, and installation techniques. The hands-on portion requires the candidate to fabricate welds using specific materials and equipment. These weld samples are then submitted to a third-party lab for destructive testing. Only welds that meet or exceed performance standards are accepted. Certification is valid for five years, after which the welder must renew to remain current and compliant with evolving practices.
Materials and Methods: HDPE and LLDPE
The CWT program at UWS focuses on polyethylene geomembranes—specifically High-Density Polyethylene (HDPE) and Linear Low-Density Polyethylene (LLDPE). These materials are widely used in containment projects such as ponds, reservoirs, and landfills.
HDPE offers strength and puncture resistance, while LLDPE is more flexible and conformable. The certification covers two key welding methods: fusion wedge welding (for long seams) and extrusion welding (for detail work and repairs). A certified welder must demonstrate proficiency in these techniques for HDPE and optionally LLDPE, proving they can deliver quality seams across a variety of applications.
Standards and Testing
The CWT program is grounded in international standards to ensure technical credibility. Weld samples submitted during the exam are evaluated based on criteria defined by ASTM and the Geosynthetic Research Institute (GRI). For example, tests such as peel and shear strength are performed to verify weld integrity and ensure seams meet required tolerances.
These tests are conducted by independent laboratories to ensure objectivity and accuracy. The use of globally accepted methods ensures that CWT-certified welders can produce seams that meet real-world engineering and quality control requirements.
Global Credibility and Hands-On Integrity
The IAGI CWT is a globally respected credential that signifies a welder’s professional standing in the industry. It is widely recognized by engineers, project owners, and regulatory bodies around the world.
Unlike some certifications based on coursework alone, CWT is performance-based—earned by demonstrating real-world welding skill under exam conditions. Every certification is backed by a verified hands-on test and third-party lab results. For clients, this means confidence that the certified welder on site has already passed the same challenges they’ll face on the job. The result is a credential you can trust—built on integrity and proven expertise.
Why It Matters to Clients
Hiring Underwood Water Services means hiring a contractor who values precision and professionalism. Having a CWT-certified welder ensures that geomembrane installations are completed using verified best practices and industry-standard techniques.
Clients benefit through reduced risk, improved installation quality, and regulatory peace of mind. Whether you’re managing a landfill, pond, or wastewater facility, working with a CWT-certified technician provides assurance that your liner system will perform reliably—protecting your site, your budget, and the environment.
Kaleb Walding – Certified Welding Technician (CWT #22121) at UWS
Underwood Water Services is owned and operated by Kaleb Walding, a Certified Welding Technician under IAGI’s Polyethylene program. Kaleb holds CWT #22121, issued in 2023 and valid through July 2028. He successfully passed independent testing in both HDPE wedge welding and HDPE extrusion welding.
This certification proves Kaleb’s ability to deliver clean, consistent, and compliant welds under real-world conditions. With hands-on experience and verified skill, he ensures every project meets technical and environmental performance goals. At UWS, your installation is personally handled by a certified professional committed to getting it right the first time.