Water Industry Registration Scheme (WIRS)
GT Williams Ltd is the only North Wales based contractor to have achieved the high level of technical ability, quality and safety standards with installing new water mains connections to be awarded this prestigious accreditation under the Lloyd's Register scheme and recognised by all water utility providers.


ISO 9001
Designed to create a more disciplined work environment, ISO 9001 will help all our workforce know exactly who does what, when and how. This saves time and cost by reducing mistakes. ISO 9001 is also aimed at achieving customer satisfaction by setting out what needs to be in place in order to consistently meet our customers’ requirements.

ISO 9001

ISO 14001
ISO 14001 is an internationally recognised standard which helps our business remain commercially successful while reducing its environmental impacts. An ISO 14001 system provides a framework to allow us to meet increasingly high customer expectations of corporate responsibility as well as legal and regulatory requirements.

ISO 14001

OHSAS 18001
OHSAS 18001 is an internationally applied standard for occupational health and safety management systems. It helps our business achieve the best possible working conditions, aligned to internationally recognized best practice.

OHSAS 1801

Owned by the Department for Business Innovation & Skills (BIS), Constructionline is the UK’s register of pre-qualified construction contractors and consultants.



Civil Engineering Contractors Association (CECA)
Represents the interests of civil engineering contractors in the UK. It promotes the positive contribution the civil engineering industry makes to the nation. The industry is an integral part of the economy and CECA members construct and maintain national infrastructure which is fundamental to both the social and economic needs of the country.