Our Accreditations

About our Accreditations

Drainage Advisory Services and Assistance has over 35 years experience and we are proud of the accreditations we have achieved.

DASA is committed in maintaining the highest standards of heath and safety and quality control. Service and transparency driving our commitment to delivering a professional service.


CHAS is established as the market leader for health and safety pre-qualification in the UK. It is available to suppliers (those who provide goods and services) and to organisations (buyers) looking for suitably competent suppliers.

CHAS is a founder member and past Chair of Safety Schemes in Procurement. DASA have been members of CHAS since 2011.

Construction Line

Construction Line is a national on-line database, the UK’s largest register for pre-qualified contractors and consultants.

Construction Line is a member of Safety Schemes in Procurement. DASA have been members of Construction Line since 2013.

Safe Contactor

Safecontractor has a unique level of specialist knowledge unrivalled by many of our competitors, built on our 10 years’ experience of delivering market leading accreditation services. This is further reinforced by engaging only directly employed, experienced and qualified assessors to carry out our audits.


NADC are committed to the development of a national network of certified contractors across the UK & Ireland. We intend to promote these certified contractors to clients who are seeking professional companies to carry out their work. These include but are limited to the Construction industry, hospital trusts, schools, colleges, property developers, chartered surveyors and engineers to name but a few.

Subsidence Forum

The Subsidence Forum is a forum for subsidence matters for home-owners, authorities, insurers, repairers and professionals. The Forum is open to any organisation or individual involved with the insured subsidence risk.

Water Regulations Accredited Scheme

The purpose of WRAS is to contribute to the protection of public health by preventing contamination of public water supplies and encouraging the efficient use of water by promoting and facilitating compliance with the Water Supply (Water Fittings) Regulations and Scottish Water Byelaws.

ISO 9001 Quality Management

ISO 9001 Certification assists business in demonstrating the quality of their processes, while also driving down costs, increasing productivity and boosting customer satisfaction. DASA have achieved the ISO 9001 since 2004

ISO 14001 Environmental Management

ISO 14001 Environmental Management System identifies and controls all aspects of an organisation which may have an impact on the environment; this includes the use of natural resources, energy consumption and the management of waste. ISO 14001 addresses those fundamental areas. DASA achieved the ISO 14001 in January 2014 and are looking forward to continuing there work with QMS and the ISO accreditations.