River and Watercourse Pipeline Survey and Maintenance Services

Northern Gas Networks (NGN) is seeking qualified specialist contractors to provide comprehensive survey, assessment, and remedial services for gas pipelines crossing rivers and watercourses throughout its distribution network. This work is essential for monitoring pipeline condition, integrity, and safety in these challenging environments. Services required include: determining pipeline cover depths and profiles; identifying changes to riverbeds and banks that could affect pipeline stability; confirming pipeline locations using topographical and hydrographic surveying; assessing riverbed and bank erosion or exposure; inspecting exposed pipeline sections; evaluating crossing infrastructure condition; and conducting corrosion monitoring surveys (such as Close Interval Polarised Potential surveys) as specified. The successful contractor will produce detailed survey reports that document methodology, findings, identified risks, and recommendations for remedial or risk mitigation work. The contract may also include carrying out remedial works identified during surveys to maintain pipeline safety and operational performance. This procurement establishes a framework contract across NGN's entire operating area to ensure ongoing compliance with engineering, environmental, and safety standards while protecting the long-term resilience of the gas distribution network.