As part of Northern Gas Networks’ long-term commitment to a greener future for the North of England, innovative environmental work is progressing well at a historic gasworks site in Sunderland.
The location – within sight of the North Sea – used to be home to five distinctive, gas holders – a throwback to the area’s industrial heritage. The framework of one is a listed structure and remains on the site.
Northern Gas Networks’ comprehensive land remediation programme works on sites such as this, where historical contamination has the potential to negatively impact the environment.
After extensive investigations, experts from Northern Gas Networks discovered that a nine-metre deep former gasholder tank present beneath the site contained substantial volumes of toxic coal tar – a common byproduct of gas manufacturing before natural gas was introduced in the 1960s.
The tank is well beyond its design life and at risk of structural degradation which could have led to leaks into the groundwater below.
That’s why work began in May 2025 to remove the tar. Specialist contractors Rhodar joined forces with subcontractors (environmental engineers Geo2) to carry out the work. Together, they’ve designed and installed a bespoke solar-powered pumping system that extracts the coal tar from the tank – a sustainable alternative to traditional generators. The tar is then stored in secure containers before being safely transported to a licensed disposal facility.
This work is due to last until around December 2025 – with no disruption to the local residents or environment.
Tom Keighley, Land Remediation Manager at Northern Gas Networks, said: “We want to leave a positive legacy at all of our sites, which is what our land remediation projects are all about.
“We take a proactive approach which involves investigating these sites before problems occur. This means we protect the local environment, greatly reduce the risk of future contamination and meet our obligations to the industry regulator Ofgem with confidence.
“Wherever possible, we aim to implement solutions that are innovative and sustainable, hence our use of solar power rather than traditional fuel powered generators to operate the pumps.”
Northern Gas Networks has undertaken similar projects at various sites across its region, with a project in Newcastle winning a Brownfield Briefing Award in 2018 for ‘Best In Situ Treatment’ – recognising projects which champion innovation, sustainability, stakeholder collaboration and best industry practice on brownfield sites. This project used solar powered pumps to remove more than 6000 litres of toxic coal tar from an underground tank which dated back to the Victorian era.
Similar work is planned in at two sites in West Yorkshire over the next few months.
Find out more about the land remediation programme in Northern Gas Networks’ Annual Sustainability Report.