Throughout this entire year, but scheduled to be completed by Christmas, the work of the Environment Agency and the Coal Authority in reducing the absorption of lead, zinc and cadmium from the Carrshield tailings dam into the tumbling waters of the River West Allen has probably gone unremarked by most of us.
You’d have to be travelling along the road through Carrshield (and that’s not a trip that many of us do very often, to be honest) to have observed the great extent of the work. The way I understand it, the revetment of the river banks (which along Carrshield are mostly lead mine tailings that have increasingly been falling into the river), along with a special capping material supplied by ABG-Geosynthetics to prevent rainwater entering the tailing banks, will mean that the water downstream flowing into the River Tyne will not have picked up those heavy metals on its way. On top of this membrane, a thin veneer of new topsoil is laid so that grass and heather can repopulate the bank.
As reported on the ABG website, “the river [West Allen] was the joint second worst in the Northumbria River Basin Management Plan in respect of mine water pollution, contributing around 20% of the total quantities of lead, zinc and cadmium found in the Tyne Estuary, over 40km downstream of the site.” The synthetic layer has a design life of 120 years. So perhaps by the middle of the 22nd century something else will have to be done to keep the rivers clean from the post-industrial waste that has accreted on the bankside throughout the two centuries of lead mining activity there.
We have a lot to thank the Victorians for, but they certainly didn’t have much idea of the damage, the environmental impact, of their engineering projects!
As the Tyne basin gets cleaner and cleaner, wildlife will continue to return, and the whole set of river valleys, from the ‘heeds down to the North Sea, will be that much more like it was before heavy industry wrecked it. From enhanced sewage systems to river remediation schemes, at least our generation is trying to leave a better legacy for the next generations.
Now if we could just solve the plastic problem, we could hand things over to the grandchildren with a lighter conscience!