Norrköping’s copper and iron mines

Large amounts of copper and iron lie under the surface in Norrköping. There is a worn-out DC network here, as well as city gas pipes, decoupled AC wires, wires for disused industries and trolley lines, old district heating pipes, and much more.

Over the last few years Björn Berglund, doctoral student in Environmental Technology and Management, and his colleagues at Linköping University, the Royal Institute of Technology, and the administrative agency, Statistics Sweden (SCB), have worked to chart the amounts of unused, disconnected metal found under the surface of Norrköping a city in eastern Sweden.

He started with digitalised maps, GIS data (geographic information systems from various system owners) and historical information about the city network; based on this, he has divided up the city into 36 parts. He’s studied one area, southern Butängen, a little more closely, since the municipality was already considering excavating the area. It’s an area of small industries that will make way for new housing and a new travel centre.

The existence of small industries should also mean that there is a relatively dense network of cables and pipes.

In the municipality’s streets and ground, Berglund has so far located 560 tonnes of disconnected copper, 27 tonnes of unused aluminium, and 4455 tonnes of disconnected iron and steel.

Apart from this, there are large amounts of pipework on private land that have not been documented on the municipal maps.

“It’s hard to get the information, we have to fight with an ideal world where what lies unused underground doesn’t exist,” he states.

And his estimations undoubtedly are on the low side.

“This is a pioneering work, and there are few previous estimations; we may have to dig to be sure.”

Berglund has also sought to find out why cables and pipes are taken out of operation. One big reason is when the entire system is replaced, like when city gas was given up for electricity, or when trolleys were operated on AC instead of DC. More effective systems simply take over. As a city develops, people need to increase capacity, relocate, and make new investments; the old system often remains there. A further cause is the small pieces left over when fixing water leaks, digging up a cable by mistake, or quite simply performing maintenance and replacing worn-out parts.

Today there is no incentive whatsoever to pull up the old cables and pipes; there are no ordinances or laws. Parts are also saved for strategic reasons. They may be of use later.

“The only reason to pull up the old cables and pipes until now has been if the new network is located in the exact same spot, or even deeper,” Berglund states.

He’s continuing his survey of Butängen and the economic prerequisites.

“In places where there is a disconnected network station or a really thick cable, it should pay to bring up the metals, especially if you’re going to dig there anyway,” he says.

Monica Westman Svenselius 17-01-2012

Photo: Peter Modin

Related Links

• Björn Berglund’s research 
• Department of Environmental Technology and Management 
• Royal Institute of Technology (KTH) 
• Statistics Sweden (SCB)