January 11th – Another rare daylight commute, so again I took the canal into Darlaston. On my way I became aware of a series of yellow marker paint spots on the towpath, and it took me a little while to work them out.
The canal towpath here is to be resurfaced soon, and disturbed soil in places pointed up the fact that someone had been surveying. Markers near the bridges indicate a gas main runs alongside the canal here, and the spots indicate the position of the pipes. At the old arm crossover near Haniel, the pipes emerge and cross the disused inlet, and one can observe the spots follow it’s course.
This part of the towpath would benefit a little from resurfacing, but it’s nowhere near as bad as the stretches through Aldridge and Pelsall. The resurfacing policy is absolutely baffling.
August 21st – I had stuff to do in Aldridge on the way home, and Northgate was solid with traffic, so I cut down past the back of the Vigo landfill to hop on the canal at Brickyard Road. I noticed that the final work seems to be going on with sealing this immense refuse tip. It was capped with a top layer of marl a while ago, and landfill gas is still being abstracted and used to power a large generating set, supplying power to the national grid; but amongst the bulkheads and snaking pipes, a plastic membrane has been laid and it’s being covered in topsoil, prior to final landscaping.
The membrane prevents rainwater from getting through the cap and soaking through the refuse, where it would be extracted and disposed of as a toxic brew called leachate, which is an ongoing, expensive operation.
Reducing leachate production also lowers the future chances of groundwater pollution.
Landfill is quite a high-tech operation these days, if carried out properly.
February 27th – A lot of the history of Brownhills, Walsall Wood and Aldridge is about what lies beneath. Coal, clay, industrial effluent and landfill have shaped particularly the borderlands between Walsall Wood and Aldridge. Where brick marls were abundant, soon voids in the ground where they had been extracted were too. Into these holes, we tipped refuse in huge quantities, as the remaining clay made a good seal against the contaminant waste.
In the early days, the landfill and waste disposal industry was unregulated, haphazard, and somewhat akin to the Wild West. Waste was put anywhere, and unmonitored. These days, it’s a tightly monitored industry that has to look after its dirty secrets.
At the Vigo Utopia landfill site just off Coppice Lane, gas turbine engines run 24 hours a day, driving electricity generators from the gasses harvested from the decomposing rubbish. This produces significant amounts of power from 2 generator sets in converted shipping containers, employing gas that would once have been merely vented to the atmosphere.
Nearby, a series of bunds and pools lined with thick rubber gather water and liquid pumped from deep within the mound. This poisonous soup is called ‘leechate’, and is allowed to settle out before being disposed of as hazardous effluent. Again, years ago, such concerns were not addressed and sites were allowed to pollute groundwater uncontrolled.
This is ugly, scarred landscape; but we are looking after it much better than we used to.
January 5th – In the New Year Quiz on my main blog this year, I asked about the bulkhead pipes visible sticking from the mounds of a couple of local landfill sites; the answer was that they were gas collection points, to feed a gas turbine that generated electricity from the otherwise wasted methane evolved when the buried refuse decomposes.
This plant – humming away continuously in the way only a gas turbine can – is just off Brickyard road in Aldridge and has been running for at least 3 years fuelled by as from the Vigo Utopia landfill, generating electricity which is fed back into the national grid.
Refuse operators will paint this as ‘green energy’ – it’s no such thing; it’s not renewable, is finite and is no cleaner than any other methane power plant. It is, however, making use of gas that formerly would have been wasted, so it’s a good thing.
There is a similar setup at Highfields South, not more than a mile away.
May 30th – I spent the morning at work, then late afternoon, cycled into Birmingham to meet with a couple of colleagues. I headed down to the canal at Tyburn for a decent run, and followed the canal into central Birmingham.
One of the little-known features of canals that helped keep them open for years after their commercial value declined was the fact that under their embankments and towpaths, utilities found a direct route through cities for their pipelines and cables. By laying services alongside the waterways, many of the issues with traffic and complexity of installation could be avoided.
Along the canals here in Birmingham run gas, high voltage electricity, fibre optic telecommunications links, and petrochemical fuel pipelines. The keen-eyed explorer can often spot the evidence on the surface in the form of markers, bulkheads, valve access chambers and other infrastructure.
These small, concrete gas pipeline markers indicate a high pressure gas pipeline runs below, but also serve another purpose, as can be seen in this example which has had the cover prised off. The pipeline is metal, and to prevent corrosion, a system of cathodic protection is applied; a low voltage DC supply is connected between the pipe and electrodes – called anodes – in the ground nearby. The flow of current between the anodes and the pipe means that the anodes corrode sacrificially instead of the metal they’re protecting.
A similar system is being fitted to metalwork in the supports of Spaghetti Junction to protect it from water damage.
The markers – about 50m apart along the towpath – house junction boxes for the protection wiring and test points, and contain a magnetically operated switch for test purposes. Large brass studs in the side allow connection of test equipment.
You can find out about cathodic protection here.
February 10th – I came home in the early afternoon, just as the rain was clearing. I’d had to call in at Aldridge, so found myself in the hinterlands between Walsall Wood, Leighswood and Stubbers Green. This is a very scarred landscape, mainly from brick marl extraction. The geology of the former quarries here is perfect for landfill, and for decades, as a site is abandoned by the brickmakers, it is adopted by the refuse industry.
Now at the capping and landscaping stage, Vigo Utopia was a massive hole in the ground when I was a child, but now stands high above the surrounding area. Bulkheads tap off the methane and pipe it to a generator plant. Eventually, this mound will be a public open space, but that’s some way off yet.
Of course, the brickworks are still busy, and there’s still marl to be extracted, and there will therefore be further space for landfill. A vicious cycle of blight and nuisance, it renders this landscape hostile, ugly and barren, particularly on a dark, wet and blustery February Monday afternoon.
April 18th – The landfill at Highfields South, just over the Lichfield Road from Jockey Meadows, is notable for a number of reasons. It’s pretty well managed, and is being filled in a very controlled way. It’s now generating electricity from the landfill gasses it produces, and it has a very diverse selection of gulls, and attracts birdspotters from far and wide.
I noticed as I passed tonight that the bulkheads bored into the mound were now all connected. Like the former Vigo Utopia landfill a mile away, this one will generate electricity by burning the methane it produces for some years to come.
Don’t kid yourself that this is green, however; it’s still burning fuel, it’s not renewable and merely utilises gas that would otherwise be lost. But it’s still a neat use of an unusual resource.
November 25th – A curious thing has happened at Anchor Bridge in Brownhills. There used to be a gas pipe running along the front of the bridge – it was cast iron, and painted black. When I was a kid, climbing it was a challenge and a rite of passage. Yesterday, scaffold was erected at either end of the 300mm diameter pipe; today, it had been removed and the ends capped. I wonder why it’s become redundant?