This week saw us visit the Tar Pit Trial in Derbyshire. This was the first outing carried out by me, our helpers have been on site though at least weekly throughout the Corona lockdown. It was quite an alien experience to be leaving Birmingham for the first time since March. This was made even stranger by the near deserted New Street Railway Station which is always busy in more normal times. The station was deserted, though the ticket office was staffed no café or shop was open. Platforms were near deserted. The 08.49 to Derby was empty and the same on my return.
Even at Derby the only people on the station were helpful staff hoping I was well. All so otherworldly. I was told the train to Belper was on time and to wait on the platform. I was asked to socially isolate myself. Not difficult as I was the only passenger. The train pulled in and I struggled through a heap of bicycles that it turned out were those belonging to a group of octogenarian cyclists from Nottingham heading for the Peaks and a ride back. They wished that pubs might have been open to save them carrying the water which it appeared all were carrying. They were very jolly in a self-isolating huddle laughing and joking swapping news of the last weeks. They were the only others on the train.
Belper, a lovely town was busy with middle aged tourists and the odd shoppers, most of whom were lined up waiting to enter Wilco’s. The tourists walked about looking at the closed shops and cafes and cheerfully sat on benches that line the main street. They all looked as if they could murder an ice cream.
I met up with one of our stalwarts and headed up to the Tar Pits. There were many reasons for this visit, not just that I was longing to see the willows and ensure that vandals had not done too much damage over the last months but we had also arranged a meeting between the last funders of our trial and officers of the company that now owns, through takeover of the original polluters of the site, the liability of polluting the area in the 1970s. They have many others in the area as well. These need attention as well, but more will be said later.
Going to the site was wonderful, through the gate is a small stand of willows, planted into an acid (<pH1) tar creep, highly acidic ground with little or no nutrients for the plants we put in 14 months ago. They are doing amazingly well with some now 10 feet or more tall. The weeds that had established during the autumn and winter has died. This is not the tar that has seen them off but the lack of rain since February.
The site is isolated, fenced off to protect the public from coming into contact with carcinogens and acidic (pH1) soils that are present in the pits, and at the same time the fence protects, to some degree those who deposited the waste in the 1970s from putting the problems right. When the Trust took up the site for the trial the fencing had been broken down and cars driven across the tar surface, some had been burnt on the surface, still the remains of one that had sunk into the tar still rots in situ. We have been fortunate in that for the last year we have not had vandalism on site or thieves, in the first year we lost trail cameras and willows were uprooted. The site store had been attacked and even rain gauges stolen. Repairing fencing was a regular part of each site visit.
The first time we saw the tar pit in January 2018. The remains of the car. The surface water was not pleasant being acidic with a pH1.
The tar pit in May 2020 with the car remains. Grass, wild flora, and amphibians present across the site.
Seeing the main pit was so pleasing with much taking place, the willows’ growth looking strong though with signs of stress. Yellowing on most plants, with some the leaves shrivelled completely due to the lack of rain. Signs of rabbit attack, they have tunnelled under the rabbit and deer fencing around the pit itself.
Apart from to lack of moisture, weeds and grasses have begun to colonise an area of the site that had been reserved for sampling by the University of Nottingham to monitor the untreated tar in comparison with the treated. The surface where this colonisation had taken place had developed an obvious bacterial coating and this has neutralised the acidity enough for grasses and some other plants to begin to develop. The bacteria have spread from the composted area. The majority being in good health though Juncus appearing to struggle due to lack of rain.
Some of the willows were suffering from lack of moisture, these were interspersed amongst others that were stressed but better established. Those that were losing all their leaves exhibited fresh budding nodes ready to regrow. We have witnessed defoliation due to gasses from the tar, such events do not allow regrowth to develop.
The meeting with the company who had deposited the waste oil into the pits on site was interesting. They wished to see proof that the roots of the willow had penetrated the tar beneath the compost. The first sample excavated left its new roots in the tar the second sample showed roots into the tar, it also demonstrated the bacterial action that had taken place as the roots had passed through the tar leaving 15cm of material turned into a soil like friable compound.
The well willows across the site demonstrated vigour and a branching nature. The speed of growth being slow due to the lack of rainfall precipitation. Many the weeds that were apparent last year are finding the lack of moisture hard, annual weed flora seed not germinating at a normal rate.
The company representative plainly stated that these and their other sites used for waste tars were accepted liabilities of their internal parent company. They were not surprised at what they were seeing as they had entered the site on occasion to monitor its progress without letting us know. The company did not particularly like our method as it required establishing and tending plants and was not a walk away solution, though much less costly than moving the waste to another site.
We were aware that the site had been visited at times over the last few months and that willows had been uprooted but were unsure as to by whom and why up to this point! We have photographs of damage and footprints from the winter period that show this had happened.
After the meeting had concluded and visitors left, we walked down a lagoon, part of the same network of ponds and tar pits checking the other areas that were fenced off from the public. We watched a grass snake swim lazily across another lake, the first time I have witnessed one do this. We heard a buzzard calling and later watched it lazily pass overhead.
So back to Derby and on to Birmingham and a still deserted concourse. I was glad to be back. The first trip out since the lockdown and the hottest day of the year (33oC).
Postscripts.
- Our helpers visited the site on Thursday morning (the next day) to find that the site had been visited again, willows sampled and an attempt to break into the container that houses protective equipment, the stove and kettle and tea bags. The attempt failed but the police were informed.
- The site was also watered on Thursday by our helpers, 20 tons of water was spread across the site. The watering showed plainly that the willows had roots down into the tar as the areas which were not attached to the tar floated.
