In the 1970s, the National Coal Board closed the coal mine, causing the loss of many jobs. However, Global Chemicals later opened an oil refinery there, promising prosperity for the town. Clifford Jones opposed it over environmental concerns. The Third Doctor and Jo Grant went to Llanfairfach to investigate the mysterious death of Hughes, whose body had been found glowing green. They discovered that Global Chemicals was dumping lethal toxic waste into the abandoned mine, which also had the side-effect of creating giant maggots. The refinery was shut down.
Luckily, thanks to string-pulling by Jo Grant, the United Nations decided to fund the Wholeweal commune as a research facility. The money and extra work brought needed jobs to the town. (TV: The Green Death)