“One of the materials that is particularly bad for producing odours and awful emissions is plasterboard,” she said.
“That’s one of the theories behind why Walleys Quarry got worse at that time.”
She said the landfill was in a low-lying area, and that some of the gases that came from the site were quite heavy.
“They react with water in the atmosphere, so some of the gases you smell can be quite awful and not very good for our health.
“It’s why, on some days when it’s colder and muggy and a bit misty, you can smell it more.”
Dr George added: “With any landfill, you’re putting things into the ground – and when you put things into the ground, if they can they will start to rot. When they start to rot they’re going to give off gases.”
She believed Walleys Quarry’s proximity to people’s homes was another major factor in the amount of complaints that arose from its operation.
“If you’ve got a gas that people can smell, they’re going to report it much more than perhaps a pollutant that might go unnoticed.”