Glenrath Farms hopes to house about 300,000 chickens on land in Peebles-shire and has submitted a planning application to the local authority.

However, residents are worried that an aqueduct, which runs under the land and carries the capital's water supply from the Talla and Fruid reservoirs, could be compromised.

The Blyth Bank Action Group (BBAG), commissioned Living Water, a consultancy charity which looks at the ecological treatment of water, to investigate. The charity's report claims there is a "high risk" that the development, at Blyth Bank Farm, Blyth Bridge, would contaminate the groundwater which feeds into the aqueduct.

It says it will "greatly increase" the risk of cryptosporidium, the parasite which leads to the stomach disease cryptosporidiosis, which can be deadly. The disease leads to dehydration, stomach cramps, fever and vomiting.

"The development will greatly increase the risk of cryptosporidium and will make it more difficult and expensive for Scottish Water to eliminate the risk from water supplies," the report warns. "Taxpayers and consumers will ultimately pay the cost."

According to the publication, the Scottish Environment Protection Agency (SEPA) has said the development would not cause pollution as there were no such problems when the land was used as a dairy farm.