LAND surveys are due to be carried out in a number of areas formerly used for industry.
Durham County Council will be conducting the surveys, as part of its legal responsibilities under the Environmental Protection Act 1990 to identify potentially contaminated land.
Surveys are to be carried in 10 locations.
Letters to people living in those areas are being sent out.
Joanne Waller, head of environment, health and consumer protection, said: “These surveys are being done as part of our legal responsibilities.
“We would like to reassure people that there is no current evidence which suggests that any land is actually contaminated, or that there is any risk to public health.”