An Invercargill city centre street upgrade is facing further delays after low levels of cyanide and a mix of heavy metals were discovered during earthworks.
Invercargill City Council says the level of contaminants is low and there are strict health and safety measures in place (File image). Photo: RNZ / Angus Dreaver
Work to upgrade Esk Street was paused last week after the unknown substances were uncovered.
Invercargill City Council infrastructure group manager Erin Moogan said residents could be confident that the contaminants did not pose any risk to public health following testing.
"In a site such as Esk St, which is a long-established urban roadway, contaminants can sometimes be found in materials previously used to construct roading surfaces, such as coal tar, which was used to provide a hard-wearing roading surface before the advent of asphalt."
The level of contaminants was low and there were strict health and safety measures in place, she said.
"Environmental consultants are on site to undertake further testing and examination and we are working through the processes and environmental consent requirements to ensure any contaminated materials are handled in the appropriate manner."
It meant more delays for the upgrade with work not expected to resume until some time in late January.
Moogan said the project and milestone dates might also be extended due to the delay.
"We understand this will cause some inconvenience to the community but it is important that we follow health and safety procedures and develop a robust management plan.
"We are grateful to our city retailers, businesses and community for their patience and understanding."
More information was expected to be released as further testing results were returned in the coming weeks.