by Chris Tobin
The southern section of the Redruth walkway will remain closed for the time being because of safety concerns.
The walkway from the end of Rothwell St to Redruth Park beside Saltwater Creek has been closed for more than a month.
“It will remain closed until such times as any leachate has cleared in the area or remedial work has been completed,” council waste minimisation manager Ruth Clarke said.
“We know it’s a popular walking and cycling track but we have to prioritise safety.”
Heavy rain in November and December raised the water table significantly higher than usual, resulting in some liquid spilling from the edge of the landfill into the drainage swale as leachate.
“The leaching was compounded by high rainfall, and sampling results [of the extent of leaching] varied but we take any risk to health of humans or animals seriously, so we took the action to close the path.”
Asked what contaminants were in the leaching, Mrs Clarke said testing to date was just indicator testing.
“As it is effectively water that has filtered through old and unquantifiable waste, the exact composition is unknown.
“Due to this, we treat all identified leachate as hazardous.”
She said further testing would be undertaken following a review.
Environment Canterbury said it had been advised by the council.
“The Timaru District Council hold two consents relating to the management of leachate from the Redruth landfill, one each for the closed landfill and the municipal refuse,” southern zone manager Chris Eccleston said.
“We will be meeting with them to discuss their management plan, progress finding a solution and plans for preventing a re-occurrence.”
The landfill was commissioned in the 1940s and was closed in the mid-1990s and had not caused any significant problems of this type since then, Mrs Clarke said.
“Like many of our other infrastructural services, we are now having to plan for the more frequent weather extremes being brought about by climate change.”
A programme to cap the old landfill is scheduled over the next 20 years and a plan to install a cut-off drain is also part of the 2018-28 long-term plan to capture some leachate from the southern end of the landfill.
The felling of pine trees at the northern end of the walkway also started last week, logs being removed from the site by log trucks via the southern end of the Leckie St reserve and Redruth St.