Landfill leaching closes Redruth walkway indefinitely
A popular walkway at the south end of Timaru will be closed for the foreseeable future as authorities tackle leaching from a neighbouring landfill.
The walkway, which connects Saltwater Creek, the Otipua Wetland, the Timaru cemetery and Patiti Point, was closed to the public in November when Timaru District Council staff were alerted to leaching.
Testing identified leaching just north of the bridge near the State Highway 1 entrance and on the east side to the south edge of the old landfill at Redruth.
However, further testing will be undertaken following a review of results of the sampling programme, council waste minimisation manager Ruth Clarke said.
‘‘The leachate testing done to date was just indicator testing that tells us that the liquid leachate,’’ Clarke said.
‘‘As it is effectively water that has filtered through old and unquantifiable waste, the exact is composition is unknown.
‘‘Due to this we treat all identified leachate as hazardous. Further testing will be undertaken following a review of the results of the sampling programme to date.’’
The area would remain closed until ‘‘such times as any leachate has cleared in the area or remedial work has been completed’’, Clarke said.
The landfill was initially commissioned in the 1940s and was closed in the mid-1990s, she said.
‘‘It’s not caused any significant problems of this type since then.’’
Clarke said the leaching was caused by ‘‘extremely’’ high rainfall raising groundwater levels.
‘‘Like many of our other infrastructure services, we are now having to plan for the more frequent weather extremes being brought about by climate change.’’
Higher than usual rain levels in November and December raised the water table and meant some liquid had spilled from the edge of the landfill into the drainage swale as leachate, she said.
The council was undertaking short and medium term remediation work in the area, including planting to deal with any problem spots, Clarke said.
A programme of capping the old landfill was scheduled over the next 20 years which would reduce rainwater infiltration and leachate, Clarke said.