Risk review of former township landfills
Preliminary assessments have been undertaken to identify risks associated with small, closed landfills located around the western and coastal townships of Tairawhiti.
“This work is part of the ongoing investigation into contaminated sites the Council is responsible for,” says acting director for environmental services and protection Lois Easton.
Council currently manages the aftercare of all former landfills as contaminated sites.
A report to the Environmental Policy and Regulations committee on 14 June outlined the preliminary site investigations of small closed landfills at Tikitiki, Tokomaru Bay, Tolaga Bay, Patutahi Te Araroa, Te Puia, Te Karaka, Whatatutu and Matawai.
“The work involves a preliminary risk evaluation that looks at human health and environmental risks based on available information.”
County and council engineer’s records, historical aerial photography, previous site investigations, water quality data and interviews with ex-county and council employees were used to determine high to low level risks at each site.
“For older landfills like these the risks are mainly environmental.”
The recommendation to the Committee was for further investigation of the 10 landfills, and if required, to develop remediation plans to reduce the potential for direct contact risk and gas accumulation.
Further investigation of the risk to groundwater at Te Araroa, Tolaga, and Patutahi landfills and surface water at Tikitiki and Patutahi landfills were also recommended as next steps.
“This additional work may identify the need for resource consents or remedial work such as further capping.”
An application to Ministry for the Environment contaminated sites fund would be submitted in September.
Ms Easton says Council has already assessed the former landfills in the Waikanae creek as high risk through this method and Council has received $84,500 from the Ministry for the Environment’s Contaminated Land Remediation fund to investigate the levels and sources of contamination.
“This is the first stage in working out what we can do to address the problem,” she says.
“We also have another 18 sites to evaluate and will report back to the committee in the future on these.”
It's likely that remedial work on at least some of the sites will be required to be included in the next Long Term Plan in addition to remedial work alongside Paokahu landfill.