Where a change of use and development of land is proposed and contaminant residues exceed the relevant criteria for the proposed land use then remediation or management measures may be necessary.
Once a site has been identified as requiring mediation or management a Remediation Action Plan (RMP) should be prepared. A RMP should:
- Set remediation or management goals.
- Document all risk-reducing procedures and plans.
- Establish recording and reporting mechanisms.
- Establish the environmental safeguards required to complete the remediation in an environmentally acceptable manner.
- Identify and include proof of the necessary approvals, permits etc.
In some instances remediation, or a “full clean up” will not be achievable, or the risks from are adequately mitigated by preventing exposure to the contaminant, for example through concentrating the exposed site and only using non-exposed areas. In this instance a Land Management Plan (LMP) will be used alongside an RMP. The LMP will generally set out a clear monitoring strategy.
RMPs and LMPs will generally form the basis for proposing consent conditions. Consent conditions for contaminated properties may include any of the following; full site clean-up, which can include but is not limited to excavation and removal of contaminated soils; dilution; containment such as 'cap and contain,;' 4278 treatment of the contamination to safe levels in the soil; or vertical blending by deep ploughing of the soil with clean soils. (though this is the least preferred method of the council as it can lead to larger volumes of soils being contaminated).
Ministry for the Environment 2011 (revised) Contaiminated land management guidelines No. 1: Reporting on contaminated sites in New Zealand. Wellington. MfE.
Last updated at 10:55AM on November 27, 2015