Contamination Delivery Work Plan
4.
Contamination management 4.1 Overview
This section details the procedures for the management of contaminated media (soil, groundwater and surface water) during the Karangahape Station main works. It includes control measures for reducing human exposure to contaminated soils and water and minimising contaminated discharges to air, land and/or water. These measures must be established prior to commencing and during earthworks associated with the main works. The Council (Team Leader Central Monitoring) is to be notified at least two working days prior to any of the earthworks. The CLS will observe works associated with disturbance of contaminated soil as appropriate and verify whether the construction team is following procedures. The CLS will document the inspections, with a summary to be included within a works completion report to be prepared and provided to Auckland Council (refer Section 7).
4.2 Excavation of contaminated soil While the protocols below can be applied to all earthworks associated with the Karangahape Station main works, contamination is anticipated to be confined to the fill material. Therefore, the following is most relevant to disturbance within fill: • •
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Erosion and sediment controls shall be implemented in accordance with the ESCP prepared for the Karangahape Station main works before earthworks commence; Excavated soil shall be placed directly into a truck for immediate off-site disposal, where practicable. Excavated soil retained on site as part of contingency storage shall be placed in a designated area, appropriately bunded and covered when not being worked and as weather conditions dictate so as to minimise dust and stormwater runoff; Spillages of soil during placement in trucks shall be cleaned up as soon as practicable following the spillage. Spillages shall not be left unattended as contaminated soil could be trafficked by trucks and transported off-site; and The earthworks shall be observed by the CLS. If unexpected contamination is encountered during works, the works shall cease in the immediate vicinity and the procedures documented in Section 6 of this CDWP shall be followed.
4.3 Soil material classification The spoil generated as result of the Karangahape Station main works will require off-site disposal. In the context of this CDWP, spoil generated shall be classified as per the following three categories to define disposal requirements: Cleanfill Cleanfill material is defined in the Auckland Unitary Plan – Operative in Part (AUP) as: Means natural material such as clay, gravel, sand, soil and rock which has been excavated or quarried from areas that are not contaminated with manufactured chemicals or chemical residues as a result of industrial, commercial, mining or agricultural activities. Excludes: Page 19
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