Soil Contamination Risk Stage 1 - Preliminary Site Investigation, Stage 2 – Detailed Investigation Report & Stage 3 – Remediation Action Plan 117 & 119 Kennedys Bush Road and 900 Cashmere Road, Halswell, Christchurch August 2017 Malloch Environmental Ltd 801 East Maddisons Road, Rolleston 7614 021 132 0321 www.mallochenviro.co.nz Asbestos Surveys • Soil Contamination Investigations • Environmental Planning PSI/DSI/RAP –117-119 Kennedys Bush Road, Cashmere Road Christchurch CONTENTS 1 Executive Summary .......................................................................................................................... 3 2 Objectives of the Investigation ......................................................................................................... 3 3 Scope of Work Undertaken .............................................................................................................. 3 4 Site Identification ............................................................................................................................. 4 5 Site Description and Surrounding Environment ............................................................................... 5 6 Geology and Hydrology .................................................................................................................... 5 7 Site History ....................................................................................................................................... 6 7.1 Previous Site Ownership and Use........................................................................................ 6 7.2 District Council Records ....................................................................................................... 6 7.3 Regional Council Records .................................................................................................... 6 7.4 LINZ Records ........................................................................................................................ 7 7.5 Review of Historic Aerial Photographs ................................................................................ 7 8 HAIL Uses and Possible Types of Contaminants Associated with Past Use ..................................... 7 9 Basis for Soil Guideline Values (SGV)................................................................................................ 8 9.1 Activity Description ............................................................................................................. 8 9.2 Zoning .................................................................................................................................. 8 9.3 Soil Guideline Values ........................................................................................................... 8 10 Risk Discussion .................................................................................................................................. 9 11 Sampling and Analysis Plan and Sampling Methodology ...............................................................10 12 Field Quality Assurance and Quality Control ..................................................................................11 13 Laboratory Quality Assurance and Quality Control ........................................................................11 14 XRF Quality Assurance Measures ...................................................................................................11 15 Results Analysis and Summary .......................................................................................................11 16 Site Characterisation and Recommendations ................................................................................12 17 Planning Status ...............................................................................................................................13 18 Remedial Actions ............................................................................................................................13 18.1 Remediation Goals ............................................................................................................ 13 18.2 Remedial Options and Discussion ..................................................................................... 13 18.3 Proposed Methodology ..................................................................................................... 14 18.4 Affected Volumes .............................................................................................................. 14 18.5 Unexpected Contaminated Material ................................................................................. 14 18.6 Contact Details during Remediation ................................................................................. 14 19 Site Remediation Management Plan ..............................................................................................14 Malloch Environmental Ltd Page 1 PSI/DSI/RAP –117-119 Kennedys Bush Road, Cashmere Road Christchurch 19.1 Site Setup ........................................................................................................................... 14 19.2 Stormwater and Soil Management ................................................................................... 15 19.3 Dust Control....................................................................................................................... 15 19.4 Occupational Safety and Health Issues and Measures ..................................................... 15 20 Validation Sampling ........................................................................................................................15 21 Conclusion ......................................................................................................................................15 22 Limitations ......................................................................................................................................16 Appendices A Certificates of Title B Listed Land Use Register Statement C Aerial Photos D Sample Location Plan E Table of XRF Results F Table of Laboratory Results G Laboratory Reports Malloch Environmental Ltd Page 2 PSI/DSI/RAP –117-119 Kennedys Bush Road, Cashmere Road Christchurch 1 Executive Summary The subject site is a large block of land on Kennedys Bush and Cashmere Road, in Southeast Halswell, Christchurch. It is proposed to subdivide the site for residential use. This will change the use of the land and result in disturbance of soils. The Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Health) Regulations 2011 (NESCS) require an assessment of the likelihood of soil contamination being present. It is noted also that Malloch Environmental Ltd is obligated to consider the requirements of Section 10 (4) of the Health and Safety at Work (Asbestos) Regulations 2016. This report details the work undertaken to assess the risks. The investigations have shown that the majority of the site has been used for pasture land in its known history. This type of use is unlikely to have caused any soil contamination that would pose a risk to human health, and no further investigation is required for the majority of the site. However, a dwelling and farm outbuildings have existed at 117 and 119 Kennedys Bush Road since prior to 1955, posing a risk of contamination on that part of the site. It was recommended that a Detailed Site Investigation, in terms of the Ministry for the Environments Contaminated Land Management Guidelines, be undertaken on the risk areas within these lots prior to subdivision and development for a residential use. Soil sampling and testing by portable XRF, along with lab testing, was undertaken at the site and has confirmed lead and arsenic contamination above residential soil guideline values as shown on the plan in Appendix D. There is considered to be a moderate to high risk to human health if these areas were to be used for residential use. It is recommended that remediation and validation of the areas is carried out before the land is used for a residential use. It is proposed to remediate these areas by excavating and disposing of the affected soils to Burwood landfill or an alternative authorised location. Full validation of each area will be carried out and a validation report will be provided to the authorities. In terms of planning status at the time of writing of this report, the NES does apply to the site as this investigation has shown confirmed soil contamination above the standards set out in regulation 7. Resource consent under the NES is required for the proposed subdivision, change in use and the remediation works which will involve soil disturbance. This report details all of the investigations undertaken and also details the proposed remediation actions and appropriate health and safety procedures. 2 Objectives of the Investigation This report has been prepared in accordance with the Ministry for the Environment’s “Contaminated Land Management Guidelines No 1: Reporting on Contaminated Sites in New Zealand”. This report includes all requirements for a Stage 1 Preliminary Site Investigation Report, a Stage 2 Detailed Site Investigation Report and a Stage 3 Remediation Action Plan. The objectives include determining whether there is any soil contamination present that would pose a risk to human health and recommending remedial measures for any contamination found. 3 Scope of Work Undertaken The scope of the work undertaken