MPHS Community Garden – Soil Testing

Client name: MPHS Community Trust

Site: 27 Corban Ave, Henderson

Project overview: MPHS Community Trust (the Trust) planned to develop a community garden at the site, however due to historical horticultural activities undertaken at the property, the potential for soil contamination to be present was identified. To ensure the safety of site users and suitability of the soil for the proposed garden, Thomas Consultants Limited (TCL) were engaged to complete a site assessment and soil testing. As part of the works, we conducted a site inspection, soil sampling and XRF analysis, which determined that the site soils did not pose a risk to human health and was suitable for use as a community garden.

Goal:  The goal of this project was to characterise the site soils and determine whether soil contamination exists at the site.  The project would assist the Trust with ensuring a safe working environment during the construction of the garden and to ensure the safe consumption produce grown within the garden. Our worked with representatives from the Trust and Auckland Council to ensure that the works were completed within the project time frame, and to provide timely updates on the results from the analysis.

Process:  We worked closely with the Trust and Auckland Council to establish a suitable scope of works. Our land contamination consultants conducted a review of the historical aerial photography for the site, a visual inspection to identify any additional potential sources of contamination, soil sampling and where notable features were observed, a portable X-Ray Fluorescence (XRF) device was used in the field to screen the soil for potential contamination hot spots. The XRF device provides real-time indication of contaminant levels in the soil and was used by Thomas Consultants in addition to the collection and analysis of soil samples at a nationally accredited laboratory, to assist in the accurate characterisation of the site soils. Analytical results were compared against the relevant national guidelines and a detailed report developed for the client.

Outcome: By working closely with the Trust and Auckland Council, implementing our tailored soil assessment, we were able to determine that the soil contaminant levels assessed did not pose a risk to human health. In completing the project, our team was able to assist the Trust in maintaining a safe working environment during the construction of the garden and ensuring the safe consumption produce grown within the garden.

The value that Thomas Consultants team added: 

Our Soil Contamination Team were able to use their experience and knowledge of contaminated land within the Auckland region to develop and implement a tailored soil assessment for the Trust which met the requirements of Auckland Council and helped them achieve their objectives and safely develop the community garden. We worked closely with the Trust and Auckland Council and maintained communication throughout the project lifecycle to ensure client satisfaction and that the project goals were met within the Trust’s desired timeframes.

Partners we worked with on the project: MPHS Community Trust / Auckland Council

Services provided:

• Technical advice and support from a dedicated soil contamination consultant
• Tailored soil contamination assessment, including:

• • Soil collection in accordance with the Contaminated Land Management Guidelines and analysis at an International Accreditation New Zealand (IANZ) accredited laboratory
  • XRF screening of the site soils to identity potential hot spots of contamination in real-time
  • Quality assurance checks to ensure the accuracy and reliability of results
  • Detailed report including site figures, comparison of results against the relevant guidelines and tailored recommendations

Completion Date: 17^th June 2021