Description and value of services provided by the consultant.

H&M Civil were engaged by Blacktown City Council to develop a Stormwater Retention Basin and Nature Reserve to manage excess stormwater from the Riverstone housing development

The site upon which the works were to be undertaken consisted of heavily asbestos contaminated land, existing dams which required de-watering, a sewer main, which exists below the proposed excavation area, which required continuous vibration monitoring to monitor potential damage, a frog habitat requiring regular changes to the working area and frog protection measures.

Nova Group Pacific provided various services to the project surrounding environmental control and measures to ensure compliance with the Review of Environmental Factors.

The following services and reports were also provided to the client.

1. Non-Friable Asbestos, Excavation and Clearance

Nova Group Pacific project managed the Preliminary Site Investigation (PSI) to identify Contaminants of Potential Concern (CoPC) which identified a number of areas containing Asbestos Containing Material (ACM). Nova Group Pacific were engaged to develop a Remediation Action Plan and Long Term Asbestos Management Plan to remediate the contaminated areas.

Through this process Nova Group Pacific collected several samples to confirm the presence of ACM, conducted validation work to confirm the correct remediation of the site. Non-friable asbestos was amongst the debris which required remediation and validation. Nova Group Pacific’s Environmental Scientist undertook supervision, asbestos air monitoring and validation sampling to issue a final clearance of the work area.

2. Waste Classification

Waste classification reports were prepared for the offsite disposal of contaminated and non-contaminated soils.

3. Dam Dewatering Management Plan (DDMP)

The objectives of the Dam Dewatering Management Plan were to:
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Identify background water quality parameters for the Dam waters and receiving environment.
Develop a methodology for the dewatering of the dam, chemical treatment and discharge.
Provide a management plan to effectively allow the discharge of the dam waters to the receiving environment in accordance with Blacktown City Council requirements.

4. Remediation Action Plan

The development of the Remediation Action Plan produced for the site detailed the following scope of works:
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Review all previous environmental investigations for the site.
Establish remediation goals and criteria for the site.
Evaluate remediation technologies and select appropriate remediation strategies.
Provide guidance on licenses, an Environmental Management Plan, Work Health & Safety Plan and other relevant site plans required for the remedial works.
Outline necessary site operations including excavation, stockpiling, management and disposal of soil materials, environmental controls and supply an Unexpected Finds Protocol and a Contingency Plan to manage additional identified contamination that may be discovered during remediation and validation works.
Advise processes for the unexpected finds of suspicious materials and an Unexpected Finds Protocol.
Address recommendations made in previous environmental investigations and outline additional investigations which may need to be undertaken for the site, including data gap closure.
Establish a sampling, analysis and quality control plan for remediation and validation works.

5. Vibration Monitoring

To ensure the excavation and building works did not pose or provide the potential for damage to the newly installed Water NSW Sewer Main, a Vibration Management Plan was developed. The monitoring management plan consisted of the following:
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Development of trigger levels to ensure vibratory levels are controlled to prevent vibratory impact;
Development of a monitoring program with associated monthly reporting;
Reporting requirements if exceedances occur.
Compliance with relevant standards and Council approval documents.
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Vibration monitoring consisted of vibration monitors being installed at various location within the excavation area where the sewer main was installed. Monitoring was conducted continuously whilst excavation works were undertaken, with exceedances being reported. Any potential causes of the exceedance were outlined within the Monthly report.

The purpose of the monitoring was to highlight any exceedance which may cause structural damage to the sewer main and provide remedial measures and recommendations to ensure adequate control measures were implemented to prevent damage.

6. Management Plans

Nova Group Pacific developed a number of Management Plans for the site to secure Council approval for the works to be undertaken. Nova Group Pacific developed the following site specific Management Plans for the construction site:
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