Blast Impact Assessment

Dr Elizabeth Gibson, General Manager CMPA, provides excerpts from the final Resources Victoria Regulatory Operations (RVRO) Blast Impact Assessments: A guide to documenting blasting activities for mining and quarry applications (BIA).

Background
RVRO developed the BIA as a mandatory requirement for a work plan/workplan variation application where the intent is to undertake blasting to extract stone.

The CMPA has made representations to RVRO to develop a workable BIA, however, the current document though vastly improved on the December 2024 version, was not supported. The main points of contention raised by CMPA in the submission on version two of the draft BIA (September 2025) include:

• Of concern is the requirement to identify and list the separation distance to every single house, pipe, power pole, road, etc within 1km of blasting. For a metro quarry with nearby streets, this is a mammoth task and is unnecessary. Listing roads, infrastructure, etc. less than 500m is more realistic. A suggestion was made that the information was already contained in the work plan which could be referenced. No change made by RVRO to final BIA.
• Definitions BIA: Regulatory requirements. What information would be required by the quarry to determine if blasting is in accordance with the regulations? Further clarification given in final BIA.
• BIA Requirements: “This is to enable an informed decision to be made about whether proposed blasting activities as part of a mine or quarry operation have been designed in such a way that demonstrates that, if approved, they will comply.”
• Appendix 1: number 8: Environmental considerations for air-blast overpressure, ground-vibration. For the statement “Reasonable consideration should be given to reducing ground vibration below 5mm/s as far as practicable” who and how will this be enforced? No clarification in final BIA.
• Appendix 1: number 10: Details of the exclusion zone (surface operations only). For the statement “…the exclusion zone should be conservative and provide generous protection”. This is the role of the experienced blast engineer. It should not be RVRO personnel due to their lack of blasting experience who may be unduly influenced, by say objectors. No clarification in final BIA.
• Appendix 2: Qualifications and experience of the person who prepared the Blast Impact Assessment are extreme ruling out many of the experts in this area. No changes in the final BIA.
• Ideally the BIA/work plan will reference this document, (correct at the time of preparing the work plan) and that it may be amended without triggering a work plan variation. No changes in the final BIA.

Definitions

RV is Resources Victoria.
RVsite is a site that is regulated by RV. For the purposes of this document, it includes a mineral exploration site, an opencut mine, an underground mine and a quarry but it does not include a petroleum site.
Blasting is the use of explosives to break rock at an RVsite.
Blast Impact Assessment (BIA) is the information that RV, Regulatory Operations (RO) requires to be documented to accompany an application for a work plan (and potentially a work plan variation) for an RVsite to demonstrate whether blasting can be undertaken in accordance with the Australian and New Zealand Environmental Council’s “Technical Basis for Guidelines to Minimise Annoyance Due to Blasting Overpressure and Ground Vibration”, 1990.
Blast Management Plan (BMP) is the information that WorkSafe Victoria (WorkSafe) requires to be documented prior to any blasting taking place to demonstrate how blasting will be undertaken safely.
Work Plan (WP) (includes reference to a Work Plan Variation, where applicable). The work plan is the primary document describing the earth resource’s related activities that are proposed to be undertaken at the RVsite, their potential risks and impacts, and the control or management actions required. Work Plan Variations are applicable where the original scope of work changes after the plan has been approved by RV requiring additional controls. The work plan then needs to be varied to include these controls.
Sensitive Receptors are parts of the environment, any members of the public, or land, property or infrastructure that may be impacted by blasting activities at the RVsite (and include Sensitive Sites).
Sensitive Sites are specific Sensitive Receptors including, a residence, hospital, school, or other premises in which people could reasonably be expected to be free from undue annoyance and nuisance caused by blasting (and they include a 10m wide space around the perimeter of the building). MIC is the Maximum Instantaneous Charge (in kilograms) used in a blast. It may vary significantly depending on the volume of rock that is proposed to be blasted.
AS2187.2 references the Australian Standard (AS) 2187.2 – 2006 Explosives – Storage and use – Part 2 that applies to all persons using explosives in Victoria.
ANZEC Guideline references The ANZEC Guideline (1990) Technical Basis for Guidelines to Minimise Annoyance due to Blasting Overpressure and Ground Vibration 1990 is a document that RV adopted to assist with minimising impacts to sensitive receptors.

1. Refer to RV Environmental Guidelines, ‘Ground Vibration
   and Airblast Limits for Mines and Quarries.’

Purpose
The purpose of this document is to provide guidance to the applicant of a work plan or a work plan variation for an RVsite that requires blasting how a decision will be made by RV if the application contains the minimum information necessary to satisfy RV’s requirements. It should be read in conjunction with Preparation of Work Plans and Work Plan Variations guidelines available on the Resources Victoria’s website

Background
The work plan application process for an RVsite is regulated by RV and the Relevant Planning Authority (usually the local Council). If a proposal is approved its operation is then regulated by RV, the Relevant Planning Authority and WorkSafe.

RVsites are regulated under the Mineral Resources (Sustainable Development) Act 1990 (MRSDA). The MRSDA establishes a legal framework aimed at ensuring risks posed to the environment, to members of the public, or to land, property or infrastructure by work being done under a licence or extractive industry work authority are identified and are eliminated or minimised as far as reasonably practicable.

All RVsites that carry out blasting must have an approved work plan that includes a description of the proposed blasting activities, identification of the risks and how these risks will be eliminated or minimised as far as reasonably practicable.

In addition to the application requirements in the MRSDA and associated regulations, all RVsites that blast must comply with the Dangerous Goods Act 1985 and the Dangerous Goods (Explosives) Regulations 2022 administered by WorkSafe Victoria (WorkSafe). For more information on WorkSafe’s requirements visit the WorkSafe website

Preparation of Blasting Information
RV requires a BIA to be prepared by an appropriate person (who may be a shotfirer).

However, if blasting is proposed closer than 500 metres to a Sensitive Site (e.g. a residence) or closer than 200 metres to a Commercial (or Industrial) building that may adversely impact amenity, a BIA must be prepared by a person who is likely to have tertiary qualification in engineering (or a closely related discipline) and at least 1 years’ experience designing/ supervising blasting operations at earth resource sites and a proven ability to predict blasting impacts with suitable evidence such as blast modelling. In this instance, a shotfirer is not likely to have the necessary qualifications and experience.

Appendix 2 of this document includes a sign off sheet to be completed by the person who prepared the Blast Impact Assessment.

Changes to Blasting Operations
If a change to blasting operations is required that will significantly increase the risk profile and require additional controls, then a BIA will be required and the process to vary the approved work plan (as defined in the Preparation of Work Plans and Work Plan Variations Guidelines) will need
to be followed.

In summary, the information required for the BIA is inflexible requiring a work plan variation every time it is amended (where there is a significantly increased risk – open to interpretation) which is impracticable. Additionally, RVRO has extracted parts of the Australian Standard (AS) that they feel is relevant to them leaving a document that does not by itself comply with the AS and potential confusion for the operator and community. The BIA is available at Resources Victoria website

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