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Contamination Assessments

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Please click on the tabs below to see some of the different Contamination Assessment services:
Our specialist expertise and competence allows us to deliver cost effective, and reliable outcomes and in a timely manner.

Key services include:

  • Preliminary Site Investigations and Desktop Reviews.
  • Environmental Due Diligence / Pre-Purchase Assessments.
  • Detailed Site Investigations.
  • Soil and Groundwater Investigations.
  • Vapour Investigations (vapour intrusion from contaminated soil, groundwater, and landfill gas).
  • Asbestos assessments, monitoring and management.
  • Radiation Assessments predominantly associated with Naturally Occurring Radioactive Materials (NORM) for potential risks from radiological exposures including external gamma, inhalation of dust, inhalation of gases (radon and thoron), ingestion, and presence in groundwater.
  • Remediation Action Plans – Feasibility assessment of remedial options and design of final remediation program to appropriately mitigate and manage contamination risks to meet site-specific conditions and stakeholder requirements. Remediation Services follow from stakeholder approval of the finalised plans.
  • Strategic Advice regarding Contamination Liabilities, DER Clean-up Notices, Memorials on Title, Due Diligence Pre-purchase Environmental Issues, Mandatory and Voluntary Audits, for Property redevelopment and site compliance.
  • Community Consultation including stakeholder identification and engagement, risk communication planning and management.
  • Human Health and Ecological Risk Assessment.
  • Liaison with regulatory authorities and appointed Auditors.
  • Dust Monitoring and Management.

Welarm understands that clearing WAPC and LGA planning conditions in a timely manner is crucial for property developers and appropriately, we recommend working closely with clients and stakeholders for property development projects and deliver the following:

  • Strategic advice to clients at the planning phase of the project.
  • Establishment of efficient and appropriate scopes of work at the outset.
  • Liaison with client, contractors and regulators at the earliest stages of the project to ensure works are scheduled and delivered on time and on cost.
  • Meet with necessary regulators to ensure that planning conditions are addressed without ongoing delays.

We recommend consideration of contamination liabilities during the preliminary phases of site redevelopment projects where an environmental planning condition is known to exist, or when it is expected from WAPC at a future stage of the development process. This early identification may facilitate opportunities to minimise or obviate likely development conditions requiring contamination and / or acid sulfate soils investigations of sites, and facilitate the understanding of how any issues may impact proposed development timing and costs.

Environmental & Pre-Purchase Due Diligence

Understanding the extent of contamination liability is crucial before buying, selling and often leasing properties. Unknown contamination liabilities may result in significant financial costs and redevelopment time delays, and may result in a site being unsuitable for its intended purpose. Failure to understand the nature and extent of contamination liabilities before purchasing land or businesses may result in the purchaser being held responsible for future remediation costs. Welarm has significant expertise in Environmental Due Diligence / Pre-Purchase and Baseline Assessments, with investigation scopes of work developed upon clients’ objectives, liability risk tolerances, and timelines.

Welarm can assist clients in understanding DER Memorials on title, and when their property is considered a “source site” and / or an “affected site” due to contamination.

Although asbestos containing materials (ACM) in buildings is now banned, buildings built prior to the late 1980s may have ACM present in a variety of construction materials including roofing, eaves, wall cladding, flooring, insulation, fencing and piping.

Poor or unsupervised demolition of buildings containing ACM may have cause ACM to be deposited upon the soil surface, which can become a significant contamination issue. ACM may also be present on sites through historical importation of ACM impacted fill materials.

Welarm staff have been involved with some of the largest asbestos investigations and remediation projects in WA. We have extensive experience in the assessment, monitoring and management of asbestos including quantifying the nature and extent of ACM within surface soils, determining human health risk from ACM, and development of both innovative and proven asbestos management strategies.

Welarm provide the following Asbestos services:

  • Design risk-based Remedial Action Plans to address both ACM and friable asbestos within soils.
  • Identify asbestos building materials as part of Environmental Due Diligence audits in single story or multistorey buildings and maintain Asbestos Registers.
  • Develop approved site assessment methods for sites contaminated by asbestos.
  • Monitor the integrity of work areas where asbestos is identified.
  • Monitored work areas during asbestos abatement activities, including respirable fibre monitoring.
  • Coordinate the analysis, landfill acceptance, and disposal of asbestos contaminated wastes.
  • Develop Environmental Management Plans where known and / or potential risks from asbestos are present.
  • Liaise with contractors during demolition in accordance with an EMP or in instances where unexpected ACM is identified.
Risk assessments are routinely undertaken as part of contaminated sites investigations by comparing chemical concentration data to available “Tier 1” screening criteria to determine whether substances are present at a Site at concentrations which may potentially present a risk to human health, the environment or environmental values.

Generally sourced from State, National and / or International guidance, Tier 1 screening criteria are derived based upon limited toxicological information and conservative assumptions regarding contamination source, exposure pathways and human health and ecological receptors. Welarm has the knowledge and understanding in the application and limitations of available Tier 1 screening criteria to identify and select the most appropriate screening criteria for sites following the development of robust conceptual site models (CSM).

If the concentration of substances at sites are lower than the relevant Tier 1 assessment levels, then the substances are unlikely to represent unacceptable risks. If Tier 1 screening criteria are exceeded, then further risk assessment, identified as “Tier 2” or “Tier 3” risk assessment, is generally required.

Tier 2 risk assessments involve the review of site-specific exposure scenarios that represent current and / or likely source-pathway-receptor linkages and which may significantly differ from the default conservative exposure assumptions derived for generic Tier 1 screening criteria. If required, Tier 3 risk assessments look further into the toxicological profiles of key contaminant drivers and associated quantitative uncertainties in exposure pathway models to assess the significance of identified site contamination.

Welarm has significant experience in deriving and / or adopting Tier 2 and Tier 3 risk assessments. Our expertise includes calculating tolerable limits for sites used in the derivation of management goals and / or site-specific “clean up” criteria.

At Welarm, we pride ourselves on thinking outside the box and in accordance with the Welarm philosophy, tailor environmental services to Clients’ requirements. As such, we understand that environmental issues on mine sites require a considered and pragmatic approach.

We are experienced in undertaking preliminary site inspections and desktop reviews to identify areas of mining operations and mine support industries with significant potential for contamination risks. We have developed contamination liability risk matrices for mining clients and subsequently designed targeted soil and groundwater investigation programs in consideration of operational, rehabilitation and / or mine closure requirements. Where required, Welarm can liaise with regulators, CS Auditors and other stakeholders to progress the needs of clients and avoid timely delays during approval processes.

Recent experiences have included:

  • Assessments of tailing storage facilities (TSF);
  • Assessing the nature and extent of particulate deposition (metals and NORM);
  • Determination of site-specific radiological background conditions for assessment of radiological exposure risk and development of appropriate screening criteria;
  • Investigation of surface water and groundwater impacts associated with mining operations across multiple water bearing units;
  • Assessment of contamination associated with facility infrastructure; and
  • Development of a working environmental management plan (EMP) for a site under Care and Maintenance.
Welarm provide assessment services for sites where naturally occurring radioactive materials (NORM) may be present and has specialist expertise in the determination of human health risk associated with mineral sands processing and mining operations. Previous works have included the development of conceptual site models for both occupational and public radiological exposure scenarios, and the assessment of radiological dose by exposure pathways including external gamma radiation, dust inhalation and ingestion, radon / thoron gas inhalation, groundwater and surface water ingestion.

Welarm understand the importance of establishing robust radiological baselines and background data for all relevant exposure pathways to ensure human health and ecological risks are appropriately determined. Further, site management and remediation decisions must be based upon a thorough understanding of variations in background conditions and anthropogenic radiological contamination sources.

We have successfully undertaken environmental assessments, remediation, and validation programs related to sites contaminated by NORM from processing works, which satisfied project objectives and the expectations the DER, (WA) Radiological Council, the appointed CS Auditor, and were in compliance with DMP guidance.