ENVIRONMENTAL RISK ASSESSMENT
Environmental Risk Assessment
Risk assessment and risk management are being applied more and more routinely by government and industry to evaluate the impact of potentially hazardous substances and situations. EnviroGulf Consulting undertakes environmental risk assessments as part of a multidisciplinary team and, or, solely in the execution of ecological risk assessments.
Risk management serves to prioritise the risks to which a system is exposed, so that practices and policies can be put into place, such that:
- Risk is measured and monitored.
- Risk is reduced to acceptable levels.
- Reactive measures are put into place to respond to off-specification or accidental events.
- Preventive measures are adopted to control and/or reduce the level of risk.
The most direct procedure for evaluating environmental risk attendant to contaminants in recipient waters is a field study in which the aquatic ecosystem is monitored for damage, causal factors delineated, and the results extrapolated or generalised.
By way of thorough biological assessments, environmental impact analysis, toxicity evaluations and physicochemical analyses, EnviroGulf Consulting offers technically sound solutions to complex environmental issues.
EnviroGulf Consulting provides risk assessments tailored to our clients' specific area of interest following assessment techniques approved by regulatory authorities to which their reports are submitted. This procedure ensures the greatest chance of receiving a favourable review.
The following services are available:
- Contaminated site assessment of impacts on receiving waters:
- surface water quality
- aquatic sediments
- aquatic biological resources
- cumulative toxicity, bioaccumulation and biomagnification
- Analytical services:
- PAH, volatile aromatics, cyanides, phenols, BTEX, TPH, etc.
- general water quality determinands
- Preliminary risk assessment:
- background information and data review
- initial site inspection
- need for further investigation
- Risk assessment:
- hazard identification
- dose-response assessment
- exposure assessment
- risk characterisation
- uncertainty analysis
- Ecological risk assessment.
Preliminary Risk Assessment
A review of background information and data coupled with an initial site inspection and perhaps limited sampling form part of a preliminary risk assessment that EnviroGulf Consulting undertakes on behalf of clients. The objective is either to terminate an investigation because no risk is shown or to confirm contamination and firm up subsequent site investigations to identify exposure pathways and target populations.
Risk is a measure of the probability that an adverse effect will occur. In the case of a chemical contaminant, it is a function of the intrinsic capacity of the contaminant to cause an adverse effect and the concentration (or dose).
Hazard identification as part of the risk assessment process defines the toxicological hazards posed by chemical contaminants. These hazards are summarised in a toxicity profile for each contaminant of concern.
Toxicity databases are accessed by computer to determine the relationships between observed doses or concentrations of contaminants and specified biological responses. The scientific literature is also critically appraised.
Exposure assessment as part of risk evaluation implies the need to estimate frequency of exposure. The assessment evaluates the nature and magnitude of potential exposures of receptor populations to contamination via various environmental media. Site-specific exposure scenarios are generated and environmental concentrations are presented.
Risk characterisation estimates the impact of these exposures on environmental and human health.
The best estimate of potential risk as well as the highest plausible risk are presented. The weight of evidence approach is used to identify the most defensible value.
Sensitivity and uncertainty analyses are performed to quantify the uncertainty of risk assessments made. The techniques used include quantification of the effects of changing individual assumptions on the results and probability analyses.
Ecological Risk Assessment
Ecological risk assessment methodology is based on ecotoxicological approach consisting of the following components:
- Statistical analysis of contaminant concentrations.
- Probabilistic risk assessment.
Time-varying contaminant concentrations are statistically analysed and their frequency and duration in receiving waters determined. Risk is then assessed by multiplying the probability of an event by the
event's consequential effects. Due to the nature of toxicological tests (LC50s, etc.), the consequential effects are presently limited to the direct effects of dissolved contaminant species.
This simplified approach allows comparison of various contaminants and determines whether concentrations exceed known toxic thresholds. EnviroGulf Consulting recognises the limitations of toxicity test data and therefore evaluates the results in light of such factors as the presence of other water quality parameters, life phase, food web, bioconcentration, bioaccumulation and biomagnification.
The following are example projects that contain environmental or ecological risk assessments carried out by EnviroGulf Consulting:
- Wafi-Golpu Deep Sea Tailing Placement (DSTP) Project (2016 - ongoing) - Peer reviews of baseline studies of freshwater, marine ecology and ecosystem services. Assessments of residual freshwater ecology impacts of onshore pipeline construction and residual marine biological and ecotoxicological impacts of DSTP on the submarine slope, seabed and water column flora and fauna of the Huon Gulf, PNG (for Coffey to Morobe Mining Wafi-Golpu JV).
- Solwara 1 Project (2016 - ongoing) - Underwater noise and vibration assessment and predicted acoustic damage and disturbance impacts on whales, dolphins, fish and sea snakes from a Seafloor Massive Sulphide (SMS) mining operation (to Nautilus Minerals, Inc.).
- Papua LNG Project (2016 - ongoing) - Review and gap analysis of Environmental Baseline Studies. Assessment of freshwater, estuarine and marine impacts of construction and operation of upstream facilities (central processing plant), onshore and offshore export gas pipeline and downstream facilities (LNG Plant) and assisting in the preparation of an environmental, social and health impact statement (ESHIA) (to ERIAS Group for Total Explorations and Production).
- Waisoi Copper and Gold Project, Fiji (2016 - ongoing) - Review and gap analysis of existing baseline information. Environmental impact assessment of project construction and operations on riverine water quality and freshwater ecology (to Coffey for Newcrest (Fiji) Limited).
- Pasca A Development Project (2015 - ongoing) - Integrated impact assessment of drill cutting disposal (five wells), wastewater discharges and underwater noise from an offshore gas processing platform with floating storage and offloading (FSO) vessels for condensate and liquefied petroleum gas (LPG) on local offshore water quality and marine biological environment in the Gulf of Papua (in association with ERIAS Group to Twinza Oil Limited).
- Ok Tedi Mine Pit Shell Variation (PSV) Project, PNG (2014 - 2015) - Review and assessment of the Riverine Aquatic Ecology Program for mine life extension and technical and textual inputs to the proposed Ok Tedi Environmental Management Act (OKTEMA) (to Coffey Environments for PNG Department of Environment and Conservation).
- Ok Tedi Mine Life Extension Project, PNG (2013) - Review and assessment of the appropriateness, completeness and certainty of predictions for future changes to fish biomass and diversity downstream of the Ok Tedi mine under mine life extension scenarios compared to closure in 2015 (to Coffey Environments for PNG Department of Environment and Conservation).
- West Qurna-2 Oilfield Development Project (2011 - 2012) - Treated Water Injection to the Dammam Formation: Preliminary Environmental Risk Asessment. Environmental effects of injecting treated produced waters and other aqueous wastewaters to the Dammam limestone formation in southeastern Iraq (to Coffey Environments for Technip Italy S.p.A).
- Frieda River Gold/Copper Project (2010 - 2011) - Provision of strategic and technical advice on an approach to the downstream environmental impact assessment of construction and mining operations; assess the aquatic environmental impacts of project construction, mining and hydro-electric dam operation on downstream aquatic habitats and biological communities (to Coffey Environments for Xstrata Frieda River Limited).
- Badra Oilfield Development (2011) - Identification of natural and anthropogenic sources of radioactive materials (NORM, TENORM and depleted uranium) and baseline assessment of prevailing contaminant radiation levels in the Badra Oilfield Contract Area in Wassit Governorate, Iraq (to Coffey Environments for Gazprom Neft Badra B.V.).
- West Qurna 2 Oilfield Development Project (2010 - 2011) - Baseline assessments of soil , surface water and groundwater contamination from radionuclides (depleted uranium), hydrocarbons, metals, chemical warfare agents (sulphur mustard and tabun), exploded and unexploded ordnance, drill cuttings and drilling fluids, and salinisation in south-eastern Iraq (to Coffey Environments for LukOil).
- PNG LNG Project (2008 - 2009) - Papua New Guinea Liquefied Natural Gas Project - assessment of environmental impacts on the hydrology, water quality and aquatic ecology of freshwater, estuarine and marine waters arising from upstream developments (gas production and conditioning, and onshore export gas pipeline) and downstream developments (LNG Plant and associated infrastructure)(to Coffey Natural Systems for Esso Highlands Ltd).
- Koniambo Nickel Project (2004-2005) - Phase I Sediment Impact Study: Assessment of the potential impacts of total suspended sediment (TSS) concentrations on freshwater habitats and aquatic life, and formulation of TSS Effects Threshold Criteria for the protection of aquatic life (to Roche Limited Consulting Group for Falconbridge Nouvelle-Calédonie SAS).
- Basslink Draft Integrated Impact Assessment Statement (2000-2002) - Assessment of the marine biological effects of chlorine produced oxidants and halogenated organic compounds produced at the positive electrode (anode) of the proposed Basslink Interconnector across Bass Strait - on the basis of computer-predicted chlorine residual concentrations and transport and dispersion modelling (to NSR for Basslink Proprietory Limited).
- Ramu Nickel Project Environmental Plan (1999) - Riverine, coastal and deep-sea environmental impact of lateritic nickel mining wastes and wastewaters (to NSR for Highlands Pacific Limited).
- East Perth Gasworks Site Rehabilitation (1990) - Planning and implementation of surveys for estuarine waters, bed sediments and associated fauna for environmental impact and risk assessment of polynuclear aromatic hydrocarbons in groundwater and surface runoff from a former gasworks site contaminating the Swan River, Western Australia (with NSR for Camp. Scott & Furphy Pty. Ltd.).
- ANM Boyer Pulp and Paper Mill (1989) - Analysis and interpretation of process effluent and metal residues in the River Derwent and environmental consequences of river dredging operations (with NSR for Benders Civil Developments Pty. Ltd.).
- Ramu Nickel Project (1998-99) - Riverine, coastal and deep-sea environmental impact of lateritic nickel mining wastes and wastewaters (to NSR for Highlands Pacific Limited).
- Northshore Noosa Project (1986) - Review of sewage effluent management options and assessment of potential water quality impacts on the Noosa River, Queensland (with NSR/Maunsell & Partners for Leisuremark Australia Pty. Ltd).
- Beaconsfield Gold Mine (1989) - Environmental assessment of the toxicity of cyanidation tailing and tailing pond cyanogenic supernatant and prediction of potential environmental effects on the Tamar Estuary, Tasmania (with NSR for John Miedecke & Partners Pty. Ltd.).
- Bukit Young Goldmine (1989) - Assessment of water and wastewater management, disposal and detoxification of cyanided gold mill and heap leach effluents from the Bukit Young Gold Mine, Sarawak, Malaysia (with NSR for Middle East Timber Company, Singapore).
- Port Moresby industrial Port Study (1986) - Assessment of the marine biological effects of constructing and operating a proposed copper concentrate transhipment terminal within Port Moresby's Halifax Harbour (with NSR for PNG Harbours Board).
- Butler Transport Chemical Fire (1986) - Assessment of the impact and potential toxicity of leachate from contaminated soil remaining on site after clean-up operations on aquatic life in a tidal channel and Dynon Road Wildlife Reserve (with NSR Environmental Consultants Pty. Ltd.).
- Misima Gold Project Environmental Plan (1985-86) - Assessment of the marine biological effects of at-depth marine tailing disposal and near-surface dumping of soft oxidised waste, on the basis of aeration-dilution and bioassay tests, field dump trials and predictions of waste transport and dispersion (with NSR for Placer (PNG) Pty. Limited).
- Porgera Gold Project Environmental Plan (1985-86) - Assessment of river biological effects of mill tailing and mine waste disposal, based on laboratory aeration-dilution and bioassay tests and river transport modelling (with NSR for Placer (PNG) Pty. Limited).