| EnviroGulf Consulting |  |
|---|---|---|
ENVIRONMENTAL CONSULTANTS | ||
A Links Group Company |
MINING & SEDIMENTS |
Mining and Sediment Impacts
Adverse environmental impacts can arise from the accelerated entry of sediments into receiving waters, and mining developments have the potential to create such problems.
When a surface mine is excavated, originally consolidated overburden material is fractured, removed and then backfilled as a heterogeneous mixture. This results in a large mass of permeable material (mining spoil) subject to weathering and erosion that may affect the quality of water intercepted by the spoil or receiving its drainage waters.
EnviroGulf Consulting (EGC) can make predictions of the magnitude, frequency and duration of suspended sediment concentrations in receiving waters at different flows. These data may then be used in a probabilistic assessment of aquatic biological effects.
Technical Services
The following analyses can be performed by EGC's subcontracted analytical and geochemical laboratories or measured in the field:
Turbidity:
- turbidometry.
- Secchi disc.
Sediment physical properties:
- particle size grading.
- soil moisture content
Sediment chemical properties:
- multi-scan elemental analysis.
- metal sequential extractions.
- aeration/dilution extractions.
- elutriate tests.
- batch leaching tests.
- total cation analysis.
- net acid production potential (NAPP).
- acid neutralising capacity (ANC).
- nutrient status, cation exchange capacity (CEC), pH, Eh, carbonate content, sulphur content etc.
Consulting Services
The assessment of the effects of mine-derived sediments entering receiving waters is complex. EGC uses a multidisciplinary approach comprising consultation with the client's in-house mining engineers and the use of subconsultants (hydrologists) having a proven track record in the analysis of sediment transport capacity.
EGC offers the following services to clients:
Hydrological analyses:
- Catchment erosion and erosion risk assessment.
- Flow duration analysis and synthetic flow estimates.
- Sediment rating curves.
- Sediment transport capacity.
- Prediction of suspended sediment (SS) concentrations in receiving waters.
Impact assessment:
- Prediction of physical effects of mine sediments on aquatic organisms and populations:
- fish.
- macroinvertebrates.
- algae and macrophytes.
- corals.
- mangroves.
- Prediction of sediment impacts on aquatic resource use:
- floodplain plants and crops.
- subsistence, artisanal and commercial fisheries.
- drinking water quality.
Monitoring:
- Field surveys.
- Design, planning and execution of sediment sampling and monitoring programs for effluent and receiving waters.
Relevant Experience
The Principal of EGC has carried out numerous sediment impact assessment and evaluations, for example:
- Koniambo Nickel Project: Assessment of the potential impacts of mine surface sediments on fish and invertebrates, and formulation of suspended solids effects threshold criteria for the protection of freshwater aquatic life (to Roche Limited Consulting Group for Falconbridge Nouevelle Caledonie).
- Basslink Project: shallow- and deep-water marine biological impacts of construction sediments from subsea cable installation and sea electrode emplacement (with NSR for Basslink Pty. Ltd.).
- Sepon Gold Project: review of riverine biological impacts of fugitive sediments in mine construction runoff waters (to NSR for Oxiana Resources Limited).
- Ramu Nickel Project Environmental Plan: riverine, shallow- and deep-water marine biological impacts of sediments in mine runoff waters and from Deep-sea Tailings Placement (DSTP) (to NSR for Highlands Pacific Limited).
- Misima Gold Mine: marine biological impact of sediment-laden mine runoff waters from the open-pit (with NSR for Placer Pacific).
- Lihir Gold Project: marine biological impact of mine-imposed sediments (with NSR for Kennecott-Niugini Joint Venture).
- Wapolu Gold Project: impact of exploration sediment-laden runoff on mangrove swamp (with NSR for City Resources).
- Ok Tedi Gold and Copper Mine: impact assessment of mining sediments on coastal mangroves and coral reefs at Fly River mouth (to OTML).
- Ok Tedi Gold Mine: monitoring and impact assessment of mine-derived sediments on Fly Riverecosystem (to OTML).
- Porgera Gold Project: sediment impact predictions on Strickland River system (with NSR for PorgeraJoint Venture).
- Hidden Valley Gold Project: sediment impact predictions on Watut and Bulolo river systems (with NSR for CRA).
- Wafi Gold Project: sediment impact predictions on Wafi Creek and Bulolo River system(with NSR for Elders Mining).
- See Principal's CV for others.