Mining and Sediment Impacts Services
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 can make predictions of the magnitude, frequency and duration of suspended sediment concentrations in receiving waters under different flow regimes. These data may then be used in a probabilistic assessment of aquatic biological effects.
The following analyses can be performed by EnviroGulf Consulting`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.
The assessment of the effects of mine-derived sediments entering receiving waters is complex. EnviroGulf Consulting 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.
EnviroGulf Consulting offers the following services to clients in association with subconsultant hydrologists:
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 sediments on aquatic organisms and populations:
- fish.
- macroinvertebrates.
- algae, seagrass and other 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 receiving waters.