TAILINGS. PERFORMANCE. ENGINEERING ASSURANCE.
Tailings Storage Facility Monitoring Intelligence
GeoSmar reviews tailings facility monitoring data, pore-pressure trends, deformation, seepage and remote-sensing evidence to help operators verify performance, identify change and focus engineering action.
Tailings Storage Facilities
Tailings monitoring should test the facility’s design assumptions, failure modes and changing performance.
A tailings storage facility is a dynamic geotechnical system. Embankment raises, deposition strategy, pond position, pore-water pressure, seepage, foundation response, seismic loading and changing tailings properties can all affect performance. A useful monitoring programme therefore connects instrumentation to the mechanisms that could matter, then converts the data into timely engineering review.
Global Industry Standard on Tailings Management
Modern tailings monitoring is expected to be comprehensive, integrated and linked to performance.
The Global Industry Standard on Tailings Management (GISTM), co-convened through the Global Tailings Review, applies across the tailings facility lifecycle. Principle 7 requires a comprehensive and integrated engineering monitoring system appropriate for verifying design assumptions and monitoring potential failure modes.
Verify design assumptions
The engineering monitoring system should be designed around the assumptions that matter to facility performance and the credible failure modes being managed.
Measure defined performance
Objectives, indicators, criteria and performance parameters should be measurable, recorded at appropriate frequencies and updated as the facility evolves.
Act on deviation
Technical monitoring data should be analysed at the frequency recommended by the EOR, with deterioration or performance outside expected ranges addressed through TARPs or critical controls.
Why the Observational Method matters
Why lifecycle coverage matters
Site characterisation
The monitoring system is only as good as the ground model and material knowledge behind it.
GISTM Requirement 2.2 calls for a detailed site characterisation covering climate, geomorphology, geology, geochemistry, hydrology, hydrogeology, geotechnical conditions and seismicity, together with regular characterisation of the physical and chemical properties of the tailings. Those inputs determine what should be monitored and where.
Foundation and abutments
Potentially important features include weak or compressible strata, variable weathering, buried channels, permeable horizons, faults, liquefiable materials, karst, old mine workings and seepage paths — but only where verified by the site investigation and geological model.
Tailings and embankment materials
Density, gradation, permeability, saturation, strength, consolidation behaviour, deposition history and construction materials can change over time. Monitoring interpretation should therefore use current material information rather than treat the facility as static.
Hydrology and hydrogeology
Pond location, water balance, seepage, foundation groundwater and phreatic conditions can be central to stability. The monitoring design should distinguish what is measured directly from what is inferred.
Seismic and climate loading
Facility performance can be sensitive to seismic demand, extreme rainfall, drought, snowmelt or other climate-dependent loading. Monitoring criteria should remain consistent with the governing design basis and any updates to it.
Failure modes & monitoring questions
A TSF monitoring plan should be built around credible failure modes, not a generic sensor schedule.
The monitoring programme should test conditions relevant to the facility’s actual design and risk assessment. A parameter is valuable when it helps distinguish normal performance from a developing mechanism that requires review.
Pore-pressure and seepage response
Are pore pressures, phreatic conditions, seepage rates or groundwater levels moving outside the expected range? Do they correlate with pond position, deposition, rainfall or raise construction?
Deformation and settlement
Is movement local or distributed? Is it stable, progressive or accelerating? Does the depth profile suggest embankment, foundation or tailings deformation?
Foundation response
Are settlement, lateral displacement or pore pressures consistent with the interpreted foundation model and construction sequence?
Water management
Are pond level, freeboard-related observations, inflows, outflows and seepage controls remaining within the operating envelope defined for the facility?
Construction and rate of rise
Are raises, material placement, deposition and rate of rise consistent with the design and OMS requirements? Has any change altered the expected response?
Closure and post-closure
As the facility transitions out of operation, which parameters remain necessary to demonstrate long-term stability, seepage control and acceptable performance?
Monitoring architecture
The strongest TSF monitoring systems connect internal behaviour, surface movement, water and operations.
A monitoring programme is easier to interpret when each evidence stream has a defined purpose and can be compared against another independent observation. This reduces the risk of treating one abnormal reading as a complete engineering conclusion.
Internal hydraulic behaviour
Pore pressure, phreatic response, groundwater and seepage observations relevant to embankment and foundation performance.
Deformation
Surface survey, GNSS, settlement points, inclinometers, shape arrays and other systems that show movement magnitude, direction and rate.
Water & environment
Pond level, rainfall, weather, seepage flow, downstream groundwater and other parameters tied to the facility water-management strategy.
Operations & construction
Raise geometry, deposition, rate of rise, pond location, construction records, inspections, maintenance and deviations from design intent.
Instrument selection
Choose the instrument to test the performance question.
The following table is a technical discussion framework, not a project specification. Instrument type, depth, range, accuracy, frequency, redundancy, data acquisition and trigger criteria should follow the EOR-approved monitoring design and the facility’s actual failure modes.
| Engineering question | Possible instrument / method | Typical TSF use | Important interpretation issue |
|---|---|---|---|
| Are pore pressures and phreatic conditions changing? | Vibrating-wire piezometers; standpipes where response time is appropriate | Embankment fill, tailings, foundation zones and seepage-control areas | Installation elevation, response time, drainage path, barometric / temperature effects and comparison with pond or deposition changes |
| Is lateral deformation developing with depth? | Manual inclinometers, in-place inclinometers, shape arrays | Embankments, abutments, foundations and suspected deformation zones | Point of fixity, baseline, casing / sensor behaviour, depth correlation and rate of movement |
| Is the crest, downstream face or surrounding ground moving? | Survey monuments, prisms, GNSS, automated total station | Crest, embankment faces, abutments, downstream ground and structures | Reference stability, seasonal effects, construction activities and distinction between local and distributed movement |
| Is settlement developing through the embankment or foundation? | Settlement points, magnetic extensometers or project-specific vertical deformation systems | Foundation compression, raise performance and internal settlement | Datum stability, anchor / reference depth and whether settlement matches the expected consolidation mechanism |
| Is seepage changing? | Seepage weirs, flow meters, drains, groundwater wells and water-quality monitoring | Downstream toe, drains, abutments and foundation seepage paths | Flow versus rainfall, pond level, seasonal groundwater, water quality and any change in seepage location |
| Is the pond and water balance remaining within the operating envelope? | Pond-level sensors, survey, rainfall / weather stations, flow measurements and operating records | Water management, freeboard-related control and deposition planning | Sensor datum, water-balance assumptions, extreme events and operational changes |
| Is strain or seepage developing along a distributed zone? | Fibre optic sensing where justified by the project | Selected embankments, seepage zones or structural elements | Installation configuration, thermal effects, calibration and how distributed signals relate to physical mechanisms |
| Is surface deformation occurring across the wider facility? | InSAR-derived ground-motion information | Crest, embankment, surrounding ground and regional deformation screening | Line-of-sight geometry, coherence, temporal cadence, geolocation, reference frame and comparison with ground instruments |
InSAR & remote sensing
Remote sensing can widen the field of view, but it should not replace internal TSF instrumentation.
Satellite-derived ground-motion information is useful when the question extends beyond a small number of survey points. It can help identify distributed surface deformation and historical trends across a facility and surrounding ground. It does not directly measure pore pressure, internal seepage, tailings saturation or every rapid failure mechanism.
Historical screening
Where archive radar data and suitable surface coherence exist, review whether deformation predates a monitoring upgrade or recent facility change.
Spatial comparison
Compare wider surface movement with GNSS, survey, inclinometers, shape arrays, piezometric trends and operational zones rather than interpreting satellite points in isolation.
Prioritised investigation
Use persistent or changing deformation patterns to focus engineering review and field verification, not to bypass the EOR-approved monitoring programme.
Official operator example: Anglo American
What InSAR does not replace
TARP & response
A threshold is not a safety system unless it is tied to verification, escalation and action.
GISTM Requirement 7.4 requires deviations from expected performance and deterioration over time to be identified and promptly addressed through Trigger Action Response Plans or critical controls. The monitoring programme therefore needs to define not only what is measured, but what happens when the data moves outside the expected range.
Define the performance envelope
Expected ranges, trigger parameters, reading frequency, instrument reliability, trend criteria and response ownership should be agreed before they are needed.
Verify before interpreting
Check instrument health, neighbouring sensors, recent construction, water management, weather and operational changes before assigning a mechanism.
Escalate through the defined plan
Notification, increased frequency, inspection, technical review, operational change, mitigation or emergency response should follow the facility’s approved TARP and governance process.
Monitoring QA/QC
A clean dashboard cannot rescue uncertain installation records, damaged sensors or an unstable reference.
TSF monitoring QA/QC begins with the instrument and installation record, then continues through data acquisition, maintenance, verification and engineering review. GISTM also requires construction quality control, quality assurance and Construction vs Design Intent Verification.
- Confirm instrument ID, type, range and calibration record
- Record coordinates, elevation, orientation and installation zone
- Preserve borehole / installation logs and as-built information
- Define baseline and reference conditions
- Track missing readings, drift, jumps and communication failures
- Maintain and replace instruments where continuity is required
- Compare automated data with independent checks where appropriate
- Review changes after raises, repairs, pond shifts or operational changes
- Separate raw, corrected, derived and interpreted data
- Document re-baselining, corrections and superseded records
- Compare related instruments before declaring a mechanism
- Preserve a traceable link between data, TARP status and engineering decisions
Governance & contract interfaces
Independent monitoring review must strengthen the governance structure, not blur formal accountability.
GISTM assigns defined responsibilities to the Operator, Accountable Executive, Responsible Tailings Facility Engineer and Engineer of Record, with independent review through an Independent Tailings Review Board or senior technical reviewer where applicable. A GeoSmar scope should fit around those roles clearly.
- Who is the formally appointed EOR?
- Who is the RTFE responsible for the monitoring system?
- Who approves changes to monitoring design or frequency?
- Who owns and controls raw monitoring data?
- Who installs, calibrates, maintains and replaces sensors?
- Who defines expected performance and TARP thresholds?
- Who validates an apparent exceedance before escalation?
- What information must reach the EOR and at what frequency?
- How are design changes and cumulative deviations documented?
- What is reviewed by the ITRB or independent technical reviewer?
- What statutory or local professional sign-off is required?
- How are third-party data, InSAR products and software limitations allocated contractually?
Official public examples
Leading operators and regulators increasingly combine instrumentation, remote monitoring and independent review.
The examples below come from official operator, standard-setting or government-hosted sources. They are provided as industry context only and are not presented as GeoSmar projects or endorsements of GeoSmar.
Remote instrumentation, InSAR and fibre optic sensing
Anglo American’s published tailings factsheet describes additional vibrating-wire piezometers and shape arrays, a remote real-time instrumentation system connecting sensors such as piezometers and weather stations, an InSAR specialist supported by geotechnical interpretation, and fibre optic sensing at selected tailings dams.
Piezometers, inclinometers, settlement and independent review
Newmont’s published tailings fact sheet describes routine monitoring of instrumentation including piezometers, inclinometers and settlement points, monitoring of rate of rise, groundwater wells for seepage-related assessment, and annual geotechnical review by a qualified independent senior geotechnical engineer.
Instrumentation thresholds linked to TARPs
The British Columbia-hosted 2022 Dam Safety Review for Teck’s Greenhills Operation states that monitoring and surveillance were designed to identify conditions that could signal a credible failure mode, with threshold values established for instrumentation and corresponding TARPs for exceedance levels.
GISTM disclosure and third-party validation
BHP states that it publishes GISTM public disclosure information for its operated TSFs and has engaged a third-party contractor to progressively validate conformance. The example illustrates how monitoring now sits within a broader assurance, governance and transparency framework.
Annual dam safety review and independent oversight
British Columbia’s mining framework requires annual Dam Safety Inspections for permitted mine dams and includes requirements for EORs, Independent Tailings Review Boards, registers and reporting. The current Part 10 framework was updated again in 2024.
Monitoring as part of the full TSF lifecycle
GISTM requires a comprehensive monitoring programme that supports design verification, performance-based management, TARP response, governance and lifecycle oversight. This is the framework GeoSmar uses as the starting point for international technical discussions unless the applicable jurisdiction or project requires more stringent provisions.
How GeoSmar can support a TSF team
GeoSmar is designed for the layer between monitoring data and the next engineering decision.
GeoSmar is the market-facing brand of Rauz Caucasus LLC and is structured for remote-first international delivery. For tailings facilities, the strongest fit is not replacing the EOR or site surveillance team. It is helping operators, technical teams and independent reviewers understand the evidence more consistently.
Recurring performance review
Review pore-pressure trends, deformation, seepage, survey and operational data against expected behaviour and agreed performance criteria.
Separate technical assurance
Review monitoring plans, data quality, reporting logic, TARP evidence and whether the interpretation is adequately supported by the available data.
Investigate conflicting or abnormal data
Assess sudden piezometer changes, apparent deformation, sensor discontinuities, reference problems or disagreement between remote sensing and ground instruments.
Connect sensors to failure modes
Support monitoring philosophy, instrument roles, data structure, baseline requirements, reading frequency and reporting architecture for EOR review.
Add wider deformation context
Interpret satellite-derived ground-motion information alongside GNSS, survey, inclinometers, shape arrays and facility operating context where the method is suitable.
Make recurring review more efficient
Automate repetitive charting, completeness checks, threshold screening and trend preparation while keeping engineer review around interpretation and action.
Frequently asked questions
Tailings monitoring questions that should be settled before the data is relied on.
Which instruments are normally used on a tailings storage facility?
Can InSAR replace piezometers or inclinometers?
Who should set the trigger levels?
Can GeoSmar independently review another contractor’s monitoring data?
Can a TSF be reviewed only from a dashboard?
What information does GeoSmar need for a first TSF review?
Does GeoSmar replace the Engineer of Record or Independent Tailings Review Board?
Start a technical discussion
Have tailings monitoring data that is difficult to reconcile with expected performance?
Send GeoSmar a facility brief, monitoring plan, sample dataset and the engineering question you need to answer. A first review can determine whether the useful next step is monitoring diagnostics, independent review, InSAR interpretation, monitoring-strategy support or recurring monitoring intelligence.