A Complete Guide to Monitoring Well Installation Built for Mining and Infrastructure Projects

A single poorly installed monitoring well can compromise years of groundwater data, trigger regulatory non-compliance, and cost tens of thousands of dollars in remediation-all because of avoidable construction errors during the initial build. If you’ve dealt with sand-choked screens, cross contamination between aquifer zones, or water samples that don’t reflect true groundwater conditions, you understand the frustration.

Monitoring wells are not simple holes in the ground. They are precision-engineered instruments designed to provide critical data on groundwater levels, groundwater quality, and natural groundwater flow across specific aquifer intervals. When design and installation techniques align with site hydrogeology and regulatory requirements, these wells deliver accurate monitoring over decades. When they don’t, the consequences range from biased laboratory analysis results to failed environmental audits.

Groundwater monitoring is critical for assessing the health of underground water systems in Perth and across Western Australia, where mining activities, infrastructure development, and urban expansion all place pressure on groundwater resources. Monitoring wells measure water quality and quantity over time, detect pollutants and assess contamination spread, and serve critical roles in dewatering operations and construction safety.

At Monitel, we deliver end-to-end groundwater monitoring well installation – from initial site assessment and well design through drilling, construction, development, and commissioning with automated sensor networks. Our approach ensures every bore is built to collect data you can trust and defend.

Why Proper Monitoring Well Installation Works

Here’s what separates a monitoring well that delivers reliable, defensible data from one that becomes a liability:

Accurate site assessment prevents installation in unsuitable locations – Geological investigation identifies stratigraphy, aquifer boundaries, and potential contaminants before a drill rig arrives, ensuring screens target the right zones and avoid problematic formations.
Correct drilling methods preserve borehole integrity and aquifer conditions – Selecting between hollow stem augers, mud rotary, or sonic drilling based on depth, formation type, and pressure conditions prevents borehole collapse and avoids disturbing natural groundwater flow.
Appropriate casing and screen selection ensures long-term data reliability – Matching casing materials to site chemistry (pH, salinity, chemical resistance) and sizing the monitoring well screen slot to aquifer grain distribution prevents both sediment infiltration and structural failure.
Professional filter pack and sealing prevents cross contamination – A correctly graded gravel pack paired with a bentonite or cement-bentonite low permeability seal isolates the target monitoring zone from overlying and underlying strata.
Systematic well development removes installation debris and establishes proper flow – Development pumping clears drilling fluids, fines, and mud residues so that water samples represent actual groundwater conditions-not construction artefacts.

Poor installation creates more problems than no monitoring at all. Unreliable data leads to incorrect engineering decisions, failed project approvals, and wasted remediation efforts. Every shortcut-inadequate sealing, insufficient flushing, incorrect screen placement-compounds over the life of the well.

How Monitoring Well Installation Works

Getting from bare ground to a fully commissioned monitoring bore requires five structured phases. Each phase builds on the previous one, and errors at any stage propagate forward.

Step 1: Site Assessment and Well Design

Every effective groundwater monitoring program begins with understanding what’s beneath the surface. Geological investigation includes reviewing existing stratigraphic data, conducting soil samples and sieve analyses, and identifying the target aquifer intervals. Hydrogeological assessment determines depth to water, whether aquifers are confined or unconfined, expected hydraulic conductivity, and whether artesian conditions exist.

Installation requires selection of appropriate instrumentation for the local hydrogeology. Well depth, diameter, and casing material selection are driven by formation conditions, monitoring objectives, and regulatory compliance requirements. In Western Australia, installing groundwater monitoring wells requires compliance with Western Australian environmental standards, including the Minimum Construction Requirements for Water Bores in Australia (Edition 4, 2020) and WQPN 30 guidelines. Licensing and necessary approvals are mandated for groundwater monitoring well installations in Perth – typically a 26D licence for bore construction in proclaimed areas.

Screen length and slot size determination relies on aquifer grain size distribution. Sieve analysis identifies the median particle size; screen slot size is typically matched to the 50th–60th percentile particle size, with more conservative sizing where formations are heterogeneous or corrosive. For example, in a sand and gravel aquifer, a slot opening of approximately 0.150 inch (~3.8 mm) might be selected to retain around 40% of formation material while maintaining adequate water flow.

Monitoring wells should be positioned upgradient and downgradient of potential contamination sources to intercept contamination plumes and establish baseline conditions against which changes can be measured.

Step 2: Drilling and Bore Construction

Drilling methods include auger, mud rotary, and sonic drilling, each suited to different conditions:

Hollow stem augers – Ideal for shallow monitoring bores in unconsolidated formations. The auger flights keep the borehole open during casing installation. Not suitable for artesian aquifers or deep formations. Direct Push Technology (DPT) is also popular for shallow groundwater monitoring in Perth.
Mud rotary – Preferred for deep or confined aquifer monitoring and artesian conditions where downhole pressure control is essential. Requires careful management of drilling fluids to prevent screen smearing and filter pack clogging.
Air rotary – Effective in certain consolidated formations but not recommended where water levels may rise close to or above ground surface due to pressure risks.
Sonic drilling – Produces continuous core samples with minimal formation disturbance, valuable in complex or contaminated sites.

Maintaining borehole stability during drilling operations is critical. Driller’s logs should record lithology changes at each strata transition-typically every 3 metres for bores to approximately 50 m depth, with greater frequency in heterogeneous ground. Water strike locations are documented. For bores exceeding 50 m or targeting confined aquifers, geophysical logging (gamma, resistivity) is recommended to verify formation boundaries.

Borehole diameter must accommodate casing plus sufficient annulus for filter pack placement and sealing materials. For a 125 mm external diameter casing, a minimum annulus of approximately 30 mm is required around the casing to ensure uniform gravel pack distribution.

Step 3: Casing and Screen Installation

Monitoring well casings typically range from 2 to 6 inches in diameter, selected based on monitoring objectives and the specialised equipment that must fit inside. Casing materials include PVC, stainless steel, or fiberglass-PVC (pressure-rated uPVC) for most standard applications, stainless steel where chemical resistance is required in corrosive or high-pressure environments, and fiberglass for specific chemical compatibility scenarios.

Screen placement targets the aquifer interval of interest. Well screens should be placed to capture variations across seasonal groundwater levels, ensuring the bore remains functional across wet and dry cycles. Groundwater level mapping is essential for understanding seasonal variations in Perth, and screen positioning must account for these fluctuations.

Centralisers ensure the screen is centred within the borehole so the annular filter pack achieves uniform thickness-preventing dead zones that hinder water flow and create preferential pathways. Casing diameter should exceed the maximum diameter of the outer casing for proper sealing at transition points.

A filter pack of gravel or sand surrounds the well screen. This gravel pack is sized slightly larger than the screen slot openings, graded to prevent fine material migration while maintaining hydraulic communication with the surrounding formations. Filter pack material is tremied or poured carefully to avoid bridging.

Step 4: Sealing and Surface Completion

Proper sealing is what prevents cross contamination between aquifer zones and stops surface contamination from entering the monitoring interval.

Bentonite is used to seal the well and prevent contamination. A bentonite seal is installed directly above the filter pack, creating a low permeability seal that blocks vertical flow along the annulus. Above the bentonite, a cement-bentonite grout is placed extending to approximately 300 mm below ground surface. Key groundwater monitoring considerations include borehole sealing and use of bentonite or cement-bentonite to ensure isolation between monitored zones and overlying strata.

Surface completion includes:

A concrete surface pad sloped outward to divert surface water away from the wellhead and prevent surface contamination
Protective construction casing or monument extending at least 300 mm above ground level
A locking cap to prevent tampering or accidental damage
Surveying to establish coordinates and elevation relative to Australian Height Datum, with top-of-casing and ground surface levels recorded

Step 5: Well Development and Commissioning

Monitoring wells must be developed to stabilize the water column and ensure representative sampling. Development includes flushing to remove fine materials post-installation-drilling fluids, mud cake, and formation fines that would otherwise bias groundwater samples and provide inaccurate readings of parameters like dissolved oxygen, electrical conductivity, and total dissolved solids.

Surge and pumping methods are common techniques used for well development. Surge blocks, air-lift pumping, and mechanical tools are employed progressively until stabilisation criteria are met. The monitoring process tracks turbidity, electrical conductivity, pH, and temperature across consecutive pumped volumes. Development continues until parameters stabilize-typically targeting turbidity below 10 NTU with minimal variation between successive measurements.

Following development, initial groundwater sampling establishes baseline water quality. Groundwater quality parameters include pH, conductivity, and salinity, along with major ions, metals, and site-specific analytes. Collecting water samples at this stage provides the reference dataset against which all future monitoring groundwater quality results are compared.

Installation of monitoring instrumentation follows – piezometers, pressure transducers, water level sensors, and dataloggers depending on project objectives. Groundwater monitoring systems should utilize telemetry for data acquisition and reporting, enabling continuous data collection without manual intervention.

What Makes Professional Installation Different

Most monitoring well failures trace back to shortcuts during installation. Professional installation delivers measurably different outcomes:

Technology-agnostic approach – Rather than defaulting to standard specifications, materials and construction techniques are selected based on actual site conditions. Chemical compatibility, formation pressures, and monitoring objectives drive every decision.
Complete quality control from drilling through commissioning – Field supervision by qualified hydrogeologists verifies materials, slot sizes, filter pack gradation, seal integrity, and development completion at each stage. Routine maintenance prevents clogging and ensures data reliability from day one.
Integration with automated monitoring systems – Automated groundwater monitoring can reduce site visits and improve safety. Sensors measuring conductivity, temperature, total dissolved solids, and pressure are installed during well construction for seamless data collection. On the Mardie Salt and Potash Project, Monitel deployed CT2X sensors across a 50 km plain under mining operations, providing real-time continuous monitoring that overcame the lag time of manual sampling methods.
Detailed documentation and as-built records – Driller’s logs, construction logs, as-built drawings, survey data, and development records provide the audit trail that regulatory compliance demands. Monitoring wells must meet conditions set by regulatory approvals, and incomplete documentation is a common cause of compliance failure.

By contrast, typical installation shortcuts-using incorrect screen lengths, failing to seal the annulus completely, or cutting development short through insufficient flushing-produce wells that deliver misleading data. Inaccurate measurements of groundwater levels or water quality can misdirect resource management strategies, delay project approvals, and undermine remediation efforts.

Proof That Proper Installation Works

Accurate groundwater data impacts engineering decisions and project approvals. The difference between professional and substandard installation is visible in real-world project outcomes.

Monitel’s deployment of CT2X sensors across mining operations provided automated measurement of conductivity, temperature, total dissolved solids, and pressure, replacing manual sampling rounds and delivering continuous data streams. This approach demonstrated how proper well construction paired with automated instrumentation transforms groundwater management from periodic snapshots into real-time operational intelligence.

Environmental compliance is fundamental to groundwater monitoring systems in mining and infrastructure. Continuous monitoring supports compliance with WA legislation, and groundwater monitoring is essential for mining project approvals in WA. Across these projects, properly installed wells consistently deliver data that withstands regulatory scrutiny and supports operational decision-making.

Who Needs Monitoring Well Installation

Monitoring well installation serves anyone who needs to collect data on groundwater conditions with confidence:

Mining operations – Groundwater monitoring is required by WA environmental regulations for dewatering operations, environmental compliance monitoring, and protecting surrounding environment water resources from mining activities. Wells positioned to extract groundwater for dewatering must be complemented by monitoring bores tracking impacts on the broader aquifer system.
Infrastructure projects – Construction dewatering, groundwater impact assessments, and ongoing monitoring groundwater quality around tunnels, embankments, and foundations all require properly constructed monitoring bores providing critical data for design and safety.
Environmental consultants – Contaminated site investigations and remediation programs depend on collecting samples that accurately represent subsurface conditions. Wells designed to intercept contamination plumes and track potential contamination require materials with appropriate chemical resistance and sampling methods that prevent sample bias.
Industrial facilities – Ongoing groundwater quality monitoring around manufacturing sites, waste facilities, and storage areas ensures compliance with environmental regulations and provides early warning of impacts to groundwater resources.

Groundwater monitoring is essential for balancing water availability and ecosystems. If your project requires defensible groundwater data, proper monitoring well installation is the foundation.

Common Installation Methods and Applications

Shallow Wells – For Water Table Monitoring

Shallow monitoring wells typically target unconfined aquifers at depths from 5 to 30 metres. Hollow auger installation is the most common construction technique-hollow stem augers advance the borehole while keeping the formation open for casing placement. PVC casing systems with slotted screens are standard for these applications.

These wells suit construction dewatering monitoring, seasonal water table tracking, and early-warning detection of surface contamination reaching shallow groundwater. Well screens should be placed to capture variations across seasonal groundwater levels, which is particularly important in Perth’s Mediterranean climate where water table fluctuations can be significant.

Deep Wells – For Confined Aquifer Monitoring

Deep monitoring wells targeting confined aquifers at depths of 50 to 200+ metres require mud rotary or sonic drilling methods to maintain borehole stability and manage formation pressures. Stainless steel casing provides the structural integrity needed for high-pressure applications and long-term durability at depth.

Multi-level monitoring systems allow depth-discrete measurements within a single borehole, reducing surface footprint while providing data across multiple aquifer zones. These installations require precise sealing between intervals to prevent cross contamination and maintain hydraulic isolation. Adequate development at each screened interval ensures representative water flow and accurate data from every monitored zone.

Contamination Assessment Wells

Wells designed for contaminated site investigations require specialised materials and protocols. Casing and screen materials are selected for chemical resistance to site-specific contaminants-stainless steel or specialty polymers where PVC might leach or degrade. Dedicated sampling equipment prevents cross-contamination between wells.

Low-flow purging techniques and careful collecting water samples protocols ensure that groundwater samples are representative of formation conditions rather than stagnant casing water. Quality assurance procedures-field blanks, duplicates, and chain-of-custody documentation-produce data that withstands regulatory and legal scrutiny, supporting defensible remediation efforts.

Frequently Asked Questions

How long does monitoring well installation take?

A shallow monitoring bore (5–20 m depth) in favourable conditions can typically be drilled, cased, sealed, and developed within a single day. Deep or confined aquifer wells (100–200+ m) may require several days to a week depending on drilling methods, formation conditions, and development time. Factors affecting installation duration include rig mobilisation, site access logistics, permitting timelines, and the complexity of geological formations encountered. Regular inspections maintain structural integrity of monitoring wells over their operational life.

What permits are required for monitoring well installation?

In Western Australia, a 26D licence under the Rights in Water and Irrigation Act 1914 is required to construct or alter a well in proclaimed groundwater areas or where artesian conditions exist. Monitoring bores used solely for water level and quality observation-where you do not extract groundwater-are generally exempt from 5C water take licences in non-proclaimed areas. All construction must comply with the Minimum Construction Requirements for Water Bores in Australia and WQPN 30 guidelines. Groundwater monitoring serves to ensure compliance with environmental approvals and regulatory standards, and monitoring wells must meet conditions set by regulatory approvals including works approval conditions that may reference ASTM D5092.

How do you ensure data quality from new monitoring wells?

Development procedures continue until water quality parameters-turbidity, electrical conductivity, pH, dissolved oxygen-stabilise across consecutive pumped volumes. Monitoring wells should be cleaned regularly to ensure performance, and wellheads must be maintained to prevent contamination. Quality control includes verifying screen slot sizes against sieve analysis results, confirming filter pack gradation, testing seal integrity, and establishing baseline water quality through initial laboratory analysis. Proper monitoring confirms the well is providing representative groundwater samples before operational data collection begins.

Can monitoring wells be integrated with automated systems?

Yes. Telemetry installation during well construction allows real-time data acquisition from the moment commissioning is complete. Pressure transducers, water level sensors, and multi-parameter probes measuring electrical conductivity, temperature, and total dissolved solids can be installed within the casing during or immediately after construction. Automated groundwater monitoring can reduce site visits and improve safety, particularly on remote mining sites. Monitel’s telemetry systems record data continuously and transmit to cloud dashboards, enabling teams to collect data, identify trends, and respond to anomalies without physical site visits.

Get Started with Professional Monitoring Well Installation

Every monitoring well you install either strengthens or undermines the data your project depends on. Accurate groundwater data impacts engineering decisions and project approvals-there is no room for construction errors or design compromises.

Monitel delivers complete monitoring solutions from site assessment through commissioning and ongoing automated data collection. Whether your project requires shallow water table monitoring, deep confined aquifer assessment, or a network of monitoring bores across a mining tenement, we bring the hydrogeological expertise, drilling capability, and instrumentation technology to build wells that deliver reliable, defensible data for the life of your project.

Ready to discuss your groundwater monitoring requirements? Contact our team to start your project assessment and ensure your monitoring wells are built to perform from day one.

Groundwater Monitoring Well Installation Explained: Accurate Data Collection Without Installation Failures