Dust Suppression and Erosion Control for Mining, Quarrying and Construction in New Zealand
New Zealand is experiencing a minerals sector revival unlike anything in the past two decades. The coalition government has set a target of doubling mineral export revenue to NZ$3 billion by 2035. The Fast-track Approvals Act 2024 is compressing consent timelines from years to months. Of the 178 new mineral permits issued in 2025, 163 listed gold as the primary target — 91.6% of all permits granted that year. The Snowy River underground gold mine at Reefton is targeting production by the end of 2026, creating 250 local jobs. Santana Minerals’ Bendigo-Ophir project in Central Otago holds a 30-year mining permit for approximately 120,000 ounces per year.
At the same time, the construction pipeline is rising from its 2025 low, with total construction values forecast to reach $24.5 billion annually in Auckland alone by 2030 and the Waikato/Bay of Plenty region growing by 28.6% over the forecast period. Housing, transport infrastructure, water three-waters reform and renewable energy projects are driving activity across both islands.
Every one of these operations — gold mines, coal mines, aggregate quarries, building sites, road construction and infrastructure projects — generates dust and is subject to the same fundamental obligation under the Health and Safety at Work Act 2015 (HSWA): the PCBU must ensure, so far as is reasonably practicable, the health and safety of workers and others who may be affected by the work. Dust exposure is a health hazard. Sediment discharge is an environmental harm. Both must be controlled.
This guide covers the New Zealand regulatory framework for dust and erosion control, the environmental conditions that make Aotearoa’s dust and erosion challenges distinct from Australia’s, and the proven engineering solutions that are already deployed across Australian mining, quarrying and construction operations and are available for New Zealand projects today.
The New Zealand Regulatory Framework for Dust and Erosion Control
Health and Safety at Work Act 2015 (HSWA). The overarching workplace health and safety legislation. PCBUs must eliminate risks so far as reasonably practicable, and if elimination is not reasonably practicable, minimise risks so far as reasonably practicable. Dust exposure from mining, quarrying and construction is a risk to health that the PCBU must manage through the hierarchy of controls. WorkSafe New Zealand is the primary regulator.
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Health and Safety at Work (Mining Operations and Quarrying Operations) Regulations 2016 (MOQO Regulations). Amended in 2022, these regulations prescribe specific requirements for mining and quarrying operations including the appointment of a site senior executive (SSE), the development of a health and safety management system (HSMS), the identification and management of principal hazards (of which airborne dust is one), and competency requirements for safety-critical roles. The HSMS must be in place from the start of physical development including earthworks and construction of infrastructure.
WorkSafe Good Practice Guidelines. Updated in November 2025, the guidelines for health and safety at opencast mines, alluvial mines and quarries provide practical guidance on implementing the MOQO Regulations. They include specific requirements for dust monitoring, control measures and health surveillance. The guidelines are not prescriptive in specifying particular products or methods but require the PCBU to demonstrate that the controls implemented are effective.
MinEx Codes of Practice. MinEx, the health and safety council for New Zealand’s extractive industries, publishes codes of practice including the ‘Control of Dust and Associated Hazards in Surface Mines and Quarries’ guide. These codes are developed by industry and provide practical, sector-specific guidance that WorkSafe recognises as demonstrating good practice.
Workplace Exposure Standards. New Zealand’s WES for respirable crystalline silica is 0.05 mg/m³ (8-hour TWA) — the same as Australia’s current standard. WorkSafe NZ publishes a complete list of workplace exposure standards under the HSWA Hazardous Substances Regulations 2017. The WES applies to every workplace where workers are exposed to RCS, including mines, quarries, tunnels and construction sites.
Resource Management Act 1991 (RMA). Environmental effects of dust and sediment discharge are managed under the RMA through regional and district plan rules, resource consent conditions and the National Environmental Standards. Discharges to air and water — including dust emissions and sediment-laden stormwater — require consent or must comply with permitted activity rules. The Resource Management reforms and the Fast-track Approvals Act 2024 are changing consent processes but not the environmental performance standards that consented activities must meet.
New Zealand’s Mining and Quarrying Landscape: Where Dust Control Matters
New Zealand mining, quarrying and construction: sector overview
| Sector | Location | Key Activity | Dust and Erosion Challenge |
| Gold mining (hard rock) | West Coast (Reefton, Waihi), Central Otago (Bendigo-Ophir, Macraes) | Underground and open pit; drilling, blasting, crushing, hauling | High silica in host rock; community proximity (Waihi); high rainfall (West Coast 5,000+ mm/yr) |
| Coal mining | West Coast (Stockton, Spring Creek), Waikato (Huntly) | Open cast and underground; hauling, stockpiling, port loading | Coal dust; steep terrain; extreme rainfall; sediment to sensitive waterways; Lyttelton export |
| Aggregate quarrying | Nationwide (every region) | Drilling, blasting, crushing, screening, hauling, stockpiling | Community proximity; truck traffic on public roads; silica dust; limited water supply in some regions |
| Alluvial gold mining | West Coast, Otago | Excavation, screening, washing, tailings management | Sediment control in waterways; erosion of exposed surfaces; rehabilitation |
| Construction and infrastructure | Auckland, Wellington, Canterbury, Otago, Waikato/BOP | Earthworks, road construction, civil works, building | Urban proximity; silica in concrete and aggregate; council consent conditions; sediment discharge |
| Roading and transport | Nationwide (state highways, local roads) | Road maintenance, resurfacing, unsealed road management | Dust from unsealed roads; gravel loss; corrugation; community complaints; council maintenance budgets |
The common thread is that every sector generates dust and sediment, every sector is subject to HSWA and RMA obligations, and every sector operates in environmental conditions that are distinctly different from the Australian mining and construction context that most dust suppression products were originally developed for.
New Zealand’s Environmental Conditions: Why Aotearoa Is Different
Dust and erosion control products proven in the Pilbara or the Bowen Basin must perform in conditions that are fundamentally different in New Zealand.
Extreme rainfall on the West Coast. The West Coast of the South Island receives 2,500–5,000+ mm of rainfall per year, with some locations exceeding 7,000 mm. Coal and gold mining operations on the Coast must manage erosion and sediment control under rainfall intensities that exceed most Australian design standards. Road surfaces must survive prolonged saturation. Erosion control must prevent sediment from reaching the river systems that support native fish, whitebait and other sensitive aquatic species.
Earthquake-affected ground. Canterbury and wider South Island operations contend with ground conditions affected by the 2010–2011 earthquake sequence and ongoing seismic activity. Liquefaction-prone soils, lateral spreading and ground settlement affect road stability and erosion patterns. Soil stabilisation solutions must account for ground conditions that differ from the geologically stable substrates of most Australian mining regions.
Volcanic soils. The Taupo Volcanic Zone and surrounding regions contain pumice soils, ash deposits and other volcanic materials with unique engineering properties. These soils are lightweight, free-draining and highly erodible under both wind and water. Dust generated from volcanic soils has different particle characteristics from the clay-rich or ironstone materials common in Australian mining.
High wind environments. New Zealand’s exposure to Southern Ocean weather systems means that many mine and quarry sites experience sustained high winds that drive wind erosion on stockpiles, cleared surfaces and unsealed roads. Canterbury, Manawatu and coastal sites are particularly affected.
Proximity to sensitive waterways. New Zealand’s river systems, estuaries and coastal environments are among the most ecologically sensitive in the Australasian region. Sediment discharge from mining, quarrying and construction is regulated under the RMA with conditions that are typically stricter than Australian equivalents. The consent conditions for a West Coast coal mine or an Otago gold mine will prescribe sediment limits in receiving waterways that require engineering-level erosion control, not just silt fences and hay bales.
Proven Products for New Zealand Conditions
GRT’s product range is developed, manufactured and proven in Australia — deployed across hundreds of sites from the tropical Bowen Basin to the arid Pilbara to the temperate coal fields of NSW. The products are engineered to perform across a wide range of soil types, rainfall regimes and temperature conditions. For New Zealand operations, the product selection matches the same source-to-solution approach used in Australia, with consideration for the specific NZ conditions described above.
Haul Roads, Quarry Roads and Unsealed Access Roads
GRT: Haul-Loc polymer dust suppression reduces watering frequency by 80–90%, keeping roads dust-free with minimal water consumption. For New Zealand quarries where water supply may be limited or where consent conditions restrict water take from local waterways, the water reduction is a compliance benefit as much as a cost benefit. SMART Dosing Units ensure consistent dosing regardless of which operator fills the water cart.
GRT7000 soil stabilisation creates a waterproof, dust-free wearing course that is particularly valuable in New Zealand’s high-rainfall environments. On the West Coast, where conventional gravel roads can be saturated for weeks at a time, GRT7000’s waterproof matrix sheds rainfall rather than absorbing it, maintaining all-weather access to mine and quarry operations that cannot afford wet weather closures during the production season.
Erosion Control and Sediment Management
GRT: Enviro-Binder is the lead erosion control product for New Zealand conditions. Its ability to create a waterproof, erosion-resistant surface that survives high-intensity rainfall — verified by Landloch testing at 2, 10 and 50-year storm intensities with near-zero sediment — makes it directly applicable to the West Coast and other high-rainfall NZ environments where conventional erosion blankets and mulch are overwhelmed by rainfall intensity.
For New Zealand’s sensitive waterway environments, Enviro-Binder’s non-toxic, biodegradable formulation means it can be applied near rivers, streams and wetlands without risk of contamination. It supports seed germination and vegetation establishment, enabling native revegetation programmes that meet both RMA consent conditions and ecological restoration objectives.
GRT: CC (coagulant), GRT: Liquid-Floc (flocculant) and GRT: Floc Blocs provide sediment basin treatment that clarifies turbid water to compliant quality for discharge. In New Zealand’s high-rainfall environments where sediment basins fill rapidly, the ability to treat and discharge quickly is essential to maintaining basin capacity. Floc Blocs in drainage structures provide passive treatment without pumps or operator intervention — critical during prolonged West Coast rain events.
Crusher, Screen and Processing Dust
GRT: Activate and GRT: 12X are dosed into the water supply feeding crusher, screen and conveyor spray systems. The chemical activation overcomes the hydrophobic properties of silica-rich dust from New Zealand’s quartz-bearing gold ores, greywacke aggregates and volcanic materials. For underground operations like the Snowy River mine, GRT: Activate UG provides the same super-activated dust control that has been independently validated in Australian underground coal operations.
Stockpiles and Wind Erosion
GRT: Ore-Loc protects stockpile surfaces from wind erosion, retaining product value and preventing dust that would affect boundary air quality and neighbouring properties. GRT: Soil-Loc provides broadscale protection for cleared areas, waste dumps, topsoil stockpiles and inactive surfaces that generate dust between active operations.
Construction and Roading Applications in New Zealand
New Zealand’s construction industry faces the same dust and erosion challenges as Australia’s, amplified by the high-rainfall environments that characterise much of the country and the strict sediment discharge conditions that councils and regional authorities impose under the RMA.
Construction site roads and earthworks. GRT: Haul-Loc on water carts and GRT7000 for permanent site roads eliminate construction traffic dust. For housing developments, commercial construction and infrastructure projects in urban areas, the visible dust reduction addresses neighbour complaints and council compliance simultaneously.
Erosion and sediment control for earthworks. GRT: Enviro-Binder on exposed batters, cut faces and stockpiles provides the erosion protection that Auckland, Canterbury and Wellington councils require as conditions of earthworks consent. The product’s performance under high-intensity rainfall means it does not fail during the weather events that conventional controls are designed for but often cannot withstand.
Unsealed road networks. New Zealand has approximately 30,000 kilometres of unsealed roads managed by territorial authorities. These roads generate dust that affects rural communities, contaminate roadside properties, degrade pastoral land and require continuous maintenance. GRT7000 stabilisation and Haul-Loc suppression offer the same cost reductions documented in Australian council and gas field applications — 37% OPEX savings (Deloitte/SMEC analysis) — translatable to New Zealand district council budgets.
Working with GRT in New Zealand: Trans-Tasman Deployment
GRT is headquartered in Queensland, Australia, with products deployed globally across mining, construction, oil and gas, government and defence sectors. The company already services New Zealand clients, with GRT products available for delivery across both islands.
Product supply. GRT products are manufactured in Australia and shipped to New Zealand. Products are supplied as liquid concentrates in IBCs (intermediate bulk containers) or drums, diluted with locally available water on site. The concentrate form means the freight cost per kilometre of road treated or per hectare of erosion control is a small fraction of the total application cost.
Technical support. GRT’s engineering team provides remote and on-site technical support for New Zealand projects, including product selection, dosing design, application methodology and monitoring programme design. For complex or large-scale projects, GRT engineers can travel to New Zealand for on-site commissioning and training.
Regulatory alignment. GRT products are ISO 9001 quality-assured, non-toxic, biodegradable and safe for use near waterways, communities and sensitive environments. Product Safety Data Sheets comply with the Globally Harmonised System (GHS), which is the standard adopted in New Zealand under the HSWA Hazardous Substances Regulations 2017. The products satisfy the ‘reasonably practicable’ test for engineering controls under HSWA.
New Zealand’s Minerals and Construction Future Needs Dust Control That Works in New Zealand’s Conditions
The minerals sector revival, the construction pipeline recovery and the infrastructure investment programme are creating demand for dust suppression and erosion control across New Zealand at a scale not seen in decades. The regulatory framework — HSWA, the MOQO Regulations, WorkSafe guidelines and RMA consent conditions — requires engineering controls that are effective, verifiable and appropriate to the conditions.
New Zealand’s conditions are not the same as Australia’s. The rainfall is higher. The waterways are more sensitive. The soils are more varied. The communities are closer. The consent conditions are stricter. The dust and erosion control solutions deployed in New Zealand must be proven to perform under these conditions — not just in the arid environments where most products were originally developed.
GRT’s product range is proven across Australia’s most extreme environments and is available for New Zealand projects today. From polymer road suppression and soil stabilisation to erosion control, processing plant activation, sediment treatment and automated dosing — the complete toolkit for mining, quarrying and construction dust and erosion management is a phone call across the Tasman.
For New Zealand mine managers, quarry operators, construction managers and council engineers looking for dust and erosion solutions that are engineered for performance, not just compliance, contact GRT to discuss your specific project requirements.
Sources and References
NZ Government / Beehive: Large-Scale Mining on Track for 2026 — Snowy River gold mine, 250 jobs, NZ$3B exports target
NZ Petroleum and Minerals: Developing Our Minerals Sector — Minerals Strategy to 2040, Fast-track Approvals Act, Crown Minerals Amendment Act 2025
Discovery Alert: Investing in New Zealand Gold Mining: 2026 Opportunities — 178 new permits (91.6% gold), Bendigo-Ophir 120,000 oz/yr
NZ Minerals Council / Mining Outlook: Spotlight: CEO Josie Vidal — Fast-track process, gold, coal, mineral sands, seabed mining
MBIE: National Construction Pipeline Report 2025 — Auckland $24.5B by 2030, Waikato/BOP +28.6%
WorkSafe NZ: Health and Safety at Opencast Mines, Alluvial Mines and Quarries — Good Practice Guidelines (updated November 2025)
WorkSafe NZ: Mining Operations and Quarrying Operations — Safe Work Instruments, competency requirements
WorkSafe NZ: Silica Dust in the Workplace — quick guide, WES 0.05 mg/m³
MinEx: Documents and Guidelines — Control of Dust and Associated Hazards, codes of practice
NZ Legislation: Health and Safety at Work Act 2015
NZ Legislation: MOQO Regulations 2016
GRT: GRT: Haul-Loc
GRT: GRT7000
GRT: GRT: Enviro-Binder
GRT: Dust Suppression Solutions
GRT: Sediment Control Solutions
GRT: SMART Dosing Units
