Dust suppression

Understanding dust on unsealed roads

Unsealed roads rely on natural moisture to bind surface particles and maintain road integrity. During hot, dry periods, this moisture evaporates, leading to increased dust generation. This can affect road conditions and local amenity for residents.

The materials used in the construction and maintenance of unsealed roads are typically derived from natural rock, often granitic in origin. As with most natural soils and rock, these materials can contain silica, which is a common and naturally occurring mineral found in the environment.

Environmental monitoring undertaken in comparable areas has not identified dust levels exceeding relevant regulatory thresholds. Based on current evidence, there is no indication of a risk requiring action under applicable legislation.

Dust suppression on unsealed roads

Unsealed roads are an integral part of the rural landscape and contribute to the character of non-urban areas. Dust generation is an inherent environmental factor, particularly during dry conditions and with vehicle movement.

The Shire undertakes a targeted annual dust suppression program to improve amenity and manage road conditions in selected locations. It is important to note that there is no legislated requirement for Council to undertake dust suppression on unsealed roads, including in relation to naturally occurring components such as silica. Dust suppression is therefore provided as a discretionary service rather than a regulatory obligation.

Selection criteria for annual program

Roads are selected for treatment based on a range of factors, including:

• Traffic volume
• Proximity to community facilities (e.g. recreation reserves, schools)
• Road classification (e.g. higher priority access roads)
• Environmental considerations

The Infrastructure Services team is not currently assessing additional roads for inclusion in the Shire-funded dust suppression program due to current funding constraints and pending updated traffic data for the unsealed road network.

Treatment process

Dust suppression is applied using a hygroscopic solution that attracts and retains moisture from the air.

The process involves:

• Cut open the roads surface
• Grading the road surface
• Applying the solution via tanker

The treatment binds fine particles together, increasing their weight and reducing their ability to become airborne due to wind or traffic. It also helps stabilise the surface by locking finer materials with coarser aggregates.

Effectiveness and duration

Dust suppressant treatments are typically effective for 3–6 months, depending on weather conditions, traffic volumes, and site-specific factors.

While treatments can significantly reduce dust, they do not eliminate it entirely and do not provide a permanent solution.

Resident-funded dust suppression options

For roads not included in the annual Shire funded program, residents may apply for privately funded dust suppression through the Shire’s contractor.

This allows property owners to:

• Treat the section of road adjacent to their property, or
• Work collaboratively with neighbours to treat longer sections of road

These arrangements are optional and provided as a service to the community.

Application process

Residents interested in participating can submit an application through the online portal during the annual application period.

For more information, please contact:

dustsuppression@mornpen.vic.gov.au

Additional notes and recommendations 

• Dust suppression is applied to the road carriageway only. Dust may still occur from vehicle movement on road shoulders.
• Passing vehicles can generate dust, though this is less frequent on lower traffic roads.
• Larger treatment areas generally achieve better results. Treatments under 30–40 metres may be less effective.
• Resident contributions are charged at cost, with no additional margin applied by the Shire. 

By implementing targeted treatments and offering optional participation, the Shire aims to manage dust impacts while recognising that unsealed roads, and the naturally occurring materials they are formed from, are a standard feature of the local environment.

Unsealed Road grading program

Supporting safe access while maintaining rural character

Unsealed roads are a defining feature of many non-urban areas, contributing to the rural character and landscape. These roads are designed to provide functional access while retaining the natural environment, rather than the sealed, urban standard seen in built-up areas.

As a result, conditions such as loose surfaces, dust, potholes, and corrugations can occur—particularly during dry periods or following heavy rainfall. These characteristics are expected as part of using unsealed roads.

Why we grade unsealed roads

Grading is undertaken to maintain the safe and functional use of unsealed roads.

Grading works typically include:

• Smoothing out corrugations and uneven surfaces
• Filling potholes and reshaping the road profile
• Restoring drainage to allow water to run off effectively
• Reworking existing surface materials

Where required, additional gravel or crushed rock may be added to help maintain the road structure and improve longevity.

The materials used are derived from natural sources and may include granitic rock containing naturally occurring minerals such as silica, which is commonly found in soils and road-making materials.

How grading is scheduled

Unsealed roads are not graded on a fixed routine across all locations. Instead, grading is delivered through a combination of:

• Programmed inspections, and
• Intervention-based maintenance, delivered under contract

Roads are inspected periodically, and grading is undertaken when conditions reach defined intervention levels—for example, when corrugations, potholes, or surface deterioration impact safety or drivability.

Timing of inspections and grading can vary depending on:

• Weather conditions (e.g. rainfall or extended dry periods)
• Traffic volumes
• Availability of resources

Use the search tool below or zoom into the map to view the anticipated inspection periods (and grading, if required) for specific roads. Please note that timeframes are indicative and may change.

Reporting a problem

If you have concerns about the condition of an unsealed road, you can request an inspection at any time.

Requests can be submitted through standard customer service channels, including:

• Online service request forms
• Customer contact centre

Each request is logged and assessed, and where intervention levels are met, works may be scheduled in line with operational priorities.

Managing expectations

While grading improves road conditions, it does not provide a permanent solution. The effectiveness and duration of grading works depend on environmental factors such as weather and traffic.

As unsealed roads are part of a natural and evolving environment:

• Dust, loose material, and surface variation will continue to occur
• Recently graded roads may change quickly, particularly in dry or wet conditions
• Some variability in driving conditions is expected
  
  

Working with the environment

Unsealed roads are constructed using locally sourced, natural materials. These materials are selected for durability and performance, but like most natural soils and rock, they may contain components such as silica.

These materials are standard for road construction and maintenance, and their use reflects common practice across rural and regional road networks.

Note-Shire generally does not automatically upgrade or seal unsealed roads, and sealing is considered separately based on criteria such as traffic volumes, funding, and community benefit. (This is typically assessed through specific proposals or funding schemes rather than routine maintenance.)

By maintaining unsealed roads through targeted grading and responsive maintenance, we aim to provide safe access while preserving the valued rural character of the area.