Dust deposition gauges and real-time monitors, they’re the two most common dust monitoring methods on WA construction and mining sites. But they answer very different questions.
Dust deposition gauges measure how much dust settles on surrounding land over a month. Real-time monitors measure how much particulate is in the air right now. The right choice depends on your site, your neighbours and how quickly you have to act on a problem.
What a dust deposition gauge measures
A dust deposition gauge (DDG) is a passive sampler: a collection bottle and funnel on a stand, open to the air. Dust collected over about 30 days goes to a laboratory to be weighed, with results reported as g/m²/month or mg/m²/day, usually split into insoluble and soluble fractions.
With no power or moving parts, DDGs are cheap to run and suit networks of several locations around a boundary. They show the cumulative nuisance effect on the community, such as dust on cars, roofs, washing and water tanks. They can’t show when dust left the site, which activity was the source or how high concentrations peaked on a windy afternoon.
What a real-time dust monitor measures
A real-time dust monitor draws air through a size-selective inlet and measures suspended particles continuously, usually as PM10 or PM2.5 in µg/m³. Readings are averaged over minutes and sent by telemetry, so you see a spike as it happens and can act before it becomes a complaint or an safety concern.
There are three main types:
- Beta attenuation monitors (BAMs): collect particles on a filter tape and measure their mass by how much beta radiation they absorb.
- Tapered element oscillating microbalances (TEOMs): weigh particles on a filter mounted on a vibrating element.
- Optical (light-scattering) sensors: estimate concentration from light scattered by particles. This equipment is cheaper and portable but indicative, so it suits trigger alerts and site management rather than compliance against a standard method.
We usually pair real-time monitors with a weather station so each reading can be matched to wind speed and direction, which shows if the source is your works or a neighbouring activity.
DDGs and real-time monitors side-by-side
| Feature | Dust deposition gauge | Real-time dust monitor |
|---|---|---|
| What it measures | Dust that settles on surfaces | Dust suspended in the air (PM10, PM2.5) |
| Units | g/m²/month or mg/m²/day | µg/m³ |
| Result timing | Monthly, after lab analysis | Continuous, viewable live |
| Typical use | Nuisance impacts, baselines, trends | Trigger alerts, activity control, compliance with air quality criteria |
| Power and telemetry | None needed | Solar or mains power, modem |
| Cost | Low per location | Higher, especially BAM or TEOM |
| Shows the cause of a spike | No | Yes, with weather data |
| Standard method | AS/NZS 3580.10.1 | AS/NZS 3580.9.11 (BAM), AS/NZS 3580.9.8 (TEOM) |
What WA regulators call for
WA has no state-wide limit for deposited dust. Requirements are specific to your site’s approval, licence or management plan:
- DWER dust guideline: the state’s guideline for land development, remediation and similar sites ranks sites from Class 1 to 4. Medium and high-risk sites (Class 3 and 4) need on-site monitoring against short-term triggers and off-site monitoring at the boundary or nearest receptors.
- Licences and Ministerial Statements: prescribed premises and major projects often have conditions naming the parameter, the method and the standard, such as PM10 by BAM to AS/NZS 3580.9.11, or deposition to AS/NZS 3580.10.1.
- Councils: local governments set dust conditions on development approvals and investigate complaints. Gauges are a common way to answer ongoing nuisance complaints.
For deposited dust, many Australian assessments use NSW guidance as a benchmark: 4 g/m²/month in total as an annual average, and no more than 2 g/m²/month above background. Our team will work with your site and project managers to see what your approval specifies.
Which does your site need?
Use deposition gauges when:
- Your approval or licence asks for deposited dust.
- You want a low-cost baseline before works start, or trend data over months and years.
- Neighbours complain about dust settling on property rather than visible plumes.
Use real-time monitors when:
- Your site is Class 3 or 4 under the DWER guideline, or your conditions set PM10 or PM2.5 criteria.
- Sensitive receptors are close, and alerts must stop or change work before dust leaves the site.
- You have to show which activity caused a spike, or prove the dust came from elsewhere.
Many sites use both: real-time monitors at the boundaries facing the nearest neighbours, and gauges further out to record the overall picture.
Speak with a dust and air monitoring expert at ENVSS
We fabricate rust-proof dust deposition gauges at our WA facility, install them to AS/NZS 3580.10.1 and send samples to NATA-accredited laboratories.
Our real-time stations use BAMs and TEOMs, run on solar power and send SMS and email alerts when trigger levels are reached, with data on our remote portal. All dust monitoring programs combine the technology necessary to match your site’s approval and monitoring needs.