Air quality monitoring for industrial sites

Fenceline monitoring — also referred to as perimeter or site-boundary air monitoring — measures ambient pollutant concentrations at or around the boundary of an industrial facility. It is used to identify spatial and temporal variations in air quality, detect pollutant plumes and support the investigation of fugitive or diffuse emissions that may move beyond the operating area.

Unlike stack emissions monitoring or occupational exposure monitoring, fenceline monitoring observes ambient conditions around the site and can be implemented using a network of fixed monitoring points.

Aernode monitoring stations can be configured for continuous multi-pollutant measurements across industrial perimeter and near-source monitoring applications.

Continuous perimeter air monitoring can support industrial facilities where process operations, material handling, combustion or equipment leaks may create variable emissions that are difficult to characterise through periodic measurements alone.

Typical applications include petroleum refineries and oil & gas facilities, petrochemical and chemical manufacturing plants, bulk storage and tank areas, coke and steel production, metal-processing facilities, cement and mineral-processing sites, and other manufacturing plants handling dust, solvents, VOCs or process gases.

The monitoring strategy should always be adapted to the site's actual emission sources, operating processes, surrounding receptors and environmental objectives rather than applying the same configuration to every industrial facility.

There is no standard pollutant package for every industrial site. The appropriate parameters depend on the processes, materials, potential emission sources and expected concentration ranges at the facility.

Common monitoring targets include particulate matter PM₁₀ and PM₂.₅, VOCs, NO₂ and other nitrogen oxides, SO₂, CO, H₂S and NH₃, while specific industrial processes may require additional gases or more targeted sensing technologies.

Aernode uses a modular sensing architecture that allows different pollutant combinations to be configured for each project. Aernode Sensor Kits combine the Core Sensor Board with configurable gas-sensing options, allowing the monitoring network to be matched to the actual industrial application rather than using a fixed sensor package.

There is no fixed number of monitoring stations for an industrial site. Network size depends on the monitoring objectives, site geometry, potential emission sources, prevailing meteorological conditions, surrounding receptors and the level of spatial coverage required.

A simple project may focus on a limited number of representative locations, while complex facilities can require multiple monitoring points distributed around the perimeter and near selected operational areas.

The objective is to create a network capable of distinguishing background conditions from site-related variations and capturing relevant pollutant plumes or events.

Monitoring locations should be selected from the monitoring objective rather than by placing stations at equal distances around the site. Relevant factors include potential emission sources, prevailing and variable wind directions, site geometry, property boundaries, nearby sensitive receptors, operational areas and suitable background or upwind locations.

Combining pollutant measurements with wind speed and direction can make it easier to interpret short-term concentration changes and assess whether observed events are consistent with emissions originating from specific areas of the site.

For complex facilities, network design should therefore be treated as part of the environmental monitoring project rather than as a fixed hardware layout.

No. Continuous perimeter air quality monitoring generally complements rather than replaces regulatory stack emissions measurements, reference monitoring or other sampling required by an environmental permit.

Its value is different: continuous ambient monitoring provides higher temporal resolution and additional spatial information around the site, helping operators identify changing conditions, investigate short-duration events and determine when further investigation or targeted measurements may be appropriate.

Aernode is intended for indicative and supplementary monitoring applications and should be integrated into the wider monitoring strategy according to the regulatory and operational requirements of the project.

Continuous monitoring creates a time-resolved record that can help operators identify when pollutant concentrations change and compare those events with meteorological conditions, site operations and measurements from other points in the monitoring network.

This can support the investigation of fugitive emissions, intermittent releases, dust events, odour-related episodes and unexpected changes in site-boundary air quality.

Measurements do not by themselves prove the origin of an emission, but spatial differences, timing and wind information can provide useful evidence for deciding where additional investigation or corrective action should be focused.

Monitoring data can be managed centrally through Aernode Cloud and extended with Reporting Tools for historical analysis, event review, alerts and project-specific reporting workflows.