air sensors

May 17, 2017

Oil and gas processing facilities, federal and local governments, landfills, land developers, contractors, industries with industrial hygiene plans can spend too much money for too little information if they don’t have an understanding of the limits and capabilities of their equipment and methods before the development of their Air Monitoring Plan (AMP) . That’s before considering the risk to their employees and to public health.

Even if you can’t afford a dedicated air monitoring group, you can eliminate the health risks, overwriting a plan, or overburdening your budget. A cost-benefit analysis and integrating stakeholders’ goals can help provide the guidance you need to develop a balanced air monitoring plan.

Start with this list of considerations when developing an Air Monitoring Plan (AMP). The list is followed by tips and suggestions which are helpful under specific circumstances.

The development of an AMP requires the following:

• Understanding the monitoring objective(s).
  • Compliance Monitoring for Specific Compound(s)
  • Employee Health and Safety
  • Prevention of Significant Deterioration (PSD) Monitoring
  • Fence-line Job Site Monitoring
  • Active Dust Control
  • Source Related or Regional Monitoring
  • Determination of highest concentrations expected to occur

• Identifying the spatial scale most appropriate for the monitoring objective(s).
  • Sampling Site Density
  • Upwind and Downwind Monitoring
  • Background Monitoring

• Determination of the required temporal scale of the monitoring objectives:
  • Time-averaged Sampling and/or Real Time Monitoring
  • Desired Averaging Periods
  • Grab Samples

• Determination of most appropriate monitoring equipment to be utilized.
  • Desired Detection Limits
  • Data Logging Required
  • Site Access Limitations
  • Power Availability
  • Real-Time Alarms if Needed
  • Meteorological Parameters

The information required for selecting the number of samples (5) and the sample locations include isopleth maps, population density maps, and source locations. The following are suggested guidelines:

• The priority area is the zone of highest pollution concentration expected to occur in the area covered by the network; one or more stations should be located in this area;
• Close attention should be given to densely populated areas within the region, especially when they are in the vicinity of heavy pollution;
• The quality of air entering the region should be assessed by stations situated on the periphery of the region; meteorological factors (e.g., frequencies of wind directions) are of primary importance in locating these stations;
• Sampling should be undertaken in areas of projected growth to determine the effects of future development on the environment;
• A major objective of compliance monitoring is the evaluation of progress made in attaining the desired air quality; for this purpose, sampling stations should be strategically situated to facilitate evaluation of the implemented control strategies; and
• Some information of air quality should be available to represent all portions of the region of concern.

The primary monitoring objectives should be determined before any data is collected.

Location of the monitoring site is initially dependent on the monitoring objective. For example, once it is known that there is a requirement to monitor for peak ambient H2S at a microscale site, it reduces the monitoring site location to specific areas. Hence, the first task when evaluating a possible site location is to determine the scale for which a candidate location can qualify by considering the following:

1. Location and emissions strengths of nearby sources, especially major source;
2. Prevailing wind direction in the area;
3. Nearby uniformity of land use;
4. Nearby population density.

To select locations according to these criteria, it is necessary to have detailed information on the location of emission sources, the geographical variability of ambient pollutant concentrations, meteorological conditions, and population density. Therefore, selection of the number, locations, and types of sampling stations is a complex process. The variability of sources and their intensities of emissions, terrains, meteorological conditions and demographic features require that each network is developed individually. Thus, selection of the network will be based on the best available evidence and on the experience of the decision team.

Developing an Air Monitoring Plan (AMP) can be a daunting task. There are many decisions to make that have downwind ramifications relative to budget, logistical constraints, and labor requirements. In addition, there may be competing goals in regards to the project stakeholders. SCS has the experience developing and implementing air monitoring plans and systems to meet these challenges; including developing site specific and network-wide AMPs for various monitoring objectives. SCS also understands the costs and demands of the implementation of AMPs on industry and government.

Performing a cost-benefit analysis is a crucial step in the AMP development in order to assure that the required data is attainable within the budget constraints.

If you need to perform Air Monitoring or are in the initial steps of developing an AMP please contact for expert advice and guidance specific to your region and industry. We have robust programs and experts nationwide. We can also incorporate the use of remote monitoring controls and monitoring by our FCC authorized drones.

Author: Paul Schafer, SCS’ National Expert Ambient Air Monitoring