|2010 March 1: Particulate Pollution: Planning for Fence-Line Monitoring
by John Carney
March 1, 2010
The discovery of air pollution problems in the neighborhood invariably leads to blame games. Proper preparation will save money and headaches.
Whenever there is a perceived issue related to either the air quality of a neighborhood or a concern of property damage due to air quality, the first suspects are the industrial facility with the large stack(s) and/or the cement plant down the road. Despite the fact that all the circumstantial evidence might rule out that facility as the culprit, inevitably a call comes in and the facility has to quickly develop and implement a fence-line monitoring plan.
These plans often need to be implemented on incredibly short timescales and in the midst of intense pressure from all directions. Such a scenario can lead to hastily developed plans, which when implemented may not obtain the necessary information to resolve the issues. Poorly designed fence-line plans can ultimately lead to additional long-term monitoring and reporting at a facility where none may have been necessary, because the initial data collected was inadequate.
The important questions
No facility wants or expects to do fence-line monitoring, therefore, they seldom plan for it. Here are some simple questions to consider when developing a framework for such monitoring:
• What is the emissions inventory for the facility? This goes to the heart of the type of fence-line monitoring most facilities will have to do. For those facilities with a continuous emission monitoring system (CEMS) installed, those compounds being monitored in the CEMS will probably be the first candidates requiring monitoring. Criteria pollutant monitoring will likely be necessary, using a complete ambient air monitoring station. For those with dust or particulate emissions, it may be simple particulate sampling or monitoring that will be required. Each type of monitoring has significant different requirements in siting, operation and maintenance
• Who are the neighbors? This will determine the number of potential monitoring locations along the facility’s perimeter. If there is a residential neighborhood along just one side of the property, then the focus of any monitoring will most likely be along that perimeter. On the other hand, if bordered by a residential area, but also surrounded by other industrial facilities with potential emissions, additional monitoring sites along those perimeters might be prudent so one facility is not blamed for another’s emissions.
• What is the geography of potential sites? This question goes to where would be the best places to locate the monitoring sites. When dealing with ambient-air monitoring requirements at the fence line, stations should be placed in accordance with best engineering practices. This especially includes paying attention to locations of obstructions such as trees, buildings or other structures, which could impact the quality of the data. In this case, facilities are strongly recommended to follow EPA guidance outlined in the agency’s Quality Assurance Handbook for Air Pollution Measurement Systems, which was put together specifically for locating ambient air monitoring stations where practicable. Keep in mind that it is quite possible that the issue driving the fence-line monitoring may end up in litigation, therefore data collected as part of the monitoring plan will have to be scientifically defensible.
• Where are the closest utilities? Another consideration is the location of utilities and general access to a site. In some cases a facility’s layout may be such that is it impossible to provide grid power to a site, and therefore use of battery or solar powered operated samplers or monitoring equipment may be required. Accessibility also is a major consideration; as in the case of particulate sampling, these sites may need to be visited on a daily basis, and therefore vehicle access may be required.
Asking these questions can help form the foundation for any fence-line monitoring plan, and tackle about 50 percent of the upfront work required to get a plan implemented.
Time and cost-saving measures
There are additional items to consider when developing a fence-line plan, in order to make monitoring easier and reduce operational costs.
1. Bigger systems are not necessarily better – Often, the facility will be required to monitor or sample for only one or two parameters, say ozone or particulate. A system like this does not necessarily require a complete walk-in shelter to house the equipment. One or two instruments and supporting equipment should only require small climate-controlled equipment cabinets to house the instrumentation.
For example, a recent fence-line monitoring project involved installation of a system with a particulate monitor, criteria pollutant analyzer, calibration system and data logging system. One of the major challenges of the project was that the particulate monitor was required to be placed at a different location than the gas analyzer – well over a mile from one another. In order to save costs, a radio modem system was implemented to transmit the particulate monitoring data to the data logger at the gas analyzer site. This meant that only a single data logger and cellular modem was required for the entire system.
Additionally, since the particulate monitor and gas analyzer were in two locations, climate-controlled equipment cabinets were utilized instead of a full walk-in shelter for the gas analyzer system. The result was an upfront cost savings on shelters; with a total of $14,000 for two separate climate-controlled equipment cabinets (whereas a single 8- by 8-foot walk-in shelter would have started at $25,000). It is fully expected that there will also be a long-term cost savings realized as these cabinets require smaller HVAC systems to maintain operational temperatures.
2. Automate, automate, automate – Even if a facility utilizes a consultant to manage its fence-line monitoring program, facility managers will likely be called on to assist in day-to-day operations of the system. Data acquisition technology exists to automate much of the required oversight in a monitoring system, as well as the ability to remotely view the operational status of the system. The less time required to keep the systems operating, the more time to attend to other tasks.
Automation can greatly reduce operational monitoring costs as well as reducing data loss due to equipment problems. It is possible on a daily basis to get a complete snapshot of the operational status of the system in as little as 15 minutes each morning, while enjoying a cup of coffee, through generation of automated e-mail status reports of the previous night’s calibrations or the previous day’s data. Employing this sort of automation results in less time required to visit the site and check operational status. These daily snapshots also will help site operators pinpoint potential problems with instrumentation before any significant data loss results.
In the project mentioned above, an additional requirement was to use particulate monitoring data to alert station operators when particulate concentrations were approaching a certain threshold, so that dust control methods could be implemented at the site if needed. In order to meet this requirement, a data logging system was set up to generate automated e-mails to station operators and project managers.
3. Where feasible, integrate meteorological data into the monitoring system – Industrial facilities often have meteorological equipment on-site, as it is often required as part of health and safety monitoring. In many instances this data is kept separate from a fence-line monitoring program and must be manually brought in to any data set, which is not as simple a task as it seems.
This does not have to be the case, as it is possible now to integrate the meteorological data into the monitoring database directly through the use of dedicated data loggers. The loggers often can communicate with the remote software acquisition programs, or simple radio modem systems to transmit the meteorological data to the monitoring station data loggers. The upfront cost to accomplish this task is minimal compared to the time required to manually import meteorological data into the air monitoring database.
4. Consider vector sampling for particulate samplers – While there may be a requirement for regularly scheduled sampling of particulate for fence-line monitoring, it may be possible to implement vector sampling methods for capturing particulate samples. This can be accomplished through the use of high- or low-volume smart samplers, i.e. those samplers able to integrate real-time meteorological data to use as a trigger for sampling when the wind is from a particular direction and above a certain speed threshold. This feature enables the sampler to only operate when conditions place the monitoring site downwind of the facility’s emission source.
The development of a general framework for fence-line monitoring can go a long way toward getting a plan quickly implemented, with less stress and potentially large cost-savings. By following the steps outlined above, the alert facility will be ready to implement a monitoring plan before the finger-pointing wheel starts. PE
For more information on fence-line monitoring systems contact John Carney, environmental instrumentation specialist at American Ecotech at (877) 247-0403 or e-mail firstname.lastname@example.org.