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Who Needs Real-time Onsite Meteorological Data? You Do, and Here’s Why

Posted: July 30th, 2019

Author: All4 Staff 

Does your facility receive odor or fugitive dust complaints from the neighboring community? Do you rely on a nearby airport for fenceline monitoring obligations, rain data, or wind data? What happens if that nearby station goes out of service?


No, I am not referring to Roger Daltrey and Pete Townshend, and the English rock band. I am talking about WHO can benefit from having onsite meteorological data. Since the 1980s, the collection of on-site meteorological monitoring data has supported industrial facilities with addressing:

  • Odor complaints
  • Fugitive dust emissions
  • Accidental emissions releases
  • Triangulating onsite or offsite fugitive emissions sources
  • Health and safety (e.g., snow removal and lightning)
  • Air quality modeling
  • Ambient pollutant monitoring programs
  • Automated stormwater event monitoring

The U.S. Environmental Protection Agency (U.S. EPA) states, “Organizations must ensure that data collected for the characterization of environmental processes and conditions are of the appropriate type and quality for their intended use and which environmental technologies are designed, constructed, and operated according to defined expectations.” Onsite meteorological towers may be advantageous to support certain facility operations by providing data representative of the local microclimate and weather patterns associated with your facility. This ensures that the data a facility uses meets U.S. EPA guidance for the processes and conditions at each facility.

Many industrial facilities can benefit from collecting onsite meteorological data, and ALL4 has experience with several facilities that have realized these benefits. Readily available and site-specific meteorological data can provide benefits relative to regulatory and non-regulatory issues for your facility. Three examples of non-regulatory meteorological monitoring are provided below:

Case Study #1:

A waste-to-energy facility near a major metropolitan area installed a 10 meter (m) meteorological tower to monitor for 1-minute averages of wind speed, wind direction, temperature, and relative humidity. The purpose of the meteorological tower was to dispute community complaints of odor that was assumed to be from the municipal solid waste while using accurate local wind data to determine the true source. By using the 1-minute average wind speed and wind direction, wind roses were developed indicating that the odors were originating from a meat packing facility just a few blocks away from the waste facility. An initial equipment investment of less than $15,000 saved the facility approximately $50,000 in fines and relieved public pressure.

Case Study #2:

An army depot installed an elaborate meteorological monitoring and lightning detection system for the safety of their employees and onsite childcare facility. The proactive monitoring system consisted of an electric field meter sensor for atmospheric electric charge, a strike guard lightning sensor which indicated lightning strikes from up to 20 miles away, and two remote strobe and siren alarms to provide visual and audible signals of alarm or status conditions. When atmospheric conditions are critical, or a lightning strike is detected less than 10 miles from the depot, the remote strobe light changes to red and the system sounds the siren. These alarms provide enough warning for employees and other personnel to seek shelter before dangerous weather arrives.

Case Study #3:

A refinery installed a meteorological monitoring system with wind speed and direction, temperature, relative humidity, and precipitation which was wired into their programmable logic controller (PLC) for their distributed control systems (DCS). Meteorological data was used for monitoring emissions releases at the petrochemical processing stacks and flares. The refinery was located within three miles of a major airport; however, the airport data only updated once per hour and the facility was able to use their monitoring data for real-time 1-minute data. A programmable datalogger provided minute-by-minute data for more accurate measurement resolution


While it’s nice to be able to use meteorological data for the reasons above, most facilities will not invest in a meteorological monitoring station unless they are required to. Reasons for a required meteorological monitoring station include:

  • Consent decree (e.g., state or Federal obligation following noncompliance)
  • Regulatory driver (e.g., 40 CFR Part 63, Subpart CC – National Emission Standards for Hazardous Air Pollutants from Petroleum Refineries, Site Specific Monitoring Plans)
  • An upcoming prevention of significant deterioration (PSD) air permitting project that will require modeling with no qualifying local meteorological data available
  • Operation of an ambient pollutant monitoring network

Examples of regulatory-driven meteorological monitoring are provided below:

Case Study #4:

Based on the sulfur dioxide (SO2) national ambient air quality standard (NAAQS) attainment status of the surrounding area, ALL4 worked with the client, the Pennsylvania Department of Environmental Protection (PADEP) and U.S. EPA to strategically design and site the ground-up installation of a new meteorological monitoring system consisting of an instrumented (three level) 58-meter tower and a separate Doppler Sound Detection And Ranging (SoDAR) vertical wind profiling system for upper atmospheric conditions. This installation was challenging because of the intricate and tight facility footprint, set in complex terrain. Air dispersion models used the onsite meteorological and upper atmosphere data. Results of the dispersion models were used for determining permit conditions.

Case Study #5:

A petroleum refinery (Refinery) commenced operation of an on-site meteorological monitoring system in December 2016 to support the Refinery Maximum Available Control Technology (MACT; 40 CFR Part 63, Subpart CC and Subpart UUU) benzene fenceline monitoring (BFM) requirements which began January 1, 2018. The Refinery has elected to use an on-site meteorological monitoring system for the BFM reporting requirements instead of the local National Weather Service (NWS) data. The meteorological monitoring program consists of a 10-meter tower equipped with meteorological sensors and data recording equipment. On a semiannual basis, a quality assurance performance audit and a system audit are performed on the meteorological monitoring equipment. The system and performance audits are conducted in accordance with the requirements outlined by U.S. EPA which are incorporated by reference in the Refinery MACT (40 CFR Part §63.14). As part of the audit process, U.S. EPA-recommended practices and equipment certified to National Institute of Standards and Technology (NIST) standards are used.

Case Study #6:

A mining facility has been continuously monitoring hourly concentrations of particulate matter less than 10 microns (PM10) since 1999. The ambient and meteorological monitoring was part of a settlement agreement in a consent decree. The monitoring program includes three federal reference method PM10 monitors and one 10-meter meteorological tower. Onsite personnel were notified when PM10 concentrations exceeded the 24-hour NAAQS of 150 micrograms per cubic meter (µm/m3). Quarterly reports were included to provide:

  • Summary of the sampling events.
  • Monthly summaries of hourly meteorological and PM10 data for all measured parameters.
  • Wind Roses for the quarter months.
  • Summary of the Year to Date (YTD) recoveries for PM10 Sites.


If your facility elects or is required to install a meteorological monitoring station, the accuracy, precision and resolution requirements of U.S. EPA for selecting the type of meteorological instrumentation is critical to the collection of measurement quality objectives. Approved instrumentation needs to have minimal error between real and measured values and demands the smallest resolution of magnitude from the measured value. For example, data quality objectives exist for wind, ambient temperature, relative humidity, barometric pressure, precipitation, and solar radiation depending on the purpose of the data collection. A few meteorological measurements and associated uses for each are listed below.

  • Wind Measurements – 1-minute data profile of wind speed and direction create detailed wind roses which provide insight into the transport of emissions in the atmosphere. Triangulation of the wind measurements, in conjunction with ambient pollutant data, can also verify findings when researching an unknown source of fugitive emissions.
  • Ambient Temperature – Measured at a height of 2 m and/or 10 m (for delta temperature) with a thermistor. Temperature is used to determine the amount of rise experienced by a buoyant plume in an air quality dispersion modeling evaluation.
  • Relative Humidity – Humidity is an important variable in determining impacts from moist sources, such as cooling towers; it is also used in modeling ozone chemistry.
  • Barometric Pressure – Atmospheric pressure provides meteorologists with information that is useful in evaluating data trends at the monitoring facility and is also used in conjunction with air quality measurements.
  • Precipitation – Rainfall is measured real-time in increments of 0.01 inches (in.). Data can be logged with hourly, daily, and monthly precipitation amounts. Instantaneous alerts can be triggered when stormwater event amounts have been achieved.
  • Solar Radiation – Solar radiation, the electromagnetic energy in the solar spectrum, is used for the determination of atmospheric stability. Pyranometers are used for measuring energy fluxes in the solar spectrum.

The meteorological towers used to position the data collection equipment add another layer of complexity. There are many types of meteorological towers and several ways to install them. The proper installation and siting of the tower and equipment determine the effectiveness of a system and the data reliability.

Siting and exposure for meteorological sensors can be complex and challenging when trying to avoid the influence of obstructions, such as buildings and trees. The distance for siting depends on both the variable to be measured and the type of obstruction. Improper siting of instruments can result in wind speed and direction error, inflated ambient temperatures, and/or obstruction of solar and precipitation measurements.

Learn more about ambient pollutant and meteorological monitoring

Daily review and quality assurance checks can identify instrumentation problems and reduce the period of downtime and loss of data. Custom data collection can record 1-minute, 5-minute, and 60-minute data averages. This is significantly more real-time and useful than Automated Weather Observing Stations (AWOS) which are used at airports and only report 1-hour snapshot values. Onsite data telemetry systems use a cellular modem to remotely download to a data management center.

The remote telemetry system can also be designed to alert and notify responsible parties of any weather conditions which are cause for concern. Air pollutant monitoring systems can also be incorporated with the weather station to send emails and text messages with real-time concentrations and meteorological information. The data can also be made available using a web and mobile based software application. Data is then tailored for viewing numeric values or graphs.


ALL4 can design and install meteorological monitoring systems to support air pollution monitoring which follow the U.S. EPA guidance in regulatory air quality modeling applications. The meteorological instrumentation is wired and programmed into an onsite datalogger which can provide real-time data and communication to web and mobile based devices for immediate conditions.

ALL4 has meteorologists, scientists, and engineers with extensive knowledge of all siting and instrumentation requirements to produce quality meteorological data, especially to stay in compliance with U.S. EPA guidelines and requirements. Our custom programming, automation, operations and maintenance, and auditing capabilities keep the monitoring station running and provide QA/QC.

The first task of each business day is for the meteorologists, scientists, and engineers at ALL4 to utilize a checklist and table of accepted data ranges to review the previous day’s monitoring data for reasonableness and completeness. ALL4 can also audit and calibrate new or existing meteorological towers according to U.S. EPA guidelines. Most State and Federal quarterly data completeness requirements are greater than 80%; therefore, a routine schedule of daily data validation and checks are necessary.

Whether you have your own tower already, or you desire the benefits of one, there is a fair amount of planning and care involved in setting up and maintaining an onsite meteorological tower, especially to stay within U.S. EPA guidelines and requirements.

With over 30 years of ambient and meteorological experience, ALL4 can “see for miles and miles” all the opportunities and benefits of monitoring real-time at your facility. Contact ALL4 to discuss how we can customize an automated, continuous meteorological monitoring system that is both accurate and reliable and is tailored to your specific needs.

Please reach out to me at dpelc@all4inc.com or 610.933.5246 x169 if you have any meteorological tower comments or concerns, or to talk weather conditions at your facility.


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