It is important to understand that the Curtis Bay Piers facility is located in a heavily industrialized area surrounded by a variety of other permitted industries. Investments have been made to advance long-term operational safety, improve dust control, and collect 100% of storm water for onsite reuse at our facility.

The 2022 construction permit added a requirement to implement a Fence Line Monitoring Plan designed to monitor for fugitive dust, or dust that is not emitted from definable point sources. CSX has been working with outside consultants and Maryland Department of Environment (MDE) to ensure the planned implementation meets or exceeds permitting and agency requirements.

In 2023, CSX installed a fence line monitoring system to continuously monitor particulate matter along the perimeter of the Curtis Bay Piers property. Fence line monitoring is a way to gather information and quantify the amount of fugitive dust in the vicinity of the facility. Air monitoring data creates a “map” of air quality measured at the fence line, which can be used by CSX, MDE, and the community to help understand area conditions.

CSX utilizes multiple control measures to mitigate dust from operations, including an automated dust suppression system with water sprayers.

How to Read the Data?

  • Measurement data are displayed as the Air Quality Index (AQI) based on a 24-hour rolling average.
  • Hover your mouse over a monitor location to view the 24-hour rolling average data for PM2.5 and PM10.
  • Detailed PM2.5 and PM10 24-hour data are graphed in µg/m3 units.
  • The arrow displayed at the monitor location indicates the current wind direction.
  • Data is color coded as the current AQI value in accordance with EPA standards (see image below).
  • While these fence line monitors measure air quality in the surrounding area, they are not able to attribute a specific source for high AQI.
Sources: AirNow

A grey colored location indicates equipment maintenance needed.

Disclaimer: We are sharing this real time data before it has gone through the full state agency and technical quality assurance review. This data is published to provide the community with all information available as we work with the agency to review and finalize.

Fence Line Locations in Curtis Bay

  • Eight (8) onsite monitoring locations were selected along the perimeter of the Curtis Bay Piers operating areas in accordance with EPA site selection criteria and to collect data for inbound and outbound wind scenarios.
  • The monitor locations are numbered AQ1 through AQ8. The first monitor, AQ1, is located at the southern boundary of the facility, near the Benhill gate. The remaining locations are numbered in a clock-wise direction from AQ1 around the perimeter. The last monitor, AQ8, is located west of the transfer tower, and in line with Church Street.

Learn more about the monitoring equipment in use at Curtis Bay Piers

  • The Fence Line Monitoring System is required to include:
    • One (1) continuous federal equivalent method (FEM) monitor for both PM2.5 and PM10 and at least one (1) collocated PM2.5/PM10 sensor.
    • Multiple PM2.5 /PM10 sensors around the CSX property.
    • A 10-meter meteorological monitoring system.
  • Federal Equivalent Method (FEM) Monitor
    • EPA has established that air monitoring equipment must be designed and tested to meet performance criteria for obtaining reliable and repeatable measurements to meet either Federal Reference Methods (FRMs) or Federal Equivalent Methods (FEMs).
    • CSX has installed Teledyne T640x monitors at two locations (AQ5 and AQ8) around the Curtis Bay Piers property.
    • The Teledyne API T640X is a real-time, continuous particulate matter (PM) mass monitor that uses scattered light spectrometry for measurement of PM2.5 and PM10. The T640X is designated by EPA as an FEM for making measurements of both PM2.5 and PM10.
  • Low cost sensor technology
    • A low-cost air pollution monitor is a device that uses one or more sensors to detect, monitor and report on specific air pollutants like particulate matter and environmental factors such as temperature, humidity, wind speed, and wind direction.
    • CSX is utilizing a low-cost sensor technology, manufactured by QuantAQ Modulair, to satisfy the fence line monitoring system requirements for measuring both PM2.5 and PM10.
    • Sensors have been installed at all eight locations around the terminal property and collocated with the two FEM locations.

Monitoring equipment is regularly tested and compared to U.S. EPA performance standards to verify that they can accurately detect compounds at the required detection limits.

Air Quality Background Information and Definitions

Air Pollutants Explained

  • Particulate Matter
    • Particulate matter (PM) is the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope.
    • Particle pollution includes:
      • PM10: inhalable particles, with diameters that are generally 10 micrometers and smaller; and
      • PM2.5: fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller.

Sources of Particulate Matter

  • Particulate matter comes in many sizes and shapes and can be made up of hundreds of different things.
  • Some are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires.
  • Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from automobiles, power plants, and other industries.
  • Natural sources of PM include pollen, soils, fires, animals and other anthropogenic sources.
  • Common community sources of PM include fireplaces, grills, cars and trucks, fuel powered lawn equipment, natural gas furnaces, water heaters and fireworks.

Air Quality Index via

  • One method to review air quality data around the world is with the Air Quality Index (AQI), which is a system developed to have a consistent, singular numeric index for characterizing air quality. Based on measurements of different criteria pollutants (including particulate matter), the index provides an instant value for the current air quality conditions.
  • AirNow is a source for air quality data from EPA, state, local, and tribal agencies reported as the U.S. Air Quality Index (AQI), a color-coded index designed to communicate whether air quality is healthy or unhealthy for you.
  • The AQI for PM2.5 and PM10 is based on the 24-hour rolling average of hourly concentrations.

Air Transport

  • Air transport refers to pollution from upwind emission sources that impact air quality in a given location downwind. The particulates traveling through the atmosphere impacting the community can come from a variety of different sources – some from hundreds of miles away.
    • For example, NASA watches millions of tons of dust that is transported in the atmosphere from northwest Africa across the Atlantic Ocean onto the soils of America each year. It’s a visual reminder of how Earth’s systems are interconnected. 
  • A more recent example is the 2023 Canadian fires, which resulted in air quality being affected thousands of miles from the origin of the fires.
  • Within a city, the air quality can vary greatly, and sources of pollution can stem from a variety of sources, including mobiles sources (cars, trucks, and locomotives).
  • Atypical events (natural disasters, wildfires, or high wind events, and increases in automotive emissions) can cause short-term elevated spikes in air pollution measurements.