Why is air monitoring occurring at Indiana Harbor & Canal Confined Disposal Facility?
There are two air monitoring programs which are occurring concurrently at the Indiana Harbor & Canal (IHC) Confined Disposal Facility (CDF) that have overlapping but distinct objectives: long-term air monitoring and short-term air monitoring.
The primary goals of long-term air monitoring are to:
- Establish a long-term air quality database (including pre-construction, construction, and dredging air monitoring data).
- Monitor and evaluate trends in ambient air quality at the CDF and East Chicago Local High School.
- Assess the impact of weather conditions on air quality measurements can be made.
- Obtain data on seasonal variations in air quality in and around the CDF site.
- Quantitatively asses the impacts of potential CDF emissions on the surrounding community.
- Obtain quantitative data on the occurrence of Volatile Organic Compounds (VOCs), Polycyclic Aromatic Hydrocarbons (PAHs), and Polychlorinated Biphenyls (PCB), particulate matter, metals, dioxins and furans, in air samples at the CDF site.
The primary goals of short-term air monitoring are to:
- Provide an air monitoring program for the dredging and CDF operations that monitors, notifies, and verifies the air quality at the site.
- Manage site operations to avoid negative impacts of potential air emissions.
- Ensure that work is conducted in a safe and effective manner for workers at the site as well as the community.
- Ensure that CDF operations are consistent with USEPA guidance for air quality impacts and IDEM regulations for air quality.
In conjunction, the air monitoring programs establish safety levels and protocols for ensuring that possible emissions from the CDF or dredging activities which may affect air quality are safe for everyone involved with the project, including the local community. The two programs also provide for a statistical analysis of data on whether construction or dredging activities are causing degradation of the ambient air near the site. The Indiana Harbor and Canal Air & Water Quality Monitoring Guidance Document provides a more thorough description of the air monitoring regime for the CDF.
What long-term air monitoring activities are taking place?
Long term air monitoring at Indiana Harbor and Canal has been occuring since 2001. In May 2004, the construction phase of the ambient air monitoring program was implemented. The location of ambient air monitoring data and reports is given below. These reports include detailed information on the selection of the monitoring sites, the handling of data, and statistical analysis of the data.
Currently, there are five air sampling stations that operate in tandem, one monitor at the East Chicago High School and four around the perimeter of the CDF.
Prior to the start of dredging, the air monitor south of the Lake George Branch Canal will be de-activated and replaced with four long-term air monitors along the dikes of the CDF. These four monitors, as well as the air monitor at the East Chicago High School will be collected every 6 days.
The long-term air monitoring program is designed to establish a continual air monitoring database of ambient air quality at and around the site (consisting of pre-site construction activities and between site construction activities), air quality during construction activities, and air quality during and between dredging events. Long-term monitoring will be used to show that the surrounding community is not adversely impacted from the CDF emissions, and to confirm that the CDF is being operated efficiently to minimize emissions.
As of 2014, there is no indication that construction activities at the site are causing degradation of the ambient air at the high school. This data will be re-evaluated on an annual basis.
What short-term air monitoring activities are taking place?
The purpose of short-term monitoring is to have data available to manage the daily operation of the CDF. The dredging and facility operation contractor collects air monitoring data at four monitoring stations around the perimeter of the CDF cells and at the off-loading barge. The air monitoring data is generated and posted online in real-time, it can be found at the Contractor’s Indiana Harbor & Canal Dredging website. Additionally, this data is archived by USACE on a weekly basis and can be found at the links below.
Short-term monitoring at IHC CDF consists of two parameters: PM emissions and volatile emissions. The Indiana Department of Environmental Management (IDEM) issued an air registration document which includes emission limits for PM and VOCs. The USEPA conducted a Supplemental Risk Assessment (SRA) to evaluate the risk of exposure to incremental emissions from the CDF. The SRA considered exposure scenarios for cancer and noncancer health effects through several populations for chronic and acute inhalation exposures as well as various other parameters. The SRA concluded that the emission limits in the IDEM air registration permit would provide for a health risk that is “relatively low and below USEPA’s established risk level” for nearby residents. Thus, short-term monitoring will be conducted according to conditions set by the IDEM Air Registration Permit.
Short-term action levels were developed to ensure that cumulative daily emissions would not approach the levels described in the IDEM Air Registration Permit and the SRA. The action levels are described in more detail below, and include maximum levels for both PM and naphthalene, which was determined to be the most significant HAP and VOC that could be emitted from the dredging operations. The facility operations and dredging contractor is required to ensure that emissions do not exceed the permit limits, and may take the actions described below if emissions approach these levels.
The perimeter air monitors are stationed on the corners of the clay dike crests which will be used to store the dredged sediment. Each perimeter air monitoring station consists of two continuously operating real-time monitors: a hybrid ambient particulate monitor for measuring PM10 and PM2.5, and a two-part open-path ultra-violet differential optical absorption spectrometer (UV-DOAS) (Figure 2). Each UV-DOAS monitor measures naphthalene concentrations across an open-path, as indicated by the arrows in Figure 2. A meteorological station at the CDF site was installed by the U.S. Geological Survey (USGS) in 2012, and is used to differentiate between upwind (background) and downwind (background plus CDF component) data. Background levels were determined by historical air quality statistics and are updated periodically based on upwind data, and action levels are solely based off of the CDF component of the air quality results.
In addition to the perimeter air monitoring, the facility operations and dredging contractor will conduct air monitoring at the dock area using a photo-ionization detector (PID). This PID monitoring will take place daily prior-to and during dredging for VOCs. Conducting PID monitoring at the dock area provides data on the effects of sediment activity at the barge on emission levels for worker and community safety.
Real-time perimeter air monitoring data and PID monitoring can be found at the contractor’s Indiana Harbor & Canal Dredging website, and is archived by USACE.
What are the short-term action levels?
Real-Time VOC Monitoring: Regarding the VOC action-levels, there are three action levels which make-up a ‘tiered’ approach to community protection:
Action Level 1: 150 µg/m3 naphthalene above background– (24-hr average)
Action Level 2: 300 µg/m3 naphthalene above background – (5 consecutive days)
Action Level 3: 5,000 µg/m3 naphthalene above background– (1-hr maximum)
Action Level 1 triggers a heightened awareness of air monitoring activities and off-loading procedures. Action Level 2 provides the CDF operator an adequate response time prior to reaching the maximum action level. Action Level 3 requires the cessation of dredged material off-loading. These action levels were conservatively determined based on the SRA, which were determined to be both low-risk and protective of human health. For more information on how the action levels were determined, please reference the USEPA Supplemental Risk Assessment or the Air and Water Quality Guidance Document which can also be found in the Reports & Studies page.
Real Time Particulate Monitoring: The IDEM Air Registration Permit requires property line emissions to be less than 50 µg/m3 above background for 60-minutes for total particulate emissions at the property line (Condition 3b). This limit is below the Air Registration limit which was determined in the SRA to be of low health risk and was therefore used as a basis for the action levels.
Action Level 1: 50 µg/m3 above background (15-min exceedance)
Action Level 2: 50 µg/m3 above background (30-min exceedance)
During the first action level, an exceedance triggers a heightened awareness of the air monitoring levels, while the second action level triggers the activation of control measures. The facility operations and dredging contractor then has 30 minutes to respond with appropriate particulate matter emission controls before 1 hour of 50 µg/m3 is reached. No actions would be required if the exceptions given in 326 IAC 6-4-6 are met (i.e. adverse meteorological conditions 326 IAC 6-4-6 (6)).
PID VOC Monitoring: The facility operations and dredging contractor conducts air monitoring for VOCs at a single location in the vicinity of the dock area using a PID for a 30-minute continuous period. This monitoring takes place once per day when a barge with dredged material is docked at the site and for 10-days prior to dredging. The PID is set to record 30 minute averages with an alarm at 10ppm VOCs for heightened awareness and an alarm at 100 ppm VOCs to immediately implement emission controls.
What are the responses to exceeded action levels?
In general, an initial air quality alarm is intended to trigger awareness by the facility operations and dredging contractor. Upon an initial alarm, the contractor may:
- Determine if the sources are considered upwind or “background”, meaning the source is from outside the CDF and barges.
- Recalibrate the air monitors or check for other malfunctions.
- Conduct air monitoring more frequently (for PID monitoring)
- Take steps in preparing operations for emission controls.
The specific types of emission controls the contractor may employ are at their discretion, as site conditions may prove some control measures more effective during operation. These control measures may include, but are not limited to:
- Adjusting the sediment placement rate (to minimize mass transfer to the air).
- Adding additional water cover (to wet particulates or prevent VOC off-gassing).
- Applying foams or tarps.
- Applying activated carbon to the slurry line or CDF cells.
- Temporarily ceasing all dredging activities.
Where is the air monitoring data located?
Compilations of data and reports, as well as links to relevant websites can be found at Air Quality Data & Reporting.