Real-time (short-term) air monitoring occurs during dredging and CDF operations to ensure activities are conducted safely to avoid negative impacts consistent with USEPA guidance.
Real-time air monitoring data is collected at four monitoring stations around the perimeter of the CDF cells and at the off-loading barge. This data is used for the management of the daily operation of the CDF. Air monitoring along the perimeter of the CDF measures emissions of particulate matter (PM). Each perimeter air monitoring station consists of a hybrid ambient particulate monitor for measuring PM10 and PM2.5. Air monitoring at the dock area is also performed daily during dredging using a photo-ionization detector (PID).
The primary goals of real-time air monitoring are to:
Each perimeter air monitoring station includes a hybrid ambient particulate monitor for measuring PM10 and PM2.5 (dust). Data is collected every 15-minutes during operations.
In addition to perimeter air monitoring, air monitoring at the dock area is performed daily during dredging using a photo-ionization detector (PID). This monitoring provides data on the effects of sediment activity at the barge on emission levels for worker and community safety. PID monitoring takes place daily prior-to and during dredging for VOCs.PID Monitoring Data
From 2012 to 2021, each perimeter air monitoring station included a two-part open-path ultraviolet differential optical absorption spectrometer (UV-DOAS) that measured naphthalene. These monitors collected data along an open path between two points. Naphthalene monitoring was discontinued in 2021. Historical data is available.
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. Action levels are based solely on the CDF component of the air quality results.