It is important for the aviation industry and airports in particular, to better understand the potential impact of airfield and aircraft deicers on the environment.  EPA made an initial estimate in 2000 indicating nearly 21 million gallons of aircraft deicers where used in the United States.  Airports believe this number is inaccurate and outdated, but to date, have not been able to find data to substantiate or rebut the EPA’s estimate.  ACRP can assist the airport industry by gathering data and developing a robust estimate of what potential deicing chemical use may be today and how it may vary by geographic location and or seasonal weather characteristics. In particular, ACRP should closely examine the  EPA's 2000 estimate of deicer discharges to the environment, to determine whether that report was flawed and  more importantly, to suggest an approach to more accurately characterize the potential for discharges based on available NPDES permit data and industry knowledge of BMPs in use today.  The following general tasks have been identified.

Assess magnitude of deicer usage based on multiple sources of information, including:

• Outreach to airlines/ATA and FBOs, and deicer manufacturers (both aircraft and pavement) to identify volumes of product purchased by geographic region of the US. Use EPA questionnaire data to the extent appropriate.
• Look at airport areas to develop mass balance for discharges.
• Calculate the percent of total national usage accounted for by the top 35 OEP airports. 
  Evaluate enplanement and geographic regions to better understand the distribution of aircraft deicer applied. 
  Develop computational tool for future analysis of data.

• Facilitate sensitivity analyses with estimated uncertainty in the data using the computational tool.

Assess potential deicer (aircraft and pavement) discharges from NPDES permit data and industry knowledge:

• Compile NPDES permit database, look first to EPA PCS, then go to individual state agencies and airports.
  Identify likely future site-specific regulatory requirements (e.g., airports subject to future TMDL development).
• Aggregate goals for deicing capture (baselines for full compliance with existing regulations, and current practices and controls/compliance).
• Characterize NPDES permit requirements effecting deicer discharge and understand how much may be discharged in various regions of the US and seasonal weather characteristics.
• Consider available deicer BMP performance characteristics and include in analyses.
  Develop best estimates of deicer discharges under baseline scenarios (current practices, and full compliance with existing regulations). 

Summarize data in a report mimicking EPA's 2000 presentation of application and discharge of deicers across the US.

Status:  This project has been completed and the final report, Estimate of National Use of Aircraft- and Airfield-Deicing Materials, is available for download from the TRB website.