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Tonawanda Community Air Quality Study

Tonawanda Coke Facility Shutdown

On October 23, 2018, DEC completed the safe shutdown of operations at the Tonawanda Coke Corporation (TCC) facility. The facility's extensive system of gas lines was completely purged and all coke ovens are empty‎. DEC and the U.S. Environmental Protection Agency (EPA) were on-site to assess environmental conditions and investigate contamination at the site.

About the Study

From July 2007 through June 2008, DEC initiated a year-long Tonawanda Community Air Quality Study (Study) in Erie County. The Study measured the concentrations of air pollutants within the community and evaluated the potential risks to public health from exposures to those pollutant concentrations. The Study community was an urban area and home to some of the largest industrial facilities in New York State. It was documented that high levels of benzene were released from TCC's operation, so the facility was ordered to make repairs and operational modifications to address the releases of this pollutant.

DEC continues air monitoring at the Brookside Terrace Residential Site (BTRS), located in a residential neighborhood on Brookside Terrace West 8,000 feet northeast of the TCC. A second monitor, located at the Grand Island Boulevard Industrial (GIBI) site located 1,500 feet northeast of TCC near Interstates 190 and 290 and other industrial facilities, was shut down at the end of 2019. The results from these monitors were used to examine air quality and trends in air toxics in the community since the conclusion of the Study year (2007-08). Only the BTRS monitor was kept in operation after measurements taken for more than a year follwing the closure of TCC indicated the concentration levels of the air contaminants, including benzene, were substantially low enough to be considered representative of background levels for the State, as seen in Figure 3.

Major Findings of the Study

  • The results of the Study provided a strong basis for further compliance monitoring and regulatory actions to reduce the risks associated with exposures to air pollution in the Tonawanda community.
  • Elevated concentrations of benzene and formaldehyde were found at the GIBI monitor. Higher daily concentrations of benzene were found when the wind came from the direction of the largest known point source of benzene, TCC. The formaldehyde evaluation indicated that the measured concentrations were influenced by local facilities and mobile sources.
  • The annual average concentrations for six air toxics (1,3-butadiene, acetaldehyde, acrolein, benzene, carbon tetrachloride, and formaldehyde) exceeded their respective health-based DEC Annual Guideline Concentrations (AGCs).
  • Observed benzene reductions were the result, in part, of operational modifications made by TCC in response to DEC and EPA inspections of the facility and subsequent federal and state enforcement actions against TCC, as well as a reduction in overall production following the Study year.

Benzene Monitoring Update July 2020

Benzene concentrations at the GIBI monitor from July 2007 to 2019
Figure 1a. Time-series of benzene concentrations at the GIBI monitor from July 2007 through the completion of 2019.
Benzene concentrations at the BTRS monitor from July 2007 to 2019
Figure 1b. Time-series of benzene concentrations at the BTRS monitor from July 2007 through the completion of 2019.

Figures 1a and 1b present the 1-in-6-day 24-hour benzene concentrations measured at the GIBI and BTRS monitors, respectively. Substantial reductions in the concentration peaks from the first several years of measurements (2007-09) to the subsequent years can clearly be observed. The concentration measurements have decreased even further since TCC permanently ceased operations, as seen in the most recent data. The slight rise in the benzene concentrations measured during 2018 at the GIBI monitor resulted from operational problems experienced at TCC.

Comparison of annual benzene concentration averages from Tonawanda monitors
Figure 2. Annual benzene concentration averages from the initial Study year (2007-8) through the end of 2019 at the two Tonawanda monitoring locations. The black horizontal line represents the DEC AGC of 0.13 µg/m3.

Figure 2 presents the annual benzene concentration averages at the BTRS and GIBI monitors for the Study year (2007-08) and the years after the Study, incorporating the air monitoring data through the end of 2019. Please note that the same date range as the Study year was used for 11 years post-Study (July through June), but then the 2019 calendar year (January through December) was used for the final year of the analyses. Therefore, there is an overlap of roughly six months for which the same data are included in both the "2018-19" and "2019" averages. The annual benzene concentration averages in 2019 were 0.34 µg/m3 and 0.38 µg/m3 at the BTRS and GIBI monitoring locations, respectively. These most recent annual benzene concentration averages represent reductions of 83% and 96% for BTRS and GIBI, respectively, when compared to the Study year.

The annual benzene concentration averages have decreased substantially within the Tonawanda community as seen in Figure 2. The much reduced 2019 BTRS and GIBI annual benzene concentration averages were at levels that represent background concentrations for the State, as seen in Figure 3.

Comparison of annual benzene concentration averages from Tonawanda monitors and NYS monitors
Figure 3. Comparisons between the 2019 benzene concentrations at the Tonawanda monitors (GIBI and BTRS) and the rest of the Statewide monitors measuring benzene. The black horizontal line represents the DEC AGC of 0.13 µg/m3.

Figure 3 presents the 2019 annual benzene concentration averages measured at the GIBI and BTRS monitors as compared to other areas of the State where benzene measurements were recorded for the 2019 calendar year. The 2019 annual benzene concentration averages at BTRS and GIBI were below the majority of the 2019 averages calculated for the other New York State "Urban and City Center" and "Suburban" monitors where benzene was also measured, and comparable with the remaining few monitors. The 2019 annual benzene concentration averages at every one of the State monitoring locations where benzene was measured, including the two rural sites, exceeded the AGC.

Public health interpretations of measured air concentrations

Overall, the excess cancer risk estimate from benzene exposure has decreased substantially in the Tonawanda community. At the conclusion of the Study, the excess cancer risk estimate from benzene was 75-in-one-million and 15-in-one-million at the GIBI and BTRS monitoring locations, respectively. For the 2019 calendar year, these estimated excess cancer risks for benzene were substantially decreased to 2.9-in-one-million at GIBI and 2.6-in-one-million at BTRS.

Historical presentations and information

Additional information, including the original Study, updates about the improvements observed in local air quality since the Study concluded, and information on the state/federal civil and criminal enforcement actions undertaken at TCC, is available as downloadable PDFs.

2018:

2016:

2013:

2011:

2009:

2008:

Links leaving the DEC Website:

Decreasing exposure to air pollutants in the community

  • The benzene concentrations found in the Study varied greatly across the community. The highest concentration was found at the GIBI monitor adjacent to the industrial site. The benzene concentrations found at the Sheridan Park Water Tower (SPWT) and Beaver Island State Park (BISP) monitors, both in residential neighborhoods, were similar to outdoor air concentrations found in the New York City (NYC) area. The BTRS monitor, in a residential neighborhood, measured benzene concentrations slightly higher than the concentrations found in NYC.
  • In 2008 and 2009, DEC increased compliance inspections of all air pollution sources within the Study community and also inspected additional sources outside the Study area. These inspections focused on known facilities releasing benzene and other air toxics.
  • In April 2009, EPA and DEC conducted a comprehensive compliance inspection of TCC. Civil enforcement actions were issued to TCC for violations of the Clean Air Act, the Clean Water Act, and the Resource Conservation and Recovery Act. Through the enforcement actions, the agencies continued efforts to further reduce emissions from TCC.
  • In December 2009, the US Attorney's Office for the Western District of NY led federal investigators on a raid of TCC and subsequently commenced a criminal action against TCC.
  • In March 2014, TCC was ordered to pay a $12.5 million penalty and make $12.2 million in community service payments for criminal and civil violations of the Clean Air Act and the Resource Conservation and Recovery Act. For a summary of the criminal actions, visit EPA's enforcement page (2014 Major Criminal Cases) (leaves DEC website).
  • In the beginning of 2018, TCC began to encounter operational problems with the coke oven batteries, which caused opacity (dark smoke) violations from its waste heat stack. Benzene concentrations also increased at the GIBI monitoring location during 2018. Later that same year, TCC permanently ceased operations with the facility's shutdown occurring from October 14-21, 2018.
  • After TCC's closure, benzene concentrations were at the lowest levels they had ever been at the GIBI and BTRS monitoring locations. The 2019 annual benzene concentration averages at BTRS and GIBI were below the majority of the 2019 averages calculated for those other NYS "Urban and City Center" and "Suburban" monitors where benzene was also measured and comparable with the remaining few monitors.

Questions about Emission Sources

NYS DEC
270 Michigan Avenue
Buffalo, NY 14203
(716) 851-7130
Email: region9@dec.ny.gov

Questions about the Study

NYS DEC
Division of Air Resources
625 Broadway
Albany, NY 12233
(518) 402-8402
Email: DAR.Web@dec.ny.gov