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Tonawanda Community Air Quality Study - Benzene Monitoring Update December 2018

Benzene Monitoring Update

Addressing Air Quality Concerns

The New York State Department of Environmental Conservation (DEC) has been closely reviewing the concentrations of pollutants at the monitoring stations located in the Tonawanda community. DEC continues to operate two monitors installed in 2007, for the Tonawanda Community Air Quality Study, which evaluated air quality in the community and emissions from Tonawanda Coke.

One monitor, located on Grand Island Boulevard, is 1,500 feet northeast of the facility and near Interstates 190 and 290 and other industrial facilities. The second monitor is in a residential neighborhood on Brookside Terrace West, 8,000 feet northeast of the facility. In 2009, the study documented high levels of benzene released from Tonawanda Coke's operation. The facility was ordered to make repairs and operational modifications to address the releases of this pollutant. Benzene can be an indicator of certain improper operations at the facility.

In the beginning of 2018, the facility began to encounter operational problems with the coke oven batteries, causing opacity (dark smoke) violations from its waste heat stack. Benzene concentrations also increased at the Grand Island Boulevard monitoring location during 2018.

The United States Environmental Protection Agency (USEPA) also conducted air monitoring for benzene at multiple locations in the area during the shutdown of Tonawanda Coke from October 14 - 21, 2018. This fact sheet provides information on the benzene results collected by DEC and USEPA.


In July 2018, DEC supplemented the routine one in six-day benzene monitoring with a continuous instrument (Synspec) that provides 15-minute average benzene values at the Grand Island Boulevard monitoring station. DEC installed this monitor to continuously monitor ambient benzene concentrations to ensure that the facility was not emitting high concentrations of benzene into the community. Figure 1 presents the benzene concentrations from the DEC real-time continuous Synspec monitor.

Graph of Benzene levels is Grand Island Boulevard
Figure 1. Continuous benzene concentrations measured at the Grand Island Boulevard monitoring station.

The continuous benzene concentrations are presented as 15-minute averages (blue line) and 24-hour averages (black line) since July 24, 2018. The red dash is the corresponding 24-hour SUMMA canister samples. This figure also includes a yellow box, which represents the shutdown of Tonawanda Coke.

As illustrated, there has been a decrease in benzene concentrations since the facility shutdown period. During the shutdown period (October 14 - 21, 2018), USEPA also monitored for benzene at numerous locations in the community using canisters to collect 18 to 24-hour samples (Figure 1.1). EPA reported all results from this sampling as non-detect. One of sampled locations was at the Grand Island Boulevard monitoring station. The concentrations measured by DEC's continuous instrument during this period were all below the benzene reporting limit used by the EPA laboratory. This explains why EPA samples for benzene were reported as non-detect. During emergency sampling events, analytical reporting limits are usually set higher in anticipation of measuring elevated source oriented concentrations.

EPA Sir Sampling map
Figure 1.1 EPA Air Sampling and Monitoring Locations (October 14 - 21, 2018)
Graph of GIBI Benzene
Figure 2. Time-series of benzene concentrations from July 2007 - November 10, 2018
2017 and 2018 Average Benzene Concentrations at Tonawanda Sites
Figure 3. A comparison between 2017 and 2018 benzene concentrations at the Tonawanda monitoring locations.

Overall, the benzene concentrations increased during 2018 in comparison to 2017 annual concentration at the Grand Island Boulevard monitor. The annual average benzene concentration in 2017 was 0.28 ppb. The average concentration for 2018 through November 10, 2018, was 0.36 ppb. There is no difference between the 2017 concentration and the 2018 concentration (through September 29, 2018) measured at the Brookside Terrace monitor. The average benzene concentrations in 2017 and 2018 was 0.16 ppb. The DEC expects the benzene concentrations will continue to decrease at the Tonawanda area monitors resulting from the closure of Tonawanda Coke.

Public health interpretation of measured air concentrations.

Overall, the potential cancer risk estimate from benzene exposure continues to decrease in the community. In 2008, DEC estimated the lifetime cancer risk for benzene exposure at 75-in-one-million at the Grand Island Boulevard location. In 2017, DEC estimated the lifetime cancer risk for benzene exposure decreased to seven-in-one-million at this location. This estimated cancer risk is considered low by federal and state public health and environmental protection agencies. DEC expects the annual cancer risk estimate from benzene exposure to decrease further since Tonawanda Coke has shut down. The decrease in ambient air benzene concentrations after the shutdown is evident in Figure 1 and it is expected to remain in this range in the future.

Where can I find more information?

DEC has developed a public webpage that contains all this updated information and historical information. This page will continue to be updated with air quality information for the community.

Who should I contact to discuss this information?

If you have any questions about this information, please contact the following representatives:

Regional Contact:
Christopher M. LaLone, P.E.
270 Michigan Avenue
Buffalo, NY 14203
(716) 851-7070

Central Office Contact:
Thomas Gentile
625 Broadway
Albany, NY 12233
(518) 402-8402