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DTE Shenango Coke: Violation Review from 3Q 2015

This is our report on Shenango, Inc.’s compliance data from the third quarter of 2015. We review Shenango’s data every quarter to check its compliance with four limitations:

  1. a limitation on the sulfur content of Shenango’s coke oven gas;

  2. a limitation on visible emissions (in other words, smoke) from Shenango’s coke oven doors;

  3.  a limitation on density of the visible emissions from Shenango’s battery combustion stack which prohibits visible emissions with opacity greater than or equal to 60%; and

  4.  another limitation on visible emissions from Shenango’s battery combustion stack which prohibits visible emissions with opacity greater than or equal to 20% for more than three minutes during any one-hour period. Opacity is a measure of smoke’s density; smoke with an opacity of 60% blocks 60% of the light that would otherwise pass through it.

Shenango violated the applicable limitation on the sulfur content of its coke oven gas three times in the third quarter of 2015. The number of violations in the third quarter is down from the 20 violations that occurred in the second quarter of 2015, but is greater than the one violation that occurred in the third quarter of 2014.

Shenango must operate its battery of coke ovens so that smoke does not leak from more than five percent of its coke oven doors that are both in operation at a given time and not obscured from an inspector’s view. Shenango’s Title V Operating Permit requires it to inspect its door emissions at least once a day and is also subject to random inspections performed by the Allegheny County Health Department (ACHD).

Shenango’s inspectors detected three violations of the 5% door standard in the third quarter of 2015. In contrast, the Health Department’s inspectors appear to have found twenty violations of that standard during the same time period, despite conducting fewer inspections. By way of further comparison, Shenango’s inspectors found no violations of this standard in both the second quarter of 2015 and the third quarter of 2014, while ACHD’s inspectors appear to have detected thirteen violations of this standard in the second quarter of 2015 and five violations in the third quarter of 2014.

In the third quarter of 2015, Shenango violated the 60% combustion stack opacity standard 11 times; Shenango violated that standard ten times in the second quarter of 2015 and thirteen times in the third quarter of 2014. Shenango violated the 20% combustion stack opacity standard 204 times in the third quarter of 2015; Shenango violated that standard 168 times in the second quarter of 2015, and 204 times in the third quarter of 2014.

The graphs that follow show that Shenango’s violations of the 20% and 60% combustion standards have continued at an increasing rate despite government enforcement actions in 2012 and 2014 that purportedly were designed to reduce those violations. The black diagonal line in each graph is a trend line generated by Microsoft Excel:

Shenango20 11-13-15
Shenango60 11-13-15

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