At the heart of all of our operations is a commitment to the safe receipt, storage and distribution of products. Here in South Portland, we report emissions to both the EPA and the Maine Department of Environmental Protection (DEP), and our operations are subject to conditions set by our air permit.
The EPA believes we violated the potential to emit limit in that permit. The DEP believes we have been in compliance. To settle that dispute, we entered into a proposed settlement agreement with the EPA.
Under the proposed agreement reached with the EPA:
- We will heat only four of our bulk storage tanks containing No. 6 oil or asphalt, and no more than two of them will hold No. 6 oil at any one time.
- Heat will not be applied to the heated-product tanks for at least 120 days each year.
- Throughput limits will be set at 50 million gallons per year of No. 6 oil, and 75 million gallons per year of asphalt.
- We will install mist eliminators on the heated-product tanks.
- At the EPA’s suggestion, we will provide $150,000 to replace or retrofit wood-burning appliances in the area, helping reduce emissions from another source of outdoor VOCs
- Separate from the Consent Decree, we are participating in area-wide air monitoring in coordination with the DEP and City of South Portland. We are also working on ways to address odor from our facility.
What were the alleged violations?
The EPA’s Notice of Violation (NOV), issued in June 2014, alleged that the terminal’s potential to emit (PTE) exceeded certain regulatory thresholds which establish what type of permit a facility must apply for.
Potential to emit is calculated for permitting purposes by considering the emissions generated by a facility operating at full capacity, 24 hours a day, 365 days per year. Because terminals, including our South Portland terminal don’t actually operate in a continuous manner, actual emissions are well below potential emissions.
Think of your car or truck. Its potential to emit is the amount of exhaust produced if you drove your car 24 hours a day, 365 days a year. No one does that, and so the actual emissions of your vehicle depend on how much you actually drive.
Additionally, the EPA NOV is based on a disputed methodology for calculating emissions that we believe overestimates emissions. Global and DEP use a methodology called AP-42, which is widely used in calculating emissions from heated storage tanks.
Did Global exceed its emissions limit?
No. Although EPA alleged that the PTE for the terminal exceeded 50 tons per year, the terminal never reported emissions exceeding those allowed by its license. Each year, we are required to report actual emissions to the Maine Department of Environmental Protection (DEP). Our permit allows for up to 21.9 tons per year of what’s known as volatile organic compounds (VOCs).
After the EPA issued its NOV in 2014, we opted to calculate emissions using the EPA’s disputed methodology. Even then, at no time did the reported emissions exceed 21.9 tons per year.
We recently completed our 2018 reporting, this time using a revised AP-42 methodology proposed by the EPA – a methodology that will likely become the new national standard. Our 2018 VOC emissions totaled 4.81 tons.
While we don’t have 2018 data from other South Portland facilities, based on 2017’s reported emissions, our 2018 number would represent just 2% of the total VOC emissions in South Portland. There is more on AP-42 below.
What are VOCs?
VOCs are organic chemicals that can evaporate in the air. They are found both indoors and outdoors and are essential ingredients in many every-day products. Sources of indoor VOCs include cleaning supplies, personal care products, paint and paint thinners, cooking and wood-burning stoves. Outdoor sources include diesel and gasoline emissions from stationary and mobile (cars, trucks, trains, etc.) sources, wood burning, and industrial emissions.
Why is the EPA’s emission test methodology disputed?
This requires some background, on testing and Global’s facility. We have operated in South Portland since 2001, but the facility has operated since the early 1900s. It’s one of 15 permitted facilities in the area that report VOC emissions to the DEP.
Global’s terminal includes 12 bulk storage tanks, four of which can be heated (as necessary to keep the product in liquid form), plus truck loading. Those four heated tanks are designed to hold No. 6 oil (fuel for ships and industry power systems) and asphalt.
Between 2011 and 2013, in response to EPA requests, Global retained Eastmount Environmental Services to test emissions associated with those heated storage tanks and the truck loading area. The EPA insisted on a testing method known as temporary total enclosure (TTE), in which a tank’s vents are covered with enclosures that are kept at a slight vacuum. Global disagreed with the methodology based on belief that maintaining a vacuum on the enclosures would draw vapor out of the tank, resulting in an overestimate of emissions that would not have existed under normal conditions.
Heated tanks create two types of emissions. Standing emissions exist when the tank is idle, or simply holding its product. Working emissions exist when the tank is being filled, the level of product is rising and that change pushes emissions out the vents. Under standard methodologies and AP-42 calculations relied on by EPA and the industry, standing emissions on an hourly basis are normally a small fraction of working emissions on an hourly basis since vapors are actively pushed out of the tank vents during filling.
Using the EPA’s requested TTE method, the data indicated the standing emissions on an hourly basis were unexpectedly high when compared to the working emissions on an hourly basis. This supported the belief that the TTE enclosure testing method artificially elevated the standing emissions. As a result, the potential to emit number was also artificially high.
The DEP agreed with Global that the TTE methodology is not representative of normal
tank venting conditions.
What is AP-42?
AP-42 is a document published by EPA that includes methodologies for calculating emissions from a wide variety of industrial sources, including petroleum facilities and associated storage tanks. In 2018, the EPA proposed revisions to AP-42 specifically to address the calculation methodologies for emissions from heated storage tanks. Although the comment period has closed, those revisions haven’t yet been finalized. It’s expected the proposed revision to AP-42 will be the standard methodology going forward.
If Global doesn’t believe it violated its permits, and the DEP agrees with Global, why settle?
As a company we believe in working with environmental regulators and the cities and states where we operate. We don’t always agree, but we can come to an understanding and ensure that we continue to do things the right way.