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SUMMARY

1.1 Project Goals

In late 1989, Amoco Corporation (Amoco) and the United States Environmental Protection Agency (EPA) began a voluntary, joint project to study pollution prevention opportunities at an industrial facility. The Amoco/EPA workgroup (Workgroup), composed of EPA, Amoco, and Commonwealth of Virginia staff, agreed to use Amoco Oil Company's refinery at Yorktown, Virginia (the Refinery), to conduct a multi-media assessment of releases to the environment, then to develop and evaluate options to reduce these releases. The Workgroup identified five tasks for this study:

1.

2.

3.

4.

Inventory refinery releases to the environment to define their chemical type, quantity, source, and medium of release.

Develop options to reduce selected releases identified.

Rank and prioritize the options using a variety of
criteria and perspectives.

Identify and evaluate factors such as technical, legislative, regulatory, institutional, permitting, and economic, that impede or invite pollution prevention.

5. Enhance participants' knowledge of refinery and
regulatory systems.

Figure 3.1 shows a schematic diagram of the Refinery, potential
release sources, and a number of pollution prevention options
identified in this Project. Table 3.2 describes specific options
to reduce releases. At the time this Project began, pollution
prevention was a concept predicated on reducing or eliminating
releases of materials into the environment rather than managing
the releases later. The Workgroup adopted this general concept
and agreed to consider all opportunities--source reduction,
recycling, treatment, and environmentally sound disposal--as
potential choices in pollution management. Since then, Congress,
in the Pollution Prevention Act of 1990, and other organizations,
have put greater emphasis on source reduction as the primary, if
not the exclusive, means to accomplish pollution prevention.
A central goal of this Project was to identify criteria and
develop a ranking system for prioritizing environmental
management opportunities that recognized a variety of factors
including release reduction, technical feasibility, cost,
environmental impact, human health risk, and risk reduction
potential. Due to the inherent uncertainties in risk
assessments, the Project focused on relative changes in risk

compared to current levels, rather than establishing absolute risk levels. Because of difficulties in quantifying changes in ecological impact from airborne emissions, changes in relative risk were based primarily on human health effects indicated by changes in exposure to benzene. The risk assessment did not include a quantitative analysis of VOCs due to limited information on their health effects.

This project focused on pollution and potential risks posed by normal operation of the Refinery and chronic exposure to its releases into the environment. Minimizing emergency and upset events is a top priority of Amoco's facility managers. Such events can have catastrophic results. However, they were not studied in this project because: (a) prevention and control of such events involves significantly different skills, technical resources, and analyses than controlling releases from day-to-day operations (AIChE, 1985); (b) the number, type, and frequency of incidents at Yorktown is very low; and (c) data regarding the type of release, and relevant meteorology during the release are not available for analysis. Appendix D describes potential emergency and upset events that might occur at a petroleum refinery and the general preventative measures used to minimize their severity and the likelihood of their occurrence.

1.2 Project Organization, staffing and Budget

Project Content: The Pollution Prevention Project has many components. Each component defines and addresses an issue associated with pollution prevention and facility management choices. These include pollutant source identification, sampling, exposure modeling, risk assessment, etc. Table 1.1 provides a complete list of the components in this Project. Project workplan outlined the purpose and content for most of these components (Amoco/EPA, 1990).

Exclusions/Limitations:

The

A number of areas specifically excluded or limited in this Project are described in Appendix B. Some are listed below:

Limited sampling time and data provided a "snapshot" of
releases rather than measured annual values.

Very few generally accepted methodologies exist for the sampling used to obtain a site-wide release inventory, particularly for measuring air emissions. Both EPA and Amoco concerns about specific sampling issues are highlighted in Appendix B and discussed in more detail in Air Quality Data, Volume II (Amoco/EPA, 1992 b).

The Project considered available technologies rather than
exploring innovative techniques for reducing releases.

• Chemical changes of airborne pollutants were not evaluated.

Data and analysis focused on the Yorktown Refinery. Sitespecific features of this facility and its emissions may not apply to other refineries. Broader regional concerns were not evaluated.

The forthcoming human health risk assessment focuses on
potential cancer risks associated with benzene exposure
outside the facility fenceline.

Peer Review: At the Workgroup's request, Resources for the Future organized a group of outside scientific and technical experts. This Peer Review Group provided evaluation and advice on the Project workplan, sampling, analytical results, and conclusions. Members of this group were paid a small honoraria for their participation and reimbursed for travel expenses to Washington by EPA. A report summarizing their comments is included as part of the documentation for this Project. C lists all Project documentation.

Appendix

Workgroup: Monthly Workgroup meetings provided Project oversight, a forum for presentations on different Project components, and an opportunity for informal discussion of differing viewpoints about environmental management. Although attendance varied, each meeting included representatives from various EPA offices, the Commonwealth of Virginia, and Amoco. Workshop: A special Workshop, held during March 24-27, 1991, in Williamsburg, Virginia, reviewed sampling data and identified reduction options and ranking criteria. More than 120 people from diverse backgrounds--EPA, Amoco, Virginia, academia and public interest groups--attended the Workshop. The Workshop sessions resulted in suggestions that further refined and directed Project activities (Amoco/EPA, 1991a).

Participants: More than 200 people, 35 organizations, and many disciplines have been involved in this Project. Table 1.2 lists the various participating organizations.

Cost: Total cost for this Project was approximately $2.3 million. Amoco Oil Company provided 70 percent of the funding and EPA the remainder.

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Existing estimates of environmental releases were not
adequate for making a chemical-specific, multi-media,
facility-wide assessment.

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The Yorktown Refinery had good information about the quantity of material released to the York River from NPDES Permit monitoring requirements, and for solid wastes as a result of internal programs and participation in recent American Petroleum Institute surveys (API, 1991b). These releases, however, made up only 11 percent of the total releases from the facility. Available data did not include adequate chemical-specific characterization of the water discharge or solid waste streams.

The Refinery (and other refineries as well) could not easily identify specific airborne hydrocarbon compounds released or the quantity released because:

(a)

(b)

(၁)

Refineries typically do not manufacture products with
specific chemical compositions, and therefore do not
routinely measure chemical compositions of their
products or emissions. Rather, refinery products
have specific properties such as octane, freeze
point, and sulfur content. Crude oil, the raw
material used to make these products, contains
thousands of distinct chemicals that are never fully
separated during the manufacturing processes.
Airborne releases from this kind of facility are
similarly complex.

Most hydrocarbons are released through a large number of widely distributed sources (valves, flanges, pump seals and tank vents). Even a small refinery may have more than 10,000 potentially different sources. Direct measurement of each of these sources is not practical.

The quantities released through any single source are
extremely small--on the order of pounds per
year--dilute and difficult to measure. In addition,
some large sources that emit pollutants in the amount
of tons per year are difficult to measure and
quantify. Total hydrocarbons released from Yorktown
Refinery from all sources were approximately 0.3
weight percent of the total crude oil processed.
Therefore, they would not be detected through normal
mass balances and materials accounting (NRC, 1990).

Thus, collecting detailed, chemical specific release information used to characterize the Refinery was expensive and time consuming. This Project developed a sampling and monitoring program that included about 1,000 samples (see Figure 2.2). Each sample was analyzed for 15-20 chemicals. The sampling program took about 12 months to complete at a cost of about $1 million. Even with this time and dollar commitment, only selected sources were sampled. The final release inventory was assembled using a

combination of sampling, measurements, dispersion modeling, and estimates based on emission factors.

Because this sampling program was a first of its kind effort, its scope was intentionally broad. Subsequent analysis showed that not all of the information obtained was necessary to identify significant sources and potential reduction options. For the Yorktown Refinery (and the petroleum refining industry overall), more general information, such as source specific VOC emissions, is adequate to identify many of the pollution prevention projects developed in this study. Total VOC emissions are a good indicator of overall emissions and can be used for tracking emissions reduction progress.

B. A substantial portion of pollution generated at this refinery is not released to the environment.

The release inventory process allowed a comparison of pollutant generation, on-site management and ultimate releases to the environment. The Refinery generates about 27,500 tons/year of pollutants. As a result of site hydrogeology, on-site wastewater treatment, and solid waste recycling practices, about 12,000 tons are recovered, treated or recycled and do not leave the Refinery site. of the remaining 15,500 tons about 90 percent are released to the air.

Figure 2.4 illustrates the transfers which take place between generation and ultimate release. Figure 2.5 characterizes pollutants released from the Refinery. This site-wide analysis of pollutant generation and release characteristics allowed the Workgroup to focus much of the remaining Project resources on the largest releases--airborne emissions.

Modeling studies indicated relatively little naturally occurring transfer of hydrocarbon emissions from air into other media (Cohen and Allen, 1991). Most hydrocarbons are not very water soluble, and so are not easily removed from the air by rainfall. Section 2.0 includes a more detailed discussion of the potential for transfer to other media. Although the fate of criteria airborne pollutants (like NOX and S02) was not studied in this Project, they are known to be scavenged by rainfall and can contribute to nitrogen loads and pH changes in lakes and soil (See Appendix B). Measurements and modeling results showed small transfers from some surface water ponds to groundwater. Groundwater also enters the wastewater treatment system through the underground sewers, resulting in a net groundwater inflow. Transfers of pollutants between media do occur, particularly as a result of pollution management activities. Over 370 tons/year of hydrocarbons initially present in wastewater streams are volatilized into air from the water collection system. More than

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