Southwest Lake Michigan Pilot Study

Final Report

Developing an Inventory of Toxic Air Emissions from Area Sources in the Chicago, Milwaukee and Gary Urban Areas, 1993

Illinois, Indiana and Wisconsin, working together through the Great Lakes Commission, have completed the first multistate inventory of emissions of toxic air contaminants that are identified as being potentially harmful to the Great Lakes ecosystem or human health.

Specifically, these states created an inventory of small point and area sources of toxic air emissions from the combined 12-county urban areas of Chicago, Gary and Milwaukee. The study identified small point and area source categories that contribute the most to the total emissions of 49 hazardous air pollutants, including arsenic, chromium, mercury and lead.

The project was the first test of the regional protocol, the Air Toxics Emissions Inventory Protocol for the Great Lakes States, and provided an opportunity to develop and test state-of-the-art inventory software, the Regional Air Pollutant Inventory Development System (RAPIDS).

Purpose
The federal incentive for the SWLM project was to assist the U.S. EPA in meeting requirements of Section 112 of the Clean Air Act. The SWLM final report documents substantive progress toward meeting the urban area goals of the CAA Sections 112(c)(6) and 112(k) and the Great Lakes goals of Section 112(m).

The Great Lakes region had an additional incentive to undertake the SWLM project. The development of multistate client/server toxic air emission inventory software and procedures goes a long way toward meeting provisions of the Great Lakes Governors' Toxic Substances Control Agreement of 1986, which called on the states to jointly identify sources of persistent toxic substances contaminating the Great Lakes.

• Section 112 of the Clean Air Act
• Great Lakes Governors' Toxic Substances Control Agreement of 1986

The SWLM pilot study is part of a larger initiative to develop a Great Lakes regional database of airborne toxic pollutant emissions. Once a quality controlled/quality assured data inventory has been established, the states and the U.S. Environmental Protection Agency can begin to work separately and in concert to define and regulate sources; evaluate control technology; establish guidelines for siting new facilities; and reduce airborne deposition of persistent toxic chemicals to the Great Lakes.

Relevance to Mission
By promoting cooperation among the Great Lakes states and the province of Ontario in identifying and quantifying emissions of toxic substances known to be detrimental to the Great Lakes ecosystem, the project responds directly to the mission of the Great Lakes Commission as outlined in the Great Lakes Basin Compact (P.L. 90-419), and the 1995 Strategic Plan.

The Basin Compact directs the Commission "To promote the orderly, integrated, and comprehensive development, use, and conservation of the water resources of the Great Lakes Basin; (Article I.1) and, "To plan for the welfare and development of the water resources of the Basin as a whole as well as for those portions of the Basin which may have problems of special concern. (Article I.2)

The deposition of airborne toxic substances on the Great Lakes is an issue that must be addressed on a multijursidictional basis and is clearly a problem of special concern to all basin jurisidictions. Successfully meeting this challenge will require the states, federal governments and provinces to share large amounts of data and information.

The Strategic Plan of the Great Lakes Commission direct the Commission to "coordinate and contribute to the development of databases that permit broad access to comprehensive and consistent Basinwide data and information." The RAPIDS database designed and tested during this study directly addresses this goal.

Products

1. Pilot Study Final Report
2. Regional Air Pollutant Inventory Development System (RAPIDS) client/server software
3. The Southwest Lake Michigan Urban Area Source Inventory. The U.S. EPA Great Lakes National Program Office serves as the inventory repository. Internet access to the inventory, using the RAPIDS client software, is available to approved state and federal employees.
4. Air Toxics Emissions Inventory Protocol for the Great Lakes States
5. Improved state air emissions inventory systems for criteria and toxic air pollutants. At least two of the region’s states are now adapting part or all of the state-of-the-art RAPIDS client/server software developed during the SWLM study to serve as their in-state toxic and criteria pollutant emission estimation and inventory system for major sources and area sources. In addition, several other states are using various RAPIDS modules as an adjunct to existing or planned systems to house the state toxic air emissions inventory.
6. Finally, perhaps the most important product of this effort has been the jump start that the Great Lakes region's state, provincial, federal and regional project partners have gained in the understanding and use of client/server and Internet communications technology. The SWLM project successfully demonstrated the cost-effective and time-efficient use of the Internet as an aid to solving regional environmental problems. With the assistance of the U.S. EPA GLNPO office, the project introduced the concept and successfully demonstrated the feasibility of states using client/server technology via the Internet to transmit and exchange environmental data with other states, federal agencies and industry.

Background / History
Atmospheric deposition is a significant source of certain toxic pollutants entering the Great Lakes. Toxic chemicals enter the atmosphere through a variety of mechanisms and sources, adhere to particles, rain or snow, and then settle into the Great Lakes through direct deposition or run-off from land. For some of the most problematic pollutants, such as PCBs, studies indicate atmospheric deposition contributes more than 90 percent of the loadings to the Lakes. Many of these toxics have the potential to bioaccumulate in species high on the food chain, posing a health risk for humans.

To implement effective air pollution control strategies, it is vital to understand how these pollutants enter the atmosphere. Wind can widely disperse the pollutants; thus, identification and quantification of emission sources throughout the Great Lakes region is mandatory.

The 1986 Toxic Substances Control Agreement signed by the Governors of the eight Great Lakes states contains a provision ensuring cooperation toward "quantifying the loadings of toxic substances originating from all sources, with the purpose of developing the most environmentally and economically sound control programs."

To pursue this goal, in 1987 state environmental administrators recommended development of a computerized air toxics database to better understand the nature and sources of toxic air emissions, and their migration, dispersion and resulting impact upon the Great Lakes Basin. They also agreed that such a database was necessary not just for evaluating impacts, but for identifying potential problems and developing appropriate control strategies. The Great Lakes Commission has coordinated the development of this database.

As recommended during the July 1987 workshop, a list of 30 priority pollutants/pollutant classes was constructed based on potential threat to aquatic and human life. Recognizing the need for a consistent level of quality information on emissions of these pollutants across the region, the eight Great Lakes states developed a protocol for inventorying toxic air emissions from point, area and mobile sources. The states also worked with U.S. EPA to identify the best available emission factors for use in estimating emissions of compounds of interest under differing operating conditions.

The states expanded the list of toxic compounds of interest from 30 to 49 during 1994. The states of Illinois, Indiana and Wisconsin then led an effort to test the protocol and develop a relational database system to inventory emissions for these 49 compounds from point and area sources. The inventory software, the Regional Air Pollutant Inventory Development System, was developed with U.S. EPA funds during FY 1994. The Southwest Lake Michigan Pilot Study began in FY 1994 to test the the regional protocol, and provided an opportunity to develop and test RAPIDS. The pilot study's final report was released in December 1995.

In the News

• Southwest Lake Michigan multistate air toxics inventory released, January 25, 1996

Methodology
The SWLM study concentrated on locating significant sources not currently regulated under the CAA. These sources include many traditionally unregulated sites with relatively small gas-fired, coal-fired, or oil-fired boilers; asphalt and concrete plants; industries dealing with primary metals (including zinc, aluminum and iron), or secondary metals (primarily used in the processing of refined metals); cultured marble companies; woodburning stoves and fireplaces; non-road engines; and generally, any place with an incinerator. The focus was on finding many small sources within one county or urban area that collectively release large amounts of one or more toxic air pollutants of concern. For detailed discussions of methodology, see the Air Toxics Emissions Inventory Protocol.

Timeline
In December 1995, Illinois, Indiana and Wisconsin completed the first multistate inventory of emissions of toxic air contaminants that are identified as being potentially harmful to the Great Lakes ecosystem or human health. Specifically, these states created an inventory of small point and area sources of toxic air emissions from the combined 12-county urban areas of Chicago, Gary and Milwaukee for calendar year 1993. Work began on the SWLM study in October 1993.

Milestone dates include the following:

• June 1994: Publication of the Air Toxics Emissions Inventory Protocol;
• Mid-1995: First release of the Regional Air Pollutant Inventory Development System data management system;
• December 1995: Final SWLM inventory compiled and report released.

Ongoing efforts for 1996 include state, provincial, federal and academic review of the inventory content and methodology; discussion with U.S. EPA of proposed addition of mobile and large point source inventory to the study; and collective work by the eight Great Lakes states and province of Ontario to follow the methodology developed by the SWLM study in compiling an inventory of point and area sources for the region.

Funding
The SWLM pilot study began in October 1993 with primary funding provided by the U.S. Environmental Protection Agency under the auspices of the Urban Area Source and Great Waters programs. It built upon four previous years of effort by the Great Lakes states, funded by the Great Lakes states themselves through the Great Lakes Protection Fund. In addition, the project benefited from substantial in-kind contributions of staff time by the lead states of Illinois, Indiana, Michigan and Wisconsin and federal collaborators at U.S. EPA.

Project Team
The Southwest Lake Michigan Pilot Study Subcommittee led development of this unique effort, under the leadership of Dave Kolaz, former chair of the Steering Committee for the Great Lakes Regional Air Toxics Inventory Project, and Carol Ratza, former project manager, Great Lakes Commission.

Emission inventory specialists from the pilot study states, as well as staff from the other Great Lakes states, U.S. EPA and the province of Ontario, worked together closely, making the study a team effort.