The relevance of three chosen data sets (TRI, LIT, and RCRA) has been substantiated by previous research and interviews with professionals in the field. Other data on the environmental condition of land is available and would be useful to identifying potential brownfields, however due to the format and accessibility, it was not possible to utilize much of this data for a regional analysis. For example, the Facility Compliance Tracking System (F.A.C.T.S.) is a database managed by the IEPA that tracks facilities in noncompliance of certain environmental regulations and codes. Additionally, the IEPA manages a comprehensive database, known as the Inventory, that lists all sites in the IEPA data management system with some activity or status that requires them to report to the IEPA. Both these datasets have potential to be useful in identifying potential brownfield sites, however acquiring the data in a format for a regional analysis was not feasible for this research, and so other more useable relevant data was selected, further described:
Toxic Release Inventory (TRI)
The Toxics Release Inventory (TRI) is a publicly available U.S. EPA database that contains information on toxic chemical releases and other waste management activities reported annually by certain covered industry groups as well as federal facilities. The database fulfills the legal right of residents to have access to information on toxic chemicals being released in the environment, as required by the federal law: Emergency Planning and Community Right to Know Act. The inventory of sites includes information on the release of nearly 650 chemicals and chemical categories from manufacturers, metal and coal mining facilities, electric utilities, commercial hazardous waste treatment, and other industries with activities that warrant environmental concern. A facility must report to TRI if the following conditions are met:
- Has 10 or more full-time employees, and
- Manufactures or processes over 25,000 pounds of the approximately 600 designated chemicals or 28 chemical categories specified in the regulations, or uses more than 10,000 pounds of any designated chemical or category, and
- Engages in certain manufacturing operations in the industry groups specified in the U.S. Government Standard Industrial Classification Codes (SIC) 20 through 39.
The TRI data used in this research is current as of January 2008.
Hazard Waste Handlers (RCRAInfo)
The information in the hazard waste handlers database comes from source reports by various stationary sources of air pollution, such as electric power plants, steel mills, factories, and universities. This data on hazard waste handlers is released by the U.S. EPA, managed in the Resource Conservation and Recovery Act Information (RCRAInfo) inventory. In general, all facilities that generate, transport, treat, store, or dispose hazard waste must provide information about their activities to state environmental agencies. The U.S. EPA collects and manages all records in an online database which can be queried by facility name, geography, NAICS code, and type of processes reported. The IEPA administers a clean-up program specifically for sites that have contamination under the RCRA corrective action program. The RCRAInfo data is current as of January 2008.
Local Incident Tracking (LIT)
The Illinois EPA manages a funding program and database for records of Leaking Underground Storage Tanks (LUST). The Leaking Underground Storage Tank Incident Tracking (LIT) database identifies the status of all Illinois LUST incidents reported to the Illinois Emergency Management Agency (IEMA) and to the Illinois Environmental Protection Agency. An Illinois EPA staff person explained that when an underground storage tank is being removed or an investigation of the land is undertaken and it is discovered the tank has been leaking, the incident must be reported to the IEPA. The LUST is recorded in the LIT database and remains in the database until it has been resolved. Once it has been remediated, it would be removed from the LIT database, and if appropriate, be moved into the Site Remediation Program database. The LIT data is current as of January 2008.
Assumptions and Land Type
In order to implement such a typology on a regional scale, several assumptions needed to be made. To identify the sites where contamination may exist and the site is not in current use and thus are assumed to be in need of redevelopment, i.e., vacant or tax-exempt publicly owned vacant land and vacant buildings, tax assessment data for each of the seven counties was used. A parcel was identified as vacant if the improvement value on the parcel was zero or if the assessor's data included a vacant class description. A parcel was considered exempt if the class description included exempt status, otherwise parcels that had a land value of zero were considered exempt. Many functional sites are tax exempt, including schools, hospitals, parks, municipal buildings, and forest preserves. To increase the accuracy of identification of land that may be in need of redevelopment, NIPC's 2001 land use inventory was used to screen out such functional tax exempt sites.
In order to analyze and evaluate the data used in this research, GIS was used extensively. Each layer of information required organization and filtering to create a valuable dataset. The data could then be mapped to provide a spatial analysis and recognize any trends and patterns in the location of potential brownfields and the location where land remediation has occurred.