If a picture is worth a thousand words, the Environmental Protection Agency (EPA) has provided the ability to talk up a storm. By making a series of geographic information system (GIS) mapping applications available over the Internet, the EPA is allowing government agencies and citizens to look at information such as air and water pollution sources in new ways. Instead of looking at pages of text, users can now map complex GIS information for any geographical area in the United States from their desktop computers.

This new mapping capability is useful for local governments that don't have the budgets to implement mapping technology, and for state regulatory staffs who may use the information to help set priorities for their permits and inspections. It also helps community and environmental justice groups as they research facilities that might be impacting watersheds and other natural resources.

The EPA has made this possible by combining its Web-enabled Envirofacts facility data warehouse -- an Oracle relational database of EPA-regulated facilities -- with an ArcInfo GIS database containing national spatial data. This combination of data systems -- called Maps on Demand (MOD) -- gives users a powerful Web-based tool to map and access air pollution levels, water-discharge permit compliance reports, Superfund clean-up decisions, and trends of toxic chemical releases and hazardous waste handlers, using site maps and text reports.

MOD helps users better understand regulatory information by showing them EPA-regulated facilities in relation to surrounding geographic features. By making GIS mapping available over the Internet, users have a more accurate, less expensive way to map information on their own. In the past, EPA staff had to research records manually to fulfill a request for information, which was slow and expensive.


Envirofacts is an application within the EPA's main Web site . Its purpose is to make all EPA information subject to the Freedom of Information Act -- including regulatory, spatial and demographic data -- accessible to federal, state and local regulators, citizens, and private industry. The general public and the EPA's 17,000 employees use Envirofacts to access information such as hazardous waste, air and water emissions, and toxic releases. The site receives more than 200,000 hits a month from the Web and thousands more from those using database access software.

Through the Envirofacts database, users generate queries by entering a specific facility name, ZIP code, city, county or state into an online form. The query generates a list of facilities that match the criteria. Users select a facility to receive a detailed environmental profile with information such as the toxic chemicals released over the last year, and air emission estimates for pollutants regulated under the Clean Air Act. Regulators can use this information to monitor noncompliant companies by regularly checking permit status, and to ensure compliance to permit limits. The public can use the information to better understand how a facility is regulated and what a facility discharges in a community.

Envirofacts uses custom software to extract data from EPA's five national mainframe systems. The software pulls information into the Oracle Envirofacts database, which is updated monthly by the agency. The Oracle7-based data warehouse is currently 40GB and contains 2,400 pages of metadata information describing how information in the warehouse is structured.

The data warehouse includes regulatory information on more than 700,000 facilities over the past five to eight years. The Envirofacts database will grow to hold over a terabyte of information as the agency adds up to three more national databases -- drinking water, hazardous waste and water treatment project information -- to the data warehouse this year, and configures its spatial data holdings into the warehouse data management system.

When Envirofacts went live in March 1995, the EPA rolled out a Web-based interface and desktop tools to its regional offices so staff could access the online data.