Days Exceeding NAAQ Standards for Fine Particulate Matter

This layer displays the percentage of days (in a single year) with the concetration of fine particulate matter (fine particles 2.5 micrometers or less) above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter.

Days Exceeding NAAQ Standards for Ozone

This layer displays the percentage of days (in a single year) with the maximum 8-hour average ozone concetration above the National Ambient Air Quality Standard (NAAQS) of 0.070 parts per million.

Brownfield Sites

Layer displays the locations of brownfield sites based on the September 2013 version of the EPA Assessment, Cleanup and Redevelopment Exchange System (ACRES) database.

Toxic Release Inventory by County

This layer displays the amount of toxic releases based on the Environmental Protection Agency (EPA) Toxics Release Inventory (TRI), a national program which tracks the management of over 650 toxic chemicals that pose a threat to human health and the environment. Facilities must report how each chemical is managed through recycling, energy recovery, treatment, and releases to the environment. A “release” of a chemical means that it is emitted to the air or water, or placed in some type of land disposal. The information submitted by facilities to the EPA and states is compiled annually as the Toxics Release Inventory or TRI, and is stored in a publicly accessible database ( Envirofacts. For more information, please visit the EPA Toxics Release Inventory web page.

Air Toxics – Non-Cancer Risk by Census Tract

Layer displays the modeled non-cancer risk associated with air toxics exposure. A hazard index (HI) of 1 or lower means air toxics are unlikely to cause adverse noncancer health effects over a lifetime of exposure.