This layer displays the locations of air quality monitoring stations in the United States. The Air Quality System (AQS) contains ambient air pollution data collected by EPA, state, Local, and tribal air pollution control agencies from thousands of monitoring stations. AQS also contains meteorological data, descriptive information about each monitoring station (including its geographic location and its operator), and data quality assurance/quality control information. For more information, please visit the EPA Air Quality System web page.
Electric Bulk Power Transmission Lines
This layer represents electric power transmission lines. Transmission Lines are the system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power system. Lines are operated at relatively high voltages varying from 69 kV up to 765 kV, and are capable of transmitting large quantities of electricity over long distances. Underground transmission lines are included where sources were available.
Safe Drinking Water Information System Sites
This layer displays the locations of a subset of the Environmental Protection Agency (EPA) Safe Drinking Water Information System (SDWIS) sites. The SDWIS contains information about public water systems and their violations of EPA’s drinking water regulations. Data can be accessed through the EPA’s Clip N Ship map application. For more information, please visit the Safe Drinking Water Information System web page.
Army Corps Floodwalls
This layer displays United States Army Core of Engineers surveyed Floodwalls. The USACE defines an Floodwall as a structure erected to protect areas from high river stages. For more information about USACE data, visit the National Levee Database.
Watershed Boundary Dataset, 4-Digit Hydrologic Units
The 4-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the second level hydrologic subdivision of the United States. A 4-digit hydrologic unit includes the area drained by a river system, a reach of a river and its tributaries in that reach, a closed basin(s), or a group of streams forming a coastal drainage area. There are 240 4-digit hydrologic units with an average size of 17,521 square miles (45,378 sq. km.).
Location Affordability Index for Family at AMI
This layer displays the estimated percentage of household income for housing and transportation for a family earning the Area Median Income (AMI). The expected values for housing and transportation are modeled by HUD using data from the US Census Bureau and the US Department of Transportation, including:
- The average household size for a family earning AMI in the neighborhood
- The average number of workers, vehicles, and vehicle miles traveled for a family in the neighborhood
- The average utility and rental costs or average utility and mortgage costs for a housing unit to accommodate the family size above
- The proportion of housing units that are either rentals or owner-occupied in the neighborhood
Note: The LAI does not predict what families are actually paying to live in a particular area, but rather what a family would pay (either in USD or as a percentage of income) if average or reasonable housing and commuting conditions for a particular neighborhood were achieved.
Drought Severity, 2017-2019
This layer displays the percentage of weeks in Any Drought based on analysis of US Drought Monitor weekly drought data files for years 2017-2019.
Location Affordability Index for Family Below AMI
This layer displays the estimated monthly cost for housing and transportation for a low-income, single-parent family (earning 50% of the Area Median Income). The values for housing and transportation are modeled by HUD using data from the US Census Bureau and the US Department of Transportation, including:
- The average household size for a single-parent family earning 50% AMI in the neighborhood
- The average number of workers, vehicles, and vehicle miles traveled for a family in the neighborhood
- The average utility and rental costs or average utility and mortgage costs for a housing unit to accommodate the family size above
- The proportion of housing units that are either rentals or owner-occupied in the neighborhood
Note: The LAI does not predict what families earning 50% AMI are actually paying to live in a particular area, but rather what a family would pay (either in USD or as a percentage of income) if average or reasonable housing and commuting conditions for a particular neighborhood were achieved.
Uninsured Population by County
Layer displays information about the insurance status of the population age 0-64. The data are from the 2018 Small Area Health Insurance Estimates, released by the US Census Bureau on April 09, 2020.
Wildfire Perimeters
The layer displays historic wildland fire perimeters. The Geospatial Multi-Agency Coordination group, or GeoMAC, is an internet-based mapping tool originally designed for fire managers to access online maps of current fire locations and perimeters in the U.S. Perimeters are submitted to GeoMAC by field offices and made available to the public. Perimeter data is not the final or official perimeter for any incident and is provided for informational purposes only. The final official perimeter should be obtained from the host unit which can be determined by looking at the Unit ID for any specific fire.