Type File Geodatabase Feature Class
This digital layer is intended for use by Orange County staff to identify those portions of the county area where homes are more likely to have indoor-air radon concentrations exceeding the U.S. EPA recommended radon action level of 4.0 picocuries per liter. This digital layer should assist them in identifying areas where indoor-radon testing should be encouraged and public awareness programs may be beneficial.
This digital layer contains polygons (vector format) of those geographic portions of Orange County, California designated as having high, moderate, low, or unknown potential for homes to exceed the U.S. EPA recommended radon action level of 4.0 picocuries per liter in indoor air. The polygons are shown on the plate (map) for the California Geological Survey Special Report--232--Radon Potential in Orange County, California, 2015.
Churchill, R.K., 2015, Radon Potential in Orange County, California, California Geological Survey Special Report 232, 113 p., and 1 map plate. Report and map available for viewing and downloading online at: https://www.conservation.ca.gov//Documents/
This map layer is intended for use by Orange County staff to identify portions of their county where homes are more likely to have indoor-air radon concentrations exceeding the U.S. EPA recommended radon action level of 4.0 picocuries per liter (pCi/L). The three radon zone categories indicate the likelihood of a home having indoor-radon concentrations at or above the 4.0 pCi/L action level: Moderate (5 to 19.9 percent), Low (< 5 percent), and Unknown (insufficient data to estimate the radon potential). The map layer does not provide specific information about the indoor-radon concentration of a home at any given location within a zone. The only way to accurately determine the indoor-radon concentration within a home at any location is by testing the indoor-air of that home. This can be done by the homeowner using inexpensive testing devices which are sent to commercial laboratories for evaluation or by certified radon testing professionals. This map layer is designed to be used at a map scale of 1:100,000 and not more detailed scales. At this scale it is not unusual for geologic unit boundaries (and, consequently, corresponding radon zone boundaries) to have accuracy limitations of plus or minus tens to several hundred feet and sometimes more. Consequently, radon zone classifications are less certain for locations nearer zone boundaries. CGS does not guarantee the accuracy of radon potential limitations for property parcels based on this map.
| West | -118.123091 | East | -117.403631 |
| North | 33.952293 | South | 33.382891 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
Churchill, R.K., 2015, Radon Potential in Orange County, California, California Geological Survey Special Report 232, 113 p., and 1 map plate. Report and map available for viewing and downloading online at: https://www.conservation.ca.gov//Documents/
publication date
This map layer is intended for use by Orange County staff to identify portions of their county where homes are more likely to have indoor-air radon concentrations exceeding the U.S. EPA recommended radon action level of 4.0 picocuries per liter (pCi/L). The three radon zone categories indicate the likelihood of a home having indoor-radon concentrations at or above the 4.0 pCi/L action level: Moderate (5 to 19.9 percent), Low (< 5 percent), and Unknown (insufficient data to estimate the radon potential). The map layer does not provide specific information about the indoor-radon concentration of a home at any given location within a zone. The only way to accurately determine the indoor-radon concentration within a home at any location is by testing the indoor-air of that home. This can be done by the homeowner using inexpensive testing devices which are sent to commercial laboratories for evaluation or by certified radon testing professionals. This map layer is designed to be used at a map scale of 1:100,000 and not more detailed scales. At this scale it is not unusual for geologic unit boundaries (and, consequently, corresponding radon zone boundaries) to have accuracy limitations of plus or minus tens to several hundred feet and sometimes more. Consequently, radon zone classifications are less certain for locations nearer zone boundaries. CGS does not guarantee the accuracy of radon potential limitations for property parcels based on this map.
The 1:100,000 scale radon zone polygon boundaries are based on boundaries of geologic units from the following geologic maps: the U.S. Geological Survey San Bernardino and Santa Ana 30’ X 60’ quadrangles geologic map (2006); the California Geological Survey Oceanside 30’ X 60’ Quadrangle geologic map (2007) ; and the California Geological Survey Long Beach 30’ X 60’ Quadrangle geologic map (2003), The digital layer of radon potential zones was produced using MapInfo Geographic Information System software and translated to ESRI Shapefile format.
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Feature geometry.
ESRI
Coordinates defining the features.
Unique identification number for each radon zone in the study area.
The chance a home within a given radon zone would have a test result where the U.S. EPA would recommend fixing that home to lower the radon level. Possible zone potentials are: Very High, High, Moderate, Low and Unknown. Please refer to the related report for details.
An area where a certain percentage of homes are likely to need action to reduce radon levels. Please refer to the related report for details.
The geographical region covered by the report.
The report identification number.
Report descriptive name.
URL to report.
Addition information that is relevant to the data presented here.
Length of feature in internal units.
Esri
Positive real numbers that are automatically generated.
Area of feature in internal units squared.
Esri
Positive real numbers that are automatically generated.
The digital layer was produced to be utilized by Orange County government.