Type File Geodatabase Feature Class
This digital layer is intended for use by Tulare County staff to identify those portions of the 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. 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 Tulare County, California, designated as having high, 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 California Geological Survey Special Report--238--Radon Potential in Tulare County, California, 2016.
Churchill, R.K., 2016, Radon Potential in Western Tulare County, California, California Geological Survey Special Report 238, 92 p., and 1 map plate. Report available for viewing and downloading online at: https://www.conservation.ca.gov/
This map layer is intended for use by Tulare County staff to identify portions of the 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: High (20 percent or more), Low (less than 5 percent), and Unknown (insufficient data to estimate the radon potential). No areas with Moderate radon zone criteria (5 to 19.9 percent of homes with indoor radon concentrations at or above the 4.0 pCi/L action level) were found during map compilation. 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 | -119.577247 | East | -118.760659 |
| North | 36.662769 | South | 35.784063 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
Churchill, R.K., 2016, Radon Potential in Western Tulare County, California, California Geological Survey Special Report 238, 92 p., and 1 map plate. Report available for viewing and downloading online at: https://www.conservation.ca.gov/
This map layer is intended for use by Tulare County staff to identify portions of the 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: High (20 percent or more), Low (less than 5 percent), and Unknown (insufficient data to estimate the radon potential). No areas with Moderate radon zone criteria (5 to 19.9 percent of homes with indoor radon concentrations at or above the 4.0 pCi/L action level) were found during map compilation. 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.
Western Tulare County geology consists largely of alluvial fans and other surficial geologic units. No geologic maps showing surficial geologic units at 1:100,000-scale or at more detailed scales had been published for western Tulare County as a whole at the time of this project. Consequently, part of the radon potential map development for western Tulare County required compilation of a digital layer of these surficial geologic units for use at 1:100,000 scale. Clifton Davenport, of the CGS Regional Mapping Program, developed a surficial geology digital layer for use in this radon mapping project using GIS and a number of information sources listed in Appendix E of SR 238. Figure 1 in SR 238 shows Davenport’s surficial geology layer (at reduced scale) overlain on a simplified Tulare County base map.
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 explanation of the value indicated in the RN_ZONE_POTENTIAL attribute field.
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 Tulare County government.