Type File Geodatabase Feature Class
This digital layer is intended only for internal use by County of Santa Cruz staff to identify those county areas where homes are more likely to have indoor-air exceeding the U.S. EPA recommended action level of 4.0 picocuries per liter. This digital layer should assist Santa Cruz County 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 areas in Santa Cruz 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 picocurie per liter in indoor air. The polygons are shown on plate (map) for California Geological Survey Special Report 216--Radon Potential in Santa Cruz County, California.
Churchill, R.K., 2010, Radon Potential in Santa Cruz County, California; California Department of Conservation, California Geological Survey, Special Report 216, 92 p. and 1 map plate.
This map layer is intended for use by County of Santa Cruz staff to identify those county areas where homes are more likely to have indoor-air radon concentrations exceeding the U.S. EPA recommended action level of 4.0 picocuries per liter (pCi/L). The four 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); Moderate (5 to 19.9 percent); Low (< 5 percent); or 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 home owner 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 at 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 determinations for property parcels based on this map layer.
| West | -122.320489 | East | -121.580230 |
| North | 37.294338 | South | 36.842493 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
This data was updated to match the projection and boundaries of cnty24k09_1_Poly.shp. However, the shoreline boundary was preserved in the original form to prevent data loss whenever edge matching would threaten to eliminate relevant data mapped in the original GIS work.
Churchill, R.K., 2010, Radon Potential in Santa Cruz County, California; California Department of Conservation, California Geological Survey, Special Report 216, 92 p. and 1 map plate.
publication date
This map layer is intended for use by County of Santa Cruz staff to identify those county areas where homes are more likely to have indoor-air radon concentrations exceeding the U.S. EPA recommended action level of 4.0 picocuries per liter (pCi/L). The four 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); Moderate (5 to 19.9 percent); Low (< 5 percent); or 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 home owner 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 at 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 determinations for property parcels based on this map layer.
The 1:100,000 scale radon zone polygon boundaries are based on shape-file boundaries of geologic units from the 1:62,500 scale U.S. Geological Survey Geologic Map of Santa Cruz County, California: A Digital Database, U.S. Geological Survey Open-File Report 97-489 (translated into MapInfo Geographic Information SystemTable format) with slight modifications based on 1:24,000 scale raster maps from the 2001 U.S. Geological Survey Miscellaneous Field studies Map MF-2373. Radon Zone boundaries for an area approximately 3 square miles in size in the southeast part of Santa Cruz County are based on a raster version of the 1958 California Geological Survey Geologic Atlas--Santa Cruz 1:250,000 sheet. This is an area where the county boundary was modified subsequent to the U.S. Geological Survey mapping and is not included on the 1:62,500 scale geologic map. 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 Santa Cruz County government.