Radon Zones

File Geodatabase Feature Class

Tags
Radon, California, California Geological Survey, California Department of Conservation

Summary

This digital layer is intended for use by 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.

Description

This digital layer contains polygons (vector format) of portions of 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. Only a portion of California is covered by the studies included in this dataset.

The included study areas are:
Santa Barbara County, 1995;
Southern LA County, SR 182, 2005;
Ventura County, SR 194, 2005;
Monterey County, SR 201, 2007;
San Luis Obispo County, SR 208, 2008;
Lake Tahoe Region (portions of Alpine, El Dorado, Nevada, and Placer Counties), SR 211, 2009;
Santa Cruz County, SR 216, 2010;
Palos Verdes (Los Angeles County), SR 224, 2012;
San Mateo County, SR 226, 2014;
Orange County, SR 232, 2015;

Credits

California Geological Survey, California Department of Conservation

Use limitations

This map layer is intended for use by San Mateo 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 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), 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.

Extent
'' ''

West	-122.525492	East	-117.412779
North	39.374917	South	33.386748

'' ''

Scale Range

There is no scale range for this item.

Topics and Keywords

'' Themes or categories of the resource geoscientificInformation''

'' *Content type Downloadable Data''

'' Place keywords California'' '' ''
'' '' '' Theme keywords Mineral hazards, radon, Rn, indoor radon, Geology, radon potential'' '' ''
'' ''

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Citation

'' *TitleRadonZones'' '' Publication date2016-07-12''

'' Presentation formats *digital map''

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Citation Contacts

'' Responsible party '' '' '' Individual's nameRon Churchill'' '' Organization's nameCalifornia Geological Survey'' '' Contact's positionSenior Engineering Geologist'' '' Contact's role originator''

'' '' Contact information ''

'' '' Address '' '' '' Delivery point801 K Street, MS 12-31'' '' CitySacramento'' '' Administrative areaCA'' '' Postal code95814'' '' e-mail addressron.churchhill@conservation.ca.gov'' ''
''

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'' ''

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Resource Details

'' Dataset languages *English(UNITED STATES) '' '' Dataset character set utf8 - 8 bit UCS Transfer Format''

'' Spatial representation type *vector''

'' *Processing environment Version 6.2 (Build 9200) ; Esri ArcGIS 10.4.1.5686''

'' Credits '' '' '' California Geological Survey, California Department of Conservation
'' '' '' ArcGIS item properties '' '' '' *NameRadonZones'' ''

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Extents

'' Extent '' '' '' Vertical extent '' '' '' *Minimum value0.000000'' '' *Maximum value0.000000''

'' '' '' Extent '' '' '' Geographic extent '' '' '' Bounding rectangle '' '' '' Extent type Extent used for searching'' '' *West longitude-122.525492'' '' *East longitude-117.412779'' '' *North latitude39.374917'' '' *South latitude33.386748'' '' *Extent contains the resourceYes'' ''
'' '' '' Extent in the item's coordinate system '' '' '' *West longitude-13639475.365200'' '' *East longitude-13070330.760600'' '' *South latitude3946751.547500'' '' *North latitude4775518.428600'' '' *Extent contains the resourceYes'' ''

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Resource Points of Contact

'' Point of contact '' '' '' Individual's nameJohn Churchill'' '' Organization's nameCalifornia Geological Survey'' '' Contact's positionSupervising Engineering Geologist'' '' Contact's role point of contact''

'' '' Contact information ''

'' '' Phone '' '' '' Voice916-323-7696'' ''
'' Address '' '' '' Typephysical'' '' Delivery point801 K Street, MS 12-31'' '' CitySacramento'' '' Administrative areaCA'' '' Postal code95814'' '' e-mail addressjohn.clinkenbeard@conservation.ca.gov'' ''
''

HideContact information

'' ''

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Resource Constraints

'' Constraints '' '' '' Limitations of use '' '' '' This map layer is intended for use by 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 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), 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.
'' '' ''

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Spatial Reference

'' ArcGIS coordinate system '' '' '' *TypeProjected'' '' *Geographic coordinate referenceGCS_WGS_1984'' '' *ProjectionWGS_1984_Web_Mercator_Auxiliary_Sphere'' '' *Coordinate reference details '' '' '' Projected coordinate system '' '' '' Well-known identifier102100'' '' X origin-20037700'' '' Y origin-30241100'' '' XY scale10000'' '' Z origin-100000'' '' Z scale10000'' '' M origin-100000'' '' M scale10000'' '' XY tolerance0.001'' '' Z tolerance0.001'' '' M tolerance0.001'' '' High precisiontrue'' '' Latest well-known identifier3857'' '' Well-known textPROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator_Auxiliary_Sphere"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0],AUTHORITY["EPSG",3857]]'' '' '' ''
'' Reference system identifier '' '' '' *Value3857'' '' *CodespaceEPSG'' '' *Version8.8(9.3.1.2)''

''

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Spatial Data Properties

'' Vector ''

'' '' *Level of topology for this dataset geometry only''

'' Geometric objects '' '' '' Feature class nameRadonZones'' '' *Object type composite'' '' *Object count37'' ''
''

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'' ArcGIS Feature Class Properties ''

'' '' Feature class nameRadonZones'' '' '' *Feature typeSimple'' '' *Geometry typePolygon'' '' *Has topologyFALSE'' '' *Feature count37'' '' *Spatial indexTRUE'' '' *Linear referencingTRUE'' ''
''

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Distribution

'' Distribution format '' '' '' *NameFile Geodatabase Feature Class''

'' '' Transfer options '' '' '' Online source '' '' '' Locationhttp://docarcgis:6080/arcgis/rest/services/CGS/RadonPotentialZones/MapServer'' ''
''

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Fields

'' Details for objectRadonZones ''

'' '' *TypeFeature Class'' '' *Row count37''

'' FieldOBJECTID''

'' '' *AliasOBJECTID'' '' *Data typeOID'' '' *Width4'' '' *Precision0'' '' *Scale0'' '' *Field description'' '' '' Internal feature number.
'' '' '' *Description source'' '' '' Esri
'' '' '' *Description of values'' '' '' Sequential unique whole numbers that are automatically generated.
'' ''

''

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'' FieldShape''

'' '' *AliasShape'' '' *Data typeGeometry'' '' *Width0'' '' *Precision0'' '' *Scale0'' '' *Field description'' '' '' Feature geometry.
'' '' '' *Description source'' '' '' Esri
'' '' '' *Description of values'' '' '' Coordinates defining the features.
'' ''

''

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'' FieldZONE_ID''

'' '' *Data typeString'' '' *Width15'' '' *AliasZONE_ID'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' Unique identification number for each radon zone in the study area.
'' '' ''

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'' FieldRn_ZONE_POTENTIAL''

'' '' *Data typeString'' '' *Width15'' '' *AliasRn_ZONE_POTENTIAL'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' 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.
'' '' ''

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'' FieldDESCRIPTION_RN_ZONE''

'' '' *AliasDESCRIPTION_Rn_ZONE'' '' *Data typeString'' '' *Width254'' '' *Precision0'' '' *Scale0''

''

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'' FieldSTUDY_AREA''

'' '' *Data typeString'' '' *Width140'' '' *AliasSTUDY_AREA'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' The name of the study area (generally the county covered)
'' '' ''

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'' FieldCGS_REPORT''

'' '' *Data typeString'' '' *Width15'' '' *AliasCGS_REPORT'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' The California Geological Survey report id.
'' '' ''

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'' FieldREPORT_NAME''

'' '' *AliasREPORT_NAME'' '' *Data typeString'' '' *Width254'' '' *Precision0'' '' *Scale0''

''

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'' FieldAREA_ACRES''

'' '' *AliasAREA_ACRES'' '' *Data typeDouble'' '' *Width8'' '' *Precision0'' '' *Scale0''

''

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'' FieldCOMMENTS''

'' '' *Data typeString'' '' *Width254'' '' *AliasCOMMENTS'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' Brief notes on the report or zone.
'' '' ''

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'' FieldOBJECTID_1''

'' '' *AliasOBJECTID_1'' '' *Data typeInteger'' '' *Width4'' '' *Precision0'' '' *Scale0''

''

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'' FieldZONE_ID_1''

'' '' *AliasZONE_ID'' '' *Data typeString'' '' *Width15'' '' *Precision0'' '' *Scale0''

''

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'' FieldREPORT_LINK''

'' '' *Data typeString'' '' *Width200'' '' *AliasREPORT_LINK'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' URL for the original report
'' '' ''

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'' FieldDATA_LINK''

'' '' *Data typeString'' '' *Width200'' '' *AliasDATA_LINK'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' URL for GIS data downloads.
'' '' ''

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'' FieldMETADATA_LINK''

'' '' *Data typeString'' '' *Width200'' '' *AliasMETADATA_LINK'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' URL for metadata
'' '' ''

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'' FieldPopupInfo''

'' '' *Data typeString'' '' *Width2000'' '' *AliasPopupInfo'' '' *Precision0'' '' *Scale0'' '' Field description '' '' '' A compiled HTML snippet for use in popup info boxes
'' '' ''

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'' FieldShape_Length''

'' '' *AliasShape_Length'' '' *Data typeDouble'' '' *Width8'' '' *Precision0'' '' *Scale0'' '' *Field description'' '' '' Length of feature in internal units.
'' '' '' *Description source'' '' '' Esri
'' '' '' *Description of values'' '' '' Positive real numbers that are automatically generated.
'' ''

''

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'' FieldShape_Area''

'' '' *AliasShape_Area'' '' *Data typeDouble'' '' *Width8'' '' *Precision0'' '' *Scale0'' '' *Field description'' '' '' Area of feature in internal units squared.
'' '' '' *Description source'' '' '' Esri
'' '' '' *Description of values'' '' '' Positive real numbers that are automatically generated.
'' ''

''

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Metadata Details

'' *Metadata languageEnglish(UNITED STATES) '' '' Metadata character set utf8 - 8 bit UCS Transfer Format''

'' Scope of the data described by the metadata *dataset'' '' Scope name *dataset''

'' *Last update2016-07-13''

'' ArcGIS metadata properties '' '' '' Metadata formatArcGIS1.0'' '' Metadata styleFGDC CSDGM Metadata''

'' Created in ArcGIS for the item2016-07-1216:51:23'' '' Last modified in ArcGIS for the item2016-07-1309:44:57''

'' Automatic updates '' '' '' Have been performedYes'' '' Last update2016-07-1309:44:57'' ''
''

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Metadata Contacts

'' Metadata contact '' '' '' Contact's role point of contact''

''

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