Water Wells and Pollution Sources of Loudoun County, VA

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Loudoun County, VA, Health Department

Publication_Date: 20140814

Title: Water Wells and Pollution Sources of Loudoun County, VA

Geospatial_Data_Presentation_Form: vector digital data

Description:

Abstract:

WELLPOLL is a data set of water wells and pollution sources in the county that have been identified and assigned a unique SITE-ID number. Cemeteries are included as a potential groundwater and soil pollution source. Within this data set, the majority of wells are individual potable water wells and the majority of pollution sources are individual sewage disposal (septic/drain field) systems. Other types of wells and pollution sources, like cemeteries, also exist in the data and are listed and explained in the data dictionary. Note that all identified pollution sources are not necessarily causing pollution, but rather, can be simply a potential source of pollution. Information for wells comes primarily from State Groundwater Well Completion (GW2) forms completed by well drilling contractors and varies in accuracy and completeness. Information for pollution sources comes primarily from the Health Department permitting and inspection process and/or date of discovery from field verification. This layer is maintained and administered by the Health Department and Department of Building and Development.

Purpose:

WELLPOLL was created to provide an easily accessed record of wells and pollution sources and to link these sites to other geographic data within the GIS. For most records, specific construction information and other physical characteristics are available from the County. This information may be used to aid in the evaluation of the groundwater resource in the case of wells, or of certain types of observed or potential pollution problems in the case of pollution sources.

Supplemental_Information:

The WELLPOLL layer was developed in 1988 by the County's Environmental Health Department. Records were entered into a database from 40 years of historical paper files, which exhibited a wide range of completeness and accuracy. This was an on-going process until early 1996 at which time the layer was no longer maintained. In late 2000, the Department of Building and Development began a process of updating the layer by entering data from the permit files, which had accumulated since 1996. Data are stored in the corporate ArcSDE Geodatabase as a point feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN (vertical datum, if applicable, NAVD88), US Survey foot units.

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -77.954511

East_Bounding_Coordinate: -77.333817

North_Bounding_Coordinate: 39.321706

South_Bounding_Coordinate: 38.848383

Keywords:

Theme:

Theme_Keyword_Thesaurus: none; Employee generated

Theme_Keyword: drain field

Theme_Keyword: pollution source

Theme_Keyword: storativity

Theme_Keyword: septic system

Theme_Keyword: pollution

Theme_Keyword: groundwater

Theme_Keyword: yield

Theme_Keyword: transmissivity

Theme_Keyword: well

Theme_Keyword: sewage disposal

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories

Theme_Keyword: health

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories

Theme_Keyword: health

Place:

Place_Keyword_Thesaurus: none; Employee generated

Place_Keyword: Virginia

Place_Keyword: County

Place_Keyword: Loudoun

Access_Constraints: None

Use_Constraints:

These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, Health Department

Contact_Position: Public Information Counters

Contact_Address:

Address_Type: mailing and physical

Address: MS 68

Address: 1 Harrison Street SE, 2nd Floor

City: Leesburg

State_or_Province: VA

Postal_Code: 20175

Country: US

Contact_Voice_Telephone: (703)777-0234

Contact_Electronic_Mail_Address: health@loudoun.gov

Hours_of_Service: 8:00-5:00 EST, M-F

Native_Data_Set_Environment:

Microsoft Windows Server 2008 Version 6.0 (Build 6002) Service Pack 2; ESRI ArcGIS 10.0.5.4400

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Retention of attribute accuracy throughout the coverage to geodatabase feature class coversion process was ensured by a QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have, on a record by record basis, identical attribution when comparing all concatenated fields to all the user-defined attribution.

Logical_Consistency_Report: Topologically clean

Completeness_Report:

Features may have been eliminated or generalized due to scale and intended use. To assist Loudoun County, Virginia in the maintenance of the data, please provide any information concerning discovered errors, omissions, or other discrepancies found in the data.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Retention of coordinate accuracy throughout the coverage to geodatabase feature class conversion process was ensured by a QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have the same record total, and on a record by record basis, area, perimeter, and length differential of less than +/- 0.5%.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Loudoun County, VA, Health Department

Publication_Date: 19880101

Geospatial_Data_Presentation_Form: Vector digital data

Type_of_Source_Media: None

Source_Contribution:

Loudoun County Health Department decision to develop WELLPOLL coverage in 1998

Process_Step:

Process_Description:

.Records were entered into a database from 40 years of historical paper files, including State Ground Water Well Completion Forms and Health Department permits, inspections, and field checks. They exhibited a wide range of completeness and accuracy. This was an on-going process until early 1996 at which time the layer was no longer maintained.

Process_Date: 19880104

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Loudoun County, VA, Office of Mapping and Geographic Information (OMAGI)

Contact_Position: GIS Systems Analyst

Process_Step:

Process_Description:

The Department of Building and Development began a process of updating the existing layer by entering data from the permit files, which had accumulated since 1996.

Process_Date: 20000101

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, Health Department

Process_Step:

Process_Description:

This data set was part of a batch process that converted legacy data from ArcInfo coverage in Librarian to a single-tiled ArcInfo coverage in preparation for a final coversion to ArcSDE Geodatabase Feature Classes. Data were extracted from Librarian using the EXTRACT TOPOLOGICAL command. Multi-tiled data sets were extracted into multiple coverages and then combined based on the feature type(s). Layers with both polygon and arc feature classes were processed with the Arc commands, MAPJOIN and DISSOLVE. Arc feature classes alone were processed with the Arc commands, APPEND and DISSOLVE. Layers with both arc and point feature classes and point feature classes alone were processed with the Arc command, APPEND. When used, the Arc command, DISSOLVE, was given with the <#all> option. All coverages were then reprojected to HARN 83 using the following .prj file specifications: INPUT PROJECTION STATEPLANE UNITS FEET ZONE 5551 DATUM NAD27 NADCON PARAMETERS OUTPUT PROJECTION STATEPLANE UNITS FEET FIPSZONE 4501 DATUM HPGN NADCON PARAMETERS END This dataset was then converted to a feature class in a geodatabase in ArcSDE

Process_Date: 20040105

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference: Loudoun County

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Entity point

Point_and_Vector_Object_Count: 37848

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Lambert Conformal Conic

Lambert_Conformal_Conic:

Standard_Parallel: 38.03333333333333

Standard_Parallel: 39.2

Longitude_of_Central_Meridian: -78.5

Latitude_of_Projection_Origin: 37.66666666666666

False_Easting: 11482916.66666666

False_Northing: 6561666.666666666

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.000085115229035903

Ordinate_Resolution: 0.000085115229035903

Planar_Distance_Units:

Geodetic_Model:

Horizontal_Datum_Name: D North American 1983 HARN

Ellipsoid_Name: GRS 1980

Semi-major_Axis: 6378137.0

Denominator_of_Flattening_Ratio: 298.257222101

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: GISDBB.GISBROW.WELLPOLL_POINT

Attribute:

Attribute_Label: WE_UPD_SOURCE

Attribute_Definition: Source that created or edited feature class

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 2

Enumerated_Domain_Value_Definition: County

Enumerated_Domain:

Enumerated_Domain_Value: 1

Enumerated_Domain_Value_Definition: Legacy (prec2002)

Enumerated_Domain:

Enumerated_Domain_Value: 0

Enumerated_Domain_Value_Definition: Undetermined

Enumerated_Domain:

Enumerated_Domain_Value: 3

Enumerated_Domain_Value_Definition: Contract

Attribute:

Attribute_Label: WELLPOLL_ID

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: WE_TYPE_HP

Attribute_Definition: Describes if the item is a well or pollution source

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: P

Enumerated_Domain_Value_Definition: Pollution Source

Enumerated_Domain:

Enumerated_Domain_Value: W

Enumerated_Domain_Value_Definition: Well

Attribute:

Attribute_Label: WE_ID_SEQ

Attribute_Definition:

A sequential cataloging number to create unique SITE-ID numbers when multiple sites of the same TYPE and ID-CODE are completed during the same year.

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: User defined text code

Attribute:

Attribute_Label: WE_ID_YEAR

Attribute_Definition:

The year the well or pollution source was completed or date of discovery from field verification identifier.

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: User defined text code

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: WE_OLD_ID

Attribute_Definition:

Same as the SITE-ID except it uses a two-digit year of completion or date of discovery from field verification identifier.

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: User defined text code

Attribute:

Attribute_Label: WE_ID_CODE

Attribute_Definition:

A four-letter code categorizing the type of well or pollution source

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: PSBD

Enumerated_Domain_Value_Definition: Building (e.g. barn)

Enumerated_Domain:

Enumerated_Domain_Value: PCEM

Enumerated_Domain_Value_Definition: Cemetery

Enumerated_Domain:

Enumerated_Domain_Value: WWCS

Enumerated_Domain_Value_Definition: Community spring

Enumerated_Domain:

Enumerated_Domain_Value: WWDU

Enumerated_Domain_Value_Definition: Dug well

Enumerated_Domain:

Enumerated_Domain_Value: WWTS

Enumerated_Domain_Value_Definition: Test well

Enumerated_Domain:

Enumerated_Domain_Value: WWUN

Enumerated_Domain_Value_Definition: Unknown well

Enumerated_Domain:

Enumerated_Domain_Value: WWHP

Enumerated_Domain_Value_Definition: Heat pump well

Enumerated_Domain:

Enumerated_Domain_Value: PSSD

Enumerated_Domain_Value_Definition: Sewage disposal system

Enumerated_Domain:

Enumerated_Domain_Value: PSTP

Enumerated_Domain_Value_Definition: Sewage treatment plant

Enumerated_Domain:

Enumerated_Domain_Value: WWNC

Enumerated_Domain_Value_Definition: Non-community well

Enumerated_Domain:

Enumerated_Domain_Value: WWQM

Enumerated_Domain_Value_Definition: Water quality monitoring well

Enumerated_Domain:

Enumerated_Domain_Value: WWOB

Enumerated_Domain_Value_Definition: Observation wel

Enumerated_Domain:

Enumerated_Domain_Value: WWDH

Enumerated_Domain_Value_Definition: Dry well

Enumerated_Domain:

Enumerated_Domain_Value: WWII

Enumerated_Domain:

Enumerated_Domain_Value: WWSP

Enumerated_Domain_Value_Definition: Spring

Enumerated_Domain:

Enumerated_Domain_Value: WWIR

Enumerated_Domain_Value_Definition: Irrigation well

Enumerated_Domain:

Enumerated_Domain_Value: WWIN

Enumerated_Domain_Value_Definition: Individual well

Enumerated_Domain:

Enumerated_Domain_Value: PSSW

Enumerated_Domain_Value_Definition: Solid waste/landfill

Enumerated_Domain:

Enumerated_Domain_Value: WWID

Enumerated_Domain:

Enumerated_Domain_Value: WWCO

Enumerated_Domain_Value_Definition: Community well

Enumerated_Domain:

Enumerated_Domain_Value: WWMN

Enumerated_Domain_Value_Definition: Monitor well

Enumerated_Domain:

Enumerated_Domain_Value: PSCS

Enumerated_Domain_Value_Definition: Chemical storage tank

Attribute:

Attribute_Label: WE_SITE_ID

Attribute_Definition:

A unique alphanumeric identifier for each well or pollution source. Composed of the four-letter ID-CODE (what the item is), the four-digit year of completion, and a four digit sequential cataloging number.

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: User defined text code

Attribute:

Attribute_Label: WE_UPD_DATE

Attribute_Definition: Date that feature class was created or modified

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: User defined text code

Attribute:

Attribute_Label: WE_UPD_USER

Attribute_Definition:

Not for public distribution. Internal User ID of editor creating or modifying feature class

Attribute_Definition_Source: Loudoun County

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Contact_Position: Public Information Counter

Contact_Address:

Address_Type: mailing and physical

Address: MS 65

Address: 1 Harrison Street SE, 2nd Floor

City: Leesburg

State_or_Province: VA

Postal_Code: 20175

Country: US

Contact_Voice_Telephone: (703)771-5778

Contact_Facsimile_Telephone: (703)771-5075

Contact_Electronic_Mail_Address: mapping@loudoun.gov

Hours_of_Service: 8:00-4:30 EST, M-F

Distribution_Liability: See access and use constraints information.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: DXF

Format_Specification: AutoCad Digital Exchange File

Digital_Transfer_Option:

Offline_Option:

Offline_Media: dvd

Fees:

Loudoun County distributes spatial data in ArcGIS database or shapefile & DXF format for the cost of reproduction. Countywide spatial datasets may be purchased for $22 per DVD for up to 4.5 GB of data. There is a $100 surcharge to purchase countywide topography, and a $3 charge if the item is to be mailed. If the customer wants the data in DXF format and/or would like OMAGI to custom select specific geographic areas of the County, there is an additional $7 per 15 minute increment labor charge. Select aerial imagery is also available.

Ordering_Instructions:

Size limit: 4.5 GB. Visit our website at: <http://www.loudoun.gov/omagi>, click on "Loudoun County Mapping Documents & Order Forms." The "Forms" directory will lead you to custom & standard (countywide) data order forms. Hardcopy maps may also be available; please contact the Mapping Office Public Information Counter for more information regarding all data requests.

Metadata_Reference_Information:

Metadata_Date: 20140820

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Loudoun County, VA, Office of Mapping & Geographic Information (OMAGI)

Contact_Position: Metadata Specialist

Contact_Address:

Address_Type: mailing and physical

Address: MS 65

Address: 1 Harrison Street SE, 2nd Floor

City: Leesburg

State_or_Province: VA

Postal_Code: 20175

Country: US

Contact_Voice_Telephone: (703)771-5778

Contact_Facsimile_Telephone: (703)771-5075

Contact_Electronic_Mail_Address: mapping@loudoun.gov

Hours_of_Service: 8:00-4:30 EST, M-F

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Use_Constraints:

This metadata reflects the source Geodatabase format and specific elements may not apply if your data is exported to SHP or DXF products. User must be aware that changes to data schema occur during data export that may not be reflected in this metadata, which represents Loudoun County's corporate geodatabase. Acknowledgement of Loudoun County would be appreciated in the use of this metadata.