Internal feature number.

ESRI

Feature geometry.

ESRI

ArcView Legend. Text field for symbolizing polygon feature types on a map. For a legend, the following substitutions can be used: value GA - label GA; value GAA,GAAs - label GAA, GAAs; value GB - label GB; value GC - label GC; value To GA,GAA - label GA, GAA May be impaired.

State of Connecticut, Department of Energy and Environmental Protection

Ground Water Quality Polygon Code. Text values that identify water quality feature types. Certain attributes (GAA-Well, GAA-NY, GA-Impaired, GAA-Impaired and GAA-Well-Impaired) are used only in the digital data for retrieval of features and not as labels (unless LABEL_FLG = "Y"). The Enumerated_ Domain_Value_Definitions come from the Summary of the Water Quality Standards and Classifications found at the http://www.dep.state.ct.us/wtr/wq/wqsinfo.htm website.

State of Connecticut, Department of Energy and Environmental Protection

The field identifies polygon features that are 500 ft buffer areas around public water supply wells.

State of Connecticut, Department of Energy and Environmental Protection

Area of a polygon feature in acres.

State of Connecticut, Department of Energy and Environmental Protection

The field is used to select those polygon features that should be labele.

State of Connecticut, Department of Energy and Environmental Protection

This data source provided a visual record of the ground water classification features and the classification applied to each feature.

publication date

This data source provided the ground water classification features and the classification applied to each feature for digitizing.

calendar date

This data source provided the base map and the registration points for digitizing the ground water classification features.

publication date

This data source provided the ground water classification features and the classification applied to each feature for the Housatonic, Southwest Coastal and Hudson basins for digitizing.

calendar date

This data layer provided the point locations of Public Water Supply Wells which were buffered to a radius of 500 feet to create areas representing the areas of contribution.

publication date

This data layer provided polygon areas representing the areas of contribution to the public water supply by buffering the point locations of Public Water Supply Wells to a radius of 500 feet.

calendar date

These data layers provided line features to build the polygons where the Ground Water Quality Classifications features were coincident with the 1:24,000-scale base map. Included are 1:24,000-scale Hydrography, Roads and Trails, Town Boundaries and Railroads.

publication date

This data layer provided line features to build the polygons where the Ground Water Quality Classifications features were coincident with the 1:24,000-scale natural drainage basins published by the State of Connecticut, Department of Environmental Protection.

publication date

This data source is a point data layer of surface and groundwater discharges that have received a wastewater discharge permit from the state, are active or historic (no longer active) waste disposal sites, salt storage, or are locations of spills, leaks, deposits or discharges of a variety of liquid or solid wastes. This data provided a guide for the delineation and attribution of Water Quality Classifications areas that were updated.

publication date

This data source provided additional tabular information about the Leachate and Wastewater Discharge Sources. It is published as booklet to accompany Leachate and Wastewater Discharge Sources maps.

calendar date

This source provided guidance for the delineation and attribution of Water Quality Classifications areas along the coast. This source is the classifications of shellfishing growing waters for  Connecticut shoreline towns. The shellfishing areas are delineated and classified by the Connecticut Department of Agriculture, Bureau of Aquaculture.

publication date

This data source provided maps of  Water Quality Classifications data, Leachate and Wastewater Discharge Sources data, Base map data and Drainage Basin data covering the Housatonic River and Southwest Coastal Basins for the purpose of in-house reviewing and updating of the Water Quality Classifications by DEP staff.

calendar date

This source provided town-based maps of the Water Quality Classifications data, Base Map data layers, Drainage Basin data and Leachate and Wastewater Discharge Sources data  for the Housatonic River and Southwest Coastal Basins for the purpose of reviewing Water Quality Classifications by town officials.

publication date

This source provided the updated Water Quality Classifications data on town-based maps for the Housatonic River and Southwest Coastal Basins for use during the Public Hearing phase of the Water Quality Classifications Maps adoption process.

publication date

This data source refers to all surface and ground water classification features combined in one statewide data layer. Since initial publication in 1995, subsequent publications or editions of the data layer were generated by the State of Connecticut in order to change data format, convert from NAD 27 to NAD 83, or add and modify features. Consequently, over the period of many years, different copies of this data layer were produced, representing various steps in the data layer development and maintenance process (metadata lineage). Changes made to the entire data layer are reflected in metadata process steps where this particular data source is cited as both the Source Used and the Source Produced. The Water Quality Classifications is in ArcInfo Coverage format.

This data source refers to all ground water quality classifications features separated from the statewide water quality classifications data layer and with the hydrography polygon features removed (erased). Since initial publication in 2000, subsequent publications or editions of the data layer were generated by the State of Connecticut in order to add and modify features. Consequently, over a period of years, different copies of this data layer were produced. Changes made to the entire data layer are reflected in metadata process steps where this particular data source is cited as both the Source Used and the Source Produced. The Ground Water Quality Classifications is in ArcInfo Coverage format.

publication date

This data source refers to all surface water quality classifications features separated from the statewide water quality classifications data layer and with additional hydrography line and polygon features added. The Surface Water Quality Classifications is in ArcInfo Coverage format.

publication date

Includes all polygon features from the Ground Water Quality Classifications where the AV_LEGEND attribute was not blank (AV_LEGEND  <> " "). This criterion only includes true ground water classifications features and excludes secondary polygon features from the ArcInfo coverage that represent areas where surface water features exist and the ground water is not classified. Ground_Water_Quality_Classifications_Polygon.shp is in Shapefile format.

Statewide geodatabase format ground water classification datalayer. Includes all ground water classifications polygon features except public water supply well buffered areas or final aquifer protection areas. Includes temporary (and potentially inaccurate) ground water classifications under surface waters. This layer forms the base for the derived WaterQualityClass_Ground datalayer.

publication date

Statewide geodatabase format surface water quality classifications for all waterbody area features such as lakes, ponds, bays, harbors, sounds and rivers and streams large enough to be represented as polygons at 1:24,000 scale.

publication date

Statewide geodatabase format surface water quality classifications for all waterbody line features such as rivers and streams represented as lines at 1:24,000 scale.

publication date

Statewide geodatabase format datalayer of 500 foot buffer areas around Public Water Supply Wells. These buffers are ground water classification areas and are added to the WaterQualityClass_Ground_Master datalayer during creation of the final WaterQualityClass_Ground datalayer. These buffered areas are kept separate for easier maintenance of the ground water classifications data.

Statewide geodatabase format of ground water quality classification as polygon features. It includes the 500 ft buffered areas around public water supply wells and final aquifer protection areas (as this data is adopted). It excludes ground water classifications under surface waterbodies.

publication date

Statewide shapefile format of ground water quality classification as polygon features. It includes the 500 ft buffered areas around public water supply wells and final aquifer protection areas (as this data is adopted). It excludes ground water classifications under surface waterbodies.

publication date

Statewide shapefile format of surface water quality classification as polygon features.

publication date

Statewide shapefile format of surface water quality classification as line features.

publication date

Provides the State of Connecticut and State waters as a single polygon

publication date

The ground water quality class GA assigned to the State of Connecticut and state waters as a single polygon. Provides this class during the creation of the Source 23 - WaterQualityClass_Ground.

Provides a recognizable regularly-sized, systematically-organized set of polygons.

publication date

Process Overview - The original Water Quality Classifications mapping (e.g. Source 1 Adopted Water Quality Classifications Map Sheets) contain both Surface Water and Ground Water Classifications. Both surface water and ground water features were processed as this information was recreated in a digital form as the Source 15 Water Quality Classifications data layer. The Water Quality Classifications data layer was maintain with both surface and ground  water features until 2000 when the data model was changed to separate Surface Water Quality Classifications and Ground Water Quality Classifications. Process steps up to this time refer to both the surface and ground water features.

Feature digitizing and attribution (using tablet digitizing and feature selection methods) - Source 2 Water Quality Classifications Mylar Quadrangles and Source 4 Draft Water Quality Classifications Quadrangles depict both surface water and ground water quality classifications. From these two sources line features (polygons began as outlines) for all classifications were captured and attributed as work progressed quadrangle by quadrangle in the creation of  Source 15 Water Quality Classifications. Using ESRI ArcInfo software, features were tablet digitized by registering the source map to the digitizing tablet and using the crosshairs of the digitizer's mouse to manually capture the geometry (location) of features drafted on the map. The source map was registered to the digitizing tablet by first digitizing (entering) the locations of four corner registration points shown on the USGS 7.5 minute topographic quadrangle maps. ArcInfo software compared the values of the digitized coordinates with the actual (true) values for the quadrangle corner (tic) features. The Root Mean Square (RMS) error generated by the ArcInfo software indicated the amount of error involved in transforming coordinates from the registered map to the digital layer.  RMS errors higher than 0.004 were not acceptable and required re-registering the source map by digitizing the tic locations again. The source maps were positioned on top of the USGS Topographic Quadrangles for a best fit. After correct registration, individual features that were not coincident with existing 1:24,000-scale Base Map data layers (hydrography, roads and trails, railroads, town boundaries) or 1:24,000-scale Drainage Basins were manually digitized off Source 2 or Source 4 and assigned WQCLASSA values for line features, including outlines of ground water quality classifications. Lines were not digitized for ground water quality Class GA. Where necessary, additional minor edits to feature geometry were manually digitized on the screen (heads-up digitizing) at display scales greater than 1:24,000. Using ESRI ArcInfo software, features appearing in and coincident with the existing 1:24,000-scale Base Map Data Layers (hydrography, roads and trails, railroads, town boundaries) or 1:24,000-scale Drainage Basins were manually selected, copied and used as the basis for features in the Water Quality Classifications. Hydrography features were used for surface water quality classifications features. Only features classified other than A or SA were taken from Hydrography, except for Class A waters emanating from GAA (public water supply watershed) areas. Feature geometry (location) required partial editing and adjustment to match information on Source 1 Adopted Water Quality Classifications Mylar Maps, Source 2 and Source 4. Using ESRI ArcInfo software, the Water Quality Classifications was built as both line features and  polygon features. The polygons were checked and edited to follow the topology rules. Label points were automatically added. Polygon features were assigned WQCLASSP attribute values based on information in Source 1, Source 2 and Source 4. Ground water quality Class GA was not designated since no polygon features for it were digitized directly in the Water Quality Classifications. Any ground water areas not otherwise classified are assumed to be Class GA. Most surface water quality Class A and SA were not designated since only certain instances of these features were created directly in the Water Quality Classifications. Most surface water quality Class A and  SA features were represented by those features in the 1:24,000-scale Hydrography that were not incorporated in the Water Quality Classifications. Feature location and attribute accuracy was visually checked and inspected by symbolizing and labeling features according to attribute value on the computer screen and on hard copy paper maps, and comparing this information to the orginal source data. These check plot maps were printed at the same scale as the Water Quality Classifications Mylar Quadrangles in order to visually inspect digitizing quality and the assignment of attribute values.

Feature creation and attribution  - Using ESRI ArcInfo software,  the Public Water Supply Wells were buffered to a radius of 500 feet to create areas that represent areas of contribution. Features were assigned WQCLASSP attribute values based on information in the Adopted Water Quality Classifications Mylar Map Sheets. 

Combining of data layers - Using ESRI ArcInfo software, the Public Water Supply Well Buffers features were added to the Water Quality Classifications using the Update method. Feature location and attribute accuracy was visually checked and inspected by symbolizing and labeling features according to attribute value both on the computer screen and on hard copy paper maps, and comparing this information to the orginal source data.

Update of  water quality in two major basins - In 1995, the DEP revised Water Quality Classifications in the Housatonic River and Southwest Coastal Basins. The source information for Water Quality Classifications for these two basins was in draft form and was compiled prior to 1986. A set of quadrangle-based maps showing the Water Quality Classifications, Leachate and Wastewater Discharge Sources, Base map data layers and Drainage Basins was prepared for review by DEP staff. The results of the staff review were compiled into a list of changes. A set of town-based maps with the Water Quality Classifications, Leachate and Wastewater Discharge Sources, Base map data layers and Drainage Basins was prepared and mailed to each town for review by town officials. The results of the town review were compiled into a list of changes. State of Connecticut, Department of Environmental Protection staff Randy May and Fred Banach conducted a review of the Water Quality Classifications based on the staff review, the town review, the Shellfish Area Classifications and their own extensive knowledge and experience of the area and the conditions. During the review notes for updates were placed on copies of  the same maps that DEP staff reviewed. Features and attributes of the Water Quality Classifications data were revised to reflect the decisions of  May and Banach. 1:24,000-scale Base Map data layers and 1:24,000-scale Drainage Basin data provided the source for coincident features and other feature changes were digitized on screen. Surface water and ground water were revised. The Surface Water Quality  Classifications are required by statute to be adopted through a public process. The Water Quality Classifications were printed on town-based maps and made available at the DEP and at a location in each town for a period of public review and comment. The maps were available at the Public Hearings held at several locations in these two major basins. Comments from the public review process were incorporated into the Water Quality Classifications data where acceptable by the DEP. After the revisions were finalized the adopted date for the Water Quality Classifications features within Housatonic River and Southwest Coastal Basins became 1997

Federal review - The Environmental Protection Agency (EPA) conducted a review of the updated Water Quality Classifications maps for the Housatonic River and Southwest Coastal Basins in 1997. The surface water quality classifications are subject to federal review and adoption. Edits were made to the digital data for changes to the water quality maps agreed to by the EPA and the DEP. The most significant changes were made to the marine water quality classifications along the coastline of the Southwest Coastal Basin.

Datum conversion - Using ESRI ArcInfo software, the Water Quality Classifications was converted from the Connecticut State Plane Coordinate System of 1927 (NAD27) to the Connecticut State Plane Coordinate System of 1983 (NAD83). The NADCON (North American Datum CONversion) data transformation was used.

Data model change, data layer separation - The Water Quality Classifications was separated into two data layers, one for Ground Water Quality Classifications and one for Surface Water Quality Classifications. The reasons for this change are several: the user will have the choice of displaying one or both of the classifications data layers without manipulating the data, Surface Water Quality Classifications and Ground Water Quality Classifications potentially have different user communities, Surface Water Quality Classifications has oversight by the Environmental Protection Agency, Ground Water Quality Classifications are subject to changes in classification through an application process and may change twice yearly. The separation was accomplished using ESRI ArcInfo software by eliminating the Ground Water features from a copy of the Water Quality Classifications and by eliminating the Surface Water features from a copy of the Water Quality Classifications. The Public Water Supply Wells Buffers were added to the Ground Water Quality Classifications again using the ArcInfo Update command. Each new data layer was inspected on-screen and errors in topology, pseudonodes and label errors were corrected. Printed maps at 1:24,000 scale were inspected and the data was corrected for coding errors.

Data model change, integration with hydrography - After the Water Quality Classifications data layer was separated into Ground Water Quality Classifications and Surface Water Quality Classifications, the Surface Water Quality Classifications needed to be fully integrated with the Hydrography. The reasons for this change are that the user can get a complete picture of water quality classifications without displaying the Hydrography and the data can be queried in a web or other GIS application. Previously, the user had to assume that water features not found in the Water Quality Classifications  were Class A and that areas not found in Ground Water Quality Classifications were Class GA. Using ESRI ArcInfo software and several processing iterations, the attributes of the Surface Water Quality Classifications were transferred to a copy of the Hydrography data. The line feature attributes and the polygon feature attributes were processed separately. Line features were split to allow the correct placement of line attributes. Polygon features were split where necessary by on-screen digitizing of closure lines to allow the correct placement of polygon attributes. The Ground Water Quality Classifications contained areas that were beneath surface waters where DEP does not classify ground water. Using ESRI ArcInfo software, the water features were isolated from the Hydrography and used with the ArcInfo Erase command to eliminate (knock out) polygon areas where water features exist in Hydrography. Both new data layers were inspected on-screen for errors in topology. Printed maps at 1:24,000 scale were inspected and the data was corrected for coding errors.

Attribute enhancements - WQCLASSP and WEL_LEGEND attributes were changed from storing abbreviated values in upper case to full length values in both upper and lower case. 

Export to Shapefile Format - Converted data from ArcInfo Coverage to Shapefile format and named the shapefile Ground_Water_Quality_Classifications_Polygon.shp. Excluded the AREA, PERIMETER, WQGCLASS#, WQGCLASS-ID attributes from the Shapefile because their values are only maintained by ArcInfo software with data that is in ArcInfo Coverage format. Includes all polygon features from the Ground Water Quality Classifications where the AV_LEGEND attribute was not blank (AV_LEGEND <> " "). This criterion only includes ground water classifictations areas and excludes  polygon features from the ArcInfo coverage that represent areas where surface water features exist and ground water is not classified.

Convert to GeoDatabase Feature Class format - Water Quality Classifications datalayers were converted to geodatabase format feature classes according to the following steps: defined new Feature Class, imported the spatial reference, defined or imported the attribute definitions, loaded features from coverage, imported metadata from shapefile, edited metadata. The unpublished parent to Source 16 - Ground Water Quality Classification was converted to polygon feature class Source 19 - WaterQualityClass_Ground_Master.
Source 16 - Ground Water Quality Classification was not converted from coverage format. The equivalent datalayer, Source 20 - WaterQualityClass_Ground, is generated through overlay techniques from Source 19 - WaterQualityClass_Ground_Master, Source 23 - Public Water Supply Well Buffers 500 Ft and Source 21 -  WaterQualityClass_Surface_Poly polygon feature classes. Source 17 - Surface Water Quality Classification was converted to polygon feature class Source 21 - WaterQualityClass_Surface_Poly and to line feature class Source 22 - WaterQualityClass_Surface_Line. Source 6 - Public Water Supply Well Buffers was converted to polygon feature class Source 23 - Public Water Supply Well Buffers 500 Ft. 

Spatial Reference Properties used for Feature Classes:
Coordinate System: NAD_1983_StatePlane_Connecticut_FIPS_0600_Feet
XY Domain MinX: 100000; MaxX: 2247483.645 XY Domain MinY: 200000; MaxY: 2347483.645
Precision: 1000

WaterQualityClass_Ground_Master feature class was reworked to eliminate the empty areas originally introduced by erasing the ground water quality layer with the surface water quality layer. The original purpose of the erasure was to eliminate ground water classifications occuring under surface waterbodies. This erasure step now occurs live during creation of the WaterQualityClass_Ground feature class derived from the WaterQualityClass_Ground_Master. To create the new WaterQualityClass_Ground_Master feature class the tools and processes available in ESRI ArcGIS 9.1 were employed. Automated and manual methods were used iteratively to eliminate "doughnut holes" and replace empty areas with appropriately attributed polygons. Where ground water polygons changed classification across waterbodies, centerlines following the waterbodies were manually digitized to form the boundary between classifications. Source 19 - WaterQualityClass_Ground_Master contains continuous Ground Water Quality polygon features, including temporary features that are fully or partially replaced during the generation of the final ground water datalayer, Source 20 - WaterQualityClass_Ground. The steps used to create Source 20 - WaterQualityClass_Ground are 1) used the ESRI ArcMap 9.1 Update tool to replace ares of Source 19 - WaterQUalityClass_Ground_Master with Source 23 - Public Water Supply Well Buffers 500 Ft 2) used the ESRI ArcMap 9.1 Erase tool to eliminate areas contained in Source 21 - WaterQualityClass_Surface_Poly from the output datalayer resulting from step 1. This method of maintaining the Ground Water Quality CLassifications datalayer simplifies the process and reduces errors. Changes can be made to any of the participating datalayers or another datalayer can be introduced and a new Source 20 - WaterQualityClass_Ground can be generated.The attribute field HY_LEGEND was retained for WaterQualityClass_Surface_Line, for maintenance purposes, but dropped from WaterQualityClass_Surface_Poly. During the conversion from coverage to geodatabase format certain attribute fields were dropped from the surface water quality. The attribute fields HYARC_COD, HYPOLY_COD, STREAM_NO, STREAM, STREAM_NO2, LAKE_NO, LAKE, LAKE_NO2, BAY_NO, BAY_NO2, HARBOR_NO, HARBOR_NO2, SOUND_NO and SOUND_NO2 were dropped from WaterQualityClass_Surface_Line and WaterQualityClass_Surface_Poly.

Export to Shapefile Format - Converted data from Geodatabase to Shapefile format and named the shapefiles after the geodatabase version. Excluded the SHAPE_Area and SHAPE_Length fields because their values are not maintained by the shapefile format. Excluded HY_LEGEND attribute field from WaterQualityClass_Surface_Line.shp.WaterQualityClass_Ground.shp includes all polygon features from WaterQualityClass_Ground. WaterQualityClass_Surface_Poly.shp includes all polygon features from WaterQualityClass_Surface_Poly.  WaterQualityClass_Surface_Line.shp includes all line features from WaterQualityClass_Surface_Line except for those line features classified in AV_LEGEND as "No Show". Earlier designations of "SHARED" or of "Change of Class" are subsets of "No Show" and are eliminated also.

Create an independent ground water quality Class GA datalayer - Using ESRI ArcMap software, selected and deleted Class GA polygons from  Source 19 - WaterQualityClass_Ground_Master. This makes it easier to update the areas that are subject to Class GB  reclassification. The Source 27 - Connecticut State Polygon was copied, given the same attribute fields as Source 19 - WaterQualityClass_Ground_Master and assigned Class GA to form Source 28 - WaterQualityClass_Ground_Master_GA. This single polygon layer is used to reintroduce Class GA whenever Source 23 - WaterQualityClass_Ground is recreated.

Split WaterQualityClass_Ground_Master_GA polygon into smaller sections - Using ESRI ArcMap  software, intersected Source 29 - USGS Quadrangle Index and Source 27 - Connecticut State Polygon to form Source 28 - WaterQualityClass_Ground_Master_GA. This creates a statewide polygon datalayer that is subdivided into multiple polygons equivalent to the size and shape of the USGS Quadrangle Index polygons that cover the State of Connecticut. When added back to the Source 19 - WaterQualityClass_Ground_Master to form the Source 23 - WaterQualityClass_Ground it is obvious that the Class GA areas have been deliberately split into smaller polygons. Smaller Class GA polygons improve performance when drawing or identifying the ground water quality datalayer.