Arkansas Department of Health
Center for Local Public Health - Environmental Health Branch - Engineering Section

WORK PLAN

SOURCE-WATER ASSESSMENT TO DETERMINE THE POTENTIAL SUSCEPTIBILITY OF ARKANSAS DRINKING-WATER SUPPLIES TO CONTAMINATION

U.S. Geological Survey
Center for Advanced Spatial Technology
Department of Geology, University of Arkansas

December 17, 1998

BACKGROUND AND PROBLEM

The 1996 Amendments to the Safe Drinking-Water act require that each state prepare a source-water assessment for all public water supplies. States are required to determine the sources of drinking water, to identify potential sources of contamination, and the susceptibility of the water supplies to these potential sources of contamination.

Drinking-water sources in Arkansas included both ground water and surface water. The ground- water sources include wells and the surface-water sources include free-flowing rivers, reservoirs, and springs. All of these sources, to varying degrees, are susceptible to potential sources of contamination (PSOC’s) that may be located within or near the area influencing the water source. After delineating the area directly influencing the water source, the PSOC’s existing within that critical area must be inventoried, and the potential adverse impacts of the PSOC’s on the drinking-water source must be evaluated.

OBJECTIVES AND SCOPE

The objective of the source-water assessment project is to determine the potential susceptibility of all 1,565 Arkansas public drinking-water supplies to contamination. This will be accomplished by performing four broad work elements: data-base development, delineation of source-water assessment areas, PSOC inventories, and susceptibility assessments. In addition, a technical advisory committee (composed of local, State, and Federal agency personnel) and a citizens advisory committee (stakeholders) will be formed to provide input and feedback on the assessment plan and throughout the project.

This 4-year project will be conducted by the U.S. Geological Survey (USGS) under the direction of the Arkansas Department of Health (ADH). Various activities will be outsourced to the Department of Geology, University of Arkansas and the Center for Advanced Spatial Technology (CAST). The Arkansas Water Resources Center (AWRC) will administer and coordinate the work by the Department of Geology, University of Arkansas and personnel of CAST under the direction of the USGS. The Department of Geology will perform the assessment of public drinking-water supplies in four counties (Benton, Carroll, Madison, and Washington) in northwest Arkansas. These supplies include both surface- and ground- water sources. CAST will supply and develop data layers for GIS to assist in the assessment of the drinking-water supplies in the State, and develop methodologies for assessment using GIS. Because of the divergent nature of the work by the Department of Geology and CAST, separate detailed scopes of work are attached as Appendices 1 and 2, respectively.

APPROACH

Data-Base Development

Extensive data bases exist, either in electronic or paper format, in the files of many local, State, University, and Federal entities in the State of Arkansas that will need to be brought together for this project. These files, with the help of the originating agencies, will have to be updated, verified, augmented, and made to be compatible to be useful for this effort and for the future. The USGS will act as the focal point and will assume the task of major developer of these data bases and will manage the data that are included, either directly or by oversight of work performed by another agency. The major tasks within this objective will be to identify existing data bases; determine the availability, structure, and condition of these existing data bases; and to develop a data-base management system into which these data bases and new data can be incorporated.

Consultation with State, university, local, and Federal agencies will take place to determine the existence, structure, validity, and condition of existing electronic and paper data bases needed for this project. Agreements with these agencies will be negotiated to update and validate all of these data bases. It is anticipated that assistance in accomplishing this task will come from the originating agencies and from the Arkansas Department of Health.

A determination will be made as to the final set of data bases to be developed and used in the source-water assessments. Initial efforts will focus on location coordinate data bases for all ground-water and surface-water sources within the State. Other broad categories of data bases will include, but not be limited to: basin characteristics, aquifer characteristics, and land-surface characteristics. A preliminary list of coverages to be developed are shown in Appendix 3.

Early in the project, decisions will be made as to the relative importance (ranking/prioritizing) of various PSOC data bases. Those deemed high priority will be addressed first, with those ranking lower receiving less attention.

All data bases will be housed, during the project, on USGS computers. They will be developed by USGS and by CAST using the latest versions of ESRI products including Arc/Info and Arc View. The completed package of coverages will be made available to all interested agencies and parties in Arkansas.

All data bases used in the development of the source-water assessment program will be given appropriate documentation in the form of meta data. The meta data will describe fully the fields, data within the fields, QA/QC parameters, as well as conform to existing State standards for meta data.

Delineation of Assessment Areas

For both ground-water and surface-water sources in Arkansas, "assessment areas" (as defined below by the Arkansas Department of Health) will be delineated. The "contributing basin" will be delineated for surface-water sources also. For ground-water sources, criteria already approved in the Arkansas Well-Head Protection Program will be used to delineate the "assessment areas."

It is expected that there will be special situations for selected drinking-water sources for both surface water and ground water for which criteria more specific to those selected sources will be developed. These situations may include unique or atypical basin characteristics or hydrogeologic factors or situations existing in the area that are particularly threatening to the source water. All delineated areas will be included in the statewide coverage incorporated into the overall data base.

The "assessment area" is defined as a delineated area around the intake or well head of public water systems that establishes the general boundaries of contaminant inventory and susceptibility analysis. The area will not extend past the State boundaries and will be determined by a fixed radius, topographical method, or hydrogeologic analysis method.

For impoundments (lakes, reservoirs, ponds):

Areas within the contributing watershed defined by the following criteria will be considered to be the "assessment area:"

All lands within a 5-mile radius of the intake that are

Within 1/4 mile of the shoreline at the impoundment’s high water level, and

Within 1/4 mile of the centerline of all tributaries, and

Within a 0.5-mile radius of the intake, regardless of watershed boundaries.

For rivers and streams:

All lands within 1/4 mile of the centerline of the river or stream and all its upstream tributaries within 3-days travel time during median flows. Limited by a maximum distance upstream from the intake, determined by an arc with a 20-mile radius.

For springs and "Ground Water Under the Direct Influence" (GWUDI) wells:

The assessment areas for springs and GWUDI wells, in the absence of better information, will consist of an arbitrary fixed radius of 0.5 mile. In addition to this base 0.5-mile radius, delineation and assessment of surface-water bodies that encroach upon this base area will be performed.

For an impoundment that intersects with the base assessment area, all the area within a 3.0-mile radius of the well or spring that is within 0.25 mile of the maximum water level of an impoundment and 0.25 mile either side of the centerline of any of its tributaries, will be delineated and assessed.

For a stream that intersects with the base assessment area, all the area within a 3.0-mile radius of the well or spring that is within 0.25 mile of either side of the stream or any of its tributaries, will be delineated and assessed.

For wells:

An area as defined in the State of Arkansas’ Wellhead Protection Plan, generally described as an area within a 0.25-mile radius of the wellhead.

(PSOC’s that are outside the delineated assessment area may be incorporated into an assessment at the discretion of the Arkansas Department of Health).

The USGS will be responsible for the delineation of most surface-water assessment areas. The Department of Geology will perform the delineations for both ground- and surface-water sources for a four-county area in northwestern Arkansas (Benton, Carroll, Madison, and Washington). CAST will delineate the remainder of the ground-water sources. These delineations will conform to the guidelines and definitions established by the Arkansas Department of Health and the approved State Wellhead Protection Plan. The assessment areas will be delineated on an agreed-upon base. The watershed or contributing area delineations for ground- and surface-water sources will be made on the USGS 1:24,000 topographic map base. Any delineations performed by entities outside of the USGS will be reviewed by the USGS for accuracy and appropriateness.

Source waters requiring separate special consideration will be delineated using criteria specific to their situations. There may be many of these circumstances found in the northwest portion of the State, in areas where PSOC’s are in high density, and in certain other ground-water and surface-water situations where basin or aquifer characteristics warrant additional effort.

PSOC Inventories

Inventories of PSOC’s within the assessment areas will be performed by using existing data available in both electronic and paper form from State, local, and Federal agencies having the most current data. The USGS will work with these agencies to have the locational data verified to a satisfactory resolution. Consultations will be held with all pertinent agencies/divisions that manage or regulate PSOC’s or have existing PSOC data bases, to determine the type of data attributes, data locations, quality of data, data availability, and status of documentation. Electronic data base coverages in ARC/INFO format of PSOC’s will be updated and new coverages will be created by CAST. Although locations of PSOC’s within the assessment areas will be most closely determined, the series of PSOC coverages will be statewide to the extent possible. A list of the PSOC’s likely to be included is in Appendix 3.

Susceptibility Assessments

Analysis of the susceptibility of the source waters to contamination will be performed for each public water supply. Within each delineated assessment area, an analysis of the susceptibility of the water source will be made for selected PSOC’s located in the area. Weighting factors will be assigned to classes of PSOC’s and a composite relative rating scheme will be developed to assess the overall susceptibility of the source water for each public water supply. Aquifer characteristics, geology, soils, hydrologic factors, and other factors deemed necessary will be included in the assessment. The susceptibility assessment will be developed by USGS, ADH, and members of the Technical Advisory Committee and Citizens Advisory Committee.

PRODUCTS

Quarterly progress reports will be submitted to ADH by USGS. These reports will summarize the progress from the previous quarter and outline any products developed and delivered to ADH by USGS, Department of Geology, and CAST.

WORKPLAN/TIMELINE

Federal FY ’98

Federal FY’99

Federal FY’00

Federal FY‘01

BUDGET

APPENDIX 3. Data Bases and Coverages

Source Water Assessment Program for Benton, Carroll,

Madison and Washington Counties, Arkansas

Submitted By: Ralph K. Davis, Department of Geology, University of Arkansas

118 Ozark Hall

Fayetteville, AR 72701

Telephone: 501-575-4515

Fax: 501-575-3846

Email: ralphd@comp.uark.edu

Date: October 8, 1998

Purpose

Develop a management tool for public water utilities to enhance the protection of their source of drinking water via identification of source water assessment areas of drinking water supplies and identification of potential sources of contamination within distinct delineated areas.

Scope

Delineate and assess the area for approximately 140 public drinking water sources in four counties in northwest Arkansas. This represents about 9% of the public drinking water sources in Arkansas. Table 1 lists the estimated total numbers of drinking water sources that are wells, surface water systems, springs and GWUDI located in the four county area.

Table 1

Estimated Number of Public Drinking Water Sources in Each County

(based on data provided by ADH fall 1998)

Definitions

Assessment Area: A delineated area around the intake or well head of public water systems that establishes the general boundaries for Susceptibility Analysis and Vulnerability Assessment. The area will not extend past the State boundaries and will be determined by a fixed radius, topographical or hydrogeological method.

Impoundments (Lakes, Reservoirs, etc.):

Within the watershed, the areas defined by the following criteria will be a part of the total assessment area;

all lands within a 5-mile radius around the intake that are,

within 1320 feet of the shoreline at the impoundment’s high water level, and

within 1320 feet of either side of the centerline of all tributaries, and

all lands within a 0.5-mile radius of the intake, regardless of watershed boundaries.

Rivers and Streams:

All lands within 1320 feet of either side of the centerline of the river/ stream and all its tributaries within a 3-day time of travel limited by a maximum distance upstream from the intake of 20 miles determined by an arc with a 20 mile radius. Time of travel shall be calculated using median flow conditions and a stream slope determined by the difference between the highest point in the entire watershed and a set elevation at the intake.

Springs and GWUDI Wells:

An area within a 0.5-mile radius not to exceed State boundaries. Conjunctive delinearions will be made for all areas where a surface water body exists within the 0.5 mile radius base assessment area. The conjunctive delineation will then be a 3 mile radius not to exceed State boundaries. The delineation of the assessment area for springs/ GWUDI Wells will also be based upon existing data for recharge area delineations, where available.

Wells:

An area as defined in the State of Arkansas’ Wellhead Protection Plan, generally described as an area within a 0.25-mile radius of the well head.

Ground Water: Naturally occurring water occupying the zone of saturation in the ground below the surface of the earth.

GWUDI: Ground Water Under the Direct Influence of Surface Water.

High Water Level: The line of the shore of an impoundment that is reached at the normal spillway elevation.

Mediam Flow Conditions: (USGS definition)

Off Stream Storage: A natural or man-made basin used for the purpose of storing raw water for use by a public water system as a supplement to the primary source of raw water.

PSOC’s: Potential Sources of Contamination

Surface Water: Water that flows over or rests upon the surface of the earth. The term surface water includes rivers, lakes, impoundments, reservoirs, and springs in addition to other man-made and naturally occurring bodies of water on the surface of the earth.

Time of Travel: (USGS definition & methodology)

Method

The delineation and assessment will be conducted in accordance with the procedure described in the document entitled "Source Water Assessment Program" prepared by the Arkansas Department of Health (ADH).

Task List - Surface Water**

Impoundments

I. Evaluation of existing data base quality and availability,

A. Evaluate Existing Data Bases

1. Watershed Characteristics Data

2. Hydrogeologic Data

3. Intake Locations

4. PSOC’s

5. Water Quality Data

B. Generation of Data Bases (To be provided)*

II. Perform Watershed/Assessment area Delineations

A. Watersheds (within State boundaries)*

B. Reservoir Boundaries and Tributaries*

C. Intake Locations*

D. Protection Areas*

III. Create/Transform Ancillary Data Layers

A. Agricultural Chemical Use*

B. Watershed Characteristics*

C. Geology*

D. Land USe/Cover*

E. PSOC’s

F. Precipitation Data*

G. Transportation/Pipelines*

IV. Base Maps to ADH for Editing/Updating

A. PSOC’s plotted

B. Delineations

V. Edited Base Maps

A. Modification of Delineations

B. Modification of Data Layering

VI. Perform Susceptibility Analysis

A. PSOC’s Within the Assessment Area

B. PSOC’s Within the Watershed

VII. Provide Report to ADH as each water system is completed

* Items to be provided by CAST and/or USGS

**All data layers and base maps are to be provided by CAST and/or USGS

Task List - Surface Water**

Rivers/Streams

I. Evaluation of existing data base quality and availability,

A. Evaluate Existing Data Bases

1. Watershed Characteristics Data

2. Hydrogeologic Data

3. Intake Locations

4. PSOC’s

5. Water Quality Data

B. Generation of Data Bases (To be provided)*

II. Perform Watershed/Assessment area Delineations

A. Watersheds (within State boundaries)*

B. Reservoir Boundaries and Tributaries*

C. Intake Locations*

D. 3-day Time of Travel

E. Protection Areas*

III. Create/Transform Ancillary Data Layers

A. Agricultural Chemical Use*

B. Watershed Characteristics*

C. Geology*

D. 3-day Time of Travel and/or 20 miles maximum upstream distance

E. Land USe/Cover*

F. PSOC’s

G. Precipitation Data*

H. Transportation/Pipelines*

IV. Base Maps to ADH for Editing/Updating

A. PSOC’s plotted

B. Delineations

V. Edited Base Maps

A. Modification of Delineations

B. Modification of Data Layering

VI. Perform Susceptibility Analysis

A. PSOC’s Within the Assessment Area

B. PSOC’s Within the Watershed

VII. Provide Report to ADH as each water system is completed

* Items to be provided by CAST and/or USGS

**All data layers and base maps are to be provided by CAST and/or USGS

Task List - Surface Water**

Springs and GWUDI Wells

I. Evaluation of existing data base quality and availability,

A. Evaluate Existing Data Bases

1. Spring and GWUDI Well Locations

2. Hydrologic Data

3. Geologic Data

4. PSOC’s

5. Water Quality Data

6. Well - Construction Data

7. Production/Pumping Data

8. Soils (Permeability, Depth to Bedrock) from SSURGO Data

9. Aquifer Characteristics

B. Generation of Data Bases (To be provided)*

II. Perform Watershed/Assessment area Delineations

III. Create/Transform Ancillary Data Layers

A. Agricultural Chemical Use*

B. Geology*

C. Land USe/Cover*

D. PSOC’s

E. Precipitation Data*

F. Transportation/Pipelines*

IV. Base Maps to ADH for Editing/Updating

A. PSOC’s plotted

B. Delineations

V. Edited Base Maps

A. Modification of Delineations

B. Modification of Data Layering

VI. Perform Susceptibility Analysis

A. PSOC’s Within the Assessment Area

VII. Provide Report to ADH as each water system is completed

* Items to be provided by CAST and/or USGS

**All data layers and base maps are to be provided by CAST and/or USGS

Task List - Wells**

I. Evaluation of existing data base quality and availability,

A. Evaluate Existing Data Bases

1. Well Head Locations

2. Hydrologic Data

3. Geologic Data

4. PSOC’s

5. Water Quality Data

6. Well - Construction Data

7. Production/Pumping Data

8. Soils (Permeability, Depth to Bedrock) from SSURGO Data

9. Aquifer Characteristics

B. Generation of Data Bases (To be provided)*

II. Perform Watershed/Assessment area Delineations

III. Create/Transform Ancillary Data Layers

A. Agricultural Chemical Use*

B. Geology*

C. Land USe/Cover*

D. PSOC’s

E. Precipitation Data*

F. Transportation/Pipelines*

IV. Base Maps to ADH for Editing/Updating

A. PSOC’s plotted

B. Delineations

V. Edited Base Maps

A. Modification of Delineations

B. Modification of Data Layering

VI. Perform Susceptibility Analysis

A. PSOC’s Within the Assessment Area

VII. Provide Report to ADH as each water system is completed

* Items to be provided by CAST and/or USGS

**All data layers and base maps are to be provided by CAST and/or USGS

Product

Report to ADH as each public source of water supply is completed. Report will include:

A. Base Maps With

1. PSOC’s Plotted

2. Delineation of Assessment Area

B. Susceptibility Analysis for PSOC’s Within the Assessment Area

Time-Line

Project Duration - October 1, 1998 to June 30, 2001

Year 1 - October 1, 1998 to June 30, 1999

October 1, 1998 - February 1, 1998 - Complete Delineations for surface water sources, and GWUDI wells and springs with conjunctive delineations and deliver to ADH by February 1, 1999. These will be distributed to the water systems for review of PSOC’s and returned for editing by May 1, 1999.

June 1, 1999 - Begin susceptibility analysis for PSOC’s within delineated areas. The first priority will be on surface water sources, and GWUDI wells and springs with conjunctive delineations.

Year 2 - July 1, 1999 to June 30, 2000

Continue susceptibility analysis with emphasis on surface water sources, and GWUDI wells and springs with conjunctive delineations.

Begin susceptibility analysis of other GWDUI wells and springs

Deliver final product to ADH as each system is completed so they can make delivery to the respective water system.

Year 3 - July 1, 2000 to June 30, 2001

Complete all susceptibility analyses.

Deliver final products to ADH as each one is completed.

Plan of work

for Spatial Data Development and Analysis

in Support of the Arkansas Source Water Assessment Program

INTRODUCTION

The following is a plan of work for the digital spatial and attribute data development and analysis work proposed by the Center for Advanced Spatial Technologies, University of Arkansas, Fayetteville.

The basic purpose for the work proposed here is to obtain information on the location of wells in the state of Arkansas that provide public water and the location and characteristics of Potential Sources of Contamination (PSOC) that are in their immediate vicinity (either ¼ or ½ mile – for wells). The purpose of the work is to develop base data that can be used by the US Geological Survey to assess the potential for contamination for the state’s wells. PSOC data needed for assessment of public surface water sources (impoundment’s, rivers, etc.) shall also be provided to the USGS. The assessment performed by USGS will be provided to the Arkansas Department of Health as part of the EPA required program on source water assessment (EPA 816-R-97-009 "State source water assessment and protection program guidance"). Because of the large number of wells and potential PSOCs it would be enormously expensive to field map all these data. Using Geographic Information Systems (GIS) technologies and existing data, the goal of this task of the effort is to develop a data set that can serve as a useful basis for assessing the potential for contamination for these wells. The current work is seen as the first aspect of a long-term program that will involve field work.

Proposed Tasks and Brief Descriptions

TASK 1 – Data Acquisition

Identification / Collection of PSOC data for the state of Arkansas.

Collection / Manipulation of base GIS data layers

Assessment of Digital Data sources and determination of pertinent "must-have" data sets

Department of Health will provide CAST a "geo-coded" Public Water Intake system database that contains all x, y coordinates (decimal degrees; NAD27) with related well log information that will be required for the PWS Assessment as detailed in the proposed assessment methodology (see TAC/CAC meeting notes).

GIS Data Layers

Geology (1:500k) vector

Soils (STATSGO 1:250k) vector

Poultry/Swine houses (AHTD cells, all but one county)

Land Cover reclass of GAP (30m raster)

Canals and Ditches (1:100k vector TIGER/DLG) will any attribution be required?

Irrigation Wells (as determined by ASWCC) has not been mentioned in meetings

NPDES and TRI (EPA, vector data in Arc Info)

Highways by classification, railroads, airports, bridges (AHTD)

Pipelines (TIGER/DLG? 1:100k)

RCRA

ERNS

Cemeteries (AHTD/GNIS)

Schools (AHTD/GNIS)

Septic Systems (Rural structures from AHTD)

Mines (GNIS)

Elevation (30m where available; else 80m)

Streams/Rivers (DLG 1:100k)

Dairies (Ark. Dept. of Health)

 

PSOC’s

As identified USGS and as ranked by Health/Contamination Risk to Public Water Systems by the USGS and Dept. of Health.

Above ground storage tanks

Under ground storage tanks

Leaking storage tanks

Agri Industry (fertilizer storage, sales, etc)

Pesticides applied per acre ( Rick Bell at USGS 228-3620 in LR)

Airports (Are these shown on Highway Dept. info, can we distinguish by size

Repair Shops (Auto, Farm, furniture)

Cemeteries (from Cordova's work)

Chemical Storage (dealers, paints, solvents)

Dry cleaners

electric substations (PCB’s are what we’re looking for)

Golf Courses

Gravel Pits (PC&E Streaming Mining)

Highways (can we distinguish Fed, US, state, county etc. so we can weight them

differently based upon likely hood of transport and traffic)

Manufacturing facilities (non-specific)

Pipelines

Oil and gas wells

Salvage yards

Sewage treatment plants (NPDES facilities)

Septic tanks

Landfills (PC&E should be sending)

Water wells

Confined animal operations

Aquaculture (AHTD hydro layer)

Land application(Solid Waste Div. of PC&E)

waste water lagoon (Discharge data)

In-steam gravel removal (PC&E Permits)

RCRA

CERCLA (Superfund)

Marinas (and other recreation on lakes)

Mining

 

TASK 2 - Decide to Purchase and/or Convert key PSOC data to digital format

USGS and the Department of Health will create a statewide, digital database of oil and gas wells with latitude and longitude coordinates from the Department of Health and Oil and Gas Commission’s databases. CAST will create a statewide GIS coverage from this newly created database. No commercial data will be used.

TASK 3 - Geo-code PSOC's

Geo-code ALL transient PSOC’s that have been pulled from the various sources and reclass them into their relevant "Health/Contamination Risk" as determined by the Dept. of Health and the USGS (8/18/98 meeting in Little Rock). All of these geo-coded PSOC’s will be included on the first set of draft maps and reports (see task 5 below) so that the spatial, temporal; attribute data quality can be determined by the localities. These PSOC’s will be assigned a unique ID for data editing purposes and business names will be included on the DRAFT 8.x11 maps. It is believed that this would be the most effective means of data verification.

TASK 4 - Seamless Data Base Assembly

Create seamless, statewide coverage of all PSOC's and GIS data layers.

TASK 5 - Macro Development

The draft maps will be created using various GIS macros, developed at CAST. Several macros will be developed in order to process the GIS data analysis of each well into a useful (MS Access) form for the Dept. of Health. These macros will be for CAST’s internal use and are not part of the project deliverables.

TASK 6 - Draft Map production

Individual 8-1/2"x11" black/white maps shall be produced for each of the approx. 1400 public groundwater sources in Arkansas, with the exception of wells under the direct influence of surface water (GWUDI) which require conjunctive delineation (see Task 10). Each map will identify the groundwater source, the wellhead protection zone, PSOC's, and appropriate roads and landmarks necessary for locating these features. The wellhead protection zone shall be 1/4 mile for normal wells, unless independently delineated by the Dept. of Health, and 1/2 mile for (GWUDI) wells, unless requiring conjunctive delineation (see Task10). An accompanying page for each map will list each PSOC by business name or equivalent. Due to the nature of the data being incorporated, these maps will most likely contain errors and will need QA (c.f. Task 7). These are draft maps, to be reviewed, by the Dept. of Health officials and the local water supplies, for accuracy of PSOC locations and attribution. Changes will be made, directly on a hard-copy of the map; after field verification and returned to CAST for digital data editing (c.f. Task 7). CAST is responsible for creating a set of instructions for data editing that are to be followed by the local water utilities and approved by the Dept. of Health. The Dept. of Health is responsible for shipment of these maps to and from the local water utilities and will provide, as well as enforce, the return schedule of these maps from the local water utilities. As the maps are returned to the Dept of Health, they will be checked by Dept. of Health personnel for accuracy before being mailed back to CAST for digital data editing.

TASK 7 - Digital Data Editing

As edited paper copies are returned to CAST, the digital data for PSOC locations and attribution will be updated and edited within the GIS data layers and the related MSAccess database tables.

TASK 8 - Small Format Cartographic Production of Final Maps

Final (8.5"x11", color, digital maps) will be re-created by CAST after digital data edits. These maps will be provided to the Dept. of Health in a digital format (.pdf). The maps and accompanying text report will be contained within individual files and grouped by Public Water System. This will make future Web publishing of this material very easy for the Dept. of Health.

TASK 9 - Metadata Production

FDGC compliant metadata will be created for each GIS data layer and delivered with all distributed GIS data in a report at the end of the project.

TASK 10 - Identify GWUDI Wells w/Streams inside Base Assessment Area

CAST will identify those GWUDI Wells in which the 100k hydrography passes through the base assessment area.

TASK 11 - Calculation of Upgradient / Downgradient from each well-head and report the relative elevation of each PSOC within the buffer zone around each well.

CAST will compute the upstream/downstream areas within each buffer zone using the best available raster elevation data. PSOC elevations will be computed, relative to the elevation of the Public Water Source intake. This information will be associated with all PSOCs within the "zone of influence" around each PWS (ie ¼ mile buffer from wells, etc.) and be entered as database attributes into the MS Access tables for the PSOC’s.

TASK 12 - Determination of PSOC Distance Weighting

CAST will compute distance buffers, as determined by the assessment model, from each public ground water source. This data will be required for application of a weighting factor to each PSOC, as determined within the assessment methodology.

TASK 13 - Construction, Updates and Delivery of Access/Excel base data sets suitable for final assessment calculation by Department of Health

Final modification and delivery of all digital information, according to the current assessment methodology, required to calculate each public water intake system’s relative susceptibility to local contaminants within the Department of Health’s desired software package, MS Access.

TASK 14 - Preparation, Publication and Delivery of Final Report

The final report will include metadata and GIS analysis methodologies employed by CAST during the course of the project. All digital data developed for this project will be delivered in its respective (ie corresponding) digital format (eg. Pdf, excel spreadsheet, shapefile, Arc-Info coverage, etc.) and on appropriate digital media. (CD-ROM)

For information on the national level, try EPA's Source Water Protection site