Susan Kathleen Stuver, B.S., M.S.


Presented to the Graduate Faculty of

The University of Texas at San Antonio

in Partial Fulfillment

of the Requirements

for the Degree of





Susan K. Stuver, B.S.,M.S.

The University of Texas at San Antonio, 2002

Supervising Professor:Stephen C. Brown, Ph.D.


A Geographical Information Systems(GIS) prototype model was developed to determine its feasibility for improving and expediting municipal Environmental Site Assessments (ESA’s). Data gathered for the prototype model was submitted to the City of San Antonio Information Services Department for approval of an Arcview Internet Mapping System (ArcIMS) web application. The results of this case study indicate that a GIS for the Environmental Services Department is feasible both economically as well as environmentally. This model prototype demonstrated how a GIS and ArcIMS combined standard data collection with advanced computer capabilities, allowing the Environmental Services Department to more easily maintain historical data, predict future environmental impacts more quickly, better optimize their resources, which provided added project control and better response time. It can be shown that scarce budget dollars are being used in the most cost-effective manner.


Geographic Information Systems (GIS) is a relatively young field, with antecedents that go back hundreds of years in the fields of cartography and mapping. Today, GIS provides a digital way for storing, retrieving, manipulating, analyzing, and displaying geographically referenced data. Since GIS has the potential of including ecological, biological, demographic, or economic information, it becomes a valuable tool in the environmental, and engineering sciences (Goodchild, 1992).

At the Initiative 19 Specialist Meeting in Minnesota, researchers identified that GIS emerged through methods such as metrication, land surveys, military surveillance, and mapping expeditions, which in turn, lead to the development of the contemporary GIS software and data available today. GIS was initially developed in the 1950’s and 1960’s, primarily for the public sector. By the 1970’s and 1980’s, the United States had taken the lead in GIS development and industry, and by the 1980’s and 1990’s GIS played a major role in the influence of most Geography disciplines (Harris and Weiner, 1996).

Today, GIS is variously seen as a critical factor in reviving academic geography (for example, see Abler, 1988), or on the other hand, an unhealthy influence that distorts the discipline. In fact, the vast capabilities of GIS technology has invoked great concern over the subjects of ethics, equity, technological biases, access, security, and privacy, to name a few (Abler, 1988).

Regardless, as GIS popularity grew, so did its application in government. The first known precursor to GIS was developed in the late 1960’s by the US Bureau of the Census. The GBF-DIME files (Geographic Base File, Dual Independent Map Encoding), were a coded topology of street segments, with numbered nodes at each end and numbered areas at each side. It was these types of models that eventually evolved into the GIS of today. Additionally, the GBF-DIME files developed into the 1990 TIGER files, which are a critical part of the framework data in the National Spatial Data Infrastructure (NSDI). The DIME files, and the organizations formed to produce them, also became the foundation for the geodemographics industry (Mark et. al., 1997).

As such, the DIME files had limited application and, as a result, were not very easy to use. Therefore, the first known GIS software application began as a result of the TIN project. The TIN, or Triangulated Irregular Network, can be best described as a topographic elevation surface made up of non-overlapping triangles with elevation data at each vertex. The best-known TIN project, which coined the term, was led by Thomas Poiker (formerly, "Peucker"), and was funded at a Canadian university (Simon Fraser University, or SFU) by an agency of the US Defense Department (Office of Naval research, or ONR) (Mark et. al., 1997). The main focus of the project was solving the problem of matching a radar altimetry profile against a terrain model onboard an aircraft as a navigation aid to pilots. Therefore, the TIN approach began clearly as a military function that later diffused into a major commercial software package (ARC/INFO) through the hiring of a student who had studied with one of the researchers from the SFU/ONR TIN project.

Today, the two dominant commercial GIS software producers in the United States are Esri (Environmental Systems Research Institute) and Intergraph (Mark et. al., 1997). A case study conducted by Mark et al (1997), estimates that these industries produce at least half of the GIS software in the country.

Whether restoring habitat, stopping contamination, measuring endangered species populations, or searching for environmentally sensitive land to acquire, spatially literate users have learned to utilize the power of GIS for increased efficiency with environmental issues faced by Government Agencies (Greene, 2000). The Environmental Protection Agency (EPA) is using ARC/INFO software to study the affects of air pollution on tree seedlings and to estimate the long-term impacts of air pollution to forests in the United States. The EPA is also making these applications available over the Internet for public view and data sharing (Lang, 1998). The Metropolitan Sewer District of Greater Cincinnati uses GIS to locate problem areas by tracking complaints made by citizens and overlaying the location of the complaints with the amount of rainfall to enhance preventative maintenance (Mitchell, 1998). The City and County Governments of Indianapolis and Marion County boasts one of the most extensive enterprise-wide local government GIS systems in the nation, in use by over 500 employees, and encompassing all aspects of municipal service (Greene, 2000) from environmental management to cultural politics.

On the other hand, GIS has been used by industry to meet regulatory compliance standards that are set forth by the government. For example, U.S. Borax Incorporated operates a 1.5 mile long pit mine that contains borate ore. Because of its location near Boron, California, the Borax Mine is a zero water discharge facility.

The company meets governmental regulatory compliance by creating GIS maps of ground water and its proximity to underground faults and cracks. These maps allow the company to extract chemicals without hitting ground water or opening a passage that would let groundwater into the mine. Site topography is used to see where water will drain so contaminate collection basins can be built at strategic locations. The company was able to overlay property boundary information, topography and drainage to show expansion plan compliance with the Federal Emergency Management Agency (FEMA) (Lang, 1998).

The Watershed Protection Act passed only after GIS technology clearly showed that this legislation would not do the kind of harm the opposition had feared. In 1987, State Representative David Cohen introduced legislation to establish buffer zones around watersheds that would restrict development in these areas and provide commonwealth to protect other watershed land by buying it outright. Initially, the maps used were incomplete and inaccurate paper maps resulting not just in opposition, but in wild speculation about the arbitrary and capricious government land grabs. With the introduction of GIS, detailed land parcels that the Commonwealth needs to buy to keep development from damaging the watershed and the quality of the reservoir water (Greene, 2000) could be easily and accurately demonstrated resulting in passage of the Legislation.

The Loudoun County Department of Natural Resources used GIS to find potential sites for new landfills. Layers such as slope, soils, bedrock depth to groundwater ratios, historical areas, streets, and jurisdictions were combined to design the model (Mitchell, 1998).

The Cherokee Metropolitan District in Colorado Springs provides water and sewer service to 15,000 residents. GIS helps the workers maintain the districts system of pumps, pipes, and tanks (Mitchell, 1998).

In the 1980’s, the New Jersey Department of Environmental Protection used ARC/INFO software to assess the water quality of the states major river basins and to communicate its findings to local governments, community groups, and businesses. In New York, the Mayor’s Office of Environmental Coordination heads up the city’s Brownfields Initiative, which directs the city to work with relevant public agencies, property owners, developers, and local community boards to gather information on Brownfields and analyze the data in an effort to redevelop and revitalize the local economies (Lang, 1988).

The Northern Kentucky Area Planning Commission used GIS to help the city of Park Hills, Kentucky find points in their drainage systems where storm water and sewage mix during heavy rainfall and flooding. These points are monitored by city engineers to ensure that the city meets the Clean Water Act requirements (Mitchell, 1998).

The U.S. Forest Service manages 156 national forests and 20 national grasslands. The terrestrial and aquatic habitats are home to 283 fish, wildlife, and plant species protected by the federal Endangered Species Act. The Forest Service is working together with conservation groups to improve aquatic habitat and repopulation of threatened and endangered species of fish that live in these habitats (Lang, 1988).

Over the past decade, rapid growth of the Internet has opened up new methods of supplying data, tools and models for GIS users. Internet GIS has potentially become very important to Local Governments because much of the decision-making relies upon information sharing between Federal, State and Local Governments, Environmental Groups, Industry, and the General Public. As a result, internet GIS has successfully provided an increased involvement of stakeholders and citizens in the government’s decision making process, as well as increased departmental growth through the improved sharing of datasets and models (Harreld, 2000).

In June 2000, The Department of Housing and Urban Development awarded Esri software designers a ten million dollar, five-year contract to develop and deploy a GIS that consolidates the agency’s GIS data, as well as make the data available on the Internet for use by other state and local governments (Harreld, 2000). Additionally, Environmental Systems Research Institute (Esri) software developer launched the Geography Network on June 23, 2000. This Internet data portal allows geographic information users and providers to combine, customize, and merge their data into one dynamic system. The Geography Network provides the infrastructure needed to enable the sharing of information between users and providers around the world. Through this network, one can access many types of geographic content including live maps and downloadable data from sources such as the EPA, USGS, Census Bureau, and Compu-search Software (Jordan, 2000).

With the development of new technology comes many challenges. One of which is interoperability challenges that prevent widespread WWW access of geospatial data to local governments.

To tackle this issue, the Open GIS Consortium was created in 1994 to assist in attainment of data from disparate sources through the Web Browser, and the Federal Geographic Data Committee (FGDC) is developing policies that could give state and local governments stronger voice in national decision-making (Harreld, 2000).

Lastly, the City of San Antonio Planning Department has used GIS to successfully bring diverse interests together to help build consensus. Currently, the Planning Department is working with the Information Services Department to build a GIS database and ultimately publish the datasets on the web. The Environmental Department is still in need of a Departmental GIS. Therefore, the focus of this thesis is the design of a departmental GIS with a web application for the dissemination of data to other departments and the public.


In 1995, the Texas Natural Resource Information System (TNRIS) mapped the state of Texas with 1 meter Digital Ortho Quarter Quads (DOQQ), which entered into public record along with an impressive amount of vector data courtesy of the National Spatial Data Infrastructure (NSDI) and the Federal Geographic Data Committee (FGDC). Unfortunately, many local governments like the City of San Antonio are unable to take advantage of this data because they lack both the tools and expertise in using, manipulating and analyzing GIS web data. Therefore, while good data exists, it remains unused by many Departments of the City of San Antonio.Since the City of San Antonio is very interested in the efficient and cost-effective allocation of public funds, a study was performed to determine the feasibility of incorporating a GIS database for the Environmental Services Department.

2.1 Objectives

The Environmental Services Department performs an average of 500 Environmental Site Assessments every year for property acquisitions, street maintenance projects, and highway improvement projects. To date, the Environmental Services Department is using an antiquated paper method for site investigation reports and maps. This method consists of a visual inspection, sketching sampling locations on paper, review of existing paper maps such as topography, soil, parcel, and street maps, contracting with consultants for additional contamination data from areas located near the site, and reporting the results to the property stakeholders. Although acceptable, this method is time consuming and costly.

Furthermore, there is an ever-increasing need to improve the filing and reference system of completed projects within the department. With this basic need defined, the primary objectives of this study are:

1. To design a database for an Environmental Site Assessment that combines existing data from different sources, and new data collected with Global Positioning Systems (GPS) into one digital catalog using Arcview 8.1 Software.

2. Use the database to design a GIS prototype model using Arcview 3.2 and Arcview 8.1. The objective of the model will be to demonstrate coincidence modeling for contamination within a mile of the Subject Site. Additionally, reports and digital photos will be hyperlinked to the Prototype GIS Model to demonstrate added versatility of the GIS system.

3. Review and compare the prototype model with the current methods used for Environmental Site Assessments performed by the Environmental Services Department.

7. Design a website application using Arcview Internet Mapping Systems (ArcIMS) for the prototype model and submit to the Information Services Department for approval.

2.2 Scope

The scope of this study is to demonstrate that a GIS system can improve the current environmental operations performed by the Environmental Services Department thus improving project accuracy and reducing project cost. Additionally, GIS systems can be linked together to provide a dynamic and accurate data flow among all government facilities.

By putting GIS on the Internet, city employees would only need access to the World Wide Web to have all the necessary data available. Additionally, many city employees are not well versed in GIS or how to manipulate the software. The web Graphic User Interface (GUI) is a much simpler application for users that may be unfamiliar with the GIS software.

The best and most cost effective way of merging governmental datasets is through an Internet GIS. With a municipal government of over 16,000 employees, it hardly seems cost effective to purchase the necessary hardware and software required for everyone to use the GIS system. An Internet GIS will reduce both software and hardware costs to the Environmental Services Department since the end user of an Internet GIS only requires a web browser like Internet Explorer to view GIS maps. This means that the Environmental Services Department may choose to purchase only one software license and one computer with the capabilities to run the mapping programs, and link the rest of the terminals to the mainframe computer over the network.

The merging of governmental datasets is essential. As more city staff and officials become familiar with GIS, there is a growing tendency to create subsets of GIS data that reflect the individual projects that each department is responsible for completing. This can cause a problem with accuracy of the data if each department does not communicate changes or updates made to the datasets. Therefore, unless the GIS systems are connected to the same mainframe platform, there is no guarantee as to which dataset is most recent or accurate.

Customer service might also be improved with a GIS Internet application. By empowering the public to problem solve and view data, customers can avoid the inconvenience of calling customer service.


The first step in forming a functional prototype model for environmental investigations is learning how they are performed.Environmental site investigations are performed and coordinated within the Environmental Services Department (ESD) for City projects and property acquisitions. Approximately 500 environmental investigations are completed by the ESD each year. These investigations can be categorized as Phase I, Phase II or Phase III Environmental Site Assessment’s. In addition, documents and environmental investigations that meet the National Environmental Policy Act (NEPA) requirements are prepared by ESD staff for federally funded transportation improvement projects.

3.1 Phase I ESA

Phase I ESAs are conducted for all roadway and drainage improvement projects, City facility improvements and most property acquisitions performed by the City. NEPA Documents are prepared for all transportation improvement projects that are federally funded. These investigations are similar to Phase I ESAs, but are broader in scope. Besides a Phase I type of environmental investigation, NEPA documents also include detailed historical, social, archaeological, water quality, air, noise, vegetation and endangered species impact studies.

3.2 Phase II ESA

Phase II Environmental Site Assessments are conducted when a Phase I ESA or another source has identified potential concerns that require further investigation. These investigations are designed to determine the extent of impact to the subject site. Methods of determination include sampling and analysis of surface and subsurface soil and water.

Laboratory analyses identify whether or not any constituents of concern are present on the subject site. The ArcGIS system combined with GPS should greatly assist with the data collection, records of sampling, findings, conclusions, and recommendations for remediation strategies if necessary.

3.3 Phase III ESA

Phase III activities involve the selection and implementation of remediation strategies for contaminated sites. The ESD develops Health and Safety Procedures and Soil Management Plans for City projects in contaminated areas. The ArcGIS map will ensure that these plans would be executed properly on-site during construction related activities.  Removal of contamination sources like leaking petroleum storage tanks could also be mapped in relation to the site. Contamination plumes can also be mapped with the database provided by this thesis.

3.4 Proposition 3: Parks Development and Expansion Project

According to John Cantu, Senior Engineering Associate with the Environmental Services Department, the majority of Environmental Site Assessments are performed as a result of the Proposition 3 Project.

Proposition 3, otherwise known as the Parks Development and Expansion Project, calls for the use of a portion of the 1/8 of a cent sales tax for a maximum of 10 years, in an amount not exceeding $65 million, for the acquisition of open space parks over the Edwards aquifer recharge zone and the acquisition and development of linear parks along Leon and Salado Creek.

The Edwards Aquifer Recharge Zone Includes unique plant and animal habitat as well as geological features vital to the areas underground water supply. The protection and preservation of this resource is important to maintain the quality and quantity of water that more than a million San Antonio citizens depend on every day. Approximately 20,000 acres over the recharge zone are being developed or are being planned for future development, which will reduce open space and decrease the number of recharge features key to the aquifer’s supply of water.

While rules are in place to regulate development, one way to protect the aquifer is to acquire sensitive and irreplaceable land located within the zone of Bexar County to include extraterritorial jurisdiction. By utilizing existing municipal datasets, a GIS can easily demonstrate jurisdictional boundaries for property acquisition under Proposition 3. Approximately 10,000 acres of sensitive land will be acquired over the recharge zone.


4.1 Area of Study

Identifying the area of study is the first step toward designing a GIS Prototype model. The chosen subject site is located between Old Babcock Road and New Babcock Road, within the Leon Creek Water shed. The site is approximately one-third of a mile south of Hausman Road and approximately one-fourth of a mile West of DeZavala Road, San Antonio, Texas. Old Babcock Road borders the site to the North and East, New Babcock Road to the South, and undeveloped land to the Northwest. The site is located over the Edwards Aquifer Recharge Zone, and requires Phase I and II Environmental Site Assessments, but not a phase III Environmental Site Assessment. Existing municipal data was utilized to layer the location of the subject site with floodplain, and aquifer data.

4.2 Software Applications for Data Collection and Model Design

Once the subject site was chosen, Arcview GIS software applications developed by Environmental Systems Research Institute (Esri) were used to create the departmental database. The goal of this software is to consolidate voluminous stores of data, as well as provide a tool for the development and implementation of GIS models, and web applications.

4.2.1 Arcview GIS 8.1

ArcGIS 8.1 has three Desktop applications – ArcCatalog, ArcMap, and ArcToolbox. The ArcCatalog application was used for managing spatial data holdings, database design, and the recording and viewing of metadata. This application provided the Environmental Department with the framework for organizing their large and diverse stores of data.

ArcMap was used for all modeling and editing tasks as well as map-based project analysis for the ESA Prototype Model. This application was designed to allow for the creation and interaction with data by viewing, editing, or analyzing the data in a visual context. This observation means that spatial data in ArcMap can be queried to find and understand relationships among geographic features and environmental contamination.

ArcToolbox was used for data conversion and geoprocessing. The applications ranged from simple to complex with the aid of wizards to help accurately perform the most complex geoprocessing tasks.

4.2.2 Global Positioning System (GPS) Pathfinder Office

Global Positioning System (GPS) Pathfinder Office Software was used as a tool to enhance GPS data collection for the illegal dumpsites that were discovered upon the initial site investigation. A Trimble Pro XRS GPS Receiver with a Laser Atlanta Advantage Rangefinder was used to collect illegal dumping data, with a data dictionary design to include type of contamination present. Satellite geometry and the precision dilution of position (PDOP) was studied by use of the Pathfinder Office Software to ensure the accuracy of the data collected. PDOP is an important factor of GPS data collection because it demonstrates how many satellites will be visible to the receiver at a given time, on a given date. The more satellites visible, the better accuracy of ones position. The PDOP can be viewed for future dates thus making this software an excellent planning tool for GPS data collection. This software is available with the purchase of Trimble GPS Units.

4.2.3 Arcview Internet Map Server (ArcIMS)

ArcIMS, also developed by Environmental Systems Research Institute (Esri), was used to design and deploy an Internet based system that combined GIS tools with environmental data, to be served over the city network, and to the public.

On a basic level, the Arcview Internet Map Server (ArcIMS) architecture includes the server and the client. The client requests information from the server, and the server processes the request and sends the information back to the client. More specifically, this framework includes the Spatial Server, the Application Server, the Application Server Connectors, ArcIMS Manager, and the ArcIMS Viewers.

The Spatial Server is used to process requests for the maps and related information such as streaming features, conducting queries, and address geocoding. Managing the Server involves running the ArcIMS Spatial Server along with the Virtual Servers that are defined for the ArcIMS Spatial Server. Each Virtual Server allows the ArcIMS Spatial Server to perform different operations. There are five types of Virtual Servers: Image, Feature, Geocode, Query, and Extract.

Image and Feature Virtual Servers publish MapServices called Image MapServices and Feature MapServices, respectively.

Although these two MapServices appear similar in a web browser, an Image MapService is processed as a picture, while a Feature MapService is processed as a stream of feature data.

Geocode, Query, and Extract Virtual Servers are typically used in conjunction with either Image or Feature Virtual Servers to provide support for their own functions. Choosing an Image or Feature Virtual Server depends on how the maps will be delivered to the web site, and the functionality the web site needs to provide.

The Application Server keeps track of which MapServices are running on which ArcIMS Spatial Servers, as well as handles all incoming requests. The Application Server is written as a Java application and runs as a Windows service.

The ArcIMS Application Server Connectors are used to connect the web server to the ArcIMS Application Server. The ArcIMS Servlet Connector is the standard connector used for ArcIMS, and it uses the ArcIMS language, ArcXML (Arcview Extensible Markup Language), to communicate from the web server to the ArcIMS Application Server.

The Web Server is software enables the web site to run. When a web browser makes a request for a file, the web server locates the file and sends it back to the browser.

The ArcIMS 3.1 package contains a manager application that allows the authoring of the map configuration files, the publishing of the map services, the designing of the web pages, and the administration of the web site. To accomplish this, the Manager application combines three independent applications, which are Author, Designer, and Administrator.

ArcIMS has three viewers to choose from. These viewers determine the look of the web site and offer the necessary tools for viewing and querying data. Viewers also can perform spatial analysis tasks like selecting and buffering features, as well as sharing ideas about data using such tools as EditNotes and MapNotes. The ArcIMS Viewers also feature legends, overview maps, saving and retrieving projects, and map printing. The three viewers that ArcIMS uses are the HyperText Markup Language (HTML) Viewer, the Java Custom Viewer, and the Java Standard Viewer.

An HTML viewer uses a single Image MapService and does not require a Java plug-in. This viewer has the least functionality of the three but also requires the least amount of bandwidth to operate making it the fastest viewer. It is therefore recommended to use this viewer in a situation where the client represents the general public browsing the website.

The Java Standard and Custom Viewers offer enhanced functionality by streaming features rather than images, as well as offering additional tools for the web page. However, these viewers require a java plug-in for viewing as well as a degree of GIS knowledge from the end users. Since these viewers stream feature data rather than images, it also takes more time to download images. It is therefore recommended that these viewers be installed for high end users on an intranet who require additional functionality.

Currently, the Information Technology and Services Department (ITSD) hosts municipal web applications for public consumption via a Compaq Proliant 5500 Server. It hosts a 5500 dual MHz Processor, with a 36 GB Hard Drive, and 4 GB of RAM.

Much of the municipal data is stored on a sequel server and streamed into the Compaq Server through Arcview Spatial Database Engine Software (ArcSDE). The Servlet Exec Software allows the Microsoft Internet Information Server (IIS) to communicate with ArcIMS.

The Information Services Department is currently authoring two map services, which can be very beneficial when organizing the ITSD Web Farm. If approved, the GIS Prototype configuration file will be a third MapService.

A MapService can be published with either an Image Virtual Server or a Feature Virtual Server. The difference between them is that an image server shows images only, while a feature server provides the data as well as the image. This web application will use an Image Server since ITSD’s web site coordinators prefer an HTML solution. The HyperText Markup Language (HTML) viewer on an Image Server provides a user-friendly webpage with the appropriate functionality for the client’s level of expertise as well as the tasks they need to complete. The HTML Viewer employs JavaScript and Dynamic HTML (DHTML) to enhance its capabilities. The Java Viewer was not used due to the fact that this viewer is only compatible with web browsers that support Java plug-in functionality. This viewer is designed for clients that have a certain level of GIS expertise and is therefore not feasible for public consumption. The Java Viewer is most effective when plug-ins are acceptable and client machines are large enough to handle local processing. Once approved, the Information Technology and Services Department will use the ArcIMS Administrator application to monitor the Environmental MapService usage and performance, update content, and change the configuration of the servers if necessary.

4.3 Data Sources and Acquisition

Recording and documenting environmental data must follow stringent guidelines because spatial data, site boundaries, sampling locations, and contamination must be precisely reported to state and federal regulatory agencies. To accomplish this,a typical Environmental Site Assessment includes visual site inspections, a review of state, federal and local regulatory databases, as well as a review of previous environmental reports and geologic data. This process, although adequate, requires months to track down the necessary data and reports from all over the country. This time-consuming data-gathering phase is a common problem that may be avoided by bundling existing datasets together to build a functional database.

4.3.1 Bundling Existing Datasets

Designing the database for this thesis was accomplished by using the Arcview 8.1, ArcCatalog software. Information required to build the database included setting study site boundries, bundling 14 contamination datasets currently housed by the Texas Commission of Environmental Quality (TCEQ formally the TNRCC)and the Environmental Protection Agency (EPA), and reprojecting the data to match the "Texas State Plane (South Central FIPS) Projection" currently used by the City of San Antonio.

The TCEQ data required updating the projections and adjusting the coordinate systems to match the City’s predefined State Plane Coordinate System. The data from the EPA are currently being updated to an Arcview digital format and as a result, are unavailable.

Datasets were also gathered from the City of San Antonio Information and Technology Services Department (ITSD). This Department houses all spatial data for the City of San Antonio. The data from TCEQ and The EPA were combined with the municipal data in ArcCatalog to develop a series of contamination models that answer questions related to the Environmental Site Assessment, and identify the existence of patterns.

Some of the datasets reviewed for use in the database posed challenges with accuracy. For example, underground drainage systems are currently being converted from AutoCAD to Arcview. The datasets that are present are accurate but there is very little information associated with the data since it was digitized. The flood plane data yields an inaccuracy of approximately 200 feet. Discussions with representatives of the City, County, TNRCC, and the USGS, state that this is the best 100 year flood plane data available in an Arcview shapefile at this time.

4.3.2 New Data Collection

New data for illegal dumpsites discovered at the subject site were collected using a Trimble Pro XRS GPS Receiver with a Laser Atlanta Advantage Rangefinder to quantify the extent of the illegal dumping at the subject site. On July 30, 2001, from 10:00 am to 3:00 pm there were at least 5 satellites visible resulting in a PDOP (position dilution of precision)of 6 or below which allowed for sub meter accuracy. This level of accuracy satisfies the study for the purpose of logging illegal dumpsites. Point data included sources of illegal dumping with material type attributes that were collected for tires, brush, hazardous waste, and municipal solid waste. Suspected asbestos containing materials were observed in the form of roofing materials and cement piping. The construction debris observed appeared to be associated primarily with illegal surface dumping and debris.

4.4 Site Investigations

Previous Environmental Assessments conducted by Pape-Dawson Engineers and the Environmental Services Department identified multiple stockpiles of waste materials. Approximately 6000 cubic yards of waste debris, domestic waste, plastic, glass, and soil were identified and analyzed in 1997 for waste characterization purposes. Six composite samples were analyzed for the Resource Conservation Recovery Act (RCRA) to include arsenic, barium, cadmium, lead, mercury, selenium, and silver. All of the soil sample results were below background concentrations for this area. Based on the soil sampling results, the waste material was classified as Class II non-hazardous waste.

The Environmental Department conducted a site inspection to visually observe the subject site and adjacent properties for suspect surface conditions and hazardous materials that might impact the subject site. Existing conditions, business activities, and operations on the subject site and adjacent properties were observed during this site assessment. The primary purpose for this investigation was to identify the type of waste contained within the previously observed stockpiles, describe any increases in waste at the site, and to give recommendation on any additional contamination suspected.

Baseline data collected with GPS were modeled in relation to subject site, and layered over an aerial photo. Approximately 60 stockpiles were identified on the 64-acre site. This number represents an approximate 1000 cubic yard increase over the 1997 estimates conducted by Pape-Dawson Engineers. The total volume of waste debris to be removed and disposed of properly is estimated at approximately 7000 cubic yards.

4.5 GIS Prototype Model Design

Once the datasets were collected and the database was complete, a prototype model was designed to assist in project analysis. In the planning phase it was decided which data met the project criteria. For the this site assessment, a model was required to determine if there were any leaking petroleum storage tanks within one mile of the subject site, as well as any illegal dumping within the borders of the subject site.

This Spatial Model involved several categories such as geometric modeling functions that simply calculate distances, generate buffers, calculate areas and perimeters.

Coincidence modeling included overlaying datasets to discover where values coincide. The steps in creating the Prototype Model are as follows:

1. A base map of streets, parcels, and parks were added to Arcview 8.1 from the newly-formed ArcCatalog database.

2. A digital bookmark was set approximately one mile from the subject site to show contamination sources. This was accomplished with the aid of the ArcView toolbar for a quick zoom to this area. 

3. The site boundary was digitized and saved as a new polygon, which was buffered at one quarter mile increments to total a one mile radius from the subject site.

4. Leaking Petroleum Storage Tank (LPST) data were added to Arcview 8.1 from the ArcCatalog to reveal distance estimations of LPST sites from the subject site. Each LPST dataset includes tank owner information to include phone numbers and addresses for rapid communication with the tank owners.

5. Leaking Petroleum Storage Tanks are noted suspiciously close to the subject site. By turning on the contamination zone buffers, it is simple to calculate the correct distance from the site for reporting.

6. An aerial photo and the GPS illegal dumping data were added from the ArcCatalog database.

7. A second digital bookmark was set at the subject site for rapid zoom to the area of study.

8. The aerial photo, site boundary, and illegal dumpsites reveal dumping along dirt roads located throughout subject site.


The purpose of this study was to determine the feasibility of designing and incorporating a GIS database model through an Arcview Geographical Information System (ArcGIS) and an Arcview Internet Mapping System (ArcIMS) that will enhance customer service, increase citizen empowerment and enhance communication between departments.

The approach used to design the model prototype was due partly to the problems identified, partly by the type of data used, and partly by personal preference. The existing ESA methodology uses Quadrangle paper maps, acetate overlays, and the knowledge of the area by the City of San Antonio Engineering Associates that work for the Environmental Services Department. In contrast, the prototype model uses one dynamic system that layers all requested data in a digital model that can be queried, presented and reported with ease. The prototype model successfully demonstrates that the process for conducting an ESA will improve drastically by speeding up the process while ensuring that the Environmental Services Department remains in compliance with all necessary regulations. Current challenges for the City with Phase I and II environmental investigations include the lack of communication between consultants and the various City Departments as well as the inability to layer and query contamination data from the subject site.

For many years, the City of San Antonio has used paper maps, AutoCAD, and Map Info for digital maps.

Only recently, did the City’s Information Technology and Services Department (ITSD) request the hardware and software upgrades to Arcview for use by the City Planning Department. Since this time, the Planning Department and the Police Department have successfully incorporated their departmental GIS to assist in problem solving with zoning and crime related issues. However, there have been virtually no GIS applications for the purpose of Municipal Environmental Investigations.

Furthermore, inaccurate and incomplete environmental data are a serious problem for the City of San Antonio at this time. In fact, much of the environmental data is outdated and, as a result, unacceptable for use in an ESA without extensive research and manipulation. The Environmental Services staff has noted that it may take years to upgrade all the data from its current Map Info and AutoCAD formats to Arcview shapefiles, and even longer to ensure its accuracy since the datasets are constantly changing. The Departmental GIS database that has resulted from this thesis has taken the first step in data consolidation for review and verification of accuracy.

Currently, the City of San Antonio pays a consultant up to $500.00 per site assessment to provide this information depending on the size of the subject site. The information is sent in a PDF format of which the scientist is not able to query data or perform project analysis. Because the information is secure, attempting to acquire the data from the consultant in a digital format is difficult. Furthermore, since the Environmental Services Department utilizes a consultant for data acquisition, there has been little need to maintain the municipal datasets, since the data get continually purchased from another source. Essentially, this means that current municipal datasets are outdated and incomplete.

The Incorporation of an internet linked GIS to the State and Federal Contamination databases would eliminate the need for a consultant, and would likely save thousands of dollars a year.

With an average cost of $350.00 for consulting services, at an average of 500 Environmental Site Assessments per year, the City of San Antonio could likely save an estimated $175,000.00 per year in consulting fees alone. A comparison of data shows the similarity in the ESA Prototype model and the map purchased through a consultant. It also shows a variance in data for Leaking Petroleum Storage Tanks between the State and City databases. By bringing this variance in datasets to the Environmental Services Department’s attention, they agreed to conduct an extensive data inventory in order to discover where data errors are occurring and update existing datasets.

Since much of the contamination data required for an ESA is derived from state and federal databases, an ArcIMS system will pose a future solution to the current communication gaps between Federal, State, and Municipal Governments by linking state and federal data platforms with the City’s database for real-time data upgrades.

The Environmental Site Assessment model was initially intended to be placed on the network for internal review only. A web application specifically for the municipal network is unavailable at this time, so the ESA model will remain on the GIS mainframe until such time that specific network-only applications can be approved. The City of San Antonio Information Services Department (ISD) provides information and technology services to all City Departments. Approval must be obtained from this department before any web space can be utilized by the Environmental Services Department.

A proposal containing goals and objectives of the website, layers to be included, and web page design must be submitted to the Information Technology and Services Department for approval.

Once approved, the server space must be purchased to help balance the ITSD’s web farm load. Next, the data must be checked for accuracy and completeness.

With the implementation of the necessary hardware, Arcview software and ArcIMS on the main server, the Environmental Services Department will be able to use their existing database as a platform to build ESA models like the prototype and link them to a the state and federal contamination databases to launch a more accurate and dynamic system that is cost effective and easy to use.

As the government system operates now, local governments are working independent of each other on environmental projects. Prior to this model, illegal construction waste was collected and hauled to the landfill with an estimated cost $300,000.00 per year. With the waste sites properly mapped, the municipality can assess what type of waste is present and recycle much of the materials saving hundreds of thousands of dollars, as well as saving precious landfill space.

The use of GPS in this site investigation was so successful, that the Environmental Services Department is currently discussing the benefits of incorporating a GPS system to streamline all aspects of municipal data collection to include surface and subsurface soil sampling, water, air, and biological sampling, as well as recording the location and extent of hazardous spills and how they relate to spatial data.

Additional data such as geologic, hydrologic, street maintenance projects, and jurisdictional data were also integrated within the ArcCatalog database system.



6.1 GIS Benefits

When property is acquisitioned by the City, the environmental scientist must discover if any contamination is present, where it is coming from, as well as give recommendations for remediation if necessary. Furthermore, if contamination is found, the extent of the contamination plume must be accurately shown and reported to the Texas Natural Resources Conservation Commission (TNRCC) and/or the Environmental Protection Agency (EPA). In this regard, GIS holds many benefits for the Environmental Services Department.

The delivery of geographic information through the internet or other digital means holds the potential of transforming every aspect of environmental management. GIS is essential for the internal management of utilities, emergency response, ESA’s and much more. By combining the efficiencies of GIS with the internet, government can empower its citizens by allowing them to see for themselves where the most contaminated areas are located, where they can take their household hazardous waste, and what new parks are being developed in their neighborhoods. Additionally, the usefulness of GIS through the intranet will improve communication with other departments that require environmental information to complete their daily duties.

By incorporating a GIS, the environmental scientist will also be able to research potential environmental impacts to all subject sites prior to visiting the site itself.

For example, the scientist could access ArcMap layers with the address of a subject site, and through the geographic distribution of data, might notice if a leaking petroleum storage tank or dumpsite is located up slope or upstream from the park, thus causing reason for concern. Furthermore, the site investigation requires the consolidation of databases and reports that usually must be mailed upon request taking weeks to receive. A GIS system will enable the scientist to produce the required data and reports within seconds.

In fact, the vast environmental datasets that will be provided on the server will have multiple advantages for the scientist. For example, the City acquires a parcel of property and finds contamination present. The source of this contamination is unknown and cannot be found within the site boundaries. Therefore, a map that shows where potential contamination sources can be found countywide will be of great value when confronted with this type of situation. Furthermore, the source of contamination may be coming from a property owner that is under state or federal jurisdiction. Knowing jurisdictional boundaries, as well as property ownership is useful in such situations.

The inability to overlay various databases drastically limits the ability to relate contamination data to land resources such as soil types, vegetation and aerial photos. For example, contamination of a sandy soil will yield a completely different impact than clay. By simply overlaying contamination data with soil types will result in more accurate prediction of the contamination plume. Additionally, an aerial photo reveals land scarring and dirt path’s not typically shown on paper maps.

The aerial photo provided in the ESA prototype model shows several suspicious dirt roads at the Subject Site. When investigated further, this information revealed that these paths were used to illegally dump construction debris at the subject site.

When a chemical spill occurs, it usually heads toward the nearest storm or sewer drain. Once the contamination has left the scene, it will most likely head in the path of least resistance, which is usually storm or sewer systems. Underground utilities provide paths for contamination as well due to the loose soil that surrounds the pipes. It is imperative that the Spill Coordinator has knowledge of all potential routes that the contamination may follow to include storm water, sewer, and underground utility systems.

Currently, when a spill occurs, the spill coordinator responds to stop the contamination at the source. However, if the chemical has left the site through a storm water drain or a sewer drain, the coordinator must request photocopies of paper maps showing the storm water, sewer, and utility systems for the area. Storm water and sewer data is distributed between the Planning Department and the San Antonio Water System (SAWS), the utilities must be obtained through the City Public Service (CPS). This entire process can take anywhere from four hours to four days to receive the photocopied paper maps. By this time, the contamination has most likely reached the San Antonio River.

The Environmental Services Department’s Spill Response program could be enhanced by implementation of a model that portrays a simplistic relationship between contamination paths, drainage, hydrology and geology. Discovering how these values coincide is of tremendous assistance to the City’s ongoing remediation efforts.

To demonstrate this, sewer and stormwater systems could be placed in a GIS that the Spill Response Coordinator could view at a moment’s notice and thus could cross-examine this information with possible contamination, as well as environmental factors such as soil, groundwater, and jurisdiction.

Another concern with environmental data is security. Since property acquisitions deal with real estate, land prices, as well as sensitive environmental data, the City is still working out the best ways to balance the publics right to know public information with the privacy rights of the landowner.

Prior to demolition of a building in danger of collapse, testing of any suspicious materials found on-site must be conducted to ensure compliance with EPA regulations. Maintaining good air quality during the actual demolition, proper disposal of asbestos, household hazardous waste and other debris generated by the demolition process, must be coordinated with the Environmental Services Department. This model demonstrates that the potential exists to expand interdepartmental communications and thus avoid unnecessary environmental hazards.

Additionally, the Streets Department mission is an ongoing task to upgrade the San Antonio streets and walkways. The Streets Department and the Environmental Department must communicate to avoid environmental hazards. Street Department crews will haul excess dirt from a project and use it as fill elsewhere. Currently, the Streets Department will call the Environmental Department to check for possible contamination at the site prior to hauling the dirt away. This leaves the Environmental Department staff sifting through paper maps to ensure that the site is not already undergoing some other type of remediation or investigation.

Contaminated dirt and areas undergoing remediation could be accessed in seconds via ArcIMS thus avoiding situations like lining a playground with contaminated dirt.

It is estimated that the economic payoff of GIS efficiency in e-government will be large. But efficiency is not the only benefit of an internet GIS. A survey by the Council for Excellence in Government found that the benefit people most think of is the ability to let them hold the government more accountable for what its doing (Greene, 2001). When citizens can see for themselves with IMS that hazardous contamination is much worse at one end of town than in another, or how many children live within 5 miles of a Superfund Toxic Waste Site, it increases the chances that something will get done about it (Greene, 2001).

The model design was discussed with the Environmental Services Department Director, Dan Cárdenas (Personal Interview, 2002). The presentation purpose was to discuss the benefits of the ArcGIS and ArcIMS data viewing system. It was demonstrated how each division will be combining standard data collection methodology with advanced computerized capabilities. The result will be the processing of information in less time with less effort, as well as improving customer support through the empowerment of the citizens by bridging the information gap between the Environmental Services Department and the people they serve.

The presentation showed that with the integration of the ArcGIS and ArcIMS system, the Environmental Department would be able to more easily maintain historical data, predict future environmental impacts more easily, conduct map queries, calculations, and assessments more quickly, and better optimize their resources, which provided added project control and better response time to related infrastructure systems. The Environmental Services Department as a result had confidence that scarce budget dollars were being used in the most cost-effective manner.

By direct interfacing with third-party Geographic Information Systems (GIS) for added graphic versatility, the department could integrate graphics capabilities and combine management system maps with database tables, which ultimately increased the number of management applications and the design of excellent graphic presentations.

6.2 Recommendations

Due to the fact that much of the data is in need of updating and revisement, the Environmental Services Department in partnership with the Information Technology Services Department will need to conduct an extensive review of all of the contamination data prior to publication on the World Wide Web. Therefore the web application prototype focused more as an educational tool for the general public and other City Departments. It is recommended that the Environmental Services Department complete the data inventory and place the contamination data on the World Wide Web.

Additionally, the incorporation of these systems requires an initial investment by the Environmental Services Department for the purchase of the necessary hardware and software required for using GIS, GPS, and IMS. It is recommended that business plans from staff be included in the FY 2003 budget process to justify acquisition of computer upgrades, server space from the Information Technology Services Department, an Arcview License, and funding to rent the GPS equipment from the Information Technology Services Department.

To maximize the server space in the Information Technology Services Department, a lightweight HTML-based website viewer was required. Although HTML has a more friendly Graphic User Interface, and was easier to design, it is recommended that the Information Technology Services Department upgrade to a Java-viewer using a Feature Server on a Java Custom Web Site Template that streams data along with the images over the network via a Servlet Engine.

This type of website would require large amount of server overhead and as a result the Environmental Department would have to pay for the additional bandwidth. Therefore this type of internal website is not feasible at this time. However, upon approval of the necessary budget dollars to incorporate such a system, other departments will be able to query and problem solve over the network rather than just view the images. The HTML-viewer with its standard website applications are adequate for public use.

With this done, the final ArcGIS database and associated web applications will have the power to extend well beyond environmental investigations. Thus the City of San Antonio Environmental Services Department has committed to incorporating all relative data into the GIS database to include not only environmental management but also solid waste management. Therefore, the technology architecture is available for this project to become a reality and grow into an entirely new form of e-government.

On February 17, 2002, the Director of Environmental Services Department agreed to expedite the funding mechanism that will install the necessary computer hardware and software to run the models in this thesis. Furthermore, it was agreed to begin the official environmental database design for the department which will include all site assessments, hazardous spills, Underground Storage Tank processing and remediation, asbestos surveys, brush and garbage collection management, and public outreach efforts. The Director agreed that the incorporation of a GIS was indeed feasible, and met the needs of the Environmental Services Department. The Information Technology Services Department has agreed to place the web application prototype on their server, and to begin a much needed data inventory.


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