Environmental Risk Management and Communication: A Case Study Using GIS Tools

Environmental Resources Management (ERM) used geographic information systems (GIS) technology and related tools to assist in real-time decision making and communication during a large-scale environmental cleanup in New Jersey. ArcView GIS was linked to a project data base and data analysis tools to provide rapid response and decision-making power in the field as the remediation progressed from investigation to implementation. The project involved the enactment of engineering and institutional controls to achieve an environmental cleanup of soil, ground water, and stream sediments in the coastal zone of New Jersey. Additionally, GIS was employed as a data visualization tool for communicating the project findings and progress to community stakeholders and state regulators.

Introduction

Environmental Resources Management (ERM) used geographic information systems (GIS) technology and related tools to assist in real-time decision-making and communication during a large-scale environmental cleanup in New Jersey. ArcView GIS was linked to a project database and data analysis tools to provide rapid response and implementation. Due to extreme time constraints, the client made the decision to begin implementation of the remedial action prior to completing delineation activities. This mode of operation required a short turn-around time between collection of samples in the field and a decision-point based on the data from those samples. The project involved the enactment of engineering and institutional controls to achieve an environmental cleanup of soil, ground water, and stream sediments in the coastal zone of New Jersey. Additionally, GIS was employed as a data visualization tool for communicating the project findings and progress to community stakeholders and state regulators.

Physical Setting

Environmental GIS

New Jersey Regulatory Climate and Requirements

The State of New Jersey is ahead of many of its neighbors and other states across the country in its efforts to regulate for a cleaner and safer environment. The NJDEP has built many of its programs for the protection of human health and the environment around a GIS-based reference tool. For example, the wellhead protection program, wetland delineation program and list of contaminated sites can be referenced spatially, while linking to information about other features associated with the reference point of interest.

Per the NJDEP Technical Requirements for Site Remediation (TRSR)[2], NJDEP also requires that all environmental sample data be submitted in a "GIS-compatible format." These electronic submittals must be made for data associated with site investigations, remedial investigations, deed notices for environmental restrictions, and applications for well restriction areas (WRA) or groundwater classification exception areas (CEA) due to impacted groundwater.

In New Jersey, there are two mechanisms for remediating contaminated sites. The first mechanism involves the use of engineering controls to treat, remove or contain the impacted media. The second mechanism is to employ institutional controls on the impacted area. Institutional controls include deed notice of environmental restriction for impacted soils left in place, and the establishment of CEA and/or WRA for areas where impacted groundwater will undergo monitored natural attenuation.

Other NJDEP Requirements with Spatial Components

Several physical aspects of the project area required additional interaction with the NJDEP. As discussed above, the site is located in the New Jersey coastal area. Any development or disturbance in the coastal area requires a lengthy and detailed permit application describing the activities to take place and where those activities will take place, including the areas of wetland disturbance and where and how those areas will be restored. ERM used ArcView and wetland delineation data in GIS-format, provided by the NJDEP on CD-ROM, to map out areas of disturbance and subsequent restoration for submission to the NJDEP, as part of the permit application process.

Some portions of the project area consisted of disturbed or filled areas. Again, ERM used ArcView and GIS-compatible soil classification data, available on CD-ROM from the local soil conservation district or the NJDEP, to map areas of native soil material. This was important because it limited the area that needed to be investigated based on suspected historic fill contamination.

Similar to other states, New Jersey has separate criteria for surface and subsurface soils. But, New Jersey also considers saturated soils, soils below the water table, to be a soils issue in addition to a ground water issue. The shallow water table across most of the site resulted in the need to compare most analytical results to the lower of two cleanup standards. Utilizing the query and ODBC (Open DataBase Connectivity) capabilities of ArcView and a structured query language (SQL) database, in this case Microsoft Access, we were able to quickly and easily compare analytical results for subsurface soils to the lower of both unrestricted use criteria and impact to groundwater (IGW) criteria. We then were able to analyze the spatial distribution of the contaminants based on the appropriate comparison.

Spatial analysis of inorganic compound concentrations was also performed using the ODBC features of ArcView. This analysis was successfully used to make an argument that some of the inorganic concentrations were similar to local background concentrations and therefore, those inorganics should not be considered constituents of concern for this site.

Boundaries and Stakeholders

One of the often-overlooked abilities of GIS is the ability to define and identify boundaries. There are several major types of boundaries that can be used to define a physical environment in the context of environmental remediation:

• Geo-political: municipal/governmental/property;
• Physical: geologic/hydrologic (e.g., watershed)/topographic; and
• Extent of contamination.

Stakeholders

Almost any large-scale environmental cleanup, especially one where contamination has crossed geo-political boundaries, will result in a project with many stakeholders. Some of the stakeholders involved in this project included: local residents and community leaders, local government officials, state regulators, federal regulators, and the responsible party. These stakeholders come from a variety of educational and occupational backgrounds, and present a challenge to environmental professionals whose job is to explain the nature and extent of contamination and contaminant migration. It is often critical to the continued progress of a remediation to effectively communicate the timing and scope of remedial activities to the stakeholders.

ERM found that GIS provided a cost-effective and user-friendly tool for communicating scientific data and information to the stakeholder community. ArcView GIS was used to translate the available subsurface information to easy to visualize map-style exhibits, within the framework of the geo-political boundaries with which most of the stakeholders were comfortable.

Data Management

Most environmental projects begin with an investigation of some type. It might be a government file review, a site audit, an aerial photograph review, or a subsurface investigation. This investigation can be thought of as an identification process. Initial investigations identify many physical features about a site, as well as intangibles like previous land use and site history. Much of the information collected during this identification process has spatial information associated with it. A GIS can take advantage of these spatial references by linking the data and information to a map for visualization of the features and data resulting from the identification process. But, the real power of GIS comes through its ability to improve the speed and efficiency with which a project may move from the investigation phase into the remediation or cleanup phase. It should also be noted that the best GIS in the world cannot make up for erroneous or missing data. Great care and planning should occur before any data is collected.

Data Management From a Historical Perspective

There are many techniques for developing GIS projects using a variety of methodologies. The importance of an accurate basemap is critical for an effective and efficient GIS. Data sources for base map development include a site survey, aerial orthophotographs, architectural/engineering drawings, tax maps, and USGS topographic maps. A licensed surveyor or environmental field personnel typically determine environmental sample coordinate data. Problems frequently arise when merging different data sources, especially graphically. Surveyors typically provide a digital deliverable in a computer-aided design (CAD) compatible format, which requires at a minimum aesthetic modification when merged with basemap data in order to develop an acceptable deliverable of professional quality. When subsequent field measurements are taken each sample point must be inserted into the CAD drawing individually, which is inefficient and typically inaccurate. This type of manual manipulation of the data often leads to errors of omission and/or transcription.

Data Management - Digital Mapping

A GIS is a computer mapping system used for the development of geographic-referenced data and databases. NJDEP requires that mapped information be submitted to the NJDEP so that the data can be incorporated into the NJDEP Site Remediation Program's existing HAZSITE GIS-compatible databases.

Criteria for mapping systems to be submitted to NJDEP must conform to the criteria specified in NJDEP's Mapping and Digital Data Standards (MDDS) dated April 1997 [3]. Some of the key elements of mapping accuracy include:

• All "geographic data be submitted to DEP in New Jersey State Plane Coordinates (NJSPC) referenced to North American Datum of 1983 (NAD83) horizontal geodetic datum."
• All base maps must meet United States National Map Accuracy Standards (NMAS) or conform to a standard survey technique.
• Geographic data submitted to NJDEP must be consistent with electronic formats identified in MDDS.

There are several options to satisfy criteria for determination of sample coordinates for inclusion on HAZSITE Database. The first and most reliable option is hiring a licensed surveyor to locate each sample coordinate. The second option is the establishment of control point coordinates by implementing standard surveying techniques, Global Positioning System (GPS), or facility grid coordinate system.

Data Management - Electronic Data Interchange

The New Jersey Administrative Code (N.J.A.C.) requires that "results from the analysis of environmental samples be provided in an electronic format, and that every sample point must be provided with its coordinate location in either State Plane Feet or Latitude and Longitude [4]." To submit data in compliance with NJDEP Site Remediation Program (SRP) technical regulations, three or four database files must be created. "These include: the DATASET FILE (DTST), which briefly defines the data being submitted; the SAMPLE FILE (HZSAMPLE), which contains location information about each sample; and the RESULT FILE (HZRESULT), which contains the results of the analyses of each sample [2]."

ERM's Data Management Approach

Esri's ArcView 3.2 was the selected data management software for the development of the project GIS. Site boundaries and basemaps were developed in AutoCAD Release 14. Data sources for mapping include a digitized geo-rectified aerial orthophoto and several survey events. A master drawing, which contained all site features, was split into three separate drawings. Each drawing was then inserted into ArcView as a single "theme". A theme is a collection of features and the attribute information associated with each feature drawn on a view in ArcView. ArcView themes are similar to "layers" in AutoCAD. Each theme has an associated legend that defines the symbolization of the features (See Figure 1.)

A licensed surveyor determined environmental sample coordinates. Rather than merging survey data with the site basemap using CAD, sample coordinates were imported from the surveyor's electronic file into HZSAMPLE.DBF file, which was then linked to ArcView. Sample event themes were created directly in ArcView, simply, by extracting coordinate information from the HZSAMPLE database (see Figure 2). An event theme creates point features graphically using data defined in a database, one feature per record.

Figure 1: ArcView Project Basemap

All databases for this project were developed using Microsoft Access. All analytical data was provided in digital format by a New Jersey-certified laboratory. The digital deliverable consisted of the HZRESULT.DBF file, which was linked to ArcView Project via a Structured Query Language (SQL) connection. SQL contains syntax for defining and manipulating data from a relational database [1]. This function allows a user to query a database and store the returned records in an ArcView table, which can then be linked to its respective sample coordinate, or keep the query table dynamically linked, so that no additional memory is needed. Using the latter method, only the query definition is stored in ArcView, so that the next time that query is run it will automatically call to the updated database.

Seagate Crystal Reports, software included with ArcView, was used to design report tables. The Report Designer Component provides an object model graphical user interface, allowing the operator to design custom interfaces for user input, enabling tailored report data and report output.

Another benefit of using ArcView is the ability to communicate investigation results digitally using ArcExplorer, which is freeware available from Esri. ArcExplorer can be used to view shapefiles, image data, and database information incorporated in ArcView project. ArcExplorer does however have limitations. Data sources such as CAD drawings and TIFF 6.0 images are incompatible.

Figure 2: Incorporation of Sample Data within ArcView

Benefits of Using ArcView GIS as a Data Management Platform

• ArcView combines traditional GIS software tools in a single platform for organizing and visualizing investigation data.
• Mapping information can be made essentially "read-only", so that it can be viewed and plotted, but not modified.
• Analytical data may be linked to geographic sample locations.
• Database information may be manipulated and viewed graphically, but not modified.
• Report tables can be generated using Seagate Crystal Reports, which creates a direct link to the HAZRESULT database file.
• Clients and regulatory agencies may review ArcExplorer projects to interpret investigation data.
• By including site attributes such as utility locations, equipment details, and other historic information, ERM provided a comprehensive facility-wide management tool to the Client.

Conclusions

Environmental investigations and cleanups involve the collection of many types of data in various media, for example, numeric chemical concentrations in soil, air, water and waste material. Additionally, information in the form of textual, digital and photographic data is often collected during site characterizations. The one thing that all these data have in common is a spatial component.

Most environmental problems are defined by boundaries and most corrective actions are driven by the spatial distribution of contaminants. This case study illustrates the efficiency and rapid decision-making that can be achieved through the use of GIS tools that dynamically link environmental data to spatial mapping and analysis tools. In this case, decisions regarding engineering and institutional controls were made within days of obtaining sampling data.

The swift growth and advances in desktop computing tools have paved the way for environmental managers to move from investigation to remedial action faster, more efficiently and with greater confidence.

References

1.Environmental Systems Research Institute. Copyright 1992-1999. ArcView GIS 3.2.

2.New Jersey Department of Environmental Protection. July 1999. N.J.A.C. Chapter 26E Technical Requirements for Site Remediation.

3.New Jersey Department of Environmental Protection. June 1997. Guidance for the Submission and Use of Data in GIS Compatible Formats Pursuant to "Technical Requirements for Site Remediation".

4.MacGregor, J., Geary, A., Yuill, B. April 1999. NJDEP Site Remediation Program Electronic Data Interchange (EDI) Manual.