Evaluating Cleanup at Hamilton Army Airfield Using EQuIS and ArcGIS

- By:

Courtesy of EarthSoft, Inc

The Sacramento District, US Army Corps of Engineers, is implementing EarthSoft's EQuIS and ArcGIS for better management, analysis, and response to landfill remedial activities being conducted at the former Hamilton Army Airfield. This former Air Force Base located four miles south of the city of Novato, on San Pablo Bay, in Marin County, California, is undergoing environmental clean-up as it is returned to civilian use.

With borehole, water level, and analytical data stored in EQuIS, the ArcGIS interface facilitates seamless display of information including contours in ArcMAP and geology in ArcScene. Further presentation and analysis utilizes interfaces with gINT, RockWorks, Surfer and GMS.


Many military bases in the United States have had environmental clean-up programs in place since the early 1980's. On some of these facilities extensive multi-stage investigations and remediation projects have generated large amounts of data. The management and effective use of the accumulated information for subsequent clean-up work is a daunting task unless electronic data management software tools are brought to the project. In a number of cases early forms of these software tools were applied at the military bases; however, the systems were often proprietary and therefore no longer available if the associated consultant left the site. Several environmental science software developers offer systems that can be used to make large data sets more accessible while facilitating data analysis, visualization and utilization. EarthSoft's Environmental Quality Information System-EQuIS-does this through an 'open systems' philosophy that prevents 'data hostage' situations. EQuIS has been chosen by many military agencies and organizations, including the Sacramento District of the US Army Corps of Engineers, for the management of analytical chemistry and geology data. The extensive integration with industry-standard applications for visualization and analysis make EQuIS a popular foundation for what is often an extensive environmental program or plan.

The implementation of EQuIS Geology at Hamilton Army Airfield by the U.S. Army Corps of Engineers, Sacramento District is reviewed.


Hamilton Army Airfield, near Novato, California, is a former military base in the process of conversion to civilian use. Environmental clean-up activities have been ongoing at the base since approximately 1985 and have included investigation and remediation of dozens of locations. One of the larger sites, located in a low lying area in the north section of the base, is the former garbage dump, now referred to as Landfill 26. Landfill 26 is approximately 15 acres in extent with an overlying impermeable cap about 26 acres in size. The landfill lies in a shallow valley formed by Novato Creek as it entered the tidal wetlands that historically bordered San Pablo Bay. The land occupied by the former base was reclaimed, originally for agricultural purposes, in the late 1800's and Novato Creek was redirected in a man-made channel away from the landfill. Initial investigations determined that Landfill 26 was non-methanogenic. Subsequent landfill gas monitoring, however, has found sporadic methane concentrations beginning in 1998. This discovery has triggered additional investigations and remedial activities at the landfill and surrounding area.

Large amounts of environmental data have been gathered at Landfill 26, beginning with investigations of soil and refuse, followed with an extensive groundwater monitoring program, and continuing with the methane investigations. The type of data gathered includes chemical testing results (soil, soil gas, surface water, sediment, and groundwater), groundwater elevation and soil lithology. Information has also been gathered on features that have changed with time such as topography, building locations, landfill cap construction details, new residential developments and underground utilities. Electronic data management is necessary when working with such a large data set (over 50,000 individual chemistry data points alone) combined with the need to present information to both regulatory agencies and the public.

Most of the data collected at this site were managed as bound reports, however some partial attempts were made to utilize electronic storage such as spreadsheets and databases. The early database efforts were not connected to any form of Geographical Information System (GIS) and so it was difficult to make effective use of the data. Because of these problems the initial databases were 'placed on the shelf' and were not further developed. A large number of bound reports have been generated over the years and their management is a significant effort requiring large amounts of storage space and dedicated resources to archive and retrieve the information. While the data was safely stored in the reports, it was not easily accessible or always in a format facilitating effective analysis.


To effectively manage the investigation and remediation of Landfill 26 the project team determined that it needed to accomplish the following tasks:

· Display various combinations of contaminant information on accurate scale maps of the site
· Explore trends in groundwater contaminant concentrations with time
· Understand the spatial relationships of contaminants in soil, soil gas and groundwater
· Produce groundwater elevation maps
· Model contaminant movement in groundwater
· Check for relationships between buried utilities and detected contaminants
· Visualize the site stratigraphy in both two and three dimensions

To implement comprehensive electronic data management for the Landfill 26 project it was decided to obtain software that would facilitate the creation of a single database that could be utilized by analysis applications already in use by the Corps of Engineers such as Surfer and RockWorks. The electronic data management application chosen for this project was EQuIS Geology, which would be teamed with ArcView 8.1, Surfer, RockWorks, gINT, and GMS.


One scenario frequently encountered among environmental data managers is the 'data hostage' situation. This problem may result not only from the use of a proprietary database that prevents 'back-door' access to data, but also from the process of storing data in a particular visualization or analysis application. The open systems architecture upon which EQuIS is based provides the opportunity for a data manager to access data directly, outside of the user interface. This philosophy is rapidly gaining wide acceptance as users are able to go directly into the database to build custom queries and write need-specific applications for reporting and formatting data. Whereas the EQuIS user interface provides an extensive suite of reporting tools and interfaces for sending data to many different visualization and analysis applications, the open system design also allows the development of custom interfaces without being bound by the cost and time requirements of the developer as is often the case with closed, proprietary systems.

Another benefit of the open systems architecture is that the user is not locked into a specific visualization or analysis application. They may choose between any of several popular tools for creating borehole logs, groundwater models, solid models, or performing other types of analysis. This flexibility provides the opportunity to switch to a higher-level application if the currently used application is not adequate without migrating data to a new system. Many proprietary systems provide their own visualization and analysis tools and if these do not prove adequate, the user is at mercy of the developer or is required to migrate their data to a more suitable system. Proprietary evaluation tools are also often poorly documented as to the application of algorithms and are not generally accepted throughout the industry. This creates a situation where disagreement may occur between a facility and the regulating entity as to the applicability of the evaluation tool.

The dangers of storing data in a specific visualization or analysis tool are illustrated by the hypothetical case of a project manager who has successfully used a groundwater modeling environment to produce the results needed by his client. However, when the client then needs borehole logs, cross-sections, or solid models in addition to the groundwater modeling, the manager is left in a quandary. Heretofore, the solution has been the costly investment not only in an additional product and the time required to learn the procedures necessary to produce the desired results, but also in understanding file formats and getting the appropriate data into the new application. EQuIS greatly simplifies this task by facilitating the creation of borehole logs, cross-sections, fence diagrams, reports, contours, groundwater models, solid models, and more all very quickly and easily…without having to understand the intricacies of specific file formats. This mechanism permits more time to be devoted to science and analysis rather than the overhead of a specific piece of software..............................

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