Evaluation of Unexploded Ordnance Detection

PREPARED FOR PANAMA CANAL TREATY IMPLEMENTATION PLAN AGENCY
DEPARTMENT OF DEFENSE
ROOM 2057, NAVY ANNEX
WASHINGTON, DC 20370-5001

In order to characterize the ranges and to identify the hazards that may currently exist on the Empire, Balboa West, and Pina Ranges, the Panama Canal Treaty Implementation Plan Agency (TIPA) tasked the U.S. Army Environmental Center (USAEC) and the Naval Explosive Ordnance Disposal Technology Division (NAVEODTECHDIV) to conduct an Unexploded Ordnance (UXO) assessment of the three ranges. The UXO Assessment report was finalized in January 1997 and is entitled "Unexploded Ordnance Assessment of U.S. Military Ranges in Panama: Empire, Balboa West, and Pina Ranges".

This report uses the range characterization information presented in the UXO Assessment report and evaluates UXO detection and interrogation technologies that are potentially applicable h1 the three ranges in Panama. The purpose of this report is to provide background on the different UXO detection and interrogation technologies available and to provide a qualitative cost-benefit or "trade-off" analysis of the effects that implementation of these technologies might have on the environment and on UXO hazards. Specifically, this UXO detection and interrogation technology assessment report includes three major components: (1) a characterization of the ranges with regard to environmental conditions, (2) an evaluation of UXO detection and interrogation technologies potentially applicable in Panama, and (3) a qualitative trade-off analysis of the effects that implementation of UXO detection and interrogation technologies might have on the environment and on UXO hazards. This executive summary briefly describes each of these components and summarizes the overall conclusions of the assessment.

The UXO assessment report also describes general environmental conditions on the ranges in Panama. The environmental conditions are relevant because (I ) they affect the potential applicability of UXO detection and interrogation technologies and (2) Treaty policy guidance requires that due regard be given to environmental protection and conservation. The climate in Panama varies from tropical Savannah at the Empire and Balboa West Ranges (the Pacific side) to tropical wet at the Pina Range (the Atlantic side). The tropical Savannah climate is characterized by distinct wet and dry seasons, while the tropical wet climate is characterized by heavy rains nearly year round. The topography of the ranges is generally hilly; some slopes are too steep for cultivation and would severely erode if they were cleared of vegetation. Isolated flat areas exist near the Panama Canal, along riverbeds, and on some hilltops. Soils in the region consist of weathered clays with relatively high moisture content.

Preliminary results from a rapid ecological assessment indicate that most portions of the ranges are densely vegetated. Most areas are covered by semideciduous or evergreen seasonal forests with thick, multilayered canopies ranging from 15 to 50 meters hi height. Grasslands exist in isolated areas and consist of dense, tall (up to 2 meters) tropical grasses. Fourteen endangered animal species and seven critically imperiled plant species exist on the ranges.

An evaluation of UXO detection and interrogation technologies for use on the Empire, Balboa West, and Pina Ranges in Panama was conducted based on the effectiveness and implementability of the technologies. For the purposes of this evaluation, UXO detection refers to locating and potentially identifying surface and subsurface UXO, and UXO interrogation refers to various stages of excavating and positively identifying UXO.

Five categories of UXO detection sensors were evaluated: passive magnetometry, active electromagnetic (EM) induction, ground-penetrating radar (GPR), infrared (IR), and a multisensor approach (which is a combination of the other four sensor types). UXO detection sensors were further evaluated according to the following operational platforms: airborne, vehicle-towed, and man-portable. Three categories of UXO interrogation technologies were evaluated: manual methods, mechanized systems, and remote-controlled systems. Two basic criteria were used to evaluate UXO detection (sensor) and interrogation technologies: (1) effectiveness for the intended purpose and (2) implementability.

Most of the information used to evaluate technology performance was obtained from extensive controlled site technology demonstrations conducted under the USAEC and NAVEODTECHDIV Advanced Technology Demonstration (ATD) Program. The ATD Program was initiated in response to a congressional mandate for demonstrating and evaluating the performance of commercially available and government systems that can be used for UXO detection and interrogation. In 1994 and 1995, about 50 systems, including magnetometry, EM induction, and GPR systems, were demonstrated and evaluated as part of the ATD Program.

The UXO detection and interrogation technologies potentially applicable for use on the ranges in Panama are listed in Table ES-1.

Category	Technology	General AOC Features Where Applicable
UXO Detection Sensors	Passive Magnetometry, Active EM Induction, and Multisensor	Flat to gently rolling terrain Grassland
UXO Detection Platforms	Vehicle-Towed	Flat terrain Grassland
UXO Detection Platforms	Man-Portable	Flat to gently rolling terrain Grassland
UXO Interrogation Methods	Manual	Flat to gently rolling terrain Grassland
	Mechanized	Flat to gently rolling terrain Grassland
	Romote-Controlled	Flat terrain Grassland

Because over 90 percent of the three ranges is covered with dense semideciduous and evergreen seasonal forest, very few UXO technologies can be implemented without destroying most existing vegetation. Also, the dense forest would severely limit the amount of practical operating space for UXO detection and interrogation. Many of the potentially applicable technologies are labor-intensive, and the long rainy season in Panama would limit much of the field work to a short period each year. Finally, most of the technologies have not been demonstrated in Panama; therefore, the performance of the potentially applicable UXO detection and interrogation technologies on the three ranges in Panama is uncertain without site-specific data.

A qualitative trade-off analysis was performed to evaluate the impacts associated with implementing UXO detection and interrogation technologies. These impacts were compared with hazards to EOD personnel who would implement the technologies and the potential UXO hazard level reductions that might be achieved.

Use of UXO detection and interrogation technologies on the ranges in Panama will have short and long-term environmental impacts on the soils, vegetation, and wildlife. Also, most areas of the Empire, Balboa West, and Pina Ranges are heavily Crested and have primarily hilly to steep terrain. Therefore, only man-portable UXO detection platforms and manual UXO interrogation methods are potentially applicable to these areas. EOD personnel implementing such technologies in these areas would be exposed to potentially significant UXO hazard because of extreme environmental conditions, including dense vegetation and steep topography.

UXO hazard level reductions may be achieved by Implementing applicable technologies hi small areas throughout the Empire, Balboa West, and Pina Ranges. However, reduction of UXO hazard levels to the point where areas would be suitable for limited or expanded public use may not be possible.

Both sensitive and extreme environmental conditions exist on the three ranges. The topography of the ranges is generally hilly to steep, although some relatively flat areas exist on hilltops and near rivers where they discharge to the Panama Canal. The ranges are primarily covered by dense, semideciduous seasonal and evergreen seasonal rainforests that flourish in the Panama climate of alternating wet and dry seasons. These forests are essential components of a large, sensitive ecosystem that presently contains 14 endangered animal species and seven critically imperiled plant species. Soils on the ranges are clayey and susceptible to erosion.

The actual performance of the UXO detection and interrogation technologies in mitigating UXO hazards on the ranges in Panama would require verification through limited on-site demonstrations. The particular UXO sensor technologies, system components, and operational platforms used as well as site-specific soil, vegetation, and topographic conditions would influence technology performance.

Magnetometers, EM induction systems, or a combination of these sensors would be the most effective sensor technologies for UXO detection in areas that permit human access. A multisensor system would probably be the best UXO detection approach because no single sensor technology is both effective and completely reliable. In contrast, GPR and IR sensors would not be effective on the ranges in Panama and would provide minimal (if any) UXO detection.

Many areas of the three ranges (up to 90 percent of the range land) may have excessively steep slopes and dense vegetation that would severely impede UXO detection operations. Some degree of site preparation and vegetation removal would be required before any UXO detection technology could be Implemented. However, the extensive vegetation removal activities required to implement vehicle-towed platforms on the three ranges would be particularly labor-intensive and expensive and would result in significant adverse environmental Impacts. The most effective and Implementable mode of operation for UXO detection systems on the ranges would be the man-portable platform because of its ability to access forested areas. However, even man-portable systems may be difficult to use on the rugged, densely vegetated terrain in Panama. Based on results from the ATD Program technology demonstrations, airborne systems would not be effective h1 detecting UXO on the ranges in Panama.

Manual UXO interrogation methods would be Implementable in areas of the ranges that permit human access and would result h1 fewer adverse environmental impacts than mechanized interrogation. However, manual interrogation exposes workers to UXO and is resource-intensive (in terms of labor and time). Mechanized interrogation, especially with autonomous and telerobotic equipment, would provide a higher level of operator safety. As with UXO sensor technologies, dense vegetation, extreme geophysical conditions, and rough terrain would greatly reduce the feasibility of implementing particular UXO interrogation methods.

Use of UXO detection and interrogation technologies on the ranges in Panama will have short and long-term environmental impacts on the soils, vegetation, and wildlife. In particular, soil erosion resulting from vegetation removal and other activities would lead to several short- and long-term impacts, including surface water quality degradation, increased siltation of the Panama Canal, and wildlife habitat loss. On a larger scale, any vegetation removal and deforestation activities performed to implement UXO detection and interrogation technologies would add to impacts from deforestation already occurring throughout Panama at a rate of about 64,000 hectares per year. According to the World Resources Institute, this rate includes only permanently cleared forest and does not include areas cleared for logging.

UXO detection and interrogation may reduce the UXO hazard levels associated with the ranges in Panama. Most of the potentially applicable UXO detection and interrogation technologies would be implemented in the relatively few areas with flat to gently rolling grassland.

Most areas of the Empire, Balboa West, and Pica Ranges are heavily forested and have primarily hilly to steep terrain. Therefore, EOD personnel implementing man-portable UXO detection platforms and manual UXO interrogation methods in these areas would expel fence ever, greater UXO hazards because of the extreme environmental conditions. In all cases, the specific environmental conditions associated with particular UXO AOCs should be examined before decisions are made regarding the applicability of UXO detection and interrogation technologies.

Specifically, this UXO detection and interrogation technology assessment report includes three major components: (1) a characterization of the ranges with regard to environmental conditions, (2) an evaluation of UXO detection and interrogation technologies potentially applicable in Panama, and (3) a qualitative trade-off analysis of the effects that implementation of UXO detection and interrogation technologies might have on the environment and on UXO hazards.

Environmental conditions are presented because they affect the potential applicability of UXO detection and interrogation technologies and the Treaty Policy guidance requires the United States to "give due regard to the protection and conservation of the environment" (DoD 1995b). The areas considered for technology implementation include the areas described in the "Unexploded Ordnance Assessment of U.S. Military Ranges in Panama: Empire, Balboa West. and Pina Ranges" report. A short description of each range is presented below.

The Empire Range is an irregularly shaped area bordered on the north and east by the Panama Canal, on the south by Highway l/K5, and on the west by the Balboa West Range and Panamanian land, including the nearby towns of Arraijan and Nuevo Emperador.

The Balboa West Range is located about 20 km northwest of the Panama Canal's inlet from the Pacific Ocean. The Balboa West Range is a rectangular area about 3,700 hectares in size and is bordered on the north the Panama Canal, on the east and south by the Empire Range, and on the west by the town of Huile and uninhabited, forested areas.

The Pina Range is an irregularly shaped, 2,556-hectare, training and firing range located about 5 km south of Fort Sherman Military Reservation (Fort Sherman) near the north end of the Panama Canal. The Pina Range is bordered on the east by Lake Gatun and the town of Bruja; on the south by Republic of Panama land, including the town of La Treinticinco; on the west by Republic of Panama land, including the town of Providencia; and on the north by Republic of Panama land.

Table 1-l outlines the scope of work and shows flee organization of this report with respect to the three major components. Conclusions are presented in Section 5.

This section provides an overview of the technical approach followed to conduct the UXO detection and interrogation technology evaluation and trade-off analysis. The UXO assessment was conducted ha three phases that parallel the three major UXO assessment components outlined in Section l.l. These phases include an environmental characterization of the ranges, UXO detection and interrogation technology evaluation, and a trade-off analysis. The following sections describe the technical approach for these phases.

Information regarding environmental conditions on the ranges was obtained primarily from ecological surveys performed by The Nature Conservancy (TNC) and the National Association for the Conservation of Nature (ANCON). TNC and ANCON are implementing a four-phase ecological assessment of Military Areas of Coordination in Panama that is being sponsored by the DoD Legacy Resource Management Program. Other environmental data were obtained from the National Climatic Data Center and general geological information sources.

UXO detection and interrogation technologies were evaluated for their potential applicability (in terms of effectiveness and implementability) on the ranges in Panama. For the purposes of this evaluation, UXO detection refers to locating and potentially identifying UXO, and UXO interrogation refers to various UXO clearance activities, including excavating and positively identifying UXO. The technical approach for this evaluation involved categorizing detection technologies according to sensor type and operational platform and categorizing interrogation technologies according to method of operation.

Each technology category was then evaluated based on its effectiveness and implementability so that a determination could be made regarding its potential applicability on the ranges in Panama. Much of the technology evaluation was based on performance information for currently available systems obtained from recent technology demonstrations conducted under the USAEC and NAVEODTECHDIV Advanced Technology Demonstration (ATD) Program. One of the goals of the ATD Program is to demonstrate and evaluate UXO technologies under realistic field conditions. In 1994 and 1995, two phases of UXO detection and interrogation technology demonstrations were conducted at a controlled test site at Jefferson Proving Ground (JPG) in Madison, Indiana. Results from the demonstrations at JPG provide the most up-to-date information available regarding UXO technology performance. To date, about 50 systems, including magnetometer, ground-penetrating radar, and electromagnetic induction, have been demonstrated and evaluated as part of the ATD program.

UXO detection and interrogation technologies implemented on the ranges in Panama will have short- and long-term environmental impacts. A qualitative trade-off analysis was performed to evaluate these impacts and compare them with hazards to EOD personnel who would implement the technologies and the potential UXO hazard level reductions that might be achieved. A qualitative approach was used because of the relatively large uncertainty associated with available background information regarding the types, densities, and extent of UXO on the ranges and because the qualitative hazard levels estimated for UXO AOCs cannot be used to estimate quantitative hazard reductions.

This section discusses the environmental conditions associated with. the Empire, Balboa West, and Pina Ranges. Environmental conditions are described because they are relevant to the feasibility of implementing UXO detection and interrogation technologies. Specifically, this section describes the general environmental conditions of the Empire, Balboa West, and Pina Ranges, including the climate, topography and surface water drainage, surface and subsurface soils, vegetation, and endangered animal and plant species.

The Canal Area climate ranges from tropical Savannah on the Empire and Balboa West Ranges (the Pacific side) to tropical wet in the Pina Range region (the Caribbean or Atlantic side). The tropical Savannah climate is characterized by a distinct dry season from about January through April, while the tropical wet climate is characterized by heavy rains nearly year round (TNC and ANCON 1994). Between these regions is a tropical moist climate with 1 to 2 months of dry season. During the Pacific-side dry season, most of the upland soils dry and crack, and much of the grass and bush vegetation is susceptible to fire. The mean annual temperature and relative humidity for both the Pacific and Atlantic sides are about 26.7 C and 84 percent, respectively (USDOC 1996).

Precipitation in the Canal Area gradually increases from the Pacific side to the Atlantic side. March and April are the driest months, averaging about 1.6 centimeters (cm) of precipitation on the Pacific side and about 4.3 cm of precipitation on the Atlantic side. October and November are the wettest montl1s, averaging about 24.4 cm of precipitation on the Pacific side and about 54.4 cm of precipitation on the Atlantic side. Measured over 37 years, the mean annual precipitation at Howard Air Force Base on the Pacific side is about 173 cm, while the mean annual precipitation at the town of Colon on the Atlantic side is about 348 cm (USDOC 1996).

The Canal Area has the lowest elevation on the Isthmus of Panama and is also one of the most hilly parts of Central America. Hills are numerous and range in height from about 50 to 335 meters above mean sea level (Muschett 1992). Elevations tend to increase with distance from the canal and are greatest near the boundaries of Panama. Some slopes are too steep for cultivation and would severely erode if they were cleared and plowed without terracing. The most favorable areas for cultivation are along relatively flat riverbeds.

The conically shaped hills that characterize the Canal Area are spaced irregularly, reflecting regional differences in resistance to erosion and weathering. Areas underlain by soft rock, such as the area at the confluence of the Quebrada Conga and Rio Sierpe rivers in the Empire Range Main Impact Area, are characterized by broad valleys where streams have deposited layers of alluvial material. In areas underlain by harder rock with steeper gradients, such as the central portion of the Canal Area, streams have cut narrow, steep-walled canyons. Valleys widen and stream profiles flatten as drainage passes from the hard to relatively soft formations. Flat land is generally located in lowlands along the canal, such as the Pedro Miguel Locks area and the Range 5 area on the Empire Range, and in narrow strips along many of the coastal areas and stream channels.

Numerous rivers and streams drain the hilly terrain of the Empire, Balboa West, and Pina Ranges. Intermittent and seasonal streams consistent with local topographic and climatic characteristics also exist on the three ranges (DMA 1990b). Major streams on the Empire and Balboa West Ranges eventually flow into the Panama Canal, while major streams on the Pina Range flow into the Atlantic Ocean.

Most of the soils in the Canal Area consist of clays, including alluvial soils that have a higher silt content than upland clays. Clay soils in the Canal Area are extremely friable as a result of severe, long-term weathering in a humid, tropical climate. Long-term leaching has removed most of the silica and lime, leaving iron and alumina. Upland soils are slightly acid to alkaline. Poorly drained clay soils derived from tuffs and soils in the alluvial flats and depressions that have standing water for extended periods are acidic. The organic matter content of Panamanian soils ranges from about 2 to 8 percent (USDA 1929) and would probably not exceed 4.5 percent in the upland soils of the training ranges. More current sources of information regarding the organic matter content of soils in Panama were not found.

Empire and Balboa West Range soil types include Arraijan, Paraiso, Santa Rosa, and Bluefields clays. The Pina Range soil type is primarily Gatun clay. Arraijan clay, a reddish-brown or brownish-red clay, is the most extensive soil type on the Empire Range. The Arraijan clay is slightly crumbly or friable when moderately moist and is underlain by a 51- to 127-cm-deep, red clay of slightly friable or moderately stiff consistency, depending on its moisture content. On the Empire and Balboa West Ranges, a shallow phase of Arraijan clay occupies most slopes, ridge crests, and hilltops, while a thicker phase exists hi lower and flatter areas. Destructive soil erosion occurs when sloped areas are cleared and rainwater forms gullies through the stiffer surface layer into the softer underlying material. The Arraijan clay bakes and cracks in the dry season and generally supports a lighter cover of vegetation than other soils in the area (USDA 1929).

The Gatun clay that characterizes the entire Pina Range is a uniformly red, moderately friable clay with a 2.5-cm surface layer of brownish-red, friable clay. The Gatun clay ranges in depth from about 51 cm to about 2 meters and is underlain by soft, decomposed parent material. The Gatun clay occupies ridges and lowland areas; its drainage is described as good, and it shows no evidence of serious erosion (USDA 1929).

The clay soils of Panama are capable of holding a considerable amount of water in their pore space. Compared to sand- and silt-dominated soils, clay soils typically have more pore space and can thus hold more water. Reported soil water percentages (percent water by volume) are about 38 percent for the Arraijan clay and about 48 percent of the Gatun clay (USDA 1929). Actual soil water percentages are dependent on a number of factors, including the time of year, amount of vegetation, recent precipitation events, and other site specific factors. The clay soils of Panama could be susceptible to landslides, especially in the steeply sloping areas and near excavations. The clay soils, when saturated, would have a high probability of sliding, particularly when the geological bedding plane is sloping or tilted down slope.

In 1992, TNC and ANCON began an ecological survey of DoD land in the Canal Area. The survey is limited to Military Areas of Coordination and excludes the Canal Operating Area. As such, the northeast third of the Empire Range Main Impact Area, which is located within the Canal Operating Area but outside the Military Areas of Coordination, was not surveyed (NGI and DMA 1989; TNC and ANCON 1994). The ecological survey is being implemented in four phases. Phase 1 is a rapid ecological assessment designed to produce an overview of the ecosystem and biodiversity on the ranges. The rapid ecological assessment, which was conducted in 1994, classified and described vegetation based on field observations, satellite imagery, aerial photographs, site surveys, and literature reviews. Phases 2, 3, and 4 involve intensive field surveys to generate habitat and species inventories for all the DoD installations. Phase 2 focuses on DoD lands on the east, Pacific side of the Panama Canal; Phase 3 focuses on DoD lands west of the canal; and P!.ase 4 focuses on the Caribbean side of the canal At the time of this report. TNC and ANCON had not yet completed the detailed inventories associated with the Empire, Balboa West, and Pina Ranges (TNC and ANCON 1994).

Preliminary results from the rapid ecological assessment indicate that most portions of the Empire, Balboa West, and Pina Ranges are densely vegetated. The exceptions are areas where (1) range maintenance practices such as mowing and controlled burning take place in the immediate vicinity of target and impact areas and (2) encroachment in the form of slash-and-burn farming has occurred.

The rapid ecological assessment identified eight vegetation classes in the Canal Area: ( I ) mangrove swamp; (2) marshes; (3) grasslands, pastures, and crops; (4) shrub land; (5) swamp forest; (6) deciduous forest; (7) semideciduous seasonal forest; and (8) evergreen seasonal forest. Of these, the semideciduous and evergreen seasonal forests dominate the Empire, Balboa West, and Pina Ranges. Aside from rather small, isolated pockets of grassland, pasture, and cropland, the other vegetation classes are absent from the ranges. The rapid ecological assessment also revealed that the area has high biodiversity and potentially contains new plant species (TNC and ANCON 1994). Moreover, the deciduous and semideciduous seasonal forests are considered rare in Central America.

The deciduous, semideciduous seasonal, and evergreen seasonal forests are upland forests and are distinguished by their degree of leaf loss during the dry season. More than 75 percent of the deciduous forest, upper-canopy trees lose their leaves in the dry season; between 25 and 75 percent of the semideciduous seasonal forest, canopy trees lose their leaves in the dry season; and less than 25 percent of the evergreen seasonal forest, canopy trees lose their leaves during the dry season (TNC and ANCON 1994). Many subclasses of vegetation with significant variation of species exist within these upland forests.

Semideciduous seasonal forest covers about 91 percent of the Empire Range. Two subclasses of semideciduous forest are present: medium-statured and tall-statured. These forests feature thick vegetative canopies ranging from 15 to 50 meters in height. Medium-statured forest covers most of the area, especially near roads and a pipeline that crosses the Empire Range. The extent of the medium-statured forest is attributed to timber extraction and general forest clearing activities that took place early in this century. Tall-statured forest generally exists away from access roads and is frequently associated with steep slopes. The tall-statured forest represents a mature, relatively undisturbed tropical ecosystem. The greatest concentrations of tall-statured forest are found in the north and northeast parts of the Empire Range near the Balboa West Range. Some of the most common species in this forest are the wild cashew (Anacardium excelsum), yellow wood (Terminalia amazonia), and kapok tree (Ceiba pentandra) (TNC and ANCON 1994).

Grasslands cover about 9 percent of the Empire Range and are located primarily in the southwest near the towns of Arraijan and Nuevo Emperado. Grasslands also exist in the Main Impact Area near Cerro Sierpe and along roads. Grasslands are dominated by Vietnam grass (Saccharum spontaneum) and Guinea grass (Panicum maximum), which are tall (up to 2 meters), thick-growing grasses. In addition, migrant farmers from nearby settlements have planted crops such as corn, rice, cassava, and yams in the forest clearings, and grasslands in these areas are the result of recent deforestation.

Semideciduous seasonal forest covers about 96 percent of the Balboa West Range, and grasslands mixed with pastures and cropland cover the rest of the range. Tall- and medium-statured semideciduous seasonal forests are distributed throughout the Balboa West Range, with the medium-statured forest covering most of the range. Some of the dominant trees of this forest are West Indian elm (Luehea seemannii), Ecuador laurel (Cordia alliodora), and wild plum (Spondias mombin) (TNC and ANCON 1994).

Grasslands that occur along roads on the Balboa West Range are dominated by Vietnam grass. Grasslands mixed with pastures and cropland exist in the southwest corner of the Balboa West Range near Huile as a result of disturbances caused by Panamanians cutting and burning the forest to plant subsistence crops (TNC and ANCON 1994).

Semideciduous seasonal forest and evergreen seasonal forest cover about 98 percent of the Pina Range. Evergreen seasonal forests differ from the semideciduous forests by keeping their leaves through the dry season, which is very short on the Atlantic side. Most of the Pina Range consists of relatively pristine, mature, tall-statured evergreen forest and ecosystems that have not been significantly disturbed by human activity. Medium-statured evergreen seasonal forest, which has been more disturbed than the tall-statured forest, is found in the extreme northeast and northwest parts of the Pina Range and near La Treinticinco. The most common evergreen forest species on the range include the kapok tree, male trumpet tree (Pourouma guianensis), star apple tree (Chrysophyllum cainito), and suicidal tree (Tachigalia versicolor) (TNC and ANCON 1994).

The rapid ecological assessment revealed that diverse plant and animal species exist on DoD land hi the Canal Area. Fourteen animal species listed as endangered under the U.S. Endangered Species Act and up to 56 animal species protected by Panamanian law exist on DoD lands, including the ranges, hi the Canal Area. The Phase 3 ecological assessment will produce detailed species inventories. The 14 endangered animal species are listed below.

Wood stork (Mycteria americana)
Peregrine falcon (Falco peregrinus)
Brown pelican (Pelecanus occidentalis)
Titi Monkey (Saguinus oedipus)
Howler monkey (Alouatta palliata)
Spider Monkey (Ateles geoffroyi)
Ocelot (Felis pardalis)

Margay (Felis wideii)
Jaguarundi (Felis yagouaroundi)
Jaguar (Panthera onca)
River otter (Lontra longicaudis)
Baird's tapir (Tapirus bairdii)
Manatee (Trichechus manatus)
American crocodile (Crocodylus acutus)

Also, seven plant species found on the Empire, Balboa West, or Pina Range are considered to be critically imperiled globally because of their extreme rarity or because of some factors making them especially vulnerable to extinction. Of these plant species, three belong to the custard apple family (Annonaceae), two belong to the myrtle family (Myrtaceae), one belongs to the pepper family (Piperaceae), and one belongs to the buckwheat family (Polygonaceae). The seven critically imperiled plant species are listed below.

3.0 EVALUATION OF UXO DETECTION AND INTERROGATION
TECHNOLOGIES FOR USE IN PANAMA

One assumption underlying this evaluation is that some degree of site preparation would be required before any UXO detection or interrogation technology could be used in Panama. Over 90 percent of the three ranges is covered with dense semideciduous forests with medium-size to tall trees (up to 50 meters high and 3 meters in diameter). In addition, the forested areas are often heavily entangled with vines and have a thick undergrowth of shrubs and other vegetation. To minimize the hazard to personnel and machinery during UXO detection and interrogation activities, much of the forest vegetation would need to be removed. Vegetation removal in Panama would likely consist of burning the aboveground vegetation (grass and trees) and removing the unburned stubble and stumps to about 0.3 meter above the ground surface. UXO detection and interrogation activities would need to be completed during the dry season, when the vegetation is most conducive to burning and the soils are less muddy. Vegetation removal activities would be very labor-intensive and expensive and would result in adverse environmental impacts. Finally, range operations at an UXO Area of Concern (AOC) would need to be discontinued during UXO detection and interrogation activities.

Two basic criteria were used to evaluate UXO detection (sensor) and interrogation technologies: ( I ) effectiveness for the intended purpose and (2) implementability. These criteria are defined as follows:

Sections 3.1, 3.2, and 3.3 describe UXO detection sensors, detection operational platforms, and interrogation technologies, respectively. Section 3.4 summarizes the potential applicability of UXO detection and interrogation technologies to the UXO AOCs on the ranges in Panama.

Five categories of UXO detection sensors were evaluated for use on the ranges in Panama: (1 ) passive magnetometry, (2) active EM induction, (3) GPR, (4) IR, and (5) a multisensor approach. Most of the technology performance information presented in this section was obtained from controlled site technology demonstrations conducted under the USAEC and NAVEODTECHDIV ATD Program (PRC 1994 and 1996c). ATD Program results represent baseline indicators of current UXO detection technology performance. During Phase I of the ATD Program, 29 systems were demonstrated; during Phase 11 of the program, 20 systems were demonstrated. Phases I and II were both conducted at a controlled test site (with inert ordnance placed at known depths and locations) at JPG in Madison, Indiana. In addition, systems that performed well during the Phase I controlled site demonstrations and new systems with high performance expectations were further tested at one or more sites that contained live ordnance. During the live site demonstrations, airborne, vehicle-towed, and man-portable systems were used to detect and identify actual ordnance at unknown locations.

Measures of performance presented in this section are based on sensor detection capabilities demonstrated during the ATD Program Phase I and II controlled site demonstrations (hereafter referred to simply as the controlled site demonstrations). The effectiveness of sensor systems in detecting UXO was evaluated based primarily on three measures of performance:

UXO detection systems evaluated during the controlled site demonstrations were generally capable of locating detected targets within acceptable limits (less than 1 meter radial distance). However, these systems were generally unable to classify detected items as ordnance or nonordnance. The UXO location capabilities of specific sensor systems are discussed in detail in the controlled site demonstration reports (PRC 1994 and 1996c).

Passive magnetometry, which involves use of magnetometers and "radiometers, locates buried ordnance by detecting irregularities in the earth's magnetic field caused by the ferromagnetic materials hl the ordnance assembly. Magnetometers and gradiometers have been successfully used by the military since World War II and are still considered the most effective technologies for detecting subsurface UXO and other ferromagnetic objects. There are numerous types of magnetometers, including fluxgate, proton precession, optical pumping, superconducting quantum interference device, thin film, Hall effect, and fiber optic magnetometers. These magnetometers were developed to improve detection sensitivity under varying soil conditions. Gradiometers typically consist of two magnetometers configured to measure the rate of change of the magnetic field. Detailed information on the components of these magnetometers is presented hi NAVEODTECHDIV's "Range Clearance Technology Assessment" (NAVEODTECHDIV 1990).

The components of a passive magnetometer system include the detection sensor, a power supply, a computer data system, and a means to record locations of detected anomalies. More technologically advanced systems typically incorporate a navigation system, such as a differential global positioning system (DGPS), to determine locations. Advanced navigation systems may also include a graphical output device (printer), a mass data storage recorder, and telecom systems (NAVEODTECHDIV 1990). A typical passive magnetometer system is shown in Figure 3-1.

Passive magnetometers perform best when used on a man-portable platform. Magnetometers configured on vehicle-towed platforms perform reasonably well, provided that the area to be surveyed is accessible to the vehicles. The results of several airborne magnetometer system evaluations conducted during the controlled site demonstrations indicate that airborne magnetometers currently have no capability to detect UXO. Additional information pertinent to the evaluation of UXO detection sensors associated with different operational platforms is presented in Section 3.2.

Passive magnetometer systems are extremely sensitive, and some are capable of detecting subsurface UXO at depths of up to 5 meters as well as providing location and depth estimates (NAVEODTECHDIV 1990). The detection capability depends on the distance between the magnetometer sensor and the UXO, the ferromagnetic mass of the UXO, background magnetic noise, and site-specific soil properties. Most of the UXO in Panama contains ferromagnetic metal and could therefore be detected with passive magnetometers. Passive magnetometers were evaluated during the controlled site demonstrations (PRC 1994 and 1996c). Ground-based (man-portable and vehicle-towed) magnetometers detected between 4 and 80 percent of the ordnance present at the JPG test site, and their FARs ranged from 5 to greater than 200 false alarms per hectare. However, the actual effectiveness of these magnetometers in Panama would require verification through limited, on-site demonstrations. Airborne magnetometers evaluated during the controlled site demonstrations were not able to detect individual UXO.

As noted above, the effectiveness of magnetometers in detecting UXO depends on many factors, including the distance between the sensor and the UXO, the ferromagnetic mass of the UXO, and background noise levels. In general, the ability of a magnetometer to detect UXO decreases with increasing distance between the sensor and the UXO. Therefore, magnetometers are most effective in detecting buried UXO when the sensors can be placed close to the soil surface. This might be difficult in Panama, particularly hi the rough, densely vegetated semideciduous forests on the ranges. In addition, in areas with high concentrations of surface ordnance fragments, passive magnetometer results might show high background magnetic noise levels. These noise levels might also limit the effectiveness of passive magnetometers in Panama.

Implementing passive magnetometers for UXO detection in Panama would be time-consuming and labor-intensive, especially if man-portable platforms were used. UXO detection would be limited by the speed and stamina of the operators; the climatic conditions; and the site-specific soil, vegetation, and topographic characteristics. Before any ground-based UXO detection system could be implemented at a UXO AOC, the site would need to be prepared, and vegetation would need to be removed.

The passive magnetometer systems (especially the vehicle-towed technologies) used during the controlled site demonstrations experienced numerous mechanical failures because of wear and tear caused by uneven and rough terrain (PRC 1994 and 1996c). Site conditions in Panama are more extreme than at JPG. For example, many areas in Panama have steep and relatively inaccessible slopes, dense forest vegetation, and wet soil conditions (soils in Panama typically consist of fine-textured silt and clay and have high residual water content throughout most of the year) that would severely hinder site access. Logistical and support requirements would include site preparation and vegetation removal activities for the dry season and constructing additional roads to improve site access.

Active EM induction sensor technologies can be used to detect both ferrous and nonferrous metallic UXO. EM induction systems transmit electric current into the soil to detect metallic objects. EM induction systems measure either the secondary magnetic field induced in metallic objects or the difference between the electrical conductivity of the soil and the electrical conductivity of buried objects such as UXO. Detailed information on the components of the EM induction systems demonstrated during Phase II at JPG is presented in the "Phase II Controlled Site Report (Draft Final)" (PRC 1996c).

The components of an active EM induction detection system include the transmitting and receiving units, a power supply, a computer data acquisition system, and a means of recording locations of detected metallic anomalies. More technologically advanced systems typically incorporate a navigatio;. system such as DGPS to determine locations that permit mapping.

Almost all active EM induction systems are configured on man-portable units. Such units often consist of a small, wheeled cart used to transport the transmitter and receiver assembly; an electronics backpack; and a hand-held data recorder (see Figure 3-2). However, multiple EM induction systems have been mounted together, requiring the use of a towed vehicle. Applications of such systems would be restricted to accessible, relatively flat to gently rolling grassland areas on the ranges in Panama, which constitute less than 10 percent of the total range land. EM induction systems have not been demonstrated using an airborne platform. Additional information pertinent to the evaluation of UXO detection sensors associated with different operational platforms is presented in Section 3.2.

Active EM induction systems are most effective ,r, detecting metallic objects near the sol! surface. EM induction systems are less sensitive than magnetometers and generally have a detection depth Emit of about I meter. EM induction systems were evaluated during the controlled site demonstrations (PRC 1994 and 1996c). Such systems detected between 10 and 85 percent of the ordnance present at the JPG test site. The FARs for EM systems ranged from 10 to 80 false alarms per hectare. The actual effectiveness of EM induction systems in Panama would require verification through limited, on-site demonstrations. The exact system configuration and site-specific soil, vegetation, and topographic conditions in Panama would influence system performance.

The performance of active EM induction systems h1 detecting UXO is highly dependent on the distance between the transmitter-receiver assembly and the UXO. In general, the performance of an EM induction system decreases with increasing distance above the ground; therefore, system performance is optimized when the sensor is positioned relatively close to the ground surface. In extremely rough terrain, the EM induction assembly can be carried rather than pulled on a small cart. Like passive magnetometers, EM induction detectors experience high background magnetic noise levels when they are used to survey areas with significant concentrations of surface ordnance fragments.

Implementing active EM induction systems for UXO detection in Panama would be time-consuming and labor-intensive. Before any ground-based UXO detection system could be implemented in Panama, the site would have to be prepared, and most of the vegetation would have to be removed.

Implementing active EM induction systems in areas on the ranges that may contain electronically fuzed ordnance (artillery projectiles, mortar projectiles, or CBUs with VT fuzes) could be unsafe because the induced magnetic field could detonate the ordnance. The likelihood of commercially available EM induction detectors creating a detonation is low because of the relatively low power density and induced current used by most systems. Nevertheless, additional UXO and fuze characterization research would need to be performed before conclusive decisions could be made in all areas on the ranges in Panama regarding the implementability of this technology.

Logistical and support requirements for EM induction systems would be similar to those for passive magnetometers and would include scheduling field activities during the dry season and constructing new roads to improve site access.

GPR is a well established remote sensing technology that has only recently (within the last 10 years) been applied to the problem of locating and identifying UXO at military sites. The main elements of any GPR system are the transmitter unit, the receiving unit (antenna), the control unit, and the display/recorder unit. GPR systems produce short pulses of high-frequency EM energy that are directed toward the ground. The transmitted signals travel into the ground and are reflected by buried objects. Reflected signals travel back to the receiving unit, are recorded, and are processed into an image. For optimal performance, the GPR antenna should be positioned so as to be perpendicular to the ground surface.

Many environmental factors significantly affect the ability of GPR systems to produce accurate images. Important factors include the density and type of vegetative cover; water content in the vegetation and soil; and topography. Water in the vegetation and soil are efficient absorbers of GPR energy. At forested sites, airborne GPR signals may not even contact the soil surface because the signals are reflected by the vegetation or are absorbed by water in the vegetation. The effects of soil moisture on GPR imaging may dominate all other factors. A surface soil moisture content of less than 2 percent is considered to be the acceptable upper limit for GPR soil penetration (Hanson and others 1992). High signal attenuation decreases the ability of GPR systems to discriminate UXO and increases the relative amount of noise, or clutter.

Nine GPR systems were evaluated during the controlled site demonstrations (PRC 1994 and 1996c). A typical GPR system is shown in Figure 3-3. GPR systems were not effective during the demonstrations, primarily because the wet clay soils at JPG caused excessive GPR signal attenuation. GPR systems detected between 0 and 32 percent of the ordnance present at the JPG test site. The FARs for the nine GPR systems ranged from 4 to 320 false alarms per hectare.

GPR systems can be operated from airborne, vehicle-towed, or man-portable platforms; however, vehicle-towed systems were the most commonly demonstrated (six out of nine demonstrators) during the controlled site demonstrations. Several airborne GPR configurations were also demonstrated. Results indicate that GPR systems, regardless of the operational platform used, have low capabilities for detecting buried ordnance. Additional information pertinent to the evaluation of UXO detection sensors associated with different operational platforms is presented in Section 3.2.

GPR would not be an effective sensor technology for detecting surface or subsurface UXO in Panama. The dense forest vegetation (particularly during the wet seasons) and high soil moisture content would limit the effectiveness of GPR systems. The minimum in situ soil water content (about 15 percent) in the fine-textured clay soils found extensively throughout the Empire, Balboa West, and Pina Ranges is considered to be well above the acceptable limit for GPR soil penetration (Hanson and others 1992). Actual GPR system performance in Panama would depend on site-specific environmental and climatic factors.

The potential value of a GPR survey for detecting UXO on the ranges is questionable for the reasons described above.

IR sensor technologies can be used to identify objects by measuring their thermal energy signatures. UXO on or near the soil surface may possess a different heat capacity or heat transfer properties than the surrounding soil, and this temperature difference can theoretically be detected and used to identify UXO. For IR sensor technologies to produce results useful for detecting UXO, a sharp thermal contrast must exist between the UXO and its surroundings (usually the soil surface). IR sensor technology results also depend on the type and density of vegetation present, weather conditions, time of day (thermal loading and gradient), and specific size and properties of the UXO. In practice, IR sensor technologies can only detect UXO located on an unvegetated soil surface. One IR sensor system mounted on a helicopter was demonstrated during the controlled site demonstrations, but it was not effective in detecting UXO (PRC 1994). The IR sensor system showed almost no ability to locate UXO (7 percent ordnance detection) and had a FAR of 20 false alarms per hectare.

The only IR sensor system demonstrated during the controlled site demonstrations was an airborne system. No other operational platforms were evaluated for this sensor technology. Additional information pertinent to evaluating sensor technologies associated with different operational platforms is presented in Section 3.2.

In general, IR sensor systems would not be effective in detecting UXO in Panama. The type and density of vegetation covering most of the three ranges in Panama would severely limit the effectiveness of IR sensor systems.

The potential value of an IR sensor survey to detect UXO on the ranges is highly questionable for reasons described above.

Combining two or more sensor technologies into a multisensor approach has been demonstrated to improve UXO detection performance (PRC 1994 and 1996c). For example, during the controlled site demonstrations at JPG, combining magnetometers with an EM sensor (an EM induction sensor or a conductivity detector) resulted in a higher ordnance detection percentage (from 63 percent to 80 percent) and a corresponding decrease in the FAR (from 30 to 23 false alarms per hectare) (PRC 1996c). Higher UXO detection percentages from combining sensor technologies may be due to several factors. With multiple sensor systems operating in a given area, complementary data sets can be collected to confirm the presence of UXO, or one system may detect a characteristic that another system does not.

Multiple operational platforms could easily be incorporated into a multisensor approach. For example, a man-portable active EM induction system could be combined with vehicle-towed passive magnetometers to provide greater overall UXO detection. Combining UXO detection sensors and operational platforms (with the exception of airborne platforms) was demonstrated to improve overall performance at the JPG controlled sites. Figure 3-4 shows an example of a multisensor system. Additional information pertinent to the evaluation of multisensor technologies associated with different operational platforms is presented in Section 3.2.

A multisensor system would be the most effective UXO detection approach for Panama. Based on results from the controlled site demonstrations, no single technology that is both effective and completely reliable exists for detecting UXO (PRC 1994 and 1996c). Each UXO detection technology has some advantages and some disadvantages. For example, magnetometers currently constitute the most effective UXO detection technology, but they can detect only ferromagnetic metallic objects and cannot distinguish between UXO other ferromagnetic metallic objects. Adding a second sensor technology that could detect all types of metals (for example, EM induction) would improve the probability of detecting UXO and would improve the overall system's ability to distinguish between UXO and non-ordnance items, thus decreasing the number of false alarms. Multisensor systems demonstrated at the controlled site detected between 9 and 80 percent of the ordnance and had a FAR range of 15 to 209 false alarms per hectare. The actual effectiveness and performance of a multisensor system in Panama would depend on the system's configuration, the types of UXO present and their characteristics, and site-specific environmental and climatic factors.

Implementing a multisensor approach for UXO detection in Panama would be similar to implementing any of the ground-based sensor technologies (for example, magnetometry and EM induction). To be effective, all ground-based UXO detection systems would require some degree of site preparation and vegetation removal, which would be labor-intensive and expensive and would result in adverse environmental impacts. Access to the more densely vegetated or steeply sloped areas of the ranges might be restricted to the smaller, man-portable systems. Logistical and support requirements would include configuring the necessary system components and acquiring the appropriate operational vehicle.

The configuration of UXO detection technologies for use on the Panama ranges was further evaluated in terms ofthree operational platforms: (1) airborne, (2) vehicle-towed, and (3) man-portable. This categorization is consistent with platform categories used during the ATD controlled site demonstrations (PRC 1994 and 1996c); therefore, some ATD performance information and demonstration results are considered in this evaluation. Available cost information from some controlled site demonstrations is provided in boxes for illustrative purposes only; the cost information provided in this section is specific to the controlled site demonstrations at JPG and cannot be directly applied to use of operational platforms in Panama.

Several prototype airborne systems were demonstrated during the controlled site demonstrations. A typical airborne detection system is shown in Figure 3-5. The primary advantage of airborne survey methods is their ability to survey large parcels of land relatively quickly. Technological advances in airborne systems have primarily involved improving the navigational components (for example, DGPS), antenna designs, and computer hardware and software for data processing. One of the primary challenges faced by airborne systems is accurately correlating sensor data with ground positions.

Airborne UXO detection technologies were included in the controlled site demonstrations at JPG, and the results were unfavorable (PRC 1994 and 1996c). Eight airborne technology vendors demonstrated their systems, and all were able to survey the entire 32-hectare test site. Airborne systems detected between O and 7 percent of the ordnance at the JPG test site. The performance of the airborne systems was affected by JPG's forested terrain (for example, magnetometer sensors could not he lowered to their optimal height) and wet soil conditions (which limited the performance of the GPR systems).

An airborne technology (GPR with synthetic aperture radar postprocessing) was also demonstrated at the U.S. Marine Corps Air-Ground Combat Center at Twenty-Nine Palms, California, to determine the feasibility of detecting metallic and nonmetallic mines from the air. The conclusion drawn from this technology evaluation was that the airborne technology was not capable of detecting buried metallic and nonmetallic mines (Hansen and others 1992).

Navigational accuracy is an essential aspect of an airborne UXO detection technology, but sufficient accuracy can be difficult to achieve because of the additional EM interference, high aircraft accelerations, and turbulence encountered by airborne systems.

Airborne UXO detection technologies would not be effective for detecting UXO in Panama. In relatively open grassland areas, airborne technologies (with towed magnetometer sensor assemblies) might be capable of detecting surface UXO in higher-density areas as well as some larger metal objects, such as bombs and old vehicles used as targets. However, most high-density surface UXO areas (for example, impact areas) and large surface targets in open areas could also be effectively surveyed using other UXO detection techniques.

Vehicle-towed systems for detecting UXO include various mounted sensor units, remote-controlled units, and self-propelled units (see Figure 3-6). The primary advantages of vehicle-towed technologies are their ability to increase survey rates and provide a higher level of safety for the operators. Technological advances in vehicle-towed technologies have involved improving the navigational components and the computer hardware and software for data processing.

Vehicle-towed UXO detection technologies were included in the controlled site demonstrations at JPG. The vehicle-towed systems were able to cover the test sites quickly but were often subject to breakdowns that caused time-consuming delays. The vehicle-towed systems also were hampered by the wet site conditions and had difficulty moving through deeply rutted areas at JPG.

Navigational accuracy is also an important aspect of vehicle-towed systems, especially with regard to system efficiency. However, vehicle-towed systems in forested areas at JPG had difficulty maintaining communication with DGPS satellites (PRC 1994 and 1996c).

Ten controlled site demonstrators used only vehicle-towed systems. These systems detected between 0 and 60 percent of the ordnance at the JPG test site. The controlled site demonstration results indicate that a wide range of performance can be expected from vehicle-towed platforms, depending on the sensor types involved (PRC 1994 and 1996c).

Vehicle-towed UXO detection systems would be effective and implementable only for areas on the ranges that are currently accessible to vehicles or that would be accessible with limited road construction. In addition, most of the current vehicle-towed systems would not be capable of transversing the uneven terrain and frequently muddy soil in Panama without modifications. Under certain conditions, vehicle-towed systems would provide a quicker, safer, and less strenuous means of detecting UXO than man-portable systems.

Man-portable UXO detection technologies have been employed world-wide by the military since World War II. Man-portable systems may weigh up to 23 kg and require significant operator stamina and physical strength to handle (see Figure 3-7). Many of the man-portable systems used during the controlled site demonstrations incorporate a wheeled cart that is manually pulled or pushed across the survey area. Other man-portable systems require two or more people to operate. One person may carry the sensors while another carries the data acquisition unit tethered to the sensors. If no navigation system is included, additional field personnel are required to spatially survey the detected UXO. Man-portable systems generally have lower survey rates than vehicle-towed and airborne systems.

Fourteen man-portable systems (seven magnetometers, four multisensors, two EM induction, and one GPR) were evaluated during the controlled site demonstration at JPG (PRC 1994 and 1996c). These systems detected between 4 and 85 percent of the ordnance at the JPG test site and had a FAR range of 3 to 38 false alarms per hectare.

The controlled site demonstration results indicate that a wide range of performance can be expected from man-portable systems. In general, performance results from demonstrations indicate that man-portable UXO detection technologies are continuing to improve (PRC 1994 and 1996c). Qualitative comparisons of the man-portable systems and the vehicle-towed and airborne systems demonstrated at JPG indicate that the man-portable systems were the most successful in accessing all areas of the test sites. Uneven and forested terrain did not significantly impair man-portable system access because the systems could easily maneuver around obstacles. Man-portable systems also proved to be the most durable and required the least amount of maintenance.

Man-portable UXO detection systems would be effective and implementable in many areas of the ranges in Panama, but not in steeply sloping or very densely vegetated areas, which would severely hinder the employment of any UXO detection technology. The actual effectiveness of man-portable technologies would depend on the specific sensor configuration, the type of UXO and its characteristics, and other site-specific factors. Man-portable systems are inherently more hazardous for operators to implement than vehicle-towed or airborne systems.

Available UXO interrogation technologies can be grouped into three categories: manual methods, mechanized systems, and remote-controlled systems. Historically, the UXO interrogation phase involved mostly manual methods (using shovels and other digging tools) that were extremely labor-intensive. Research and development efforts over the last 20 years have focused on increased mechanization to improve interrogation efficiencies and enhance operator safety. For the purposes of this evaluation, UXO interrogation encompasses various UXO clearance activities, including excavating and positively identifying UXO.

Based on the results of the controlled site demonstrations, most of the mechanized and remote-controlled UXO interrogation technologies are unreliable and slow. The systems demonstrated had difficulty in operating remotely and experienced numerous mechanical breakdowns (PRC 1994 and 1996c). Evaluation of UXO interrogation technologies for use in Panama must also consider factors other than their effectiveness and implementability. For instance, the designated land use for a site would influence the required interrogation depth and thus the selection of the most appropriate UXO interrogation method for the site. In addition, the locational accuracies and ordnance detection percentages of the various detection technologies, their FARs, the types of ordnance present, and the availability of historical records would all influence the selection of an appropriate UXO interrogation technology for a specific area on the ranges in Panama. This section discusses the general capabilities, effectiveness, and implementability of manual, mechanized, and remote-controlled UXO interrogation technologies with regard to the ranges in Panama.

Manual UXO interrogation methods use human energy and are performed entirely without mechanized equipment. Standard manual interrogation methods include using shovels and other digging tools to excavate soil and expose potential UXO targets; such methods are obviously labor-intensive. Additional UXO detection activities are generally required with manual interrogation methods to confirm target removals and increase the probability of clearing all UXO present.

Manually interrogating surface UXO is much less difficult than manually interrogating subsurface UXO. Most of the surface UXO and other ordnance items in Panama should be small items such as small-arms ammunition, grenades, and small-caliber artillery projectiles. Larger and heavier UXO should have penetrated deeper into the soil because of their size and weight. Therefore, as the UXO detection and interrogation depth increased, larger UXO containing potentially larger amounts of explosives would be found. Also, as the interrogation depth increased, the precise location of the buried UXO would become more difficult to determine, and the interrogation activity could become a major excavation effort. The practical UXO depths for manual interrogation methods in Panama would depend on the types of UXO detected and their characteristics as well as site-specific soil and geological conditions.

Manual methods would be effective for interrogating surface and shallow subsurface (0.3 to 0.6 meter bgs) UXO in many areas of the ranges in Panama. Manual methods would be most effective for interrogating small UXO such as small-arms ammunition, grenades, and small-caliber artillery projectiles on or near the surface. Manual methods would not be effective for interrogating larger, heavier, and potentially more hazardous UXO that is deeply buried in the soil. The large quantity of soil excavation necessary to interrogate deeply buried UXO would be more effectively conducted using mechanized or remote-controlled methods.

Manual UXO interrogation methods could be implemented with varying degrees of difficulty in nearly all areas of the ranges in Panama. However, implementing manual interrogation methods without mechanized equipment would be extremely labor-intensive. Also, manual UXO interrogation methods are inherently dangerous for the operator to implement. To ensure a high level of personnel safety, site preparation, including some degree of vegetation removal, would be required so that personnel could visually Observe any surface UXO. Vegetation removal might include burning vegetation and removing stumps and stubble, which are labor-intensive and expensive and would have adverse environmental impacts. Areas with very steep slopes (greater than 20 percent) or with dense semideciduous forest vegetation that cannot be effectively removed might be too dangerous to interrogate manually. A limited amount of new road construction might also be required to facilitate site access for field crews and equipment.

Implementing manual UXO interrogation methods in Panama would have some negative impacts on vegetation, soils, and surface water resources. Vegetation removal activities would increase surface soil erosion and might result in short-term degradation of water quality in nearby streams and tributaries. Some stream bank erosion occurs naturally in forested areas; however, erosion would be accelerated in upland areas once the more resistant surface soil layers were disturbed (USDA 1929). In practice, manual UXO interrogation methods would have fewer environmental impacts than mechanized or remote-controlled systems because less soil excavation would be required. The quantity of soil disturbed during UXO interrogation would also depend on the accuracy of the detection system used to locate the UXO. Some UXO might be too deeply buried to interrogate using strictly manual methods. Logistical and support requirements would include scheduling site preparation and vegetation removal activities during the dry season and acquiring a relatively large labor force and numerous manual excavation tools. Additional UXO detection technologies would also be required to support the interrogation effort. Vehicles would be required to transport crews and equipment to the UXO AOCs.

Mechanized UXO interrogation systems include excavators, bulldozers, front-end loaders, and other heavy construction equipment used to assist with interrogation efforts. Historically, backhoe-type excavators have been the most commonly used UXO interrogation equipment (see Figure 3-8). One recently developed interrogation machine is a modified vacuum-excavation system. Vacuum-excavators use high-speed air to penetrate soil and dislodge it from the ground, a vacuum to extract the dislodged soil from the hole, and a conveyor belt to transport the soil away from the excavation. A vacuum-excavator demonstrated during the controlled site demonstrations was capable of excavating to 3 meters bgs in the relatively soft, silty soils at JPG (PRC 1996c) (see Figure 3-9).

Mechanized systems would be effective for interrogating surface and subsurface UXO in many areas of the ranges in Panama. Using these mechanized systems (primarily backhoe-type excavators) would be faster and more efficient than using only manual interrogation methods. In addition, interrogation of subsurface

UXO often requires that large quantities of soil be excavated, and mechanized systems may provide a higher level of safety for personnel performing this task. However, ensuring operator safety during UXO interrogation involves making site-specific determinations. For some sites and situations in Panama, manual methods might be the safest interrogation approach because they involve slow, limited excavation activities. Mechanized systems, on the other hand, are generally considered safer because some protection is provided by the mass of the machines used.

Specific areas of the ranges might require UXO interrogation to depths of 1.2 to 3.0 meters bgs. Interrogation of areas to these greater UXO depths would be more complicated and difficult. Deeper UXO interrogation could involve digging into the groundwater table, resulting in muddy groundwater filling the excavation and obscuring the system operator's view of the UXO.

Mechanized UXO interrogation systems could be implemented in many areas of the ranges in Panama. Much of the commercially available mechanized UXO interrogation equipment is large and heavy. Gaining access to remote areas on the ranges with many of the larger pieces of equipment would be difficult. Because muddy conditions would be more difficult to work in, the mechanized UXO interrogation efforts should be conducted during the dry season.

To ensure the highest level of safety for the equipment operators, site preparation and removal of much of the aboveground vegetation would be required. Areas with very steep slopes and with dense semideciduous forest vegetation that cannot be effectively removed could create unsafe situations for the operators and equipment because of decreased equipment stability and UXO visibility. A limited amount of new road construction might also be required to facilitate access of the machines and operators to the UXO AOCs.

Implementing mechanized UXO interrogation methods on the three ranges in Panama would have negative impacts on vegetation, soils, and surface water resources. Vegetation removal activities would increase surface soil erosion. The large excavations would negatively impact vegetation and soil resources by destroying the existing soil layers, disrupting nutrient cycling, and reducing soil fertility. Excavation below the groundwater table might require dewatering (pumping) activities that could result in short-term degradation of water quality in nearby streams and tributaries. Some stream bank erosion occurs naturally in forested areas; however, erosion would be accelerated in upland areas once the more resistant surface soil layers were disturbed (USDA 1929).

Logistical and support requirements would include scheduling site preparation and vegetation removal activities for the dry season and constructing and improving roads for site access. Additional UXO detection technologies would also be required to support the interrogation effort. Vehicles would be required to transport the crews and machinery to areas identified for interrogation.

Remote-controlled UXO interrogation systems include telerobotic and autonomous systems. In general, the capabilities, effectiveness, and implementability of remote-controlled UXO interrogation systems are the same as those of the mechanized systems discussed hi Section 3.3.2. The primary difference between remote-controlled and basic mechanized equipment is that the operator of a remote-controlled system remains outside the area of immediate hazard.

Remote-controlled excavation systems were demonstrated during the controlled site demonstrations at JPG (PRC 1994 and 1996c). The results of the demonstrations indicate that remote-controlled excavators had difficulty finding small targets in the fine-textured, silty soil at JPG and that in some cases, the remote-controlled systems needed the assistance of a man-portable UXO detection system to search the excavated soil for UXO targets. The remote-controlled systems also had difficulties with hard soil, rainy weather, rough terrain, and deep targets.

Remote-controlled systems typically include a navigation and positioning system component, which is usually a DGPS. DGPS satellite signals can be obstructed by tall trees and dense vegetation, limiting the system's location accuracy and thus its application in densely forested areas. For less densely vegetated areas, a DGPS can be integrated with an inertial navigation system that can provide navigation for a period of time (usually less than 3 minutes) when DGPS positions are not available (PRC Inc. 1995); the time interval depends primarily on the required positioning accuracy and the quality of the inertial navigation system.

Remote-controlled technologies for UXO interrogation are still being developed and improved. UXO interrogation with current robotic technologies can be a relatively slow process. For example, one remote-controlled system demonstrated at JPG during the controlled site demonstrations interrogated an average of only five ordnance items per day. Additional time was required for the system to travel to target coordinates, set up and level the machine, and retrieve the UXO.

Remote-controlled systems could be effective for interrogating UXO in some areas of the ranges in Panama. Remote-controlled systems would likely require the supplemental use of a man-potable UXO detection system to help verify UXO locations, especially in the clay soils on the ranges.

Remote-controlled UXO interrogation systems would be most implementable in the relatively flat grassland areas of the ranges where the equipment could be easily maneuvered. Remote-controlled systems should also be implemented during the dry season, when soils are most dry and vegetation can be most effectively removed. Remote-controlled UXO interrogation systems would offer the highest level of safety for equipment operators. For additional operator safety, the site should be prepared and much of the aboveground vegetation should to be removed before interrogation begins.

3.4 SUMMARY OF POTENTIALLY APPLICABLE UXO DETECTION AND INTERROGATION TECHNOLOGIES

Sections 3.1, 3.2, and 3.3 evaluate UXO detection and interrogation technologies in terms of their potential effectiveness and implementability on the ranges in Panama. Based on this evaluation, this section summarizes UXO detection and interrogation technologies and their potential applicability in Panama. Four major sensor categories (passive magnetometry, active EM induction, GPR, and IR) and one system configuration (the multisensor approach) and three basic operational platforms (airborne, vehicle-towed, and man-portable) were evaluated. In addition, three categories of UXO interrogation technology were evaluated: manual methods, mechanized systems, and remote-controlled systems. Results of the ATD controlled site demonstrations at JPG and experience from the live site demonstrations were used heavily throughout this technology evaluation because they represent the most current and dependable performance data for UXO detection and interrogation technologies. Quantitative results from the live site demonstrations have not been completely analyzed; therefore, only qualitative conclusions from these demonstrations were used for this evaluation. For each technology evaluated, Table 3-1 summarizes its capabilities and limitations, effectiveness, implementability, and potential applicability to the ranges in Panama.

TABLE 3-1
SUMMARY OF UXO DETECTION AND INTERROGATION TECHNOLOGY EVALUATION

Category	Technology	Capabilities and Limitations	Effectiveness	Potentially Applicable in Panama
UXO Detection Sensors	Passive Magnometry	UXO detection up to 5 meters bgs Detects olny ferromagnetic, iron-based metal objects Sensor should be placed close to the soil surface to optimize performance	High to Medium	Yes
	Active EM Induction	UXO detection up to about 1 meter bgs Detects all types of metals Sensor should be placed close to the soil surface to optimize performance Potentially unsafe if electronically fuzed ordnance is present	Medium	Yes
	GPR	Detects metallic and monmetallic objects Severely limited by vegetation and wet soils	Low to Not Effective	No
	IR	Detects only surface ordnance Limited by vegetation No field-proven systems available	Low to Not Effective	No
	Multisensor	Collects and combines data from two or more sensors Higher probability of detection and lower FAR than single-sensor systems Systems may be more expensive and complex	High to Medium	Yes
UXO Detection Platforms	Airborne	Can cover large areas efficiently No proven sensor detection capabilities from this platform demonstrated during controlled and live site demonstrations	Not Effective	No
	Vehicle-Towed	Requires extensive vegetation removal Higher operator safety than the man-portable systems Cannot transvers steep jungle terrain	Medium	Yes(mainly in flat grassland areas)
	Man-portable	Requires some vegetation removal Best option for forested areas Labor-intensive Poses higher risks to operators than vehicle-towed or airborne systems	High to Medium	Yes(on flat and rolling terrain)
UXO Interrogation Methods	Manual	Labor-intensive highest risks to operators Fewest environmental impacts	Medium to High	Yes
	Mechanized	Not safe on steep jungle slopes Moderate risks to operators Potentially significant adverse environmental impacts	Medium	Yes(on flat and gently rolling terrain)
	Remote-Controlled	Not safe on steep jungle slopes Moderate risks to operators Requires navigation and control system Potentially significant adverse environmental impacts	Medium	Yes(mainly in flat grassland areas)

The UXO detection and interrogation technologies potentially applicable for use on the ranges h1 Panama are listed in Table 3-2; for each technology, the table describes the general features of UXO AOCs where the technology could be applied.

Because over 90 percent of the three ranges is covered with dense semideciduous forest, very few UXO technologies can be implemented without destroying the majority of existing vegetation. Also, the dense forest would severely limit the amount of practical operating space for UXO detection and interrogation. Many of the potentially applicable technologies are labor-hltensive, and the long rainy season in Panama would Emit much of the field work to a short period each year. Finally, most of the technologies have not been demonstrated in Panama; therefore, the performance of the potentially applicable UXO detection and interrogation technologies on the three ranges in Panama is uncertain without site-specific data.

TABLE 3-2
UXO DETECTION AND INTERROGATION TECHNOLOGIES
POTENTIALLY APPLICABLE IN PANAMA

Category	Technology	General Features of UXO AOCs Where Applicable	Percent of Range Land Where Applicable
UXO Detection Sensors	Passive Magnetometry, Active EM Induction, and Multisensor	Flat to gently rolling terrain Grassland	Less than 10
UXO Detection Platforms	Vehicle-Towed	Flat terrain Grassland	Lass than 2
UXO Detection Platforms	Man-Portable	Flat to gently rolling terrain Grassland	Less than 10
UXO Interrogation Methods	Manual	Flat to gently rolling terrain Grassland	Less than 10
	Mechanized	Flat to gently rolling terrain Grassland	Less than 10
	Remote-Controlled	Flat terrain Grassland	Less than 2

UXO detection and interrogation technologies implemented on the ranges in Panama will have short- and long-term environmental impacts. A qualitative trade-off analysis was performed to evaluate these impacts and compare them with hazards to EOD personnel Alto would implement the technologies and the potential UXO hazard level reductions that might be achieved. A qualitative approach was used because of the relatively large uncertainty associated with available background information regarding the types, densities, and extent of UXO on the ranges and because the qualitative hazard levels estimated for UXO AOCs cannot be used to estimate quantitative hazard reductions.

UXO detection and interrogation activities on the ranges in Panama will have both short- and long-tenn environmental impacts on soils, vegetation, and wildlife diversity and abundance. Short-term impacts are defined as those lasting for the duration of a detection or interrogation project (assumed to be 5 years or less). Long-term impacts are defined as those lasting beyond the duration of a detection or interrogation project and likely persisting more than 20 years. The degree and extent of the environmental impacts depend on the type and extent of UXO detection and interrogation applied. For example, manual surface clearance would have relatively few environmental impacts, while a UXO interrogation to 3 meters bgs would require extensive vegetation removal and excavation and could result in significant long-term impacts.

Short-term impacts of UXO detection and interrogation would include increased soil erosion resulting from vegetation burning and removal and deforestation activities. Surface soil disturbance and subsequent erosion might also occur as a result of access road construction. Increased surface soil erosion might result in short-term degradation of water quality in nearby streams and tributaries. Some stream bank erosion occurs naturally in forested areas; however, erosion would be accelerated in upland areas once the more resistant surface soil layers were disturbed (USDA 1929). Surface soil erosion resulting from vegetation loss is a potentially significant concern for the ranges in Panama. For example, based on the deforestation rate in Panama during the 1980s, its watersheds above the Panama Canal could lose their forest cover by the year 2000, resulting in extensive erosion and increasing siltation in the canal. Increased siltation in the canal would cause the water level to decrease and this would limit the type and volume of ship traffic through the shipping channel (as it has in the past) or would necessitate dredging the shipping channel more frequently (Miller and Tangley 1991).

If significant range vegetation is removed to allow UXO detection and interrogation, soil quality n1igllt decline severely, resulting in negative long-term impacts. Potential soil quality impacts include rapid decomposition of organic matter and associated depletion of nutrients needed to sustain a rainforest ecosystem, changes in the soil's physical qualities, and rapid erosion resulting from high-intensity rains falling on the unprotected soil surface. Such impacts, compounded by encroachment activities such as subsistence farming that also remove nutrients from the soil, might lead to irreversible changes in the rainforest ecosystem.

Short-term impacts on vegetation resulting from UXO detection and interrogation would be primarily associated with burning of grassland areas and removal of surface stubble. These grassland areas would be expected to revegetate in 1 or 2 years. However, UXO interrogation to significant soil depths would result in destruction of plant root systems, which in turn would lead to long-term adverse environmental impacts.

Long-term impacts on vegetation would occur if forested areas were cleared for mechanized UXO detection and interrogation activities. Tl1e long-term impacts of deforestation would include the potential loss of flora species and diversity, wildlife habitats and food supplies, and the biological wealth of the rainforest ecosystem. Such impacts would be particularly threatening to already declining tropical ecosystems. For example, by 1995, Panama had lost about 59 percent of its original forest cover (PRC 1996d). The current deforestation rate in Panama is about 64,000 hectares (about 1.7 percent) per year (World Resources Institute 1995). This rate includes only permanently cleared rain, moist deciduous, hill, and montane forests and does not include areas cleared for logging.

Short-term impacts on wildlife resulting from UXO detection and interrogation would primarily take the form of species displacement during vegetation burning and ground-based activities. Native wildlife species would be expected to return as the grasslands revegetated. Long-term impacts on wildlife resources would include loss of habitats and potential loss of threatened and endangered species.

Table 4-1 summarizes potential short- and long-term environmental impacts associated with implementation of the potentially applicable UXO detection and interrogation technologies discussed in Section 3 and summarized in Table 3-2.

TABLE 4-1
POSSIBLE ENVIRONMENTAL IMPACTS OF POTENTIALLY APPLICABLE
UXO DETECTION AND INTERROGATION TECHNOLOGIES

Potentially Applicable Technology	Resource Impacted	Potential Short-Term Impact	Potential Long-Term Impact
Detection: Man-Portable Sensor	Soils	Minor disruption of surface soil Minor increased erosion	None
	Vegetation	Minor visual impacts	None
	Wildlife	Minor displacement	None
Detection: Vehicle-Towed Sensor	Soils	Moderate disruption of surface soil Moderate increase erosion and off-site sedimentation	None
	Vegetation	Moderate visual impacts Moderate increase in "weedy" species Moderate decrease in "climax" species	Minor loss of flora species and diversity Minor loss of wildlife food supplies Minor loss of biological resources(for example, new medicines from plants)
	Wildlife	Moderate displacement of wildlife Moderate reduciton in wildlife species and diversity	Minor loss of wildlife habitat Minor loss of threatened and endangered species
Interrogation: Manual	Soils	Moderate destruction of surface and subsurface soils Moderate increase in erosion and off-site sedimentation	Moderate increase in erosion and off-site sedimentation Moderate impacts on water quality
	Vegetation	Moderate visual impacts Moderate increase in "weedy" species Moderate decrease in "climax" species	Moderate loss of flora species and diversity Moderate loss of wildlife food supplies
	Wildlife	Moderate displacement of wildlife Moderate reduction in wildlife habitat Moderate reduction in wildlife species and diversity	Moderate loss of wildlife habitat
Interrogation: Mechanized and Remote-Controlled	Soils	Severe destruction of surface and subsurface soils Severe increase in erosion and off-site sedimentation	Minor increase in dredging of nearby water channels Moderate negative impacts on water quality and aquatic resources(for example, fisheries)
	Vegetation	Severe visual impacts Severe increase in "weedy" species Sever decrease in "climax" species	Moderate loss of flora species and diversity Moderate loss of wildlife food supplies Moderate loss of biological resources (for example, new medicines from plants)
	Wildlife	Severe displacement of wildlife Sever reduction in wildlife habitat Severe loss of wildlife species and diversity	Moderate loss of wildlife habitat Moderate loss of threatened and endangered species

UXO detection and interrogation may reduce the UXO hazard levels associated with the ranges h1 Panama. As discussed in Section 3, most of the potentially applicable UXO detection and interrogation technologies could be implemented h1 areas with flat to gently rolling grassland, which accounts for less than 10 percent of the ranges. Such areas exist in portions of the impact areas on the Empire, Balboa West, and Pica Ranges, including the old Stokes mortar range in the Range l/IA Area on the Empire Range. Also, some encroachment areas along the southwest boundaries of the Empire and Balboa West Ranges would be suitable for application of detection and interrogation technologies, but no UXO have been found in these areas. UXO hazard levels in the impact areas are higl1 and, in some areas, could be reduced by removing UXO with potentially applicable technologies. However, reduction of UXO hazard levels to the point where the impact areas would be suitable for limited or expanded public use may not be possible. Also, the UXO hazard levels to EOD personnel who would implement UXO detection and interrogation technologies are potentially high. At the old Stokes mortar range, the current UXO hazard level is medium, but this level might be reduced by removing UXO with potentially applicable technologies. Once again, however, the UXO hazards to EOD personnel who would implement the technologies are high.

The remaining areas of the Empire, Balboa West, and Pina Ranges are heavily forested and have primarily hilly to steep terrain. Therefore, only man-portable UXO detection platforms and manual UXO interrogation methods are potentially applicable to these areas. However, EOD personnel implementing such technologies in these areas would experience even greater UXO hazards because of the extreme environmental conditions. In all cases, the specific environmental conditions associated with particular UXO AOCs should be examined before decisions are made regarding the applicability of UXO detection and interrogation technologies.

Table 4-2 summarizes the trade-offs and potential benefits associated with implementing potentially applicable UXO detection and interrogation technologies at UXO AOCs throughout the Empire, Balboa West, and Pina Ranges. Technologies potentially applicable to UXO AOCs are assigned based on general vegetation and terrain features (see Table 3-2). Trade-offs include the environmental impacts of implementing the technologies (see Table 4-1) and the UXO hazards to EOD personnel who would implement the technologies. The UXO hazard to EOD personnel is assumed to equal the fuze LD for heavy disturbance energy activity because EOD personnel are conservatively assumed to encounter all UXO present in an AOC. Potential benefits include UXO hazard level reduction resulting from decreasing the UXO density by implementing the applicable technologies. However, because of the limited effectiveness of the available UXO detection and interrogation technologies and because none of them has been tested in a Panamanian environment, it was assumed that UXO density could be reduced by only one category (for example, from high to medium). Moreover, if the UXO hazard level of an AOC is not reduced by decreasing the UXO density, negligible benefit is gained. Reducing UXO density by one category (for example, from very high to high) does not necessarily reduce the UXO hazard level because other factors also affect the hazard level.

Use of UXO detection and interrogation technologies on the ranges in Panama will have short- and long-term environmental impacts on the soils, vegetation, and wildlife. In particular, soil erosion resulting from vegetation removal and other activities would lead to several short- and long-term impacts, including surface water quality degradation, increased siltation of the Panama Canal, and wildlife habitat loss. On a larger scale, any vegetation removal and deforestation activities performed to implement UXO detection and interrogation technologies would add to impacts from deforestation already occurring throughout Panama at a rate of about 64,000 hectares per year. The negative environmental impacts would be greater if vehicle-towed sensor systems were used rather than man-portable sensor systems. In addition, because of the levels of soil disturbance they cause, interrogation technologies would have more severe negative impacts on the environment than the detection technologies.

Implementing potentially applicable UXO detection and interrogation technologies may reduce hazard levels in some areas of the Empire, Balboa West, and Pina Ranges. However, the consequences of using these technologies include a variety of short- and long-term environmental impacts as well as hazards to the EOD personnel who would implement them.

TABLE 4-2
TRADE-OFFS AND POTENTIAL BENEFITS ASSOCIATED WITH IMPLEMENTING
POTENTIALLY APPLICABLE TECHNOLOGIES AT UXO AOCs

This section presents the conclusion Is drawn from the Assessment of UXQ Detection and Interrogation Technologies for use on the Empire, Balboa West, and Pina Ranges in Panama. The conclusions are grouped according to the three major components of the report: environmental characterization of the ranges, UXO detection and interrogation technology evaluation, and trade-off analysis.

Both sensitive and extreme environmental conditions exist on the three ranges. The topography of the ranges is generally hilly to steep, although some relatively flat areas exist on hilltops and near rivers where they discharge to the Panama Canal. The ranges are primarily covered by dense, semideciduous seasonal and evergreen seasonal rainforests that flourish in the Panama climate of alternating wet and dry seasons. These forests are essential components of a large, sensitive ecosystem that presently contains 14 endangered animal species and seven critically imperiled plant species. Dense, tall grasses cover small areas in the vicinity of riverbeds. Disturbed areas such as impact, target, and encroachment areas are also covered with grasses. Soils on the ranges are clayey and susceptible to erosion.

UXO detection and interrogation technologies were evaluated for their potential applicability (in terms of effectiveness and implementability) on the three ranges in Panama. Results from the ATD Program controlled site demonstrations at JPG and experience from the live site demonstrations formed the basis of the technology evaluation. These results and experience were used because they represent the most current, reliable technology performance data available. The actual performance of the UXO detection and interrogation technologies in mitigating UXO hazards on the ranges in Panama would require verification through limited on-site demonstrations. The particular UXO sensor technologies, system components, and operational platforms used as well as site-specific soil, vegetation, and topographic conditions would influence technology performance.

Magnetometers (specifically fluxgate gradiometers and cesium vapor magnetometers), EM induction systems, or a combination of these sensors would be the most effective sensor technologies for UXO detection in areas that permit human access. In contrast, GPR and IR sensors would not be effective on the ranges in Panama and would provide minhnal (if any) UXO detection.

Many areas of the three ranges (up to 90 percent of the range land) may have excessively steep slopes and dense vegetation that would severely impede UXO detection operations. Some degree of site preparation and vegetation removal would be required before any UXO detection technology could be Implemented. However, the extensive vegetation removal activities required to implement vehicle-towed platforms on the three ranges would be particularly labor-intensive and expensive and would result in significant adverse environmental impacts. The most effective and Implementable mode of operation for UXO detection systems on the ranges would be the man-portable platform because of its ability to access forested areas. However, even man-portable systems may be difficult to use on the rugged, densely vegetated terrain h1 Panama. Based on results from the controlled and live site demonstrations, airborne systems would not be effective in detecting UXO on the ranges in Panama.

Manual UXO interrogation methods would be implementable in areas of the ranges that permit human access and would result in fewer adverse environmental impacts than mechanized interrogation. However, manual interrogation exposes workers to UXO and is resource-intensive (in terms of labor and thee). Mechanized interrogation, especially with autonomous and telerobotic equipment, would provide a higher level of operator safety. As with UXO sensor technologies, vegetation, geophysical conditions, and terrain would influence the feasibility of implementing particular UXO interrogation methods.

Use of UXO detection and interrogation technologies on the ranges in Panama will have short- and longterm environmental impacts on the soils, vegetation, and wildlife. In particular, soil erosion resulting from vegetation removal and other activities could lead to several short- and long-term impacts, including surface water quality degradation, increased siltation of the Panama Canal, and wildlife habitat loss. On a larger scale, any vegetation removal and deforestation activities performed to implement UXO detection and interrogation technologies would add to impacts from deforestation already occurring throughout Panama at a rate of about 64,000 hectares per year.

UXO detection and interrogation may reduce the UXO hazard levels associated with the ranges he Panama. Most of the potentially applicable UXO detection and interrogation technologies would be implemented he the relatively few areas with flat to gently rolling grassland. Such areas exist ha portions of the impact areas on the Empire, Balboa West, and Pina Ranges, including the old Stokes mortar range h1 the Range 1/1 A Area on the Empire Range. However, reduction of UXO hazard levels to the point where the impact areas would be suitable for limited or expanded public use may not be possible. Also, the UXO hazard levels to EOD personnel who would implement UXO detection and interrogation technologies are potentially high.

Most areas of the Empire, Balboa West, and Pina Ranges are heavily forested and have primarily hilly to steep terrain. Therefore, only man-portable UXO detection platforms and manual UXO interrogation methods are potentially applicable to these areas. However, ROD personnel implementing such technologies hi these areas would experience even greater UXO hazards because of the extreme environmental conditions. In all cases, the specific environmental conditions associated with particular UXO AOCs should be examined before decisions are made regarding the applicability of UXO detection and interrogation technologies.

DoD. 1995b. Memorandum Regarding Policy Guidance for the Transfer of Department of Defense (DoD) Installations to the Government of Panama. From Chas Freeman, Assistant Secretary of Defense. To Assistant Secretary of State, Director, Joint Staff. August 24.

Hanson, J.V., T.D. Evans, R.A. Hevenor, and J. Ehlen. 1992. "Mine Detection in Dry Soils Using Radar." U.S. Army Topographic Engineering Center Report No. R-163. March 17.

Johnson, Suzanne. 1995. An American Legacy in Panama. Directorate of Engineering and Housing (DEH), USARSO. September.

Miller, K., and L. Tangley. 1991. "Trees of Life; Saving Tropical Forests and Their Biological Wealth." World Resources Institute. Washington, DC.

Muschett, Daniel M. 1992. "Overall Environmental Assessment for Routine Field Training Exercises in the Panama Canal Area." Department of the Army. Headquarters, USARSO. Fort Clayton, Panama. August.

National Geographic Institute (NGI) "Tommy Guardia," Ministry of Public Works, Republic of Panama, and DMA Inter-American Geodetic Survey of the United States of America. 1989. "General Map of the Lands and Waters of the Panama Canal Treaty." Third Edition of Attachment No. I to Annexes "A" to the Agreements in Implementation of Articles III and IV of the Panama Canal Treaty between the United States of America and the Republic of Panama, Signed in Washington September7, 1977. November.

Tile Nature Conservancy (TNC) and National Association for the Conservation of Nature (ANCON). 1994. "Rapid Ecological Assessment of Lands in Panama Managed by the U.S. Department of Defense." December31.

Naval Explosive Ordnance Disposal Technology Center (NAVEODTECHCEN). 1985. "Range Clearance - An Economic Model, Final Report." Indian Head, Maryland. May.

Naval Explosive Ordnance Disposal Technology Division (NAVEODTECHDIV). 1990. "Range Clearance Technology Assessment (Revision 1), Final Report." March.

NAVEODTECHDIV. 1994a. "Glossary of EOD Terminology, Abbreviations, and Designations." Explosive Ordnance Disposal Procedures. Technical Manual 60A- 1 - 1- 15. April 4.

NAVEODTECHDIV. 1994b. Personal Communication Between Jerry Snyder of Naval Explosive Ordnance Disposal Technology Division (NAVEODTECHDIV) and Col. Zakrewski of DoD Explosives Safety Board.

PRC Environmental Management, inc. (PRC). 1994. "UXO Advanced Technology Program at Jefferson Proving Ground (Phase I)." U.S. Army Environmental Center Report No. SFIM-AEC-ET-CR-94120.

PRC. 1996c. "Draft Technical Report for Controlled Site Phase II at Jefferson Proving Ground." Prepared for NAVEODTECHDIV. Submitted January 4.

PRC. 1996d. Record of Telephone Conversation Regarding Panama Forest Cover. Between Donna Brunner, Environmental Engineer, and Richard Luxmore, Habitat Unit of the World Conservation Monitorhlg Commission, Cambridge, England. March 29.

PRC Inc. 1995. "System/Design Trade Study Report for the Navigation of the Airborne, Ground Vehicular and Man-Portable Platforms in Support of the Buried Ordnance Detection, Identification, and Remediation Technology." U.S. Army Environmental Center Report No. SFIM-AEC-ET-CR-95043. March.

U.S. Department of Agriculture (USDA). 1929. Soil Reconnaissance of the Panama Canal Zone and Contiguous Territory. Bureau of Chemistry of Soils. U.S. Government Printing Office. Technical Bulletin No. 94. January.

U.S. Department of Commerce (USDOC). 1996. Lever and Attachments Regarding Panama Climatic Data. From Kenneth D. Hadeen, Director, National Climatic Data Center, National Environmental Satellite Data and Information Service. To Michael Keefe, Environmental Engineer, PRC. January 10.

West, Colonel Pleasant H. 1979. "Overall Installation Draft Environmental Impact Statement, 193rd Infantry Brigade." Directorate of Facilities Engineering Environmental Of rice. Based on Studies by VTN Louisiana, Inc. July.

World Resources Institute. 1995. "World Resources 1994- 1995." Telephone Conversation Between Donna Brunner, Environmental Engineer, PRC, and Dirk Bryant, World Resources Institute. March 19, 1996

Component	Section Number
Environmental Characterization	2
UXO Detection and Interrogation Technology	3
Trade-off Analysis	4

UXO AOC	UXO AOC Characteristics^a,b	Hazard Level (AOC Group Number)	Potentially Applicable Technologies	Trade-Off	Potential Benefit
Empire Range
Main Impact Area	UXO density: High Fuze L_D: High/High Topography: Flat	High (1)	All sensors, man-portable and vehicle-towed platforms, and all interrogation methods	Moderate to severe environmental impact High hazard for EOD personnel	Negligible
	UXO density: Low Fuze L_D: Medium/Low Topography: Hilly	Medium (8)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts Medium hazard for EOD personnel	Negligible
	UXO density: Medium Fuze L_D: Medium/High Topography: Hilly	High^c (9)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Potential UXO hazrd level reduction from high to medium for heavy disturbance energy near-surface activities
	UXO density: High Fuze L_D: High/High Topography: Hilly	High (10)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts Medium hazard for EOD personnel	Negligible
	UXO density: Very High Fuze L_D: High/High Topography: Steep	High (11)	None	NA^d	NA
Range 6	UXO density: High Fuze L_D: High/High Topography: Flat	High (1)	All sensors, man-portable and vehicle-towed platforms, and all interrogation methods	Moderate to severe environmental impacts High hazard for EOD personnel	Negligible
	UXO density: Medium Fuze L_D: High/High Topography: Hilly	High (2)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Potetial UXO hazard level reduction from high to medium
	UXO density: Low Fuze L_D: High/High Topography: Hilly	Medium (3)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts Medium hazard for EOD personnel	Negligible
Range 1/1A Area	UXO density: Medium Fuze L_D: Medium/High Topography: Flat	High (4)	All sensors, man-portable and vehicle-towed platforms, and all interrogation methods	moderate to severe environmetnal High hazard for EOD personnel	Potential UXO hazard level reduction from high to medium for heavy disturbance energy activities
EOD Range	UXO density: High Fuze L_D: Very High/Very High Topography: Hilly	High^c (12)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts Very high hazard for EOD personnel	Negligible
EOD Range	UXO density: Medium Fuze L_D: Very High/Very High Topography: Hilly	High (13)			Negligible
FP 15 Area(formerly Camp Bayonet)	UXO density: Medium Fuze L_D: Medium/High Topography: Hilly	High^c(9)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazrd for EOD personnel	Potential UXO hazard level reduction from high to medium for heavy disturbance energy activities
Firing Fans Associated with the Main Impact Area	UXO density: Very Low Fuze L_D: High/High Topography: Hilly	Low (5)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
	UXO density: Very Low Fuze L_D: Medium/High Topography: Hilly	Low (6)			Negligible
	UXO density: Very Low Fuze L_D: Medium/High Topography: Flat	Low (7)	All sensors, man-portable and vehicle-towed platforms, and all interrogation methods	Moderate to severe environmental impacts High hazard for EOD personnel	Negligible
Balboa West Range
Northern Impact Area	UXO density: High Fuze L_D: High/High Topography: Hilly	High (10)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
Northern Impact Area	UXO density: Medium Fuze L_D: High/High Topography: Steep	Medium (16)	None	NA	NA
TTs and LO Areas	UXO density: Medium Fuze L_D: High/High Topography: Hilly	High (2)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Potential UXO hazard level reduction from high to medium
	UXO density: High Fuze L_D: High/High Topography: Hilly	High (10)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
	UXO density: Very High Fuze L_D: High/High Topography: Steep	High (11)	None	NA	NA
	UXO density: Very High Fuze L_D: High/High Topography: Hilly	High (14)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
	UXO density: High Fuze L_D: High/High Topography: Steep	High (15)	None	NA	NA
Pina Range
Pina Impact Area	UXO density: Medium Fuze L_D: High/High Topography: Hilly	High (2)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Potential UXO hazard level reduction from high to medium
	UXO density: Low Fuze L_D: High/High Topography: Hilly	Medium (3)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
	UXO density: High Fuze L_D: High/High Topography: Hilly	High (10)			Negligible
	UXO density: Very High Fuze L_D: High/High Topography: Steep	High (11)	None	NA	NA
	UXO density: Very High Fuze L_D: High/High Topography: Hilly	High (14)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
	UXO density: High Fuze L_D: High/High Topography: Steep	High (15)	None	NA	NA
Pina Multipurpose Range	UXO density: High Fuze L_D: High/High Topography: Flat	High (1)	All sensors, man-portable platforms, and all interrogation methods	Moderate to severe environmental impacts High hazard for EOD personnel	Negligible
	UXO density: Medium Fuze L_D: High/High Topography: Hilly	High (2)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Potential UXO hazard reduction from high to medium
	UXO density: Low Fuze L_D: High/High Topography: Hilly	Medium (3)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
	UXO density: Medium Fuze L_D: High/High Topography: Flat	High (17)	All sensors, man-portable and vehicle-towed platforms, and all interrogation methods	Moderate to severe environmental impacts High hazard for EOD personnel	Potential UXO hazard reduction from high to medium
FP1 and FP2	UXO density: Low Fuze L_D: High/High Topography: Hilly	Medium (3)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
FP3 and FP6	UXO density: Low Fuze L_D: High/High Topography: Hilly	Low (5)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible
FP4, FP5, and FP7	UXO density: Very Low Fuze L_D: Medium/High Topography: Hilly	Low (6)	All sensors, man-portable platforms, and manual interrogation methods	Moderate environmental impacts High hazard for EOD personnel	Negligible

ANCON	National Association for the Conservation of Nature
AOC	Area of Concern
ATD	Advanced Technology Demonstration
bgs	Below Ground Surface
cm	Centimeter
DEH	Directorate of Engineering and Housing
DGPS	Differential Global Positioning System
DMA	Defense Mapping Agency
DoD	U.S. Department of Defense
EM	Electromagnetic
EOD	Explosive Ordnance Disposal
FAR	False Alarm Rate
GPR	Ground-Penetrating Radar
IR	Infrared
JPG	Jefferson Proving Ground
kg	Kilogram
LO	Live Ordnance Area
NAVEODTECHDIV	Naval Explosive Ordnance Disposal Technology Division
NGI	National Geographic Institute
PRC	PRC Environmental Management, Inc.
TIPA	Panama Canal Treaty Implementation Plan Agency
TNC	The Nature Conservancy
TT	Tactical Target
USACE	U.S. Army Corps of Engineers
USAEC	U.S. Army Environmental Center
USARSO	U.S. Army South
USDA	U.S. Department of Agriculture
USDOC	U.S. Department of Commerce
UXO	Unexploded Ordnance