Title: Introduction (1 of 2) Text: The Encapco process is a physical-chemical treatment technology for the cleanup of soil contaminated with metals, explosives, and radionuclides. It was patented in 1999 under U.S. Patent No. 5,968,245 and is licensed by Encapco Technologies LLC. It involves mixing contaminated soil into an asphalt or tall oil pitch (TOP) emulsion that is chemically enhanced to bind and stabilize the target contaminants. The stabilized and encapsulated soil is then ready for reuse as a valuable construction material for road base, covers, berms, or fill. This data sheet provides an overview of the Encapco soil stabilization technology and provides initial results from the Navy's ongoing Encapco demonstration program. Visual Direction: Diagram of a pile of contaminated soil which is mixed with Encapco emulsion mix. Next, a diagram of a steamroller using the mixture as an asphalt base.

Title: Introduction (2 of 2) Text: NAVFAC is currently working with Encapco Technologies, LLC to test their patented emulsion stabilization technology at several Navy sites for the ex situ treatment of soil impacted by heavy metals, explosives, and other contaminants. The Encapco method is also being tested at DoD and DOE sites for the in situ stabilization of radionuclides in soil. The objectives of NAVFAC's ongoing demonstration program are as follows: To evaluate the implementability of the technology. To document the cost and performance of the technology. To obtain regulatory support for the overall treatment approach and product reuse options. Visual Direction: Diagram of a pile of contaminated soil which is mixed with Encapco emulsion mix. Next, a diagram of a steamroller using the mixture as an asphalt base.

Title: Background (1 of 3) Text: Emulsion The Encapco process involves mixing contaminated soil with the optimal amount of asphalt or TOP, surfactant, water, and other proprietary additives. The mixture of water and asphalt with surfactant is referred to as an asphalt emulsion. A typical emulsion formulation is shown. The surfactant is a soap-like compound which enhances the mixing of water with the hydrophobic organic compounds in the asphalt materials. The use of an asphalt emulsion improves adhesion to the soil particles. The asphalt emulsion is stable enough for pumping, prolonged storage, transportation, and mixing. Visual Direction: Table of a typical emulsion formulation including the types of materials and percent volume of each.

Title: Tall Oil Pitch Emulsion Text: Tall oil pitch (TOP) emulsion is the preferred formulation for use over large areas and/or near ecologically sensitive areas. While the asphalt emulsions are appropriate for road base applications, the pitch-based emulsions from pine tree oils have passed ecotoxicity tests and are used for other applications such as stabilizing exposed soil areas, landfill caps, etc. Visual Direction: No graphic.

Title: Background (2 of 3) Text: Emulsion (Continued) Chelating and/or precipitating agents are added into the asphalt emulsion to promote chemical bonding of the target contaminants. As the asphalt emulsion coalesces, cures, and solidifies, the contaminants in the soil are both chemically stabilized and physically encapsulated. The overall treatment objective is to minimize contaminant leaching, while retaining the overall adhesiveness, durability, and water-resistance of the final asphalt base product. The final product will exhibit reduced leachability, reduced permeability, and increased soil stability and strength. Visual Direction: Animated graphic of contaminated soil particles under a magnifying glass compared to emulsified particles which are encapsulated.

Title: Background (3 of 3) Text: Process Overview The equipment used in the ex situ Encapco treatment process is conventional and readily available. Click on the figure to find out more about the major treatment steps involved. Visual Direction: Animated diagram of contaminated soil going through a feed hopper onto a conveyor belt where hoses and mist spray bars suppress dust. Soil passes over a weight scale to a pug mill mixer where emulsifier is added, then treated soil goes into a dump truck.

Title: Text: The soil is excavated, and after screening out oversized materials, is placed into the feed hopper for treatment. Visual Direction: Rollover of the feed hopper.

Title: Text: The weight scale is used to determine how much soil will be treated so that the optimal emulsion soil mix can be made. Visual Direction: Rollover of the weight scale.

Title: Text: Mist sprays and hoses are used to suppress any dust that might be generated during soil processing. Visual Direction: Rollover of the mist sprays and hoses.

Title: Text: The emulsion mix is usually stored in a tanker truck and pumped into the pug mill for mixing with the soil. Visual Direction: Rollover of the emulsion tank.

Title: Text: Treated material is deposited into a dump truck and can be used as recycled material for a construction project. Visual Direction: Rollover of the dump truck and treated soil.

Title: Pug Mill Text: A pug mill mixer is used to blend and thoroughly mix the soil and emulsion. Visual Direction: Rollover of the pug mill mixer.

Title: Feasibility Evaluation Text: First, a site-specific feasibility evaluation must be conducted. The objective is to evaluate the effectiveness of the Encapco emulsion formulation to treat and stabilize the soil. This evaluation consists of the following steps: 1) Evaluate soil for key geotechnical characteristics. 2) Analyze soil samples to determine concentrations of contaminants present. 3) Using steps 1 and 2, select the additive level, surfactant, and organic binder for the emulsion. 4) Test emulsion samples for strength and flow characteristics using different water contents and select the optimum emulsion formulation. 5) Test soil from step 4 with the Toxicity Characteristic Leaching Procedure (TCLP) to ensure that post-treatment leachable contaminant concentrations are below action levels. 6) Additional tests may be needed before use as an engineered construction product, such as compaction tests for road base fill. Visual Direction: No graphic.

Title: Geotechnical Criteria Text: A series of geotechnical tests are used to characterize the properties of the site soil and to provide information for the optimal emulsion formulation as follows: Atterberg Limits by American Society for Testing and Materials (ASTM) D4318 Size distribution by ASTM D422 Specific gravity by ASTM D422 Percent moisture by ASTM D2216 Soil pH by EPA SW 846 Method 9045 For more information on these types of tests visit the ASTM Web site. Visual Direction: No graphic.

Title: Atterberg Limit Definition Text: The Atterberg limits are water contents at certain limiting stages of soil behavior. Keeping the water content within the Atterberg limits will ensure that the emulsion mixture will retain enough plasticity to be molded, without becoming too wet and viscous or too dry and brittle. Visual Direction: No graphic.

Title: Leaching Criteria Text: The treated product must pass a leaching test to prove that the target contaminants are no longer available for release into groundwater or surface water. TCLP as outlined in U.S. EPA Method 1311 is the most frequently used test. A solid sample of the treated product is subjected to an acidic liquid with a pH of ~ 3 to 5. This extraction fluid is then separated from the solid sample and analyzed for the target contaminant concentrations. The resulting leachate levels must be below the appropriate regulatory levels for land disposal. Visual Direction: Photo of a person working in a laboratory with samples.

Title: Implementation Text: The field-scale process consists of excavating and stockpiling the impacted soil, followed by the screening and separation of oversized materials. Next, the stockpiled soil must be re-tested for the target contaminants to ensure consistency with the initial sampling event. Once the on-site pug mill is set up, the Encapco proprietary Emulsified Treated Base (ETB) can be produced. The ETB production rates are based the size of the project and the equipment selected. After passing the appropriate testing criteria, the ETB can be placed and compacted. Visual Direction: 5 Photos: 1) loading contaminated soil into the hopper, 2) the pug mill mixer, 3) loading treated material into a dump truck, 4) placing treated material on the ground and 5) compacting treated material.

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Title: Heavy Metals Treatment Text: The Encapco process has been used in the past to successfully treat soils contaminated with heavy metals, especially lead. A demonstration for the treatment of lead-impacted soil was conducted at the Naval Support Activity (NSA) in Mechanicsburg, PA in 2003 and the results are discussed here. Visual Direction: Map of the continental United States. Pennsylvania advances showing the location of Mechanicsburg Naval Support Activity site.

Title: Background Text: For the past 50 years, NSA Mechanicsburg has served as a repository for 90,000 tons of lead and zinc ingots in four storage areas numbered 317, 413, 414, and 606. Although the storage areas were fenced, the ingots were kept in the open on bare ground. This practice left the ingots exposed to decades of weathering and resulted in an impact to the surrounding soil. The ingots were removed from all outdoor storage areas in 2002 and placed in covered warehouses. Storage area 413 was selected as a test site for the demonstration of the Encapco technology. Lead and zinc were the only soil contaminants known to exceed human health exposure criteria at Area 413 with concentrations of up to 20,400 milligrams per kilogram (mg/kg) and 3,720 mg/kg respectively. In addition, toxicity characteristic leaching procedure (TCLP) data from one soil sample collected in June 2003 showed a concentration of 6.4 milligrams per liter (mg/L) of lead in the leachate, which exceeded the applicable hazardous waste threshold for lead. Visual Direction: Photo of storage area showing chain link fence around lead and zinc ingots.

Title: Technology Implementation (1 of 2) Text: The fieldwork at NSA Mechanicsburg was conducted from October 6 through October 17, 2003. The first step consisted of soil excavation and screening of approximately 700 tons of soil. After passing the soil through a screen and removing pieces of soil and gravel greater than one inch, approximately 500 tons of lead and zinc contaminated soil were deemed suitable for processing. Visual Direction: Photo showing equipment screening the soils and piles of coarser gravel and screened soil.

Title: Technology Implementation (2 of 2) Text: Following excavation, the soil was placed in a temporary stockpile and quicklime was added to remove excess moisture. A tanker truck delivered the Encapco emulsion, which was mixed with the soil in a pug mill. The liquid emulsion was delivered to the job site and was then proportioned and mixed with the soil at a temperature between 90°F and 120°F. Visual Direction: Photo of tanker truck, pugmill, and treated soil pile.

Title: Performance Assessment Text: The performance assessment for the NSA Mechanicsburg project included an evaluation of the reduction in contaminant mobility and leachability by comparing before and after treatment TCLP results for lead and zinc. The TCLP values for lead were all less than 0.11 mg/L and met the RCRA TCLP standard of less than 0.75 mg/L for lead. The TCLP values for zinc were all less than 0.33 mg/L and met the RCRA TCLP standard of less than 4.3 mg/L for zinc. The performance assessment also included the analysis of supplemental geotechnical criteria to assess the suitability of the emulsified soil product for reuse as sub-base for a parking lot including the treated product permeability, stability, and flow under heavy loads. Visual Direction: Table of performance assessment conclusions from NSA Mechanicsberg project showing TCLP and total concentrations for lead and zinc.

Title: Total Costs Incurred Text: The major cost drivers for the Encapco process included equipment costs, labor, material (including the Encapco mixture), permitting, utilities location, location surveying, oversight, and work plan/report preparation. The unit cost for the demonstration project at $159/ton was relatively high due to the small volume of soil treated at 500 tons. However, it was still below typical values reported for excavation and off-site treatment and disposal, which are reported to range from $200 to $460 per ton for hazardous waste. This figure shows the predicted effect of scale on the unit cost of Encapco treatment. For example, with 7000 tons of soil, the unit cost per ton of treated soil would decrease to approximately $43 per ton. Due to these scalability issues, 500 tons of soil is the minimum quantity of soil that is recommended for treatment with the Encapco process, while still maintaining its cost effectiveness compared to off-site disposal as hazardous waste. Visual Direction: Graph of total unit costs vs. volume treated. Unit costs decrease with increasing volume.

Title: Explosives Treatment Text: The Ammunitions Burning Ground (ABG) at the Naval Surface Warfare Center (NSWC) in Crane, IN was selected as the demonstration site for the treatment of explosive compounds. Several explosives were detected in site soils including HMX, RDX, TNB, TNT, 2,4-DNT, 2,6 DNT, 2A-DNT, and 4A-DNT. The soil collected for the treatability study contained lead up to 686 mg/kg and was spiked with explosive compounds at 2,000 mg/kg. Based on initial treatability study results, the reduction in the TCLP of RDX, TNB, and TNT ranged from 96% to 99%. Fieldwork at this site is expected to begin later in 2003. Visual Direction: Map of the continental United States. Indiana advances showing location of the Naval Surface Warfare Center and a link to Encapco Treatability Test Results from the site. Link shows metals and explosives concentrations in treated and untreated soil.

Title: Radionuclide Treatment Text: The Encapco soil stabilization technology is also being tested on radionuclide contaminated soil at two Department of Defense (DoD) facilities in New Mexico and Arizona and one Department of Energy (DOE) facility in Nevada. The radionuclides targeted for treatment include plutonium (Pu), americium (Am), thorium (Th), and depleted uranium (DU). The objectives are to achieve dust and erosion control to reduce off-site migration of these radionuclides. This is achieved through a surface application of the Encapco TOP emulsion over impacted soil. The soil is treated in place and no excavation is required. The initial results from the treatability tests are discussed below. Visual Direction: Map of continental United States showing locations of DOE Nevada Test Site Facility in Nevada, U.S. Army Yuma Proving Ground in NM, and Kirtland Air Force Base in AZ.

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Title: Nevada Test Site Text: The Smoky area of the Nevada Test site was selected for the demonstration of the surface application of the Encapco emulsion to control erosion. The Smoky site was historically used for the detonation of small nuclear devices. The most recent of these tests was a detonation of a fission bomb by conventional explosives to verify the ability of the nuclear device to withstand the heat and pressure of a conventional explosion (or plane crash) without a critical chain reaction. As a result of these nuclear tests, the Smoky area has elevated plutonium and americium concentrations in soils. This presents a potential radionuclide migration concern because the area is upslope from the main access road through the site. After the Encapco surface application was complete, a series of hydrological, radiological, plant stress, and erosion tests were conducted to assess the performance of this remediation approach. Visual Direction: Photo of an open field with sparse vegetation in the foreground and hills in the background.

Title: Emulsion Application Technique Text: The surface application technique at the Nevada Test Site included several steps. After proper dilution was made to the emulsion it was stored in a holding tank, ready to be sprayed on the surface. It was applied with a flat spray nozzle. Multiple passes back and forth over the surface were made to insure complete and uniform coverage. Within two hours after the first application, the surface water from the initial application had evaporated and a second application was made. This consisted of a fine fog seal of emulsion that was sprayed over the surface at 0.1 gallons per square yard to further seal the surface against erosion. Visual Direction: Photo of a person holding a large hose and spraying a brown emulsion over a field.

Title: Hydrological Surveys (1 of 2) Text: A hydrological survey was conducted at the site to test the performance of the Encapco treatment process. Both surface runoff and subsurface runoff evaluation tests were conducted. To conduct the survey, the site was divided into five 10 feet wide by 15 feet long disturbed and undisturbed plots. The undisturbed plots had minimal disturbance to the natural soil surface, while the disturbed plots were hand-raked to the top 1 to 2 inches to simulate previous construction or other activities. The Encapco emulsion was applied to three of each disturbed and undisturbed sites. Visual Direction: Photo of a series of tripods connected to hoses and holding sprayers.

Title: Hydrological Surveys (2 of 2) Text: After the stabilization emulsion was applied, high intensity irrigation tests were performed at the test site. The system used a wobbler sprinkler head that discharged water at a rate equivalent to 3 inches of precipitation per hour. The surface runoff and associated sediments were then screened for radioactivity using gamma spectroscopy. The plutonium concentrations were analyzed in the water and sediment samples if a relatively high level of radioactivity was measured from the screening process. The subsurface evaluation measured the infiltration of water after the stabilizing emulsion was applied. The infiltration studies were conducted using a double ring infiltrometer. Soil water content was monitored to assess the effect of the stabilization emulsion on infiltration and redistribution of soil moisture. This data also provided support for an assessment of subsurface radionuclide transport. Visual Direction: Photo of a bucket containing a plastic bottle used to collect samples of runoff.

Title: Radiological Survey Text: After the Encapco emulsion had been applied to the 10 test plots for the hydrologic survey, a high-purity Germanium (HPGe) detector was used to conduct radiological surface measurements. With the boom system shown here, the HPGe detector was centered over each test plot without impacting the surface. These radiological tests were also repeated with the detector placed on a tripod. Profile soil sampling was also conducted to assess the effect of the stabilization emulsion on subsurface transport of radionuclides. At the start and conclusion of the project, soil samples were collected at depths of 2, 4, 6, and 10 centimeters from three locations in the treated area and three locations in the control area. Samples were analyzed by gamma spectroscopy. Visual Direction: 1) Photo of an HPGe detector mounted at the top of a tall pole at the rear of a vehicle. 2) Photo of an HPGe detector mounted on a tripod with a person looking at it.

Title: HPGe Detectors Text: High purity Germanium (HPGe) detectors are a good choice for gamma-ray spectroscopy because of their high resolution and efficiency at energies above 2 MeV. HPGe detectors collect gamma rays at a very slow rate compared to other commercially available detectors. Their advantage is high-energy resolution, which makes isotopic identification relatively easy in areas with many isotopes or, in the case of the Nevada Test site, where the low-energy gamma emitter Americum (241) is present with other isotopes. Visual Direction: No graphic.

Title: Plant Stress Protocol Text: The objective of the biological task was to determine the effects of the Encapco emulsion on the vigor of plant species native to the Nevada Test Site. The test site was divided into two different study areas. One of the areas served as a control and so no emulsion was applied to it. The other area was sprayed with the emulsion. The areas chosen were similar in their vegetative cover and acreage. In addition, each area had at least 50 plants to be included in the study. The protocol used to measure plant stress is shown here. Visual Direction: 1) Photo of a person spraying with a hose and sprinkler tripods in the background. 2) Table defining plant stress categories ranging from 0 (dead) up to 5 (excellent).

Title: Erosion Tests: Background Text: The transport of radionuclide contaminated dust by wind suspension was the primary transport pathway examined as part of this demonstration project. A series of erosion tests were conducted to better understand the role of Encapco stabilization in minimizing potential surface soil erosion. There are several sources of fugitive dust emissions including wind suspension from soils (windblown dust), vehicles traveling on paved and unpaved roads, active storage piles, and construction activities. The amount of windblown dust is related to the wind speed, the resilience of the soil surface, and the degree of vegetative cover. Depending on the type, age, and degree of contamination present, radioactive material may be associated with different sizes of soil particles from coarse aggregates to fine silts. In a process called “saltation”, particles that are slightly smaller in size (0.1 to 0.5 mm) may be lifted by aerodynamic and pressure forces and entrained in the airflow at a modest height (generally less than 30 cm above ground surface). The velocity of these particles is dominated by the component of the wind velocity that is tangential to the ground. The process of saltation can lead to the emission of huge quantities of inhalable PM10 dust (particles with diameters of 10 microns or less). Visual Direction: Animated graphic showing wind blowing over the ground surface and dust particulates moving downwind and being deposited or being suspended.

Title: Erosion Test: PI-SWIRL (1 of 2) Text: The Desert Research Institute (DRI) was contracted by NAVFAC to investigate the effectiveness of the Encapco treatment in reducing the suspension of transportable dust particles, some fractions of which may be associated with radionuclides. The erodibility index of Encapco-treated, water-treated, and untreated soils were measured directly with a technology that has been developed at DRI called the portable in-situ wind erosion laboratory (PI-SWIRL). The PI-SWIRL offers fast portable measurement of a wind erosion index, allowing for rapid assessment of the relative degree of soil stability with respect to PM10 resuspension. It is contained in a cylinder that is approximately 0.6 meters (23.6 in) in diameter and 0.5 meters (19.7 in) in height. Particle monitors, batteries, and a laptop computer are mounted on a cart that can be wheeled by one individual. Visual Direction: Two photos of the cylindrical metal chamber from the PI-SWIRL equipment.

Title: Erosion Tests: PI-SWIRL (2 of 2) Text: The PI-SWIRL uses a DC motor to spin a flat plate that induces shear stresses above the soil surface, which are intended to simulate the stresses caused by wind. The advantage of the PI-SWIRL over straight wind tunnels is the relative speed with which measurements can be performed. An average test at one location requires less than ten minutes. This allows for frequent testing of soil erodibility at multiple locations. One disadvantage is that the PI-SWIRL has not been calibrated against a known standard. Visual Direction: Animated diagram of a PI-SWIRL showing side and bottom views of the open-bottomed cylindrical chamber with a variable speed motor and rotating arms moving inside suspending particulates. The chamber is connected to a PM monitor and computer data system.

Title: Erosion Tests: Results (1 of 2) Text: Five different types of surface treatments were tested at the Nevada site including no treatment at all for control purposes (N plots), treatment with three different strengths of emulsified Encapco product (E1, E2, E3 plots), and treatment with water alone (W plots). For each type of treatment, two replicate test plots were used for a total of ten plots. After the treatment application, test plots were disturbed minimally in order to access them for measurements. This minimizes damage to the test plots caused by footsteps and equipment movement. Since the PI-SWIRL can also be destructive to the surface, it is not possible to use the same test surface twice. Measurements were performed 3 weeks, 20 weeks, 40 weeks, and 60 weeks following Enacapco treatment. The test at 60 weeks after treatment was done for assessment of the effect of the variability over one full year of seasons, temperatures, wind, and precipitation. Visual Direction: Diagram of the location of the various test plots within the Nevada site.

Title: Erosion Tests: Results (2 of 2) Text: As these graphs show, the Encapco-treated plots (E1, E2, E3) showed significantly lower dust emissions with PM10 levels at one to two orders of magnitude below the water or untreated plots. However, in all cases, the dust emissions at 1950 RPM appear to be higher in the August tests than they were during the May tests for all three Encapco test plots. It is not clear if this is a real trend indicating the deterioration of the effectiveness of the Encapco emulsion over time or if these data are simply a result of statistical variation. Future PI-SWIRL tests are planned at the site to resolve the long-term effectiveness of the Encapco treatment process. Visual Direction: Graph of PM and RPMs vs Time; 3 graphs of Avg. PM10 vs. Nominal RPMs for Encapco Emulsion Treatment, Water Only Treatment and No Treatment.

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Title: Yuma Proving Ground Text: There are several areas within the firing ranges at the Yuma Proving Ground in Arizona where depleted uranium projectiles and oxidized depleted uranium is present in soils. The Department of Army was interested in identifying a technology that could stabilize the soil at these ranges for management and containment of radionuclides migration via wind and water pathways and also to reduce potential airborne exposure to dust particles. The Encapco process was chosen for demonstration at this site to further evaluate its effectiveness in stabilizing soils contaminated with depleted uranium. Yuma Proving Ground will be evaluated in a similar manner to the Nevada Test Site through leaching tests and surveys of hydrologic, radiologic, soil morphologic, weathering, and biotic effects. Visual Direction: Map of continental United States. State of Arizona enlarges with location of Yuma Proving Grounds shown.

Title: Background Text: Firing Range 17a was selected by the Department of the Army for these tests due to its historical use for depleted uranium projectile firing. Test firing is still conducted at the site and the proposed Encapco testing will be coordinated within open windows where firing range activity is limited. One test site will be located downrange of Gun Position 17a (GP17a), where ordnance equipped with depleted uranium penetrators were test fired and depleted uranium was observed to be present on the soil surface as shown in this photograph. This site includes an ephemeral wash, which splits a floodplain, adjacent to a larger drainage unit. Representatives from NAVFAC, Encapco, and the Base personnel were satisfied that this area would be a suitable location for testing the ability of the emulsion to complex depleted uranium. The second test site is located several miles south of the gun positions in an area clear of contamination. Visual Direction: Photo of a large area of barren gray soil in the foreground with shrubby vegetation in the background.

Title: Experimental Design and Study Parameters (1 of 2) Text: Different test plots will be constructed based on varying soil age, site disturbance, and treatment levels. The study plan calls for three replicates of each condition with measurements taken over four time intervals. For each combination of factors, field tests will be run to ascertain the impact of the treatment on potential for surface runoff and deep infiltration. Soil characteristics will also be studied like particle size distribution, bulk density of the surface materials, hydraulic conductivity, and retention properties. Visual Direction: Photo of a person in protective boots holding a detector in the large barren soil area.

Title: Experimental Design and Study Parameters (2 of 2) Text: Towards the end of the project period, soil trenches will be excavated at selected areas within the old and young soil sites to study soil morphology and the hydrologic process. Soil excavated from the trenches will be observed for presence or absence of preferential flow paths, identification of soil layers, structure, calcium carbonate, and clay rinds surrounding soil peds. These and other diagnostic features will help to explain the soil’s role in the hydrologic processes observed and monitored in the field. The infiltration capacity of the soil will also be studied before and after treatment. If the infiltration capacity is lowered by treatment, it can lead to higher surface runoff and erosion. However, a higher infiltration capacity could lead to downward transport of treatment compounds. Visual Direction: Photo of a soil trench showing gray soil at surface and reddish coloration deeper in the trench. A yellow grid has been placed on the sides of the trench.

Title: Demonstration Set-Up and Start-Up Text: Based on the results of the companion study at the Nevada Test Site, the Yuma site used two water: emulsion concentrations of 4:1 and 6:1 for the tests. The emulsion was transferred by Encapco personnel into a 500 gallon holding tank, diluted to the target concentration and applied with a flat spray nozzle. The target application rate was 0.75 gallons dilute per square meter, which was checked using “calibration” squares adjacent to the test plots. Multiple passes back and forth over the surface, within a carefully timed period, ensured complete and uniform coverage. Visual Direction: Photo of a person with a large hose spraying a brown emulsion over vegetation in a field.

Title: Emulsion Application Text: On December 2, 2004, personnel from Encapco, Desert Research Institute, and NAVFAC applied the emulsion on test plots at Site 1 (with depleted uranium present) and Site 2 (no depleted uranium present). Visual Direction: This slide will have two pics from the power point presentation

Title: Encapco: Site 1 Text: The experiment at Site 1 is a complete randomized block design. Primary variables are treatment level (control, 4:1 dilution, 6:1 dilution) and time (1 pre-treatment sampling event, 4 post-treatment sampling events over 12 months). The squares are replicated, which yielded a total of 30 squares in the experiment (3 treatment x 5 times x 2 replicates = 30 squares). Each square is 1 m x 1.5 m in area. Visual Direction: This info will be a pop-up for the word Site-1 on the previous slide with the schematic available in the ppt

Title: Encapco: Site 2 (1 of 2) Text: The experiment at Site 2 is a multi-factorial design. Primary variables are treatment level (control, 4:1 dilution, 6:1 dilution), disturbance (raked, undisturbed), soil age (old, young), and time (1 pre-treatment sampling event, 4 post-treatment sampling events over 12 months). Each square is 5 m x 5 m in area. Next Page Visual Direction: This info is a pop-up to the word Site-2 on the 6.035 slide and has a schematic too present in the ppt

Title: Encapco: Site 2 (2 of 2) Text: The hydrologic and ecosystem experiments are conducted at Site 2, which is located south of the gun positions. These experiments were done at a site without presence of depleted uranium to reduce the need for logistical support. Site 2 is a desert pavement area, but is adjacent to an ephemeral drainage channel. The proximity of 'old' pavement soils to 'young' channel material allowed researchers to more efficiently stage equipment and sensors. Previous Page Visual Direction: This is the next page to the 6.0352 slide in the pop-up window with some graphics present in the ppt

Title: Hydrologic Studies Text: Hydrologic studies seek to quantify the hydraulic properties of the soil and the potential for surface runoff. A tension infiltrometer is used to measure saturated hydraulic conductivity (36 tests per site visit). The measurements take approximately 1.5-2.0 hours each. The rainfall simulator is used to estimate the surface runoff characteristics underneath a 60 cm x 60 cm area. Precipitation rate was calibrated for the 100-year, 2-hour storm event (~5.75 cm/hr). Efforts were made to keep soil conditions undisturbed so that measurements could be taken at the same location, allowing a more direct comparison of property values with time. Visual Direction: there are 2 pics in the ppt for this slide

Title: Ecological Studies Text: Ecological studies were conducted to better quantify the effects of emulsion application on native seed germination and on general health of the existing vegetation. The experiments used 5 m x 5 m plots, which were all located on the young site. Primary variables for this experiment were seeding (not seeded, seeded) and treating (control, 4:1 dilution). Each plot is evaluated for species diversity and abundance for multiple subplots within each treated square, percent biomass, root/shoot ratio, and ground cover percent. Visual Direction: has 2 pics in the ppt

Title: Dust Resuspension Studies Text: Dust resuspension studies are also being conducted on soils of known texture and samples from the Yuma site. Primary variables for these experiments are soil type (sand, sandy silt, silty sand, silt, and soil material from the Yuma site), treatment (control, 4:1 dilution) and time (3 months, 1 year post-treatment). The results will provide the data needed to make better predictions of the reduction of dust emission potential after treatment with the Encapco emulsion. Visual Direction: has 2 pics in the ppt

Title: Summary Text: In summary, field studies are being used to evaluate the benefits of the Encapco emulsion to stabilize depleted uranium with time. Broad hydrologic and ecologic studies are also being conducted to assess the potential impact from widespread application on landscapes. Results can be used by land managers to make decisions on land treatment and restoration. Using the current timeline, the field experiments at the Yuma site are scheduled for completion by November 2005. Data analysis and reports should be completed by April 2006. Visual Direction: has pics in the ppt

Title: Advantages Text: Recycles impacted soil into a valuable construction material, avoiding off-site hauling and disposal costs. (Note: additional tests may be needed such as compaction tests for road base fill.) Encapsulates impacted soil into a low permeability and water-resistant matrix. Chemically stabilizes target contaminants to meet TCLP and other regulatory criteria. The process is easily implemented and relies upon conventional equipment (e.g. backhoe, feed hopper, pug mill mixer, tanker truck, and other equipment). Can be used to eliminate dust generation and associated health risks. Visual Direction: No graphic.

Title: Limitations Text: Site soils must be suitable for the planned end use and have the appropriate structural characteristics. Pre-processing may be required to remove over-size debris such as large chunks of lead. A site-specific engineering evaluation is needed to confirm suitability of the Encapco process. Visual Direction: No graphic.

Title: Cost Information Text: Use of the Encapco process can result in significant cost savings. Off-site hauling and disposal costs are avoided. Cost savings may also be realized by off-setting the purchase price of construction materials for an existing project. Typical cost figures are listed below: Typical bench-scale testing at $10,000 per sample. Typical processing costs at $40 to $65 per ton of material. Estimated recycle value of treated material at $10 per ton. Visual Direction: No graphic.

Title: Feedback Text: Visual Direction: Picture of a feedback form.

Title: Contact Information Text: For more information about the Navy's demonstration program of the Encapco technology, please contact: NFESC POC (805) 982-1656 PRTH_NFESCT2@navy.mil For more information about the Encapco soil stabilization technology, please contact: ENCAPCO Technologies LLC Visual Direction: No graphic.