W912HN-12-T-0029-0003.doc

W912HN-12-T-0029

SECTION SF 30 BLOCK 14 CONTINUATION PAGE

SUMMARY OF CHANGES

SECTION A - SOLICITATION/CONTRACT FORM

The required response date/time has changed from 23-Mar-2012 05:00 PM to 23-Jul-2012 05:00 PM.

The solicitation issue date has changed from 02-Mar-2012 to 16-Jul-2012.

SECTION B - SUPPLIES OR SERVICES AND PRICES

SECTION C - DESCRIPTIONS AND SPECIFICATIONS

The following have been modified:

STATEMENT OF WORK

PERFORMANCE WORK STATEMENT

for a

TREATIBLITY STUDY FOR DDT/DDE/DDD IN SOIL

at

FORT BENNING, GEORGIA

Prepared By:

US Army Corps of Engineers

Savannah District

PO Box 889

Savannah GA, 31402

Revised June 2012

PERFORMANCE WORK STATEMENT:

Soil Treatability Study at Site FBSB-86

Fort Benning GA

1.0 INTRODUCTION

Building 1396 and the surrounding area was used by the Entomology Division of the Directorate of Public Works (DPW) for mixing and storage of the numerous pesticides and herbicides used across the entire infrastructure of Ft. Benning. Building 1396 was constructed around 1945 and was in continuous usage until 1990, when operations were shifted to the enclosed facilities in Building 266, nearby.

In June of 1988, The Fort Benning Environmental Management Division (EMD), in conjunction with the U. S. Army Environmental Hygiene Agency (AEHA), began investigations at FBSB-86 by collecting a limited number of soil samples. The concentrations of DDT, dieldrin, and chlordane detected were such that AEHA conducted additional sampling in late 1988 to confirm the original data.

A third round of more extensive sampling was conducted by in house by AEHA during September 1989 to further delineate the site. In October 1989, the U.S. Army Toxic and Hazardous Materials Agency (USATHAMA), now the U. S. Army Environmental Command (AEC), contracted for the preparation of a Remedial Investigation / Feasibility Study (RI/FS) under the Department of Defense Installation Restoration Program (IRP). The RI/FS was conducted between late 1989 and mid-1991. The majority of the work was conducted by ABB Environmental Services, Inc., Portland, Maine, with other portions completed by USATHAMA in-house personnel (ABB Environmental Services, Inc. 1992a and 1992b).

In 1994, Ft. Benning initiated the selected remedy for the removal and treatment at an off-post facility under the RCRA Part B permit criteria. Corrective measure activities began in March 1997 and were completed in December 1997. Soil contamination from both organochlorine and organophosphate pesticides at SWMU FBSB-86 were found in both the surface and subsurface soils and surrounding area. Samples collected for delineation include analyses for semi-volatile, volatile, PCB, and inorganic analytes. In general, semi-volatile and volatile analyses ranged from mostly non-detect to an occasional detection at an extremely low level. No PCBs were detected. As would be expected in soils, many inorganic analytes were detected in all soil samples that had analyses for inorganics performed (not all samples were analyzed for inorganics).

The most prevalent compounds detected were the organochlorine pesticides, including chlordane, lindane, dieldrin, 4,4'- DDT, 4,4' -DDE, and 4,4' -DDD. DDE and DDD were found to have the highest concentrations and widest distribution. Concentrations of DDT ranged from a high of approximately 10,000 mg/kg to non-detect. A background level of 1.0 mg/kg for DDD/DDE and DDT was agreed to between the Installation and GAEPD.

During the removal action delineations in both the vertical and horizontal directions to a detection level of less than 1.0 mg/kg DDT was required. The final excavation depth recorded for each 10-ft by 10-ft grid across the site represents removal of contaminated soil to less than 1.0 mg/kg DDT for that grid. Additionally, all surface soil areas adjoining the ICM removal zone were tested for organochlorine pesticides and were determined to be at levels less than 1.0 mg/kg DDT. Residual levels of other organochlorine and organophosphate pesticides were one to three orders of magnitude less than the DDT level.

The majority of the soils were excavated to a depth between 0.5 and 2.0 feet BGS. Three grids were excavated to 12 feet bgs and 1 grid to 11 feet bgs. Thirty-three other soil grids were excavated between 9 to 6 feet in depth. A total of 6,003.43 tons of pesticide-contaminated soil were removed; 1,319 samples were collected and analyzed, and 5,529.87 tons of clean backfill and topsoil were placed onsite.

Results from the ICM excavation determined that a "hot spot" existed adjacent to Building 267 in grids K-14, K-15, and K-16 (the three grids excavated to a depth 12 feet). Excavation was stopped at these grids due to concerns that building foundation was in jeopardy of caving-in. The residual concentrations at the 12-foot depth indicated that levels of pesticides remain in the soils beneath the building at levels above 1.0 mg/kg. Analytical results from the field lab for the soils in each grid at the 12-foot level were: K-14 – 13.5 mg/kg, K-15 – 91.5 mg/kg, and K-16 – 14.8 mg/kg. Soil was removed to depths between 12 to 15 feet in these three grids and a geotextile liner was placed over the remaining soils in place. The excavation was then backfilled with clean soil.

In August of 1998, to provide additional delineation, three soil samples were collected from the center of grid K-15 from depths of 18 ft, 28 ft, and 38 ft below ground surface to delineate the levels of pesticides left in place. Analytical results for DDT were 77 mg/kg, 6.3 mg/kg, and 0.58 mg/kg respectively.

1.1 Geology/Hydology

High Terrace Alluvial deposits underlie the former PMSA site. Historical and current site boring information indicates that these deposits range from 20 to 60 feet thick across the western end of the plateau in the Main Post area. The average thickness at the site is 40 feet. Some of these deposits are reworked sediments of the older Eutaw and Blufftown Formations; however, the bulk of the High Alluvial Terrace sediments have been transported from a source area upstream. Fort Benning and Columbus, GA are located just below the surficial contact between the Cretaceous Sediments of South Georgia and the metamorphic and igneous and metamorphic rocks that compose the crystalline Piedmont province in North Georgia. The High Alluvial Terrace Deposits consist of light to medium yellowish orange sand, gravel, clay, and silt. Thick deposits of coarse quartz and quartzite gravel/cobbles are found throughout the area. The clay is compact and mottled; the quartz gravel clasts are iron stained.

The High Alluvial Terrace Deposits are underlain by the Blufftown (near shore sands and clays) and, below that the Eutaw Formation (deep sea marine sediments). The upper unit of the Eutaw Formation contains a series of clays that act as an aquitard in the Fort Benning area, and serve as the lower boundary for the surficial aquifer (non-confined). Rain water that percolates trough the soils is trapped by the Eutaw clay and resides within the Blufftown and/or alluvial deposits, depending on which is present. Groundwater flow continues laterally to the west until a point of discharge is intercepted (the Chattahoochee River for this site).

The surface topography and the structural top of the Eutaw Formation control the groundwater flow and gradient at the former PMSA site. The surficial groundwater system in this area is recharged by local rainfall only. Therefore, the groundwater system at this site is fairly constant and stable with respect to flow directions and gradients. Depth to groundwater at the area or residual soil contamination ranges from 40 to 43 feet below ground surface.

2.0 Objective

The objective of this performance work statement is to perform a treatablility study on soils collected from the area of residual soil contamination described using an in situ thermal desorption treatment process to determine if this an in situ thermal technology will specifically reduce or destroy the concentrations of DDD/DDT/DDE in the soils from this site. The study should be designed to provide data that an in situ thermal desorption system at the in question can be designed to reduce levels of DDD/DDT/DDE to levels that are consistently below the remediation goal of 1 mg/kg for these 3 compounds.

The study should also address installation concerns about such an in situ technology, if implemented as remedial action and the effects such a treatment will have on the geotechnical and chemical properties of the soils in place. This should include any effects the treatment would have on the stability of the soils adjacent to Building 267 as well as the stability of the building and foundation itself. The study should address potential impacts to groundwater and to air, as the installation does not want to cause further impacts to the groundwater or to the air with the transfer of pesticide compounds from one media to the other.

Fort Benning will supply a 5 gallon bucket of soil collected from below the geotextile liner at the area (described above) in question for the purposes of performing the treatability study. Fort Benning will collect the 5 gallon of soil will be collected using a series of direct push sampling devices and placed in a bucket. The soil will be mixed in the process, but Fort Benning does not certify that the soils are homogenized. Fort Benning will attempt to collect soil from the same location as the historical data described above, but cannot guarantee that any of the soil collected will have the same concentrations.

Fort Benning will utilize the results of this study to determine if an in situ thermal treatment is appropriate for the site given the concerns for the stability of Building 267 and the impacts such a treatment may have for the current occupants and users of the site. Proposals should also identify related experience with implementing thermal desorption treatment systems at depth and other relevant qualifications.

3.0 SCHEDULE

The period of performance for this work shall be from notice to proceed through October 2012.

4.0 Submittal Requirements The Contractor shall submit electronic and hard copies of all submittals to the following:

5.0 Submitals will be evaluated based on the toughness and completeness of the proposal to address all issues described above as well as cost and past experience.

Draft

Final

Dena Thompson

1 Copies 2 Hard Copies, 1 Electronic

US Army Corps of Engineers

CESAS-PM-H

Savannah, Georgia

(912) 652-5243

Neil Pearce

1 Copy

1 Hard Copy, 1 Electronic

USAIC-ELN-E

Bldg. 6, Ft. Benning, GA 31905

(706) 545-5337

(End of Summary of Changes)