Life Sciences Division 1997-98 Progress Report

The necessity for the Department of Energy and the Department of Defense to remedy pollution caused by past environmental practices has resulted in the mission of the Environmental Technology Section. Environmental Technology staff are involved in characterizing and assessing the extent of environmental contamination, developing and demonstrating technologies to remedy contamination, and assuring that sites being cleaned by other organizations are adequately planned, conducted, and documented. The majority of the section's projects concentrate on developing new techniques, processes, and equipment to detect or remedy a wide variety of environmental pollutant, both radioactive and chemical. These activities are complemented by strong environmental statistical and technical programming support. Devices, technologies, and software created by section staff are transferred to private sector or other federal agencies whenever possible.

Selected Accomplishments

In Situ Chemical Oxidant Recirculation (ISCOR) Pilot Project. ETS staff designed, constructed, and operated the In Situ Chemical Oxidant Recirculation (ISCOR) pilot project in the 5-Unit Investigative Area of Quadrant I, Portsmouth Gaseous Diffusion Plant (PORTS). The project was developed based on an agreement between DOE and the Ohio Environmental Protection Agency (EPA) to gather additional technology information to assist in the development of Corrective Measures Study (CMS) alternatives at PORTS. The ISCOR approach involves injection through a central well and extraction from a network of perimeter wells located at fixed distances from the injection well. The extracted groundwater is dosed with oxidant, NaMnO₄, and re-injected to the aquifer where it degrades organic compounds (present as either dissolved phase or free phase) on contact. This oxidant delivery technique is applicable to relatively permeable, saturated subsurface media contaminated with ganglia and/or pools of DNAPLs with an underlying aquitard. Results from the pilot project conducted during July through September 1999 indicated promise of the "5-spot" ISCOR approach as a remedial technology in an area of concern at PORTS while applying an aggressive remediation technology to a known area of groundwater contamination. The work was directed and funded by DOE and implemented by Bechtel Jacobs Company and ORNL. ORNL is currently overseeing the installation of additional injection/extraction well networks in the 5-Unit Investigative Area that will be implemented and deployed in FY 1999 by Bechtel Jacobs and ORNL.

Confirmatory Radiological Survey of the National Conversion Pilot Project Buildings 883 and 865 at the Rocky Flats Environmental Technology Site. ETS staff performed an independent verification radiological survey of interior walls, floors, and machinery in Buildings 883 and 865 at the Rocky Flats Environmental Technology Site (RFETS) for DOE Rocky Flats Field Office (DOE-RFFO). The verification included reviews of pertinent project documents, field measurements for beryllium, beta and alpha radiations, and gamma exposure rate ranges. The purpose of the independent verification was to verify the accuracy and completeness of measurements and the credibility of procedures used, resulting in an independent assessment of resulting site conditions versus project plans prior to project closeout. ETS's data indicated that removable contamination of lower walls and floors had been mitigated to levels below regulatory concern. Fixed radiological contamination, primarily depleted uranium, remained on equipment and floor surfaces. The original purpose of the verification was to determine if radiation and beryllium levels were reduced to acceptable concentrations for radiation workers. However, DOE-RFFO decided to transition the buildings for decontamination and decommissioning (D&D) rather than use the building for recycling of scrap metal as originally planned. Therefore, the level of characterization requested by DOE-RFFO was determined to be inadequate for D&D purposes and ETS recommended additional characterization in its final report issued June 1998.

Final Analysis Report of a Qualitative Radiological Survey of the CS-10 BOMARC Facility at the Otis Air National Guard Base, Massachusetts Military Reservation, Falmouth, Massachusetts. ETS staff performed a radiological scoping survey at the CS-10 BOMARC missile site on the Otis Air National Guard Base Massachusetts Military Reservation for the Air Force Center for Environmental Excellence (AFCEE) and the Hazardous Waste Remedial Action Program (HAZWRAP). This project had high public visibility and regulatory oversight (U. S. EPA and Massachusetts Department of Environmental Protection) due to CS-10's proximity to the town of Sandwich. The objective of the survey was to determine if radioactivity was present at the BOMARC facility in concentrations exceeding natural background levels. There was no historical evidence to indicate that nuclear warheads were actually present or, if they were, that radioactivity escaped into the surrounding facilities and environment. Therefore, the purpose of this survey and associated soil sampling was to provide reasonable assurance of the absence of weapons-related radionuclide concentrations. The assumption for this analysis was that concentrations of radionuclides in soil and building materials did not exceed concentrations of nearby background sites. A statistical sampling procedure using the Visual Sampling Plan was developed to assess gross radiation levels in 56 abandoned missile shelters and 3 buildings (used for missile maintenance). Random locations were also selected for soil sampling in surrounding areas. Over 2500 radiation measurements and 150 soil samples were statistically analyzed. This analysis revealed that weapons-related radioactive contamination was not present at the BOMARC facility and surrounding areas and that additional characterization was not justified. More importantly, the results showed that the CS-10 BOMARC facility does not pose a radiological hazard to the environment, workers, visitors, or the public living in nearby residential areas. The sampling, statistical, and analytical techniques used held up under close public and regulatory scrutiny. A report discussing the findings was published in January 1999.

Independent Verification for Monticello Vicinity Properties Project (MVP) and Monticello Remedial Action Project (MRAP). ETS is designated the Independent Verification Contractor (IVC) for the Department of Energy Grand Junction Office (DOE-GJO) for the Monticello Projects based on a tri-party agreement between the DOE and the EPA, Region 8, and the Utah Department of Environmental Quality (UDEQ). The major scope of work for ETS staff on the MVP Project was to work with the Remedial Action Contractor (RAC) and the DOE to finalize the accelerated schedule for the delistment of the Monticello, Utah, vicinity properties. Staff conducted reviews of property completion reports and wrote a corresponding independent verification report recommending the certification status for individual properties to the DOE. ETS staff worked with the EPA to conduct investigative review and field survey on properties with suspect remedial action documentation. Independent verification funding was cut on the MRAP Project for the Monticello Mill Site (Operable Unit - I) and associated Peripheral Properties (Operable Unit - II) during the first half of 1998. In April, the DOE requested re-evaluation for independent verification for Monticello. In May, additional funds were approved by the DOE. The Independent Verification of the Monticello Remedial Action (OU- I) Work Plan Addendum report was submitted in June. ETS staff conducted on-site field survey throughout the field season on 10% of the verified Mill Site and Peripheral Properties area. Gamma surveys coupled with Global Positioning System (GPS) were completed. Contour maps were generated at the time of the survey using Surfer software. This provided for "in the field" identification of elevated gamma which exceeded 30% of the background and which required further investigation to document that the verified area was remediated to EPA standards in 40CFR192.12 and the SFMP Hot-Spot Guideline. Site remedial action protocol is guided by analysis of all soil samples for Ra-226. ETS staff provided preliminary Ra-226 analysis using their mobile Opposed Crystal Gamma Spectroscopy (OCS) van or the ETS gamma spectroscopy lab. Independent soil samples were collected to document Th-230 and total U in the area of the final Montezuma Creek alignment and soil samples were collected to document metals concentrations associated with the remediated portions of the four on-site tailings piles. Document review for MRAP included a quarterly evaluation of the RAC database for split sample selection and validation that Ra-226 as a field excavation control guide is adequate to meet site standards for Th-230 and total U.

In Situ Remediation of DNAPL Compounds in Low Permeability Media. Dense non-aqueous phase liquid (DNAPL) compounds present in low permeability media (LPM) pose major challenges with assessment of their behavior and implementation of effective in situ remediation technologies. In situ remediation technology development has largely overlooked treatment of DNAPLs in LPM. Poor accessibility to the contaminants and the difficulty in delivery of treatment reagents have rendered conventional bioremediation, vapor extraction, and pump-and-treat ineffective for this type of contaminated media. As a result of the need for solutions and the gap in the current knowledge and technology base, a project was initiated to evaluate in situ remediation technologies for both enhanced mass removal and in place destruction of DNAPL compounds in LPM, specifically chlorinated solvents (e.g., trichloroethene [TCE] and perchloroethene [PCE]). This project was sponsored by the DOE Office of Science and Technology (OST) and the DOE Portsmouth Gaseous Diffusion Plant (PORTS) Site Office with significant leveraging with the American Petroleum Institute and private industry.

Since the initiation of the project in 1993, several in situ technologies for mass recovery and in situ degradation have been demonstrated at three sites in the United States and Canada for remediation of DNAPLs in both the vadose and saturated zones of LPM. The work during the past four years has focused on in situ remediation by either (1) thermally enhanced mass recovery using hydraulic fractures and soil vapor extraction, (2) in situ destruction involving redox treatment agents (permanganate solutions and solids (oxidative particle mixtures [OPM]) and/or iron metal solids) delivered by horizontal hydraulic fractures, (3) in situ destruction involving permanganate OPM delivered by vertical coreholes, or (4) in situ destruction involving redox treatment agents (peroxide or permanganate solutions and/or iron metal solids) delivered by vertical permeation lances. In addition, numerical and experimental analyses of the mobility of residual NAPLs versus varying degrees of remediation have been conducted.

Based on these efforts, a promising in situ remediation approach selected for deployment includes enhanced delivery of reactive agents through soil fracturing and/or permeation for in-place destruction. The current goal of the ongoing project is to advance the technologies developed and demonstrated through transfer of the knowledge and experience gained into a standard of practice. This will be accomplished through multiple deployments at multiple sites over several years.

During calendar year 1997, ETS staff were responsible for oversight and field execution of the continuing comparative demonstration of in situ remediation of low permeable media at the X-231A site at PORTS. The significant activities included pre- and post characterization, operation, and reporting. The field demonstration consisted of four systems:

Hydraulic fracture enhanced steam flushing for 45 days.
Hydraulic fracture enhance hot air flushing for 45 days,
Evaluation of forced advection operation of reactive horizontal barriers with zero valence iron and oxidative particle mixtures (OPMs).
Evaluation of passive operation of reactive horizontal barriers with zero valence iron and oxidative particle mixtures.

During calendar year 1998, ETS staff provided oversight and execution of a field scale implementation of OPM propped hydraulic fractures. While several problems were encountered, valuable insight was gained into OPM handling and delivery which has lead to additional development work.

Comparison of Groundwater Alternatives (CGA) Study. ETS staff conducted Phase I of a Comparison of Groundwater Alternatives (CGA) study at Naval Air Station (NAS), Fallon, Nevada. The purpose of Phase I was to develop potential alternatives for remediating dissolved-phase groundwater contaminant plumes at six NAS Fallon sites. Primary groundwater contaminants at the sites are jet fuel and chlorinated solvents.

Potential groundwater remedial alternatives developed for the sites during Phase I included long-term monitoring, intrinsic remediation (natural attenuation), enhanced in situ bioremediation (both aerobic and anaerobic), hydraulic containment with aboveground treatment, and groundwater extraction with aboveground treatment. Potential groundwater containment and extraction technologies evaluated were pumping wells, interceptor drains, and slurry walls with pumping wells. The potential aboveground treatment technologies evaluated were aerobic bioreactor systems and air stripping with activated carbon polishing.

The CGA study (Phase II) is ongoing and will include a comparative evaluation of the potential remedial alternatives for each site based on effectiveness, implementability, and cost. Phase II will conclude with a recommendation of a preferred remedial alternative for each site.

Grand Junction Office Remedial Action Project (GJORAP). ETS was assigned as the IV contractor for DOE's GJORAP by the DOE D&D Branch Division of the Office of Environmental Restoration and Waste Management. The purpose of the GJORAP is to characterize, remediate, and verify cleanup of chemical and radiological contamination from past activities at the DOE-GJO facilities. Included in the D&D efforts are the buildings, exterior land area, and the underlying aquifer at the facility. The ETS role in this effort is to verify that all radioactively and chemically contaminated material is removed to levels that are consistent with the DOE limits of release and the Record of Decision for the site. During 1997 and 1998, ETS performed verifications on nine buildings (released for occupancy), quarterly groundwater sampling, verification of outdoor areas of the GJO facility (including USRADS surveys and soil sampling), groundwater modeling, verifications of footprints of demolished buildings (31A, 33, and 35), scans and soil sampling, and verifications of release surveys of demo debris going to municipal landfill from demolition of buildings.