Perchlorate Remediation using a Novel Autotrophic, Perchlorate-Reducing Microbial Community
Teresa A. Conneely, University of Massachusetts, Amherst, MA

Effects of Reducing Conditions on the Fate and Transport of RDX in Groundwater
Michael W. Morris, Jacobs Engineering, Bourne, MA

Rejuvenation of Biowalls Used to Treat Perchlorate in Groundwater
Tom Beisel, CH2M HILL, Atlanta , GA

Field Evaluation of Release of Explosives Compounds from a Cracked UXO Item Using a Pan Lysimeter
Christopher Abate, AMEC Earth & Environmental, Westford, MA

Grenade Range Management Using Lime for Dual Role of Metals Immobilization and Explosives Transformation Treatability Study
Steven L. Larson, U.S. Army Engineer Research and Development Center, Vicksburg, MS

Military Munitions Response Program Site Inspections for Formerly Used Defense Sites – Munitions Constituents Sampling
Deborah Dixon Walker, US Army Engineering Support Center Huntsville, Huntsville, AL

Containment of a Perchlorate Plume from the use of Road Flares in a Wellhead Protection Area

Thomas C Cambareri and Scott Michaud, Cape Cod Commission, 3225 Main Street, PO Box 226, Barnstable, MA 02630, Tel: 508-362-3828, Fax: 508-362-3136

The Barnstable Fire Training Academy is a multi-purpose training facility for public safety officials serving Cape Cod and southeast Mass.   The site has been in operation since the 1950s.  The facility has been the site of chronic releases of petroleum hydrocarbons during fire training activities.  Use of petroleum was ceased in 1986 when significant hydrocarbon pollution was discovered.  Clean-up activities consisted of an extensive monitoring network, soil removals, vapor extraction, 18 years of pump and treat and recently a C-Sparge Perozone® system.  Fire training activities have continued with the burning of straw. Expired marine and road flares are typically brought to local Cape Cod fire departments for disposal and collected at the training facility. The practice of using road and marine flares to ignite the straw was discovered at the site as the Mass DEP was promulgating a maximum contaminant level of 2 ppb, the strictest standards for perchlorate in groundwater in the nation.   Groundwater sampled from the existing monitoring network revealed perchlorate concentrations ranging from trace levels to 50 ppb in a plume extending 1500 feet downgradient to public water supplies.  Diluted levels of perchlorate below 1 ppb are observed in the water supplies.  An Immediate Response Action is being conducted to assess and model the contaminant/water supply interactions and to recover and treat perchlorate-contaminated groundwater with a perchlorate-selective resin before it is returned to the aquifer.  The IRA results will be presented along with appropriate practices for disposal of expired flares collected by public safety officials.

Perchlorate Remediation using a Novel Autotrophic, Perchlorate-Reducing Microbial Community

Student Presenter

Teresa A. Conneely, Doctoral Candidate, Department of Microbiology, 203 Morrill Science Center IVN, University of Massachusetts , 639 North Pleasant Street, Amherst, MA 01003 , Tel: 413-545-1204, Fax: 413-545-1578, Email: tconneel@microbio.umass.edu
Ashish K. Sahu, Doctoral Candidate, College of Engineering, Department of Civil and Environmental Engineering, Box 5205, Marston Hall 18B, University of Massachusetts Amherst, Amherst, MA 01003, Tel: 413-547-3229, Fax: 413-545-2202, Email: aksahu@acad.umass.edu Sarina J. Ergas, Ph.D., P.E., College of Engineering, Department of Civil and Environmental Engineering, Box 5205, Marston Hall 18B, University of Massachusetts Amherst, Amherst, MA 01003, Tel: 413-545-3424, Fax: 413-545-2202, Email: ergas@ecs.umass.edu
Klaus Nüsslein, Ph.D., Department of Microbiology, 203 Morrill Science Center IVN, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003, Tel: 413-545-1204, Fax: 413-545-1578, Email: nusslein@microbio.umass.edu

Perchlorate contamination of groundwater can be hazardous to human health. Bioremediation is an economical method for perchlorate reduction. A novel microbial community that autotrophically reduces perchlorate using perchlorate as an electron acceptor and elemental sulfur (S0) pellets as an electron donor was investigated. Benefits of using S0 pellets are: the pellets are inexpensive, readily available, a versatile packing material for ex-situ and in-situ applications and the pellets serve as an excellent electron donor since bacteria grown autotrophically produce low levels of biomass, thus, reducing system maintenance. In a packed-bed bioreactor, filled with S0 pellet and oyster shell and using an enrichment culture of denitrifying sludge from a wastewater treatment plant as the microbial inoculum, perchlorate is reduced to below detection limits. We investigated the Sulfur Utilizing Perchlorate-Reducing Bacteria (SUPeRB); samples of the bioreactor packing material and the perchlorate treatment feed were examined using culture dependent and culture independent techniques. Phylogenetic analysis, using the 16S rRNA gene sequence, showed that the microbial community was predominantly composed of members of the beta-proteobacteria. Upon comparison to the GenBank DNA sequence database sequences were found to be similar to those of sulfur-oxidizing bacteria and potential perchlorate-reducing bacteria. The detection of the chlorite dismutase (cld) gene in these samples further supports the presence of perchlorate-reducing bacteria. Also, using a fluorescent in situ hybridization (FISH) probe for members of a known perchlorate-reducing bacteria genus, Dechloromonas, it was shown that Dechloromonas spp. were present in the bioreactor. Samples were diluted to extinction in broth culture to ensure isolation of perchlorate-reducing strains. Isolated strains will be grown in pure culture for further study.

Effects of Reducing Conditions on the Fate and Transport of RDX in Groundwater

Michael W. Morris, Jacobs Engineering, 6 Otis Park Drive, Bourne, MA 02532, Tel:  508-743-0214, ext 232, Fax:  508-743-9177
Lonnie Fallin, Jacobs Engineering, 6 Otis Park Drive, Bourne, MA 02532, Tel:  508-743-0214, ext 238, Fax:  508-743-9177

Groundwater investigations conducted at the Massachusetts Military Reservation show the impact of historic range activities on the development of groundwater contaminant plumes emanating from military ranges.  Several of the plumes, located on the southeastern side of the Reservation, contain elevated concentrations of RDX.  In most cases, these plumes show continuity from the source to the leading edge, indicating very little attenuation of RDX is occurring in the aquifer.  An interesting exception to this trend are the plumes consisting of RDX and perchlorate which intercept part of the aquifer that has been previously impacted by a fuel spill, where reducing conditions due to biological activity persist.  Whereas perchlorate shows no significant correlation with any groundwater physiocochemical parameter, RDX shows a significant correlation with oxidation-reduction potential and a significant negative correlation with specific conductance.  The distribution of RDX is more consistent upgradient of the oxygen depleted zone and implies that RDX (and HMX) are degrading in the aquifer in the vicinity of the fuel spill.  Possible explanations for this pattern include 1) lack of a consistent source, 2) smearing of the plume due to shifts in the apex of the aquifer, 3) biodegradation, 4) dispersion, and 5) attenuation of RDX due to reducing conditions in the aquifer.  The mechanism for RDX attenuation could be explained by the reduction of nitro aromatic compounds to primary amines by an oxidation-reduction reaction.

Rejuvenation of Biowalls Used to Treat Perchlorate in Groundwater

Tom Beisel, CH2M HILL, 1000 Abernathy Road, Suite 1600 , Atlanta , GA , 30328 , Tel: 678-530-4033, Fax: 770-604-9183, Email: tom.beisel@ch2m.com
Mike Perlmutter, CH2M HILL, 1000 Abernathy Road, Suite 1600 , Atlanta , GA , 30328 , Tel: 678-530-4033, Fax: 770-604-9183, Email: Mike.Perlmutter@CH2M.com
Mark Craig, Southern Division of Naval Facilities Engineering Command, 2155 Eagle Drive, North Charleston, SC, 29406, Tel: 843-820-5517, Fax: 843-820-5563, Email: mark.craig@navy.mil

Biowalls are permeable reactive barriers (PRBs) that use organic media (e.g., mulch, compost, or wood chips) to provide a long-term carbon source to facilitate enhanced anaerobic biodegradation of chlorinated volatile organic compounds (CVOCs) and perchlorate. More than 13,000 feet of biowalls were installed from 2002 to 2005 in shallow weathered limestone at Naval Weapons Industrial Reserve Plant (NWIRP) McGregor , Texas to (1) reduce “source area” perchlorate plume mass, (2) remediate perchlorate-contaminated groundwater before it seeps into streams, and (3) expedite offsite property clean-up. Thirty-four biowall segments were excavated with a hydraulic excavator or rock-trencher, depending on the site geology, and backfilled with a mixture of mushroom compost, pine wood chips, soybean oil, and limestone aggregate. Diffuser pipes were installed on the bottom of each trench to allow for future injections of soybean oil or other carbon substrates as needed. Rows of bioborings, which comprise multiple, closely-spaced 12-inch diameter soil borings backfilled with the PRB media, were installed in a few locations where biowall construction was challenging due to surface conditions and an increased risk of forming a groundwater seep following trench construction.

Monitoring results indicated that the biowalls and bioborings rapidly reduced perchlorate groundwater concentrations from 1 mg/L (milligrams per liter) to below the laboratory detection limit. However, in fall 2006, after four years of operation, decreasing total organic carbon (TOC) concentrations, increasing levels of perchlorate, dissolved oxygen (DO), and nitrate, and rising oxidation-reduction potentials indicated that rejuvenation was required. Nearly 22,000 pounds of emulsified edible oil substrate (EOS®598 from EOS Remediation, Inc. of Raleigh , North Carolina ) were injected using a purpose-made injection trailer to restore the treatment capacity of 15 of the biowalls that were installed in 2002.

The impact of the supplemental substrate injection on biowall effectiveness is currently being evaluated. This presentation will discuss biowall design, construction, and carbon substrate rejuvenation, and groundwater sampling results before and after the EOS® was injected.

Field Evaluation of Release of Explosives Compounds from a Cracked UXO Item Using a Pan Lysimeter

Christopher Abate, AMEC Earth & Environmental, 2 Robbins Road, Westford, MA 01886, Tel: 978-692-9090, Fax: 978-692-6633
Kim Groff, AMEC Earth & Environmental, 2 Robbins Road, Westford, MA 01886, Tel: 978-692-9090, Fax: 978-692-6633
Herbert Colby, AMEC Earth & Environmental, 2 Robbins Road, Westford, MA 01886, Tel: 978-692-9090, Fax: 978-692-6633
Jacob Zaidel, AMEC Earth & Environmental, 2 Robbins Road, Westford, MA 01886, Tel: 978-692-9090, Fax: 978-692-6633
William Gallagher, U.S. Army, Impact Area Groundwater Study Program Office, PB 565/567 West Outer Road, Camp Edwards, MA 02542
Scott Greene, U.S. Army Corps of Engineers, 696 Virginia Road, Concord, MA 01742

At the Massachusetts Military Reservation (MMR) particulate residues of explosive filler and broken open unexploded ordnance (UXO) have been observed.  Field investigations confirm that releases of explosive compounds such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) have resulted in groundwater plumes.  Characterizing the release of these compounds is critical in evaluating future impacts to groundwater and the need for soil/UXO remediation.

Several field and laboratory studies have addressed explosives released from particulates (Lever et al 2005, Lynch et al 2002), however, few have addressed UXO.  Thus, a pan lysimeter system was installed in the shallow subsurface and a cracked 155-mm munition was placed above it and exposed to the natural environment for several months.  Soil porewater was collected from this apparatus periodically (the frequency dictated by precipitation events) and analyzed for RDX, 2,4,6-trinitrotoluene (TNT), and other explosives compounds.  In addition, measurements of precipitation, volume of porewater collected, filler surface area exposed, and other environmental parameters were recorded.

To date, porewater from 13 sampling events have been analyzed.  Observed RDX concentrations ranged from 0.4 to 8.9 ppm and TNT concentrations ranged from 0.13 to 11 ppm.  Preliminary results suggest that: 1) the volume of porewater collected is typically 60% of precipitation (indicating 40% evaporation/specific retention), 2) the compounds principally being released are RDX and TNT, 3) the cumulative mass released correlates to surface area of exposed filler and “weathering” of the surface, and 4) the ratio of RDX to TNT also correlates to the degree of weathering, indicating the more soluble TNT is depleted from weathered explosive filler.   Results will be compared to theoretical estimates of explosives release from perforated UXO (Praxis, 2004, Lever et al. 2005) and, ultimately, should contribute to an improvement in the ability to predict potential future release of RDX to groundwater and thereby assist in defining any required remedial actions.

References

Chambre, P. L., Pigford, T. H>, Futjita, A., Kanki, T, Kobayashi, A., Lung, H., Ting, D., Sato, Y., Zavoshy, S. J., Analytical Performance Models for Geological Repositories, LBL-14842, Lawerence Berkley Laboratory, University of California, Berkley, CA 1982.

Lever, J. H., S. Taylor , L. Perovich, K. Bjella and B. Packer.  Dissolution of Composition B Detonation Residules, Environmental Science and Technology, Environmental Science and Technology, 2005, 39, 8803-8811.

Lynch, J. C.; Brannon, J. M.;Delfino, J.J. Dissolution Rates of three high explosives compounds: TNT, RDX, and HMX, Chemosphere2002, 47, 725-734.

Praxis, 2004.  SERDP Final Technical Report Corrosion of Unexploded Ordnance in Soil Environments.  April 2004.  Praxis Environmental Technologies, Inc.  Burlingame, CA.

Grenade Range Management Using Lime for Dual Role of Metals Immobilization and Explosives Transformation Treatability Study

Dr. Steven L. Larson, Environmental Laboratory, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS  39180-6199, Tel: 601-634-3710, Fax: 601-634-3518
Dr. Jeffrey L. Davis, Environmental Laboratory, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS  39180-6199, Tel: 601-634-4846
W. Andy Martin, Environmental Laboratory, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS  39180-6199, Tel: 601-634-3710
Deborah R. Felt, Environmental Laboratory, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS  39180-6199, Tel: 601-634-3576
Gene Fabian, Aberdeen Test Center , 4264 Cowan Place, Aberdeen , MD 21017 , Tel: 410-278-7421
Catherine Nestler, Applied Research Associates, Inc., 119 Monument Place, Vicksburg, MS  39180, Tel: 601-634-4650
Gregory O’Connor, US Army Armament, Research, Development and Engineering Command, Armament Research, Development and Engineering Center, Picatinny Arsenal, NJ 07806-5000, Tel: 973-724-5008

The importance of live fire training for US forces cannot be overestimated.  The success of our armed forces depends upon realistic training utilizing the actual weapons and munitions that will be used in theatre during strategic and tactical operations.  However, a drawback of this type of realistic training is the potential contamination of firing ranges.  Most munitions-contaminated soils found on training ranges contain a mixture of compounds.  For hand grenade ranges (HGRs), the prevalent munitions used are the fragmentation grenade, typically composed of an iron shell and Composition B explosive material.  Hand grenades can deposit trace amounts of both RDX and TNT at the range.  The concentrations of RDX found on hand grenade ranges can pose significant health and environmental concerns depending on the range use.  Metals such as zinc, iron, manganese, calcium, lead, chromium, copper, nickel, molybdenum, and vanadium are also present.  Studies performed on ranges in both the United States and Canada have shown that there is a large degree of variability in munitions constituent type, concentration, size, and spatial distribution occurring on ranges.  The application of hydrated lime is a useful and cost effective technology to reduce explosives from leaving live fire ranges.  Under experimental conditions, the alkaline hydrolysis degraded the explosives before they left the top 15 cm of treated HGR soils.  Lime application as a range management technology is currently being demonstrated at active HGRs.  The field demonstration results from these ranges will be used to develop a guidance document on lime application for the dual role of metals immobilization and explosives transformation at active HGRs.  As a result, U.S. military forces can continue to take advantage of large scale live fire training to support world wide operations, without significant environmental limitations imposed as a result of munitions use at ranges.

Military Munitions Response Program Site Inspections for Formerly Used Defense Sites – Munitions Constituents Sampling

Deborah Dixon Walker, RHSP, CHMM, US Army Engineering Support Center Huntsville, Military Munitions Center of Expertise, CEHNC-OE-CX, 4820 University Square, Huntsville, AL 35816, Tel: 256-895-1796, Fax: 256-722-8709, Email: Deborah.D.Walker@usace.army.mil           

The June 2004 Department of Defense Financial Management Regulation added a new cleanup performance goal for the Defense Environmental Restoration Program. This goal is “Complete site inspections or equivalent for 100% of all munitions response sites by the end of 2010”.  In 2005, the US Army Corps of Engineers (USACE) initiated a programmatic Site Inspection (SI) effort under the Military Munitions Response Program (MMRP) for Formerly Used Defense Sites (FUDS) on behalf of the US Army.  As of 1Q07, approximately 330 SIs have been funded and are underway throughout the US states and territories. This presentation will provide a status update of the program with a focus on the results to date of munitions constituents sampling efforts. It is anticipated that data for more than 100 sites will be available by summer 2007.

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