Water Quality Implications of Contaminated Sediments Remediation
James W. Patterson, J. W. Patterson Environmental Consultants, Inc., Silverthorne, CO
Cecil Lue-Hing, Cecil Lue-Hing Associates, Inc., Burr Ridge, IL
Jeffrey C.  Bates, Jeffrey C. Bates, McDermott, Will & Emery, Attorneys at Law, Boston, MA
Bud Harris, University of Wisconsin-Green Bay, Depare, WI
Danny D. Reible, Hazardous Substances Research Center, Louisiana State University, Baton Rouge, LA 
Donald F. Hayes, University of Utah, Salt Lake City, UT

Determining Background For Ecological Risk Parameters in Toxic Harbor Sediments
Christopher Leadon, Naval Facilities Engineering Command (NAVFAC), San Diego, CA
Tom McDonnell, Brown and Caldwell, Irvine, CA
Janet Lear, Brown and Caldwell, San Diego, CA 
Dave Barclift, Naval Facilities Engineering Command (NAVFAC), Philadelphia, PA 

Assessment of Bioavailability of PAH Contaminated Sediments Using XAD-Assisted Desorption
Henry H. Tabak, USEPA, Cincinnati, OH
Li Lei, University of Cincinnati, Cincinnati, OH 
Makram T. Suidan, University of Cincinnati, Cincinnati, OH

Kinetics and Mechanisms of PAHs Sequestration in Freshwater and Marine Sediments
Denis Brion, University of Québec at Rimouski, Rimouski (Qc), Canada
Émilien Pelletier, University of Québec at Rimouski, Rimouski (Qc), Canada

Sediment Quality Assessment in Four Suburban Massachusetts Rivers
Lisa M. McIntosh, Woodard & Curran, Dedham, MA 
R. Duff Collins, Woodard & Curran, Dedham, MA 
Janet Robinson, Woodard & Curran, Portland, ME
Glen E. Breland, Alpha Analytical Labs, Westborough, MA

Mycoremediation of PCB Contaminated Sediments
Jack Q. Word, MEC Analytical Systems, Inc., Sequim, WA
Scott Bodensteiner, MEC Analytical Systems, Inc., Tiburon, CA
Debra Collins, MEC Analytical Systems, Inc, Tiburon, CA
Paul Stamets, Fungi Perfecti, LLC, Olympia, WA

Direct Measurement of the Sudden Uplift of a Low-Permeability Sediment Cap Due to Gas Entrapment

Robert D. Mutch, Jr., P.Hg., P.E. (MS CE), HydroQual, Inc., 1200 MacArthur Blvd., Mahwah, NJ 07430, Tel:  201-529-5151, Fax:  201-529-5728, Email: rmutch@hydroqual.com
Egon Weber, Ph.D, HydroQual, Inc., 1200 MacArthur Blvd., Mahwah, NJ 07430, Tel:  201-529-5151, Fax:  201-512-3988, Email: eweber@hydroqual.com
David Kearney, P.E., Brown and Caldwell, 101 Commerce Drive, Allendale, NJ 07401, Tel:  201-574-4700, Fax:  201-818-6057, Email: dkearney@brwncald.com

The potential uplift and deformation of low-permeability sediment cap constructed with AquaBlok^TM is being studied using highly sensitive, in-place horizontal inclinometers. The research project involves construction of several pilot scale sediment caps. One such pilot scale sediment cap consists of six inches of AquaBlok^TM overlain with six inches of sand. A horizontal inclinometer casing was constructed within the nominally 100 by 80 foot pilot-scale cap overlying the AquaBlok^TM.  A string of ten in-place horizontal inclinometers is housed in the casing and has been measuring uplift or deformation of the cap since March 26, 2004. The data have recorded initial settlement of the cap due to sediment consolidation. Following initial settlement, the further offshore portion of the cap began to slowly uplift a total of about one inch over a period of 40 days before suddenly uplifting more than two feet. The cap then settled back into position before undergoing another sudden uplift 11 days later. Initial indications point to instability caused by a buildup of decomposition gas from the sediments under the cap. Bathymetric surveys have revealed that the cap is thinner in the area of observed instability. Smaller, intermittent releases of gas have been observed at other points in the AquaBlok^TM cap, as well, suggesting more widespread jointing or imperfections in the cap.

Water Quality Implications of Contaminated Sediments Remediation
 
James W. Patterson, Ph. D., J. W. Patterson Environmental Consultants, Inc., P. O. Box 23109, Silverthorne, CO 80498, Tel: 970-262-6557, Email: J_W_Patterson@msn.com
Cecil Lue-Hing, Sc. D., Cecil Lue-Hing Associates, Inc., 6815 County Line Lane, Burr Ridge, IL, 60521, 630-986-5751, Email:  CLHAI@aol.com
Jeffrey C.  Bates, LLD, Jeffrey C. Bates, McDermott, Will & Emery, Attorneys at Law, 28 State Street, 34^th Floor, Boston, MA 02109-1775, Tel: 617-535-4068, Email: jbates@mwe.com
Bud Harris, Ph. D., University of Wisconsin-Green Bay, 2617 Sunrise River Court, Depare, WI 56415, Tel: 920-465-2796, Email: harrish@uwgb.edu
Danny D. Reible, Ph. D., Hazardous Substances Research Center, 3221 CEBA, Louisiana State University, Baton Rouge, LA 70803, Tel: 225-578-6770, Email: reible@lsu.edu
Donald F. Hayes, Ph. D., Dept. of Civil Engineering, University of Utah, 122 S. Central Campus Dr., Suite 104, Salt Lake City, UT 84112, Tel: 801-581-7110, Email: hayes@civil.utah.edu

The environmental impetus for remediation of contaminated sediments arises from adverse impacts on the overlying water column quality, adverse impacts on the aquatic ecosystem, or both.  Water quality impacts occur due to the flux of sediment-associated pollutants from the sediment zone solids and interstitial waters, into the water column.  Where sediment remediation is warranted, the array of remedial options (beyond natural attenuation) is limited.  The most common remedial technology is dredging.  An alternative, sediment capping, is under increasing consideration.  Either technology will induce transient and potentially long-term adverse water quality impacts, for an array of water quality pollutants extending far beyond the targeted sediment remedial action pollutant(s).  This extended array of pollutants reflects the chemical composition of the sediments and interstitial waters, and includes oxygen demanding organic and inorganic species, toxicants such as ammonia, PAHs and pesticides, and constituents reflective of the typical anoxic sediment zone such as methyl- or mercurous mercury, ferrous iron or sulfide.  All sediment remedial actions perturb the quasi-equilibrium between the sediment zone and water column, to the detriment of water column quality.  Impacts include sediment compaction and accelerated interstitial water release, and contaminated sediment resuspension and transport.  For dredging, large quantities of dredging water are incorporated into the dredged material.  This dredge water is heavily contaminated, and is typically segregated from the dredged solids, treated, and discharged back into the water body.  Remedial action economic constraints, or limitations of the capabilities of treatment technology, can yield mass pollutants loadings and consequent prolonged water quality deterioration far exceeding in severity initial, pre-dredging water quality conditions.  Due to economic or technological inability to achieve mandated water quality-based discharge limits, and anticipated violations of water quality standards as a consequent of the remedial action, environmental agencies rely upon regulatory variances to circumvent water quality standards violations, and the Clean Water Act anti-degradation policy designed to protect existing uses and prevent deterioration of current water quality, as incorporated into federal and states’ environmental regulations.

This paper discusses the water quality implications of contaminated sediments remediation, options for and limitations on methods of amelioration of adverse water quality impacts, and regulatory tools available to allow remedial actions to proceed in the face of water quality protection legal barriers.

Determining Background For Ecological Risk Parameters in Toxic Harbor Sediments

Christopher Leadon, Southwest Division (SWDIV), Naval Facilities Engineering Command (NAVFAC), 1220 Pacific Highway, San Diego, CA. 92132, Tel:619-532-2584, Fax: 619-532-3546, Email: christopher.leadon@navy.mil
Tom McDonnell, Brown and Caldwell, Suite 100, 400 Exchange, Irvine, CA 92602, Tel: 714-730-7600, Fax: 714-734-0940, Email: TMcDonnell@BrwnCald.com
Janet Lear, Brown and Caldwell, 1230 Columbia St., Suite 400, San Diego, CA 92101, Tel: 619-744-3012, Fax: 619-687-8787, Email: jmlear@bechtel.com
Dave Barclift, Engineering Field Activity Northeast (EFANE), Naval Facilities Engineering Command (NAVFAC), 10^th Industrial Hwy., Philadelphia, PA, 19113, Tel: 610-595-0567, Fax: 610-595-0555, Email: david.barclift@navy.mil

Background characterizations for biological parameters are necessary in ecological risk investigations of harbor sediments contaminated with toxic chemicals.  Areas with toxically contaminated sediments are defined as those with concentrations or levels above background for chemical and biological parameters.  For determination of ecological risks at contaminated sediment sites, biological parameters can include bioassay tests, bioaccumulation tests, and benthic community analyses.  Chemical parameters can include toxic chemical concentrations in sediments and the tissue of biological receptors.  Indirectly, contaminated harbor sediments can impact shellfish, fish, and marine mammal populations.

Generally, background reference stations are positioned in relatively clean areas exhibiting the same physical characteristics as nearby areas with contaminated harbor sediments.  The number of background reference stations and the number of sample replicates per reference station depends on the statistical design of a sediment eco-risk investigation, developed through the data quality objective (DQO) process.  Biological data from the background reference stations can be compared to contaminated site data by using maximum background levels or comparative statistics.  The methods used to define background for biological parameters in eco-risk investigations of marine harbor sediments at California Navy bases are summarized in this paper.  Background for regional biological indices used to quantify eco-risks for benthic communities in sediments is also described. 

Assessment of Bioavailability of PAH Contaminated Sediments Using XAD-Assisted Desorption

Henry H. Tabak, USEPA, Environmental Research Center, ORD, National Risk Management Research Laboratory, 26 West Martin Luther king Drive, Cincinnati, OH 45268, Tel: 513-569-7681; Fax: 513-569-7105, Email: tabak.henry@epa.gov
Li Lei, University of Cincinnati, Department of Civil and Environmental Engineering, Cincinnati, OH 45221, Tel: 513-556-3637, Fax: 513-556-2599, Email: LeiLi@Email.uc.edu
Makram T. Suidan, University of Cincinnati, Department of Civil and Environmental Engineering, Cincinnati, OH 45221, Tel: 523-556-3685, Fax: 513-556-2599, Email: Makram.Suidan@uc.edu

In the bioremediation of soils/sediments contaminated with  polycyclic aromatic hydrocarbons (PAHs)  it is imperative to determine the fraction of the PAHs that is amenable to remediation. For example, what fraction of the PAHs is available to the indigenous microorganisms, i.e. bioavailable?. The bioavailability of PAHs varies with the contamination history and the characteristics of soils/sediments. Research was undertaken to examine the feasibility of using adsorbent-assisted desorption of PAHs for assessing their bioavailability  in contaminated sediments containing aged PAHs. The sediment was collected from East River, NY, near Rikers=s Island and contaminated with 2-ring to 6-ring PAHs. The kinetics of desorption of PAHs from sediment were studied using abiotic sediment-seawater slurry systems, where the nonionic polymeric adsorbent XAD-2 was added in various concentrations to the sediment /water slurry to ensure that sufficient adsorption capacoty of the XAD is provided to effect the maximum rate and extent of desorption of PAHs from the sediment.  By acting as an infinite PAH sink and by maintaining a constantly low PAH concentration in the aqueous phase, XAD is used to maximize the driving force for the PAHs to desorb from sediment particles without changing the sediment-aqueous phase partitioning coefficient. Batch studies on the microbial activity in the sediment slurry systems were also undertaken under aerobic conditions to investigate the potential for PAH biodegradation by the indigenous microbial consortia. The experiments were considered complete when PAH concentration levels in the sediment ceased to decrease.

A considerable residual level of PAHs was detected at the end of the experiments in both the biodegradation and XAD assisted desorption studies. This is attributed to the fact that a substantial fraction of PAHs is irreversibly sorbed onto the sedimemnt and thus unavailable for either biodegradation or desorption activity. All 2-ring, 3-ring and 4-ring PAHs exhibited significant biodegradation under aerobic conditions, with their residual levels in two studies closely related to each other (the correlation coefficient was 0.94). 5-ring and 6-ring PAHs showed either marginal or no biodegradation activity at all. This trend suggests that these higher ring PAHs might become available but their recalcitrance to biodegradation by the indigenous microbiota limited the biodegradation activity under the experimental conditions used. The adsorption of the desorbed PAHs onto XAD  resin was a much faster process than microbial degradation, since the desorption equlibrium was attainable in just 2 weeks, while it  took 24 weeks for all PAHs to attain maximum biodegradation. Overall, the results indicate that XAD-assisted desorption could be used to assess the bioavailability and the biodegradation potential of most PAHs  in a timely manner, as long as the recalcitrance of PAHs is not the limiting factor in bioremediation of the contaminated sediments. Because XAD-assisted desorption does not change the sediment-aqueous phase distribution coefficients of the contaminants, this process could evaluate the bioavailability of aged PAHs representatively in the contaminated sediments and it can also be applied to other contaminant-matrix circumstances. To our knowledge, this is the first reported representative chemical measurement of bioavailability which does not require exhaustive search or extraction parameters for every specific contaminant-matrix pair  

Kinetics and Mechanisms of PAHs Sequestration in Freshwater and Marine Sediments

Denis Brion, ISMER, University of Québec at Rimouski, 310 Allée des Ursulines, Rimouski (Qc), Canada, G5L 3A1, Tel: 418-723-1986 ext 1601, Fax: 418-724-1842, Email: denis_brion@yahoo
Émilien Pelletier, ISMER, University of Québec at Rimouski, 310 Allée des Ursulines, Rimouski (Qc), Canada, G5L 3A1, Tel: 418-723-1986 ext 1764, Fax: 418-724-1842, Email: Emilien_pelletier@uqar.qc.ca

Chemical sequestration is a natural process taking place in sediments and soils which reduces the availability of hydrophobic compounds such as polycyclic aromatic hydrocarbons (PAHs). The rate of sequestration following the release of PAHs into the aquatic environment is still unexplored. To measure kinetic parameters and investigate governing factors of sequestration of individual PAHs, natural sediment slurries were spiked with [ 2 H]-PAHs and periodically extracted with a high molecular weight surfactant solution to determine changes in the available fraction over periods of 7 to 28 days. Dissolved [ 2 H]-PAHs were first adsorbed on particles within 4-7 days. Adsorbed molecules became slowly sequestered into sediment particles and were gradually more difficult to extract.  An empirical model based on a three-compartment dynamic system was developed to quantify the sequestration rate constants of a group of seven selected PAHs. The sequestration process was assumed to be a first-order consecutive and irreversible two-stage reaction. The model was tested with a low contaminated marine sediment and a highly contaminated freshwater sediment. Adsorption rate constants ranged between 0.056 h -1 and 0.017 h -1 and were approximately ten times higher than sequestration rate constants. Light PAHs were the faster to enter into the sequestration process. The presence of a large quantity of already sequestered PAHs in sediment played a determining role in the first step of the sorption process.

Sediment Quality Assessment in Four Suburban Massachusetts Rivers

Lisa M. McIntosh, Woodard & Curran, 980 Washington Street, Dedham, MA  02026, Tel: 781-251-0200, Fax: 781-251-0847, Email: lmcintosh@woodardcurran.com
R. Duff Collins, Woodard & Curran, 980 Washington Street, Dedham, MA  02026, Tel: 781-251-0200, Fax: 781-251-0847, Email: dcollins@wooardcurran.com
Janet Robinson, Woodard & Curran, 41 Hutchins Drive, Portland, ME 04102, Tel: 207-774-2112, Fax: 207-774-6635, Email: jrobinson@woodardcurran.com
Glen E. Breland, Alpha Analytical Labs, 8 Walkup Drive, Westborough, MA 01581, Tel: 508-898-9220, Fax: 508-898-9193, Email: gbreland@alphalab.com

The investigators evaluated sediment quality to determine the levels of sediment pollutants associated with non-point sources in suburban stretches of four Southeastern Massachusetts riverways: The Charles River (Medway), the Neponset River (Norwood), Cushings Brook (Hanover) and Furnace Brook (Quincy).  Six sediment samples were collected from a contiguous reach on each river and analyzed for total organic carbon (TOC), grain size, extractable petroleum hydrocarbons (EPH), polycyclic aromatic hydrocarbons (PAHs), arsenic, lead and chromium. Additionally, water quality parameters (dissolved oxygen, pH, temperature, turbidity, and conductivity) were recorded at each sample station.  All river sediments generally consisted of sand and silt, with minor amounts of clay. EPH fractions, PAHs and metals were detected in every sample collected within each river stretch. The concentrations of total PAHs detected ranged from 1mg/kg up to 93mg/kg.   Among all samples from each river stretch, the ranges of concentrations of contaminants were typically within one to two orders of magnitude.  The patterns of these constituents were generally reflective of those associated with roadway runoff, with heavier-weight PAHs and EPH fractions predominant.  We evaluated sediment quality results with respect to consensus-based ecological sediment screening levels as a means of assessing potential toxicity to benthic invertebrates. In most samples, detected concentrations of constituents exceeded these screening levels.  The conclusions of this study document the ubiquitous presence of these contaminants in sediments of suburban rivers and underscore the importance of considering non-point sources of contamination in suburban/urban waterways when planning assessment activities and evaluating impacts to sediment quality. 

Mycoremediation of PCB Contaminated Sediments

Jack Q. Word, Ph.D., MEC Analytical Systems, Inc., 152 Sunset View Lane, Sequim, WA 98382, Tel: 360-582-1758, Email: word@mecanalytical.com
Scott Bodensteiner, MS, MEC Analytical Systems, Inc., 98 Main Street, Suite 428, Tiburon, CA 94920, Tel: 415-435-1847, Email: bodensteiner@mecanalytical.com
Debra Collins, MEC Analytical Systems, Inc., 98 Main Street, Suite 428, Tiburon, CA 94920, Tel: 415-435-1847, Email: debra-collins@usa.net
Paul Stamets, Fungi Perfecti, LLC, P.O. Box 7634, Olympia, WA 98507, Tel: 800-780-9126, Email: mycomedia@aol.com

Conventional bioremediation techniques applied to soils contaminated with synthetic organic compounds generally consist of nutrient aided amplifications of single bacterial strains.  This approach, although partially effective, does not take advantage of the complex interactions that occur among biological communities during the process of natural organic decay.  Previous investigations have shown that using complex biological systems with “keystone” species cultured to develop optimal capacity for degrading specific organic soil contaminants (e.g. polyaromatic hydrocarbons) is significantly more effective than monoculture bioremediation.  The objective of this study was to evaluate the effectiveness of fungal mycelia as a “keystone” species in a bioremedial process (mycoremediatin) for reducing levels of polychlorinated biphenyls (PCBs) in sediment.  Sediment samples laden with significantly elevated PCB concentrations (1,000 ppm as Aroclors) were collected from a creekbed, composited and then subsampled for PCB congener analysis.  The remaining composite was used to evaluate the remedial effectiveness of mycelia cultured from excised mushroom (Pleurotus ostreatus) tissue.  Mycelia cultures successfully proliferated on agar media were transferred to loosely packed wood chips used as a substrate for application to the contaminated sediment.  Two layers of sediment (1L each) were interspersed among three layers of mycelliated wood chips.  Composite sediment only was placed in a separate container to account for natural attenuation.  The mycelium proliferated and inervated the layered sediment at a modest rate over an eight-week period.  Afterward, three sample borings were collected from the remediation container, and sediment was separated from the woodchip substrate.  Remediated and control container sediment was then analyzed for PCB congeners.  Results show that the mean PCB congener concentration was reduced by 35% in mycoremediated sediment, with individual congener reductions up to 62%.  These findings indicate that mycoremediation is a potentially effective means for attenuating PCB contamination and warrants additional investigation to identify optimal mushroom strains and exposure strategies.

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