October 2008, Issue No. 38 (PDF) by qes74153

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									                                  NEWS and TRENDS
                              A newsletter about soil, sediment, and ground-water characterization and remediation technologies
                              Issue 38                                                                                     October 2008

This issue of Technology News and Trends highlights innovative approaches for addressing                           Contents
contaminated sediment sites. Elements of these approaches include sediment dewatering through
use of geotextile containers, designed armor stone layers in caps to withstand harsh surface and
subsurface conditions, new models to predict navigational vessel impacts on cap performance,             Innovative Dredging
and placement of caps in very thin lifts over soft sediments.                                            Technology
                                                                                                         Accelerates Removal
                                                                                                         of Residual
    Innovative Dredging Technology Accelerates Removal of Residual                                       Contamination in
                   Contamination in Ashtabula River                                                      Ashtabula River     page 1
 The U.S. EPA’s Great Lakes National Program         Since 1962, the USACE had been unable to            39-Mile Dredging/
 Office (GLNPO) and their non-federal sponsor,       complete routine navigation dredging of a 1.4­      Capping Approach
 the Ashtabula City Port Authority, along with       mile stretch of the federally authorized            Used to Treat Fox
 the State of Ohio, the U.S. Army Corps of           navigation channel due to the presence of           River PCBs             page 3
 Engineers (USACE), and a consortium of              highly contaminated sediments. Although
 private companies collaborated to design and        dredging in the navigation channel was              Pilot Study Shows
 implement an innovative approach for                authorized to a depth of 16 feet or more, much      Effective Cap
 addressing extensive sediment contamination         of this river stretch experienced restricted        Design for Containing
 in a portion of the Ashtabula River near Lake       navigation depth as shallow as 0-2 feet.            PCB-Contaminated
 Erie. The approach employed a linked system         Additionally, fish consumption advisories have      Sediment              page 4
 for hydraulic dredging, an aboveground,             been posted in the lower two miles of the river
 double-walled pipeline for sediment slurry          since 1983. Average PCB concentrations                  CLU-IN Resources
 transfer, and containment of the transported        measured in the sediment were 7.5 mg/kg, with
 contaminated sediment in “dewatering tubes”         a maximum concentration of 660 mg/kg. Targeted      CLU-IN’s web page on
 at a newly constructed landfill. Over 13 months,    sediment contained approximately 150,000 yd3        sediment remediation
 the system remediated approximately 500,000         of TSCA-regulated material.                         provides key technical
 yd3 of sediment containing 25,000 pounds of                                                             resources on related cap-
                                                     To address the sediment contamination and           ping, dredging, and moni-
 polychlorinated biphenyls (PCBs), along with
                                                     stakeholder goals, federal and state agencies,      tored natural attenuation
 heavy metals, chlorinated organics, uranium,
                                                     local organizations, and private stakeholders       issues. The web page also
 radium, and thorium.
                                                     formed the Ashtabula River Partnership in 1994      provides important guidance
 In 1985, the Ashtabula River was designated a       to comprehensively address the river’s              documents and summaries
 Great Lakes area of concern (AOC). Extensive        environmental and navigational problems.            of large-scale projects
 mapping of AOC sediment characteristics             Between 1994 and 2004, the USACE led the site       developed by organizations
 began in 1990. Site investigations indicated that   investigation, alternatives analysis, and           such as EPA’s Great Lakes
 an industrial area along the Fields Brook           preliminary design work (including two value        National Program Office,
 tributary served as the primary source of river     engineering studies) to derive a proposed           the U.S. Army Corps of
                                                     dredging and disposal remedy for the river. A       Engineers, and the U.S.
 contamination. Past industrial activities
                                                                                                         Department of Defense.
 included foundries and chemical plants,             primary recommendation from the value
                                                                                                         Visit the sediments page at
 tanneries, and World War II weapons                 engineering studies was to use a single, project­   http:/www.cluin.org by clicking
 production. In 2003, under direction of U.S.        specific landfill to confine both TSCA-regulated    on the “Remediation” tab and
 EPA Region 5’s Superfund Program remedial           and non-TSCA regulated materials.                   the “Issue Areas” subtab.
 work on Fields Brook was completed from the
                                                     In April 2004, the Ashtabula City Port Authority,
 headwaters of the brook to its confluence with
                                                     with the support of the Ashtabula River
 the Ashtabula River. Additional source control
 work is underway.                                                         [continued on page 2]                                           1
    [continued from page 1]
    Partnership, submitted a request to the                                                                              Figure 1. Prior to
    GLNPO requesting funds under the newly                                                                               filling, each tube
    authorized Great Lakes Legacy Act                                                                                    was placed in an
    (GLLA). After extended technical, legal,                                                                             overlaying pattern
    and financial discussions, active                                                                                    within the landfill to
    remediation on the $58 million river project                                                                         achieve a 10-layer
                                                                                                                         stack.
    began in 2006, with the GLLA providing
    $29 million in funding. The final design
    called for hydraulic excavation of
    sediments; hydraulic transport of the
    dredged slurry to the landfill through a 2.5­   At the landfill, the sediment slurry was          equipped with an innovative Vic-Vac™
    mile long, double-walled pipeline;              pumped into geotubes that were                    suction dredge-head (Figure 2). The 8-inch
    dewatering of the sediment slurry using         approximately 300 feet long and 75 feet in        dredge operated in parallel with the 12-inch
    geotubes; and treatment of the water            diameter. As slurry moved into each tube, a       dredge, with both simultaneously
    through a 5,000-gpm water treatment plant.      polymer was added to increase coagulation         discharging to the double-walled pipeline.
    Dewatering was designed to occur at the         of sediment particles. Coagulated particles       By operating in parallel, the 12-inch dredge
    1,000,000-yd3 TSCA-permitted landfill, with     remained inside the geotubes while slurry         could focus on high production dredging
    geo-textile tubes (geotubes) left in place      water exited by gravity through pores of          that generated thicker cuts, while the 8­
    for final disposal (Figure 1).                  the geotube’s woven material. Filled tubes        inch dredge focused on cleanup dredging
                                                    were allowed to air dry for approximately 15      that generated thin residual sediment
    Construction of the landfill, pipeline, and     days in order to achieve a solids content of      layers. Typically, cleanup dredging results
    water treatment plant commenced in May          approximately 40% before additional tubes         in hydraulic slurries with just 1-2% percent
    2006 and concluded in September 2006, at        were placed on them. The 13.5-acre TSCA­          solids, which can present problems with
    which time full-scale dredging operations       permitted landfill was constructed with two       dewatering and water treatment. By
    began. Initial dredging operations were         60-mil synthetic liners, a geosynthetic clay      operating parallel dredges and combining
    conducted using a 12-inch, 750-hp,              liner, and several drainage layers along with     the slurry streams, however, operations
    hydraulic cutterhead dredge to remove           a leachate collection system.                     were able to maintain a consistent and
    sediment at a depth of 0-20 feet below water                                                      reasonably high solids content (8-15%) in
    surface. The dredge operated at a rate of       Water exiting each geotube entered the
                                                                                                      the combined slurry while performing
    approximately 3,800-4,200 gpm and               leachate collection systems and was pumped
                                                                                                      cleanup operations specifically targeted at
    produced a slurry with 6-15% total solids       to a nearby water treatment system consisting
                                                                                                      reducing residual contamination. The 8­
    by weight. Dredged material consisted of        of Lamella® gravity settlers, sand filters, and
                                                                                                      inch dredge operated at an average
    mostly fine-grained sediment, which was         activated carbon filters. The water treatment     production rate of approximately 1,000 gpm,
    pumped through a 12-inch, double-walled,        process was designed to meet discharge limits     and the 12-inch dredge operated at an
    HDPE piping system installed along the          of 0.001 μg/L PCBs, 0.16 ng/L mercury, and 10     average rate of 3,500 gpm. Cleanup
    Fields Brook corridor. Three 500-hp             mg/L total suspended solids in the water prior
                                                                                                      dredging was performed on approximately
    booster pumps were used to maintain a           to discharge to the river.
                                                                                                      10 of the site’s total 30 acres where
    consistent flow along the entire length of                                                        underlying         bedrock        prevented
                                                    In June 2007, operations integrated a second
    the pipeline, which involved a 60-foot                                                            overdredging of contaminated sediments.
                                                    but smaller (8-inch) hydraulic dredge
    vertical rise between the river and landfill.
                                                                                                      Previous experience at this and other sites
      Figure 2. The 8-                                                                                suggested that significant amounts of
      inch hydraulic                                                                                  residual contamination would remain in
      dredge with                                                                                     these dredged areas. Confirmation
      attached Vic-Vac™                                                                               sampling after dredging indicated,
      prepares to launch                                                                              however, that in areas where the Vic-Vac
      in target portions                                                                              was used, the surface-weighted average
      of the Ashtabula
                                                                                                      concentration was 0.1 mg/kg total PCBs,
      River AOC.
                                                                                                      well below the long-term cleanup goal.

                                                                                                                         [continued on page 3]

2
[continued from page 2]                           remaining $22 million was paid by the              partners also are developing and
Several areas required 2-3 dredging passes        consortium of private companies.                   initiating implementation of a habitat
with the Vic-Vac in order to achieve the long­                                                       mitigation plan to restore 3-5 acres of
                                                  A total of 25,000 pounds of PCBs have
term cleanup goal of 0.25 ppm PCBs.                                                                  shallow water habitat.
                                                  been removed from the river, and
Construction and operational costs for            commercial and recreational vessels no             Contributed by Scott Cieniawski, EPA
hydraulic dredging, dewatering, transfer,         longer are restricted from any portions of         Region 5 (cieniawski.scott@epa.gov or
and disposal of the sediment totaled              the river. The GLNPO continues to work             312-353-9184) and Natalie Farber, OH
approximately $58 million. In accordance          with the Port Authority, State, and the private    EPA (natalie.farber@epa.state.oh.us or
with GLLA provisions, GLLA funds                  companies to implement a post-dredging             614-644-2143)
covered 50% of the cost and the State             monitoring plan, including evaluation of fish­
provided an additional $7 million; the            tissue PCB concentrations. Project


                         39-Mile Dredging/Capping Approach Used to Treat Fox River PCBs
The Lower Fox River in Wisconsin contains         site-specific cleanup goal of 1 ppm. This goal     The sediments were disposed at local state­
approximately 8 million yd 3 of PCB­              and the surface weighted-average                   regulated landfills. Water generated by
contaminated sediment targeted for active         concentration goal of 0.25 ppm can only be         dredging, sand recovery, and dewatering is
remediation. The site’s records of decision       met with a combined approach of dredging,          treated through bag filters, sand filtration,
(RODs) were amended in 2007 and 2008 to           capping, and sand covers. Dredging could not       and granulated activated carbon prior to
specify dredging of nearly 4 million yd3 of       be used in areas with in-water infrastructure      river discharge. Air monitoring to date has
sediment with high concentrations of PCBs,        such as bulkhead walls or docks, near utility      shown no exceedance of thresholds for
followed by in situ capping of approximately      crossings associated with commercial               particulates or PCBs.
560 acres of sediment comprising operable         facilities, or near shorelines with steep banks.
                                                                                                     Similar operations will continue downstream
units (OUs) 1 through 4. The cap design           As a result, a capping approach using four
                                                                                                     (mainly inOUs 3 through 4) from 2009 to 2017.
included development of an innovative             designs (differing in stone and/or sand
                                                                                                     Hydraulic dredges and in-water pipelines are
method for determining an armor stone             components) was used to contain residual
                                                                                                     used to remove and transport contaminated
dimension sufficient to withstand propeller       contamination and non-dredged areas.
                                                                                                     sediment to a staging area where sand
wash from frequent recreational vessel traffic.
                                                  Design criteria for dredging included maximum      fractions will be washed or otherwise treated
The site extends 39 miles from the outlet of      horizontal/vertical slopes of 3:1 for submerged    for possible beneficial onsite or offsite use.
Lake Winnebago into Green Bay.                    areas and 5:1 for shorelines with nearby
                                                                                                     Engineered caps will be placed at locations
Contamination is found primarily in the first     infrastructure. A typical dredge management
                                                                                                     where the final cap height allows for at least
six miles (OU1) and the last 20 miles (OU3        unit covers approximately 6 acres, which
                                                                                                     3 feet of water and at least 2 feet below the
and OU4) of the river, reaching PCB sediment      involves approximately 1 week of dredging per
                                                                                                     authorized navigational water depth. In order
concentrations as high as 3,000 ppm.              unit. Prior to full-scale dredging operations,
                                                                                                     to ensure caps will have long-term stability
Contaminated sediment extends to depths           models were used to develop final plans.
                                                                                                     and effectively contain PCBs, the following
of up to 13 feet. Commercial shipping is
                                                  Dredging was initiated in OU1 in 2004 followed     conditions were evaluated during cap design:
confined to the last 3.5 miles of OU4, which
                                                  by the placement of sand covers in areas where
ends at the mouth of Green Bay. Sediment                                                              Frazil ice, particularly in areas of turbulent
                                                  residual PCB concentrations remained above
distribution in the middle 13 miles (OU2) is                                                           waters downstream of dams or possible
                                                  5 ppm; cover thickness ranged from 3 to 6
patchy with intervening bedrock exposures.                                                             high water velocities due to ice dams;
                                                  inches, depending on PCB concentrations.
OU2 contains the site’s greatest elevation                                                            High flows from tributary flooding; and
                                                  Sand covers also were placed on undredged
drop and consequently the majority of the
                                                  areas with lower PCB concentrations; caps           Combinations of river flow, due to
river’s locks and dams. OU5 comprises the
                                                  composed of sand and armor stone were                seiche effects or lake level changes.
entire bay, but dredging and capping are
                                                  placed over higher PCB concentrations. To          To further ensure effective caps, different
anticipated only near the river mouth;
                                                  date, more than 370,000 yd 3 of PCB­               cap designs will be employed for different
monitored natural recovery was selected as
                                                  contaminated sediment have been removed            river conditions. In navigable areas, nearshore
the remedy for most of OU2 and OU5.
                                                  from OU1, of which approximately 8,000 yd3         areas, or where sediment contains PCB
Based on experience in OU1, dredging did          contained PCB concentrations above 50 ppm          concentrations exceeding 50 ppm, the armor
not always remove all sediment above the          and were classified as TSCA in situ sediment.                            [continued on page 4]

                                                                                                                                                        3
     [continued from page 3]                         and 10 feet each. In addition, two­             Institutional controls currently include
    consists of a 33-inch layer of sand, gravel,     dimensional hydrodynamic models were            fish consumption advisories throughout
    and quarry spall. For design and construction    evaluated for OUs 1, 3, 4, and 5 to predict     the site, establishment of no-wake areas
    purposes, this cap type was designated as a      bottom shear stresses during maximum            in OUs 3 and 4, and limited public access
    “Cap C.” (Figure 3). In other areas, the cap     flow anticipated in a 100-year flood event.     to waters undergoing active dredging or
    consists of 13 inches of sand and gravel (Cap    USACE empirical models were used to             cap construction. Monitoring during
    A) covering approximately 200 acres, or 16       predict characteristic vessel waves. To         active dredging and cap construction
    inches of sand and gravel (Cap B) covering       consider potential impacts from propwash,       includes routine geophysical surveys
    approximately 70 acres. An estimated 25          a Monte Carlo statistical model was             and core sampling 2 and 4 years after the
    additional acres of shoreline caps will be       applied, incorporating:                         initial post-construction survey and
    constructed using larger armor stone to be                                                       every 5 years thereafter. Details of this
                                                      Capping costs and stone size;
    determined case by case. The areal extent of                                                     monitoring plan are being developed
    each cap and total acreage of cap types is        Magnitude of likely damage if movement        during the design phase for OUs 2-5.
    subject to ongoing refinement. Other areas         occurs; and                                   Long-term monitoring also will include
    having sediment profiles with PCB                 Degree to which a cap can “self-heal” to      testing of cap integrity and performance
    concentrations below 2 ppm or in thin              re-cover areas where cap materials may        with respect to contaminant containment,
    deposits (6 inches or less) are covered with 6     have moved due to propwash or other in­       and analytical sampling of water and fish
    inches of clean sand imported from local sand      fluences such as vessel anchors.              tissue at least every 5 years to evaluate
    and gravel pits. Shortly after placement, the    Finally, if regularly scheduled or event­       environmental results.
    thickness of each cap layer is verified to       triggered monitoring indicates that caps have   Approximately 30 acres of caps have been
    specified engineering standards.                 been eroded or otherwise adversely impacted,    installed to date. Following dredging and
    Design of the cap for the navigation             the caps will be repaired as necessary to       cap construction, additional time will be
    channel of OU4 involved site-specific            provide continued containment.                             needed for natural recovery, which
    models considering erosive forces such                                                                      will result in additional
    as wave-induced currents, river flows, ice                                                                  contaminant reductions meeting
    scour, seiche, and vessel propeller wash.                                                                   other cleanup goals. In OU 3, for
    This “JETWASH” model is similar to that                                                                     example, an estimated nine years
    recommended by the U.S. EPA and                                                                             of natural recovery are needed
    USACE but includes additive velocities                                                                      to reduce PCB fish tissue
    accounting for the propeller shaft pitch and                                                                concentrations to 0.049 ppm, the
    reflection relative to the river bottom, which                                                              threshold for unlimited walleye
    are critical factors for recreational boats.                                                                consumption. Construction
    The model includes a momentum-based                                                                         completion is scheduled for 2018.
    approach to analyze stability of a bed
                                                                                                               Contributed by Jim
    armoring particle that is subjected to time­
                                                                                                               Hahnenberg, EPA Region 5
    dependent propeller wash velocity
                                                                                                               (hahnenberg.james@epa.gov
    fluctuations typical of recreational
                                                                                                               or 312-353-4213)
    vessels. Due to the wide variety of
    recreational vessels and modes of
    operation used in the Fox River, the                                                                    Figure 3. “Cap C” armored
    propwash model relied on Monte Carlo                                                                    caps will cover approximately
                                                                                                            100 acres in OU 4.
    simulations using 2,500 parameter
    combinations for water depths of 3, 5, 7,

                         Pilot Study Shows Effective Cap Design for PCB-Contaminated Sediment
    A 1-acre pilot study was used to evaluate        contaminated with PCBs and other chemicals      upward transport of PCBs from the
    multiple cap designs at Silver Lake in           from past discharges of process water and       underlying sediment. Use of geosynthetic
    Pittsfield, MA, prior to construction of a       wastewater from the nearby General Electric     materials, however, did not appear to
    full-scale cap over the entire 26-acre lake      (GE) facility. Monitoring indicated that the    improve cap performance significantly.
    bottom. Sediment in Silver Lake is               pilot caps provided an effective barrier to                       [continued on page 5]

4
[continued from page 4]                           Mirafi 180N non-woven geotextile fabric were       woven geotextile cap. Puckering during
Between early October and late November           unrolled from a barge. The adjacent edges were     installation led to the addition of rebar, for
2006, the pilot study was conducted at three      sewn together to form one contiguous piece         structural support to maintain the full width
contiguous 45-ft by 300-ft sub-areas. An          (with about 2-foot overlap at each seam) and       of the fabric.
isolation layer was placed directly on the        anchored temporarily to the banks with
                                                                                                     Armor stone was installed along the
soft sediment in one sub-area (Figure 4). This    sandbags attached in an approximate 20-ft
                                                  grid. Due to puckering of the emplaced             shoreline to protect all three caps from
layer contained 2.5 parts pond sand (by
                                                  geotextile–likely resulting from its buoyancy–     erosion due to wind-induced waves. The
volume) mixed with 1 part topsoil using
                                                                                                     armor consisted of riprap placed over a
conventional earth-moving equipment to            more sandbags were added to ensure that the
                                                                                                     woven geotextile above and below the mean
achieve approximately 1% total organic            fabric would lay flat over the sediment. A
                                                                                                     water surface elevation. A gravel layer was
carbon (TOC) in the dry mix. A custom-made,       fourth roll was later placed using rebar to add
                                                                                                     placed over the armor stone below the water
barge-mounted, spreader box broadcasted           structural support to the geotextile and
                                                                                                     line to improve habitat for aquatic species.
slurried material in thin 1- to 2-inch lifts to   maintain the width of the fabric during
minimize the potential for resuspension and       placement to fully cover the sub-area.             The thickness of the three pilot caps was
mixing of the underlying sediments. The thin                                                         measured using a combination of acoustic
                                                  The third sub-area was covered with a
lifts also help avoid settlement or slope                                                            profiling, probing, and coring. The thickness
                                                  composite geotextile mat before placement
failure resulting from the relatively low­                                                           of all three caps was found to be fairly
                                                  of the isolation layer. The composite geotextile
strength, highly-compressibile sediments                                                             uniform, averaging 12 to 14 inches.
                                                  was constructed of two layers of a non-woven
and steep slope of the lake floor near the
                                                  geotextile sewn together and filled with a thin    Physical survey plates and vibrating wire
shore. The lifts were broadcasted until a
                                                  layer (less than 1 inch) of a sand/organo-clay     settlement cells were used to measure
depth of 12-14 inches was achieved.
                                                  mix. The mix had a TOC similar to the isolation    sediment settlement during, immediately
The second sub-area was covered with a            layer. This composite configuration was            after, and six months after construction of
non-woven geotextile before subsequent            prepared in nine rolls (about 15-feet wide by      the caps. The results generally indicate a
placement of the same isolation materal.          100-feet long) that were sewn together and         relatively uniform, slow rate of settlement
Three 15-ft wide by 300-foot long rolls of        unrolled from the barge similar to the non­        and compaction of the underlying native
                                                                                                     sediment, averaging 11-12 inches over the
                                                                                                     first nine months. The majority of settlement
 Figure 4. Three                                                                                     occurred during placement of the isolation
 cap designs were                                                                                    layer and appeared to be complete within
 used in the pilot                                                                                   two to six months of cap placement. Use of
 study at Silver
                                                                                                     geosynthetic layers did not appear to create
 Lake in Pittsfield,
                                                                                                     any variations in the extent of settlement.
 MA.
                                                                                                     Although settlement rates greater than the
                                                                                                     target of 1 inch/day were occasionally
                                                                                                     measured, there was no indication of
                                                                                                     sediment instability or other deleterious
                                                                                                     effects on cap performance. Coring and
                                                                                                     sediment profile imaging showed some
                                                                                                     mixing of the sediment and isolation layer
                                                                                                     material in the isolation layer-only cap, but
                                                                                                     mixing appeared to be limited to the lower 2
                                                                                                     inches of material.

                                                                                                     PCB concentrations in sample cores were
                                                                                                     low (non-detect to 14 mg/kg) relative to
                                                                                                     underlying sediments (25.2 to 178 mg/kg),
                                                                                                     with about 70% of the detections less than 1
                                                                                                     mg/kg. Collectively, the PCB distribution in
                                                                                                     the post-construction cores suggests that
                                                                                                     isolation layer materials, when placed in
                                                                                                                        [continued on page 6]

                                                                                                                                                      5
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    Technology

        NEWS           and      TRENDS




      [continued from page 5]                           a month. A portion of the decrease in PCBs                         Contact Us
      thin lifts, caused only limited disturbance       in the surface water may be attributable to
      to or mixing with the underlying sediments.       sorption of PCBs to suspended particles                   Technology News and Trends
      No indication of upward transport of              when turbidity was increased.                                      is on the NET!
      PCBs through the cap material was noted.                                                                     View, download, subscribe,
      A reduction in overall TOC in the isolation       The study results show that the sand cap                       and unsubscribe at:
      layer before and after placement was              amended with organic carbon installed in
                                                                                                                      http://www.epa.gov/tio
      observed; however, the average TOC was            thin lifts produced minimal disturbance to                 http://cluin.org/newsletters
      at or approaching the post-construction           the underlying sediments of Silver Lake
                                                                                                                  Technology News and Trends
      target level (approximately 0.5%).                and provides an effective barrier to PCB­                 welcomes readers’ comments
                                                        contaminated sediment. Addition of                         and contributions. Address
      PCB concentrations detected in the Silver         geosynthetic materials did not appear to                       correspondence to:
      Lake water column were lower during               benefit construction significantly.                               John Quander
      implementation of the pilot study than            General Electric is now designing a full­               Office of Superfund Remediation
      those prior to the study, indicating that         scale cap for Silver Lake based on the                     and Technology Innovation
                                                                                                                             (5203P)
      little or no re-suspension of existing            conceptual cap design of the pilot study.            U.S. Environmental Protection Agency
      sediments occurred as a result of cap                                                                            Ariel Rios Building
      placement. Turbidity increased while the          Contributed by Susan Svirsky, U.S. EPA                    1200 Pennsylvania Ave, NW
      isolation material was broadcasted, but it        Region 1 (svirsky.susan@epa.gov or                           Washington, DC 20460
      returned to pre-construction levels within        617-918-1434)                                                 Phone: 703-603-7198
                                                                                                                       Fax: 703-603-9135




    EPA is publishing this newsletter as a means of disseminating useful information regarding innovative and alternative treatment techniques and
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