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ORDER FORM
DRINKING WATER PUBLICATIONS
DOCUMENT #
TITLE/DESCRIPTION
QUANTITY
EPA816F02026
***NEW***
Consumer Confidence Report Rule: A
Quick Reference Guide - This is
another in a series of quick reference
guides we have prepared on our major
rules. This one is not contained in the
highly popular "Compilation of Quick
Reference Guides" below.
EPA816R03002
***NEW***
Cross-Connection Control Manual -
This manual has updated technical
corrections to the original 1998
Manual
EPA816H03001
***NEW***
Source Water Protection - It's In Our
Hands Poster -
EPA816F03008
***NEW***
Source Water Protection - It's In Our
Hands Brochure to accompany poster
above.
EPA816K03003
***NEW***
MCL Pocket Guide - Consumer
Confidence Reports: Building Public
Trust - This is the 2003 edition of the
popular small pocket guide that
contains all the MCLs
EPA816H03002
***NEW***
MCL Wall Chart - This is the 2003
edition of the wall chart listing all the
MCL. This year's version shows them
in alphabetical order with color codes
for the contaminant groups.
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EPA816H02003
EPA816F02015
EPA816B02001
11x17 inch version of the poster Safe
Drinking Water Act - Protecting
America's Public Health - This
version has information on the flip
side further explaining the multiple
risks and barriers
(great as a handout for board meetings,
plant tours, classroom visits)
Lesson Plan - Water: is It Safe To
Drink? - Lesson plan for poster above
Compilation of Quick Reference
Guides
Packet with one each of : Arsenic,
Radionuclides, Long Term 1, Interim
Enhanced Surface Water Treatment,
Filter Backwash, Stage 1 DBPs
Name:
Affiliation:
Address:
Send form to: Charlene Shaw
EPA/OGWDW/4606M
1200 Pennsylvania Avenue NW
Washington, DC 20460
Or FAX: 202/564-3757
Email:
Office of Water
EPA816-F-03-021
July 2003
www. epa. gov/safewater
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& Technology
I News and Trends
United States
Environmental Protection Agency
National Service Center for Environmental Publications
P.O. Box 42419
Cincinnati, OH 45242
Official Business
Penalty for Private Use $300
Solid Waste and
Emergency Response
(5102G)
EPA 542-N-03-003
May 2003
Issue No. 6
First Class Mail
Postage and Fees Paid
EPA
Permit No. G-35
[continued from page 5]
electrode array during system startup. Placing a
chain-link mesh outside the array and grounding
it to a distant monitoring well remedied this
problem. In addition a pre-pilot resistivity survey
would have helped to assess the potential for
undesired stray voltage during treatment.
A significant setback was encountered during
the second month of operation when cracks in
the CPVC piping (leading from the electrodes
to the vapor header) resulted in an atmospheric
release of steam and vapor. Operations were
shut down for several days but resumed after
the degraded CPVC was replaced with flexible
chemical-resistant hose. This unexpected
condition appeared to result from a
combination of excessive heat, pressure, and
chemical attack from a variety of contaminants.
Post-test analysis showed that shallow
ground-water contamination (<24 feet bgs) in
the treatment zone decreased more than 99%,
and deeper ground-water contamination (24-
40 feet bgs) decreased more than 76%.
Analytical results also indicated a 95%
reduction in contaminated soil mass.
Additional analysis of the pilot results will
determine whether ERH technology could be
used to achieve project cleanup goals that were
not met through 1997-1998 implementation of a
soil vapor extraction (SVE) system. Although
SVE treatment resulted in the removal of
approximately 12 tons of subsurface VOCs over
a 14-month period, concentrations in the vadose
and saturated zones remained significantly
higher than their maximun contaminant levels.
Results of the ERH pilot suggest that this
technology can increase mass removal
efficiencies in both the vadose and saturated
zones more effectivaly than traditional SVE.
The ERH pilot cost approximately $1.6 million,
including $50,000 for electrical power and $50,000
for vapor treatment. Modeling based on total
VOC concentrations exceeding 10 mg/kg
indicates that 1.02 million tons of soil require
additional treatment
Contributed by Sharon Hayes,
U.S. EPA/Region 1 (617-918-1328 or
haves.sharon@epa.gov) and John
Scaramuzzo, Tetra Tech FW, Inc.
(617-457-8297 or jscaramu7zp@ttfwi.com)
In the March 2003 Technology News and
Trends article, "DNAPL Treatment
Demonstration Completed at Cape
Canaveral," the contributors believe use of
the terms "treatment efficiencies" and
"cleanup efficiencies" may be misleading due
to uncertainties in mass removal estimates for
the SPH demonstration. The appropriate
language is "apparent mass reduction." The
SPH cost of "$164" for each kg of TCE
removed or destroyed should read "$64."
EPA is publishing this newsletter as a means of disseminating useful information regarding innovative and alternative treatment techniques and
technologies. The Agency does not endorse specific technology vendors.
-------
[continued from page 2]
80% lower dissolved PCE concentrations
than before treatment, with an average PCE
concentration of approximately 15 mg/L.
NRMRL and SERDP are preparing a
comprehensive summary of these
demonstration results, as well as the results
of other innovative DNAPL remediation
technologies recently tested at the DNTS.
Contributed by A. Lynn Wood,
U.S. EPA/ORD/NRMRL (580-436-8552 or
wood.lynn@.epa.gov) and
Ronald Falta, Clemson University
(864-656-0125 or faltar@clemson.edu}
Cumulative Amounts
90,000
80,000
70,000 c
.o
- - 60,000 1
o
CO
- - 50,000 o
>-Cumulative PCE
>- Cumulative n-propanoi
- - 40,000
- - 30,000
- - 20,000 IS
- -10,000
0.00 10.00 20.00 30.00
Time (days)
40.00
0
50.00
Figure 1. Cumulative profiles of PCE removal and n-propanol solution
injection during cosolvenf flooding indicate that about 80% of the
initial 92.3 kg of PCE in the test cell \vcts removed.
Biosparging Used to Remove Chlorinated Solvents at the SRS Sanitary landfill
As part of a comprehensive effort to address
ground-water contamination at the U.S.
DerrartmentofEnergy SavannahRiverSite(SRS)
near Aiken, SC, a biosparging system began
operating in 1999 at the site's sanitary landfill
(SLF>- Biosparging was selected to address (he
trichloroethene (TCE), vinyl chloride, and TCE
breakdown products in the ground water
underlying the landfill. By 2002, biosparging
treatment had reduced ground-water
concentrations of vinyl chloride and TCE within
the treatment zone by 99% and 75%,
respectively.
Large amounts of wastes were generated at the
SRS during construction and operation of,the
facility. Cafeteria and office wastes, sewage
sludge, miscellaneous construction materials,
and debris routinely were disposed at the 70-
acreunlinedSLF from the early 1970stothe mid
1990s. After the discovery of ground-water
contamination beneath the landfill, the main
section and the southern expansion area of the
landfill were covered wilh an engineered cap.
Maximum concentrations of vinyl chloride and
TCE at interior landfill wells were 480 ug/L and
31 ug/L, respectively, prior to biosparging
treatment
Three significant hydrogeologic units underlie
the landfill: an uppermost unconfined aquifer, a
confining unit, and a lower aquifer. The depth to
the water table ranges from 30 ft to 60 ft bgs.
Ground-water flow in the area of me landfill is
primarily horizontal, with an upward flow
component where it discharges to a large
wetland adjacent to the landfill. Beneath the
landfill, contaminantswere identifiedority in.lhe
upperportionsofthe shallow aquifer. Numerical
modeling estimates that the advective
transport time from the main section of the
landfill to a downgradient biosparging well
between the landfill and wetland is 11 years,
with another three years for discharge 'to the
wetland (Figure 2).
Low dissolved oxygen levels observed after
construction of the landfill cap suggested that
reductive dechlorination of chlorinated
compounds could occur beneath the landfill.
Following successful field-scale testing of
biosparging, a full-scale system was
constructed. The system consists of two
horizontal biosparging wells screened
immediately below the vertical center of the
contaminant plume: an 800-ft screened well
downgradient of the landfill for treating TCE,
and a 900-ft screened well side-gradientof the
landfill for .treating vinyl chloride. Each well
consists of a six-inch-diameter outer steel
casing, screen, and an inner four-inch, high-
densityvpolyelhylene liner. Botbwells rely on
a central air compressor unit (rated for a
maximum airflow of 540 cfm) but operate
independently to accommodate different
injection configurations. .
Optimization testing prior to full-scale
operations, demonstrated that additional
nutrients were needed for the downgradient
well area, white air injection wasmfequate for
bioremediation in the side-gradient well area.
Methane (0.7%) was injected into the
downgradient well to stimulate growth of
mefeane-oxidizmg (mefeaiK*ropie)ofgamans.
These organisms produce the sfcongoxidizmg
agent (mpnooxygenase) needed for complete
mineralization of TCE. As expected,
methanotropic degradation of TCE was
constrained to the sparging operation's radius
of influence (approximately 60 feet) but vinyl
chloride degradation was found to occur
wherever oxygen was present
(continued on page 4]
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[continued'frontpage3] > -•, '
Methane injection was terminated in January
2001 because TCE concentrations had
decreased substantially and numerical.
modeling predicted that the benefit of
additional injection was limited. -
Both wells currently treat vinyl chloride by
serving as aerobic biodegradation pathways
and by enhancing volatilization. Air is injected f
into the wells once every two weeks for 48
continuous hours "at a rate of 220 scfm in -the
downgradient weH and 250 scfm in the side-
gradient well. After 24 hours, nitrous" oxide
and triethylphosphate'nutrients (0.048% and'
-0.005% of total air/month, respectively) are
injected in the downgradient well for 8 hours.
Vinyl chloride concentrations have continued
40 decrease over the past year, with maximum
concentrations during the first quarter of 2003
reaching 80 yg/L in ah, interior landfill
monitoring well and 11 ugC'in apoint-of-
compliance well at the base of theJandfill,
XJroundrwater models predict that primary.
contaminant concentrations, will not exceed
ground-Water protection standards due'to
ongoing physical and biologicat processes,
6f natufa^attenuatioa Since concentrations^
have decreased to-regulatory^ limits for this
RC3SAfacility, plans are underway tok&pend
'operation'of the biospargmg'system^and.to
continue grqund-watef monitoring for several
years-. Nlaintenaace of the biosparging
. system wiU continue-in the event monitoring
results indicate th'at resumed operations are
.warranted. Additional information regarding
enhanced bioremediation and monitored
natural attenuation at the,SRS SLF is available
on-line at http://www.srs.gov/general/pubs/
capped sanitary
l^landfill 1
North
Contributed by David O. Ndffsinger. -
We*stinghoiise*SdVannah River • "-
"Compaq, LLC (803-952-7768 or -
d.noffsiftser@srs.sov) and Karen M.'
Adams 'U.'S. Department ofEnergy/SRS
'(803-725-4648 or
kgr-en-m-adams @ srs.eov J
creek
water table aquifer
horizontal treatment well
south of landfill
Legend
*• Water Flow Direction
Figure 2. A conceptual model of factors
affecting ground-water flow and contaminant.
transport was developed for the SRS SLF ;
Electrical Resistance Heating Pilot Conducted
f or VOC Removal
A pilot study was completed in January 2003
at the Silresim Superfund site in Lowell, MA,
to evaluate the effectiveness of electrical
resistance heating (ERH) technology in
treating contaminated soil and ground water.
The U.S. EPA/Region 1 and Army Corps of
Engineers will use the pilot results to determine
the feasibility and cost of implementing mis
technology on a full-scale basis for remediation
of the vadose and saturated zones.
Concentrations of vapor extracted over three
months of treatment indicated that an
estimated 1,500 pounds of VOCs were removed
from approximately 1,000 cubic yards of soil.
As a result of past industrial waste reclaiming
operations, the subsurface soil and ground
water at this 5-acre site contain high
concentrations of VOCs, including TCE,PCE,
1,1,1 -trichloroethane, methylene chloride, and
BTEX. Pre-treatment sampling revealed
extensive contamination with total VOC
concentrations exceeding 800 mg/L in ground
water and 1,000 mg/kg in soil. The geology
consists of fill and fine sand extending to
approximately 10 ft bgs with an approximate
hydraulic conductivity of 3.9 x 104cm/sec. A
varved clayey silt layer with an estimated
hydraulic conductivity of 5.5xlO-5cm/sec exists
at 10-30 feet bgs. Below the clayey silt is alayer
of silty and very fine sand with an estimated
hydraulic conductivity of 1.1 x 10^ cm/sec.
The pilot was conducted in a 25-ft-diameter test
cell with heating electrodes extending 40 ft bgs
(Figure 3). The site was covered by a 40-by-40-ft
cap consisting of a gravel vapor collection layer,
a polyvinylidene fluoride membrane to protect
thecap from chemical attack, 1.5-inch R-11 foam
insulation to reduce heat loss to the surface,
and a reinforced HOPE membrane for weather
protection. Fourteen electrodes were used to
deliver six-phase, 240-kW power into the
subsurface. The electrodes were installed as
six pairs in a hexagonal pattern. Each pan-
consisted of a shallow electrode providing heat
at 2-10 feet bgs and a deep electrode providing
heat at 10-40 ft bgs. Two neutral electrode
were installed at similar depths in the center of
the hexagon. All electrodes doubled as vapor
extraction wells to capture the liberated
subsurface contaminated vapors.
The electrodes consisted of vertically slotted
carbon steel piping with graphite granules as
conducting filter pack. Drop tubes were installed
[continued on page 5j
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[continued from page 4]
in the wells of each shallow electrode and
connected to the vapor extraction system to
"slurp" water and maintain a constant water
level. In addition, electrolyte drip lines were
installed in the filter pack to maintain adequate
moisture for electrical conduction. Power was
delivered to each deep electrode through a
parallel connection from its paired shallow
electrode. The shallow electrodes drew
approximately 20 amps of current, while the deep
ones drew approximately 250 amps.
The vapor collection system consisted of 4-
inch CPVC headers with 114-inch, high-
temperature, chemical-resistant hose
connections to each electrode. Emitted vapor
was directed sequentially to an air-water
separator, a plate-and-frame heat exchanger/
condenser, a cyclone separator, three 8,000-lb
vapor-phase carbon vessels in series, and a
regenerative vacuum blower. The total vapor
flow rate was approximately 300 scfin; of this,
approximately 70% was attributed to the
horizontal collection pipes located near the
perimeter of the hexagon, 20% to the shallow
electrodes, and 10% to the deep electrodes (as
apressure relief for the saturated zone). Treated
vapors were discharged through a 15-ft stack.
A total of approximately 48,000 pounds of
granular activated carbon was used for vapor
treatment during the pilot project.
Fourthermocouple strings were installed inside
and immediately outside the electrode array; the
interior strings were placed equidistant from the
electrodes, where heating was least effective.
The thermocouples (nine per string) were
installed at 5-ft intervals to a depth of 45 feet
Ground temperatures reached steam
temperatures at a depth of approximately 40 feet,
and increased to 115°C at 35 feet After eight
weeks of heating, temperatures in the target
interval for the subsurface treatment zone
achieved boiling temperatures. Measurements
of ambient vapor concentrations using field
instruments indicated no uncontrolled vapor
emission from the electrode array throughout
the pilot test operations.
Overall, soil conducted electricity at levels
higher than anticipated, possibly due to the
presence of buried metal waste. Minor stray
electrical voltages were observed outside the
[continued on page 6]
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