Site Assessment for the Presence of Mercury in Soil Using
Passive Soil Gas Sampling
James E. Whetzel, WL Gore and Associates, Inc., Elkton,
MD
Comparison
and Critique of Selective Sequential Extraction Methods
for Metals in Soils and Sediments
Deborah L. Cussen, Frontier Geosciences, Seattle, WA
Chemical
Speciation of Heavy Metals in Wetland Sediments Treating
Urban Stormwater Runoff
Swarna Muthukrishnan, US EPA, Edison, NJ
Assessment
of Ferrous Sulfate for the Remediation of Chromite Ore
Processing Residue (COPR) in an Oxygen Limited System
Mahmoud Wazne, Stevens Institute of Technology,
Hoboken, NJ
Mineral
Enriched Composts for the Remediation of Heavy Metal
Contaminated Sites
René van Herwijnen,
University of Surrey, Surrey, UK
A
Case Study of Arsenic Regulations by a Local Board of
Health Regarding Redevelopment in a Former Orchard
Jo Anne Shatkin, The Cadmus Group, Inc., Watertown, MA
Site
Assessment for the Presence of Mercury in Soil using
Passive Soil Gas Sampling
Michael Singer, CH2M Hill, 151 Lafayette Drive, Oak Ridge,
TN 37830, Tel: 931-454-7274, Email: msinger@ch2m.com
James E. Whetzel, W. L. Gore and Associates,
Inc., 100 Chesapeake Blvd., Elkton, MD, 21921, Tel:
410-506-4779, Fax: 410-506-4780, Email: jwhetzel@wlgore.com
Passive soil gas (PSG) methods have been used over the years
for site assessment, but have been primarily limited to
screening sites for the presence of volatile organic
compounds (VOCs) and semi-volatile organic compounds (SVOCs).
Detection capabilities for PSG technologies, however, are
only limited by the chemical and physical properties of
the compound, design of the sampler, and the analytical
technique used. Therefore, inorganic compounds with
sufficient vapor pressure and limited water solubility
such as mercury are viable candidates for detection.
PSG sampling was recently performed at the Engine Test
Facility (ETF) at Arnold Air Force Base in Tennessee. PSG was chosen as a cost effective tool to investigate the
large area of the facility (28 acres) for the presence of
VOCs/ SVOCs and mercury.
This presentation will discuss the sampler design, general
considerations for the use of PSG, and the design and
results from the site investigation performed at Arnold
AFB.
Comparison
and Critique of Selective Sequential Extraction Methods
for Metals in Soils and Sediments
Deborah L.
Cussen, Frontier Geosciences, 414 Pontius
Ave N, Seattle, WA, 98109, Tel: 206-622-6960, Fax:
206-622-6870, Email: DebC@FrontierGeosciences.com
Carl E. Hensman, PhD, Frontier Geosciences, 414 Pontius
Ave N, Seattle, WA, 98109, Tel: 206-622-6960, Fax:
206-622-6870, Email: CarlH@FrontierGeosciences.com
A
metals’ toxicity is often dependant upon speciation and
not strictly upon total concentration. In addition,
speciation can often predict metal mobility and potential
exposure risk. Unfortunately, certain metal species are often difficult to
measure directly, limiting analysis and interpretation.
Selective sequential extractions (SSE) offer a way
to interpret the potential compounds of metals by
examining the solubility or leachability of metals under
certain conditions. However,
rather than direct species analysis, SSEs give indirect
speciation information from which the biogeochemical
behavior and toxicological implications of the metals
present in the sample are inferred.
There are many SSE methods available, most of which are
developed with a particular target metal in mind and for a
select range of species. The range of species tends to be
limited in order to minimize confusion when interpreting
the data. Frontier has developed a SSE approach that
examines the effect of behavioral chemistry and the
resulting extraction effect on the target metals in the
sample. This in-house method will be compared with the new
EPA Method 3200 (Mercury species fractionation and
quantification by microwave assisted extraction, selective solvent extraction
and/or solid phase extraction), which is designed to assess the
bioavailability of Hg in soils. In addition, more
traditional SSEs, such as that developed by Greve for
multiple metals in mine tailings, will be performed in
parallel and the results compared. The interest of the
study is not only in comparing and critiquing these
methods for the original suggested target metals, but also
in expanding to a larger suite of analyzed metals
including Hg, As, Ba, Pb, Mn, Cr, and Se.
Chemical
Speciation of Heavy Metals in Wetland Sediments Treating
Urban Stormwater Runoff
Swarna Muthukrishnan, ORISE Post Doctoral Fellow, U.S.
EPA, Office of Research and Development, National Risk
Management Research Laboratory, Water Supply and Water
Resources Division, Urban Watershed Management Branch,
2890 Woodbridge Avenue, Edison, NJ 08837, Tel:
732-321-4436; Fax: 732-321-6640; email:
muthukrishnan.swarna@epamail.epa.gov
Ariamalar Selvakumar, Environmental Engineer, U.S. EPA,
Office of Research and Development, National Risk
Management Research Laboratory, Water Supply and Water
Resources Division, Urban Watershed Management Branch,
2890 Woodbridge Avenue, Edison, NJ 08837, Tel:
732-906-6990; Fax: 732-321-6640; email:
Selvakumar.ariamalar@epamail.epa.gov
Heavy
metals in urban stormwater runoff are primarily removed by
sedimentation in stormwater best management practices (BMPs)
such as ponds and wetlands.
Heavy metals accumulated in BMP sediments have the
potential to produce toxic effects in benthic
invertebrates and aquatic microorganisms in wetlands. In order to evaluate the possible toxicity or risk of
environmental pollution of heavy metals present in
sediments, it is imperative to assess the types of
chemical associations between heavy metals and the
sediment solid phase.
The geochemical forms of particulate heavy metals
allow a qualitative assessment of metal lability/stability,
metal bioavailability and toxicity, and ultimately
evaluate the potential for environmental degradation of
receiving water bodies.
This research is a part of the ongoing research
activity at U.S. EPA’s Urban Watershed Research Facility
in Edison, NJ, evaluating the relative efficiencies of
pond and wetland BMPs for the treatment of heavy metals in
urban stormwater runoff. The objectives of this research include: (i) evaluating the
effects of two types of structural BMPs (cattail wetland
and wet pond) on the removal of particulate-bound and
soluble heavy metals from stormwater runoff; and, (ii)
assessing the chemical associations between heavy metals
and wetland sediments by a modified sequential chemical
fractionation technique (Bureau Commun de Reference, BCR).
Preliminary results showed that structural BMPs
such as retention ponds and cattail wetlands are effective
in attenuating particulate-associated heavy metal loads,
especially, Al, Cu, Pb, and Zn in urban stormwater runoff,
and could potentially improve the water quality of
receiving water bodies.
BCR sequential extraction results for wetland
sediments showed that the residual fraction was the most
dominant for Al and Fe; Cu, Pb, and Zn were most abundant
in the potentially mobile phases.
Cu was present as the oxidizable organic
matter/sulfide bound species; Pb and Zn were bound to
amorphous Fe/Mn oxides.
The exchangeable fraction was the least dominant
for all metals except Mn.
Assessment
of Ferrous Sulfate for the Remediation of Chromite Ore
Processing Residue (COPR) in an Oxygen Limited System
Mahmoud Wazne, Stevens Institute of Technology,
Castle point on Hudson, Hoboken, NJ 07030, Tel: 201-216-8993, Fax: 201-216-8303, Email: mwazne@stevens.edu
Sarath Chandra K. Jagupilla, Stevens Institute of Technology,
Castle point on Hudson, Hoboken, NJ 07030. Tel:
201-216-5329, Fax: 201-216-8303. Email:
sjagupil@stevens.edu
Santhi S. Billapati, Stevens Institute of Technology,
Castle point on Hudson, Hoboken, NJ 07030, Tel:
201-216-5329, Fax: 201-216-8303. Email: sbillapa@stevens.edu
Christos Christodoulatos, Stevens Institute of Technology,
Castle point on Hudson, Hoboken, NJ 07030, Tel:
201-216-5675, Fax: 201-216-8303. Email: christod@stevens.edu
This study investigated the remediation of Chromite Ore
Processing Residue (COPR) using ferrous sulfate under
oxygen limited conditions.
It included a full factorial design experiment to
evaluate the effects of water content, chemical dosage,
treatment pH, particle size, and multifactor interactions
on the performance and permanency of the treatment.
Decreasing the pH of the COPR matrix from its natural
value of 12.5 to 9 destabilized Cr(VI) bearing minerals
and enhanced the release of Cr(VI) into solution.
Reduction of particle size from mesh 4 to mesh 200
enhanced the leaching of Cr(VI) by 1.5 times. Chemical and
mineralogical testing of the treated COPR combined with
statistical analysis of the experimental data elucidated
the mechanisms of the chemical treatment and pointed to
possible causes of the non permanency of some COPR
treatments using ferrous sulfate. The study indicated that
the reappearance of Cr(VI) in the treated samples in some
treatments can be attributed to incomplete reduction of
Cr(VI) due to mass transfer limitations and scavenging of
the reductant. Cr(VI) reduction occurred both during
curing as well as during alkaline digestion and TCLP
leaching. Ferrous extraction in the treated samples
indicated that the non-stoichiometric reduction of Cr(VI)
by ferrous and the apparent reversibility of the treatment
was due to the scavenging of ferrous by molecular oxygen
as opposed to the inactivation of ferrous due to
sequestration in sparingly soluble ferrous precipitates,
re-oxidation of Cr(III) by manganese present in the COPR
matrix, or re-oxidation of Cr(III) during curing or
alkaline digestion by oxygen. Low water content favored
oxidation of the ferrous by molecular oxygen thus reducing
its overall reduction effectiveness. To ensure successful
treatment of the COPR material and to minimize mass
transfer limitations the chemical reduction of Cr(VI)
should be facilitated by pH adjustment, particle size
reduction, high water content, and effective mixing.
Mineral
Enriched Composts for the Remediation of Heavy Metal
Contaminated Sites
René van
Herwijnen, University of Surrey, School of Engineering, Guildford,
Surrey, GU2 7XH, United Kingdom, Tel: +44(0)1483-689543,
Fax: +44(0)1483-450984, Email: cvs1rv@surrey.ac.uk
Sabeha K. Ouki, University
of Surrey, School of Engineering, Guildford, Surrey, GU2
7XH, United Kingdom, Tel: +44(0)1483-686633, Fax:
+44(0)1483-450984, Email: s.ouki@surrey.ac.uk
Vishnu Priya Gadepalle, University
of Surrey, School of Engineering, Guildford, Surrey, GU2
7XH, United Kingdom, Tel: +44(0)1483-689543, Fax:
+44(0)1483-450984, Email: V.Gadepalle@surrey.ac.uk
Tony R. Hutchings, Forest
Research, Land Remediation and Urban Greening Group, Alice
Holt Lodge, Farnham Surrey, GU10 4LH, United Kingdom, Tel:
+44(0)1420-526270, Fax: +44(0)1420-520180, Email:
tony.hutchings@forestry.gsi.gov.uk.
Abir Al-Tabbaa, University
of Cambridge, Department of Engineering, Trumpington
Street, Cambridge, CB2 1PZ, United Kingdom, Tel:
+44(0)1223-332715, Fax: +44(0)1223-339713, Email:
aa22@cam.ac.uk
Any J. Moffat, Forest
Research, Land Remediation and Urban Greening Group, Alice
Holt Lodge, Farnham Surrey, GU10 4LH, United Kingdom, Tel:
+44(0)1420-526202, Fax: +44(0)1420-520180, Email:
andy.moffat@forestry.gsi.gov.uk
Mike L. Johns, University
of Cambridge, Department of Chemical Engineering, Pembroke
Street, Cambridge, CB2 3RA, United Kingdom, Tel:
+44(0)1223-334767, Fax: +44(0)1223-334796, Email: mlj21@cheng.cam.ac.uk
Soil
contaminated with heavy metals can be remediated by
reducing the bioavailability of the heavy metals in order
to break the pollutant-receptor pathway. This kind of
remediation can be used prior to establishment of
vegetation to create green space. Compost is often
proposed as a suitable material for the remediation of
contaminated brownfield sites, vitalising the soil but
also for its reported immobilisation of heavy metals.
Through this immobilisation the contaminant receptor
linkage pathway will be broken and the toxicity of the
soil will be reduced. In addition of composts there are
also inorganic soil amendments that are known for their
immobilising effect on heavy metals and therefore may be
suitable for soil remediation. In our research we have
examined the usage of two composts enriched with zeolite
to increase the immobilising behaviour of the composts.
The two composts were composted garden waste and composted
sewage sludge and a combination of both. Results show that
the composted greenwaste reduced the leaching of metals
from contaminated soil efficiently while composted sewage
sludge increased leaching. In contrast however, the growth
of ryegrass was much more improved by composted sewage
sludge. This compost also reduced metal uptake by the
grass leaves more efficiently than the composted
greenwaste. The
results have also shown that the additional effect of the
minerals added to the compost is limited compared to the
metal immobilisation effect of the compost on its own.
Additional trials will be performed to demonstrate
the sustainability of the technique with minerals
addition. Overall, this study has clearly shown that the
metal immobilising capacity of composts has to be examined
for each soil separately and an increase in performance
can be achieved by higher levels of minerals added to the
composts.
1:30pm
A
Case Study of Arsenic Regulations by a Local Board of
Health Regarding Redevelopment in a Former Orchard
Jo
Anne Shatkin,
Ph.D., The Cadmus Group, Inc., 57 Water Street, Watertown,
MA, 02472, Tel: 617-673-7161, Fax: 617-673-7001, Email:
jshatkin@cadmusgroup.com
Donald D. Cooper, Esq., Nixon Peabody LLC, 100 Summer
Street, Boston, MA, 02110-2131, Tel: 617-345-6077, Fax:
866-368-6629, Email: dcooper@nixonpeabody.com
A
proposed mixed-use residential subdivision on over 100
acres of land in Central Massachusetts is on a former
orchard, historically which had been treated with
arsenical pesticides. The town is within a known area of high naturally occurring
arsenic in soils. Under
subdivision development rules in Massachusetts the
planning board seeks advice from the local board of health
on matters of public health.
The board of health recommends to the planning
board whether a development has public health issues and,
if it does, conditions the development to mitigate those
issues. Arsenic from pesticides applied in accordance with
the directions on their label is not considered a release
and is therefore not subject to the jurisdiction of the
Massachusetts Department of Environmental Protection (DEP).
Further, contaminants present at background levels
are determined not to pose a risk to health. Consequently,
the DEP Hazardous Waste Clean Up Regulations, known as the
Massachusetts Contingency Plan, are not binding on a board
of health. This
Board of Health required extensive testing of the soils
and subsoils on the site, resulting in one of the most
intensely studied orchards.
Equally intensive were the risk assessment analyses
performed to study background conditions and assess risk
under residential use. The conclusions of these tests and analyses furthers the
knowledge of arsenic in these situations.
Equally interesting are the Board of Health’s
attempts to devise remediation standards which it felt
adequately protected the future residents of the
subdivision from the perceived threat of arsenic in a town
with naturally high occurring arsenic levels.
The subdivision was eventually approved,
conditioned on a remediation plan, the cost of which to
develop and implement will be discussed in relation to the
risk reduction achieved and, in contrast, what would have
been achieved through application of the Massachusetts
Contingency Plan, had it been applied.
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