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Design
of a Lead Recovery System for Recreational Firing Ranges
in New England
Luis
Ferreira and Alvaro Rodriguez, Wentworth Institute of
Technology, Dept. of Civil, Construction and Environment,
550 Huntington Avenue, Boston, MA 02115, Tel:
617-989-4170, Fax: 617-989-4172
John W. Duggan, Ph.D., P.E., Wentworth Institute of
Technology, Dept. of Civil, Construction and Environment,
550 Huntington Avenue, Boston, MA 02115, Tel:
617-989-4181, Fax: 617-989-4172
A
pilot-scale gravity separation system was designed and
constructed to recover lead shot from skeet and trap
ranges operating in New England.
Recreational firing ranges in New England are
typically located in mixed terrain settings. Vegetation often varies widely throughout the range. Shot
is mixed with vegetation (grasses, shrubs, trees),
vegetative debris (leaves, twigs, and other humic
material), soil moisture, clay pigeons and heterogeneous
soils. Conditions change seasonally.
Site conditions present unique challenges to the
cost efficient recovery of lead shot.
Recovery efficiency was found to depend on moisture
content, load rate, soil type and mechanical settings of
the separation unit.
System operating conditions were optimized to meet
the stated design criterion: create a recycling stream of
95% lead by weight for soils collected from an active
firing range. An
assessment of system performance addressed human health
and exposures, worker safety, overall lead recovery
efficiency and the economics of a full-scaled operational
unit.
Innovative
RangeSafe Program Effectively Manages Lead at Small Arms
Firing Ranges
Michael
F. Warminsky, PE, Technical Director, AMEC Earth
Environmental, Inc., 285 Davidson Avenue, Suite 100,
Somerset, New Jersey 08873, Tel: (732) 302-9400, ext. 126,
Email: mike.warminsky@amec.com
John Cefaloni, Program Manager, US ARMY TACOM/ARDEC,
Building 1, Picatinny Arsenal, New Jersey, Tel:
973-724-3295, Email: cefaloni@pica.army.mil
The U.S. Army RangeSafe Particle Separation and
Stabilization Technology Demonstration at Fort Dix, New
Jersey involved a three-step process for the management of
lead contaminated soil at small arms firing ranges (SAFRs):
(1) reduce the lead concentration in the impact
berm soils at SAFR 25 to a maximum total soil lead
concentration of 400 milligrams/kilogram (mg/kg) which
meets the residential soil cleanup criteria of the New
Jersey Department of Environmental Protection (NJ DEP);
(2) stabilize the impact berm soils that fail to meet
residential soil cleanup criteria after particulate lead
removal so that the leachable lead content is no greater
than five milligrams/liter (5 mg/L) as determined by the
Toxicity Characteristic Leaching Procedure (TCLP), EPA
Method 1311; and, (3) range maintenance activities to
minimize the further accumulation of lead in berm soil.
The
particle separation step utilized modified placer mining
or aggregate processing equipment for physical separation
of lead particles and fragments from different soil size
fractions. The
stabilization step was an integral part of the particle
separation process, and utilized a soil additive that
immobilized the ionic lead in the soil so that it was non-leachable.
This is the first application of a combined
particle separation/stabilization process in treating
soils from SAFR’s.
The range maintenance activities will subsequently
use a mobile dry screening process to remove bullets and
bullet fragments from the impact berm soil on a regular
basis, thereby preventing accumulation of lead in the soil
and subsequently reducing the potential for lead to
corrode and leach into the environment.
This
paper includes a technology overview, and case study
summary of the successful RangeSafe project, including a
discussion of results, and lessons learned.
While the particle separation/stabilization process
was demonstrated at a military facility, it also has
potential application at industrial/brownfield sites
contaminated with heavy metals.
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