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Tidal Exchange: Summer 2008
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Harbor Estuary News Contents
The Fate of Heavy Metals in Landfills (Click Here)
Michael Aucott
HEP Awards Grants for 4 Stewardship Projects (Click Here)
How do Landfills Work? (Click Here)
Summer Time: Enjoy and Protect the Estuary (Click Here)
Public Access Activities and Programs (Click Here)
Muskrat (Ondatra zibethica) (Click Here)
The Fate of Heavy Metals in Landfills back to top
Michael Aucott
This article summarizes the
report “The Fate of Heavy
Metals in Landfills: A Review,”
by Dr. Michael Aucott, which was
commissioned by the Harbor Project
of the New York Academy of Sciences
(NYAS) to review the current knowledge
on the fate of heavy metals in landfills,
both in the short- and the long-term.
The full report describing the research
findings may be downloaded from the
NYAS website: www.nyas.org/programs/harbor/06_LFmetals.pdf
Introduction
Many heavy metals are
problematic environmental pollutants,
with well-known toxic effects on living systems. Nevertheless, because of their
useful physical and chemical properties,
some heavy metals, including mercury,
lead, and cadmium, are intentionally
added to certain consumer and industrial
products such as batteries, switches,
circuit boards, and some pigments.
Many products containing heavy metals
are disposed in municipal solid waste or
hazardous waste landfills. It is estimated
that about 400 tons of mercury, 3000
tons of cadmium, 14,000 tons of nickel,
20,000 tons of copper, and nearly
100,000 tons each of chromium, lead,
and zinc are disposed in landfills each
year in the U.S. This adds to heavy
metals already residing in municipal
solid waste landfills. Recently, there has
been an increase in the use and disposal
of electronic devices such as cell phones,
mp3 players, and computers, raising
questions about the fate of these devices,
and the metals they contain, in landfills.
These products typically contain lead,
cadmium, mercury, arsenic, copper,
zinc and other heavy metals and rare earth metals.
The large quantities of heavy
metals disposed in landfills emphasize
the importance of understanding their
long-term fate. Will they remain trapped
in the landfills, or will they eventually
be released to the environment?
Factors affecting the fate of
metals in landfills
Today’s landfills must include
an impermeable layer (a liner) that
separates the landfill and its contents
from the soils and bedrock below,
and a system to collect and treat any
liquids that seep from the landfill
(a leachate collection and removal
system). Modern landfills typically
treat their leachate to remove metals,
bacteria, biological oxygen demand
(BOD), and chemical oxygen demand
(COD) before discharging to surface
water, or they send the leachate to
a publicly-owned treatment works
(POTW).
When landf ills have reached
their capacity limits, they are “closed.”
Closure typically includes installation
of a relatively impervious cover,
grading of the surface to facilitate
water movement away from its surface,
and monitoring of groundwater for 30
years. In many cases, landfills also have
a gas collection and venting system,
which may include combustion of the
landfill gas or pumping of the gas offsite
to be used as fuel.
Metals in landfills can be found
in many different forms, depending
on the characteristics of the product
that contains the metal and the landfill
environment. Except for mercury—
which is more volatile that the others—
if heavy metals escape from a landfill,
they are likely to do so primarily in the
aqueous form, via landfill leachate or
runoff that is not successfully captured
by the leachate collection system.
It can be expected that situations in
landfills that favor the formation of
oxidized compounds would lead to
some, perhaps significant, dissolution of some heavy metal-containing
compounds in leachate. However, the
organic matter present in landfills is
likely to have some capacity to adsorb
heavy metals and other cations.
The landfill environment depends
on the climate, drainage, and other
characteristics. The environment also
changes over the years as the waste
decomposes. There are no measurements
that provide conclusive information on
the long-term fate of metals in landfills
because data are available extending
back in time no more than about 60
years. Thus, our knowledge is limited
to experiments that try to mimic landfill
conditions and models that predict
changes that are likely to occur over
decades or centuries in landfills and
what these changes might mean to the
fate and possible transport of metals.
As time passes and organic matter
decomposes, landfills may trap metals
to a lesser degree or release previously
bound metals. However, research
suggests that there are other substances
likely to be present in these later stages
that would adsorb at least a portion of
the metals.
Metals in landfill leachate and
gaseous emissions
The U. S . Environmental
Protection Agency (EPA) compiled
measurements of heavy metals in
leachate from over 200 landfills in its
“LEACH 2000” database.
These data show that landfill
leachate generally contains higher
levels of heavy metals than allowed
by drinking water standards and
groundwater maximum contaminant
levels. Arsenic and cadmium stand
out by exceeding these limits by
wide margins. This situation could be
worsened by the likelihood that more
arsenic-containing material will be
deposited in landfills in future years.
Many water suppliers will have to
treat water (typically by filtering) to
remove arsenic to keep levels below
the federal drinking water standard
of 0.01 mg/L or the lower standard
of 0.005 mg/L that is effective in
New Jersey. The arsenic contained in
used filter media may be disposed of
in landfills. Also, data indicate that
cadmium in municipal solid waste is
increasing, maybe because of increased
disposal of nickel-cadmium (Ni-Cd)
rechargeable batteries in consumer
electronic devices, such as cell
phones. Although the consumer
electronics industry has made
some attempt to encourage
recycling of these batteries, it
appears that much more needs to
be done to keep Ni-Cd batteries
out of the waste stream. See the
report on pollution prevention
and management strategies
for cadmium by the New York
Academy of Sciences (www.nyas.org/harbor).
These data demonstrate
that leachate must be kept
isolated from groundwater,
and must be treated to remove
high concentrations of metals
before it is discharged to surface
waters. Existing regulations,
including requirements for
landfill containment systems as
discussed above, are designed
to ensure that untreated leachate
does not pollute surface or
ground waters. If a landfill’s
containment system fails, it
could threaten ground waters or
surface waters. Landfills located
above fractured rock or cavernous
limestone aquifer systems could be
especially problematic.
A rough calculation using the
LEACH 2000 database can put in
perspective releases of metals from
landfills. U.S. emissions from landfill
leachate are estimated to be about
40 to 200 metric tons per year for
arsenic, cadmium, chromium, and
lead. These quantities appear relatively
low compared to other sources. For
example, 2003 releases from U.S.
facilities (from the U.S. EPA Toxic
Release Inventory or TRI) were roughly
30 to 4000 times higher for the same
compounds. However, it must be
noted that no information is available
on the species of these emissions.
If, for example, a significant portion
of a metal emitted to a water body
from a landfill was methylated (e.g.,
methyl mercury, an organic mercury
compound, which is bioaccumulative
and more toxic than inorganic forms),
a relatively small emission could
nevertheless be important.
Gaseous emissions from
landfills are typically composed of
approximately 50% methane and 50%
carbon dioxide, with trace quantities of
other gases, such as hydrogen sulfide
and elemental mercury or mercurycontaining
compounds. Mercury is
the only heavy metal reported in
gaseous emissions from landfills but
measured levels have consistently been
low enough to suggest little cause for
concern. To put it in perspective, it is
estimated that about 15 kg of mercury
were emitted from all landfills in NJ in
the year 2000. This is a relatively small
portion of the total estimated statewide
mercury emission to the air that year of
approximately 2000 kg.
Conclusions
There are no first-hand data to
definitively answer all questions about
the long-term behavior of heavy metals
in landfills. Without such data, we cannot
dismiss the concern that at some point
in the future, heavy metals currently
stored in landfills might become soluble
and released to the environment.
However, data from landfills that
have been functioning as long as 60
years have provided no evidence of
increasing leachate concentrations of
metals over time. Modeling of long-term behavior of landfills has so far
suggested that landfills will not change
over the long-term enough to release
significant amounts of their stores of
heavy metals. More comprehensive
modeling and data from actual landfills
as they age is necessary to confirm
these conclusions.
Finally, it should be noted that
there are many reasons to reduce the
amount of waste (including metalcontaining
materials) sent to landfills
even if heavy metals were indeed sequestered in landfills in the longterm.
Primarily, space for landfills is
limited, and the costs of building new
ones are high. Furthermore, from
the perspective of total management
of the waste stream, it is important
to adopt certain waste management
practices (for example waste
minimization, reuse, recycling, and
material separation and recovery).
These practices can minimize waste
of increasingly valuable resources,
and can divert the amount of material that is sent not only to landfills but also
to incinerators and Waste-to-Energy
Facilities.
Michael Aucott is Research
Scientist at the NJ Department of
Environmental Protection. He has
developed inventories of mercury
emissions and has helped examine ways
to minimize mercury releases to the
environment. He is currently researching
emissions of greenhouse gases in NJ,
potential impacts of climate change, and
emission reduction strategies.
HEP Awards Grants for 4 Stewardship Projects back to top
HEP has been a long-time supporter of stewardship efforts. From 1991 to 1994, and then from 2002 to 2007, HEP provided
close to $280,000 through its Mini Grants and Stewardship Program to over 90 projects promoting citizen involvement
in protecting and restoring the Estuary. This year, HEP, in partnership with the New England Interstate Water Pollution
Control Commission (NEIWPCC) has awarded a total of $90,000 to four stewardship projects summarized below. For more
information on stewardship and past grants, please visit www.harborestuary.org/stewardship.htm
Sebago Canoe Club: Increasing Public Access and Accessibility to the Brooklyn Waterfront
Sebago Canoe Club will improve paddlers’
access to Jamaica Bay at Paerdegat Basin Park. The
existing ramp is quite steep and narrow, hindering
its use by persons with limited mobility or those
wishing to launch larger boats. Sebago Canoe Club
has designed and will build a larger dock and a wider,
longer and less steep ramp facility to replace the
existing one, which is 40 years old and long past its
useful life. This structure will enable safer wheelchair
access while allowing launching more and larger boats
and will complement the handicap-accessible catwalk
that the group has already built to connect the street to
the dock. Sebago Canoe Club is an all-volunteer notfor-
profit organization that offers a variety of public
programs, including open paddles. Once the ramp is
completed, they plan on offering programs for disabled
paddlers.
Brooklyn Center for the Urban Environment (CUE) and New Jersey Marine Sciences Consortium (NJMSC): NY-NJ Harbor Education Program
The CUE and the NJMSC will take students out
of the classroom and onto the Estuary for engaging,
hands-on learning. These two organizations had
previously collaborated to develop standards-based
Harbor Estuary curriculum materials with HEP
support. This year, the partners will work together
again to develop new materials and deliver the
educational program to 275 students grades 4-8 from
underserved NJ and Brooklyn, NY public schools.
The program includes a classroom session; a field
session at Brooklyn Bridge Park Cove, Sandy Hook
Bay, or Liberty State Park; and a tour of the Estuary
aboard the NY Water Taxi. In addition, professional
development sessions will be offered to teachers in an
effort to incorporate project materials into their own
teaching.
Council on the Environment of New York City (CENYC): Preservation of Shoreline Areas by High School Students
CENYC will work with 325 students from
two high schools (DeWitt Clinton H.S. and the High
School for Environmental Studies) and one youth
program (SOBRO in South Bronx) to implement
stormwater management practices. Students will learn
about coastal waters surrounding NYC and how to
protect them (including stormwater issues) over the
course of 7 weekly lessons. This educational program
will conclude with a hands-on project: students will
plant 750 trees along the Bronx River shoreline, in
Pelham Bay Park, Inwood Hill Park, and in the South
Bronx within the “million trees” area. They will also
remove invasive species and plant over 1,100 ground
cover plants in Morningside Park and Riverside Park.
Several organizations will collaborate in this effort by
selecting the sites and supervising the work, including
the Bronx River Alliance, the Department of Parks and
Recreation (DPR) Natural Resources Group, Friends
of Riverside Park, and Morningside Park Gardening
Office at DPR.
NY-NJ Baykeeper:NY Oyster Program
NY-NJ Baykeeper will continue to work to
bring about the restoration of oyster reefs in the
Harbor Estuary while raising awareness among the
population about this important species. Baykeeper
and its partners—the Gowanus Dredgers Canoe Club,
New York Harbor School, and the River Project—will
expand and carry out the New York Oyster Program.
Components of this program include hands-on
educational activities for K-12 and high school
students delivered at the waterfront or at one of the
existing 25 oyster garden sites; a lecture series on
the ecology of oyster reefs, the history of oysters in
NYC, and the benefits of their restoration; an Oyster
Restoration Conference to advance restoration efforts
in the Estuary; an aquaculture experiment that will
attempt to grow oysters from larvae in NY City
(currently, oysters are imported as juveniles from Long
Island); and a shoreline cleanup at a site relevant to
oyster restoration.
How do Landfills Work? back to top
Adapted from various sources, including U.S. EPA 2005 “The Quest for Less” and NYS DEC website (www.dec.ny.gov/chemical/23682.html)
Landfills are large areas or excavated
sites designed to receive solid wastes.
Municipal solid waste (MSW)
landf ills typically accept residential,
institutional and commercial waste. They
can accept some types of hazardous waste
such as cleaning products and paint, and
industrial wastes from certain businesses.
Landfill leachate is the liquid that
seeps to the bottom of the landfill. These
liquids may already be present in the
waste or may be the result of water (e.g.,
rain) entering in contact with the landfill
contents. To prevent these liquids from
contaminating the soil and groundwater,
modern landfills must meet stringent design,
operation, and closure requirements.
Landfill contents are isolated from
the surroundings by a series of layers. The
bottom of the landfill consists of a layer of
compacted clay, on which rests a special
plastic liner. These two layers are referred
to as a composite liner. On top of this liner
sits the leachate collection system, a series
of pipes within a layer of sand or gravel,
designed to collect liquids seeping from the
landfill and send them to a treatment plant before discharge to the environment. In New York, municipal solid waste landfills
must have two composite liners and leachate collection systems, the bottom one acting as a backup for the first one.
Landfills are divided into areas or disposal cells and only one of them receives waste at a time. Every day, the waste
is compacted and covered with daily cover (soil or other solids such as ash, compost or sludge) to control insects and pests,
fires, odors, blowing litter, and scavenging.
Part of the waste in a landfill (putrescible waste) can be decomposed by microbes and this process contributes to changes
in landfill conditions as microorganisms consume oxygen and generate acids, methane (a combustible gas that is the main
component of natural gas), and other byproducts. Some wastes are not biodegradable but may be affected by these changes.
For example, metals will corrode and dissolve more easily in an acidic environment.
Microbial degradation generates methane, carbon dioxide, and other gases. These gases, along with small amounts
of volatile compounds (including many pollutants) present in the waste, constitute landfill gas. Landfill gas is often flared
(burned) to avoid spontaneous combustion or explosions. Alternatively it can be collected and purified to pipeline-quality
gas, or collected and combusted for energy generation.
Once a landfill is full, a permanent cover is installed, consisting of several protective layers: sand or gravel (pipes are
installed in this layer to collect the landfill gas), clay, soil, and vegetated topsoil. The landfill cap is shaped to facilitate water
moving away from the surface. Closed landfills are often reused as parks, golf courses, and other recreational areas. Landfill
mining or reclamation is a relatively new process whereby old landfills are excavated to recover useful materials, especially
metals, while gaining new capacity for waste disposal.
Summer Time: Enjoy and Protect the Estuary back to top
Summer is here! It’s the season
for fishing, boating, going to the
beach and enjoying the many
opportunities the Estuary offers us.
It’s also the perfect time to remember
that you can do your part to protect
or improve this wonderful resource
and help ensure that we will continue
to be able to enjoy it into the future.
Here are some easy ways you can give
something back to the Estuary:
At the Beach:
• Dispose of your garbage properly
Use available trash receptacles or
take it back home. Besides aesthetics,
garbage attracts scavengers that eat
the eggs and chicks of nesting birds.
When litter washes out to the water,
it poses a lethal threat (especially
plastics and fishing line) to marine
wildlife and birds.
• Avoid nesting areas
Many beaches are home to migratory
shore birds. Avoid these areas during
the brief periods when the birds are
nesting or feeding.
• Scoop the poop
Pet waste contains pathogen microbes
and may contribute to beach closings.
Its nutrients also degrade water
quality. So always (no matter the
location) clean up after your pet and
flush it or trash it.
When Going Fishing:
• Never leave fishing line at the beach
or in the water
It may entangle and kill wildlife. It
can even pose a hazard to swimmers,
and damage boat motors. Cut the line
into pieces and dispose of it in trash
bins, or better yet, recycle it. Some
marinas and popular fishing spots are
setting up recycling bins.
When on your Boat:
• Never throw any waste from
the vessel
You already know how it can affect
wildlife, swimmers and boat motors…
and it’s illegal!
• Do not discharge raw sewage
Use pumpout stations. This is
enforced in “No Discharge Zones”:NY side of Hudson River between
Battery Park and the Troy Dam
and Navesink and Shrewsbury rivers
in NJ.
• Never dump motor oil or any
engine fluids to the water
Recycle used motor oil at the marina
or take it to a service station that
sells and changes motor oil—most
of them are required to accept 5 to
10 gallons free of charge. Motor
oil pollutes the water and sticks to
wildlife. Used motor oil contains
numerous toxic compounds. Oil
from one oil change can contaminate
millions of gallons of water.
• Maintain your boat to minimize
oil spills.
Maintaining your boat, car and
other equipment can also help keep
pollutants out of the Estuary.
• Slow down
Treat vegetated shallows, marshes,
and mudflats as no wake zones. This
helps preserve native plants and
wildlife habitat. Also be mindful of
other areas marked as “no wake”—
it’s the law!
• Do not pick up plant and animal
hitchhikers
Reduce the spread of invasive species,
such as zebra mussels and water
chestnuts, by inspecting and hosing
down your boat’s hull and draining
all bilge water before moving to
new waterways.
• Use phosphate-free detergent when
cleaning your boat
Phosphate is an essential nutrient but
in large quantities it can cause algal
blooms, which may decrease oxygen
levels in the water to the point of
killing fish and other organisms.
• Properly dispose of old paint and
shavings
When scraping or sanding your
boat, collect the old paint and
shavings and dispose on shore as
hazardous waste.
Resources
NY-NJ HEP (www.harborestuary.org/stewardship-boatingfishing.htm): resources include fishing
regulations, fish advisories, and
much more.
Going Coastal (www.
goingcoastal.org) offers lots
of information, from pumpout
locations to kayak access points.
NY Academy of Sciences (www.nyas.org/harbor; click on “Community
Outreach”): Information on
oil and household hazardous
waste recycling
NYC Dept. of Parks & Recreation:
Many resources, including
no wake areas in NY www.nycgovparks.org/sub_things_
to_do/facilities/marinas/html/marinas.html
Fishing line recycling in NJ:
www.nj.gov/dep/njcleanmarina/fishing_line_recycling.html No internet access? Give us a
call at 212-637-3793 and we’ll
help you locate what you’re
looking for!
Public Access Activities and Programs back to top
The NY-NJ Harbor Estuar y
Program has awarded a total of
$11,400 to support communitybased
water activities and programs
by local groups throughout 2007 and
2008. These funds, administered by
the Metropolitan Waterfront Alliance,
have made possible many exciting
events starting last summer, helping
advance HEP’s Public Access Work
Plan.
Upcoming events in Summer 2008:
Memorial Day to Labor Day, Wed.
evenings & Sat. mornings, Sebago
Canoe Club—2008 Open Paddle
Program at Jamaica Bay, Brooklyn
(kayaking). For more information,
please call 718-241-3683
July 12 (also two events were
held in 2007), Jersey City Reservoir
Preservation Alliance—Kayak the
Reservoir! in Jersey City, NJ (kayaking,
fishing, nature tour). 201-656-5235
Saturdays between July 12 and
26 (several events were held in 2007),
Rocking the Boat—Community
Rowing Program at Hunts Point
Riverside Park, the
Bronx (rowing, fishing).
718-466-5799
Five dates to be
announced, Hoboken
Cove Community
Boathouse — Free
Kayaking Days at
the Hudson River in
Hoboken, NJ (kayaking).
201-963-6293
Past events:
June 28, 2008,
Rockaway Waterfront
Alliance — Blue
Canoe Day (another
event was held on Sept 26, 2007) at
Bayswater Park, Beach 35th Street,
Far Rockaway.
June 7, 2008, New York Rowing
Association—Learn to Row and
Love the River at Swindler Cove
Park in Manhattan (sculling, fishing,
nature tour)
May 18, 2008, New Jersey
Marine Sciences Consortium—
Ocean Fun Day at Sandy Hook, NJ
(seining, water quality testing, benthic
& plankton sampling, touch tanks,
research vessel tours, beach clean-up,
fishing)
May 17, 2008, Bayshore
Regional Watershed Council—
Spend a Day in May Along Raritan
Bay in NJ (seining, fish printing,
nature walk)
May 10, 2008, Lower Passaic &
Saddle River Alliance—4th Annual
Passaic River Paddle Relay at the
Lower Passaic in NJ (canoe relay,
kayak race, waterfront festival)
September 29, 2007, Alley
Pond Environmental Center—
Little Neck Bay Festival at Little
Neck Bay, Queens (canoe & kayak
rides, narrated boat ride, seining)
September 29, 2007, Brooklyn
Community Board 7—9th Annual
Waterfront Festival at 58th St Pier,
East River (multicultural festival,
canoe & ferry rides)
September 22, 2007, Harlem
River Boat Club—Learn-to-Row
Day at Sherman Creek, Harlem River,
and Hudson River in Manhattan
(learning to row on training barge)
September 29, 2007, New York
Restoration Project—2007 Harlem
River Festival and Peter Jay Sharp
Head of the Harlem Regatta at the
Harlem River and Sherman Creek
in Manhattan (seining, water quality
testing, dip-netting, oyster gardening,
watching rowing)
October 20, 2007, Place in
History—A Tree for Anable Basin,
Launch Celebration at Anable
Basin, Long Island City, Queens
(kayaking, installation of sculpture,
presentations on wildlife, collection
of oral histories)
September 30, 2007, South
Street Seaport Museum—Estuary
Access Day in Upper NY Bay/ East
River/ Bay Ridge Channel (tour of
east river on tug, touch tanks)
Muskrat (Ondatra zibethica) back to top
This article is part of a series of species profiles commissioned by HEP
and compiled by Claire Antonucci and Peter Rowe (New Jersey Marine
Sciences Consortium).
Although the number of muskrats living in the NY/NJ Harbor Estuary has
been in steady decline overall for decades, the feeding and building activities
of these mammals still play an important part in maintaining the Estuary’s
wetland ecosystems by influencing plant growth, soil quality, animal habitats
and small-scale topography. People often look upon these animals as pests with
their burrowing and building activities that can damage creek banks and other shoreline structures, but muskrat burrows or
lodges help make wetland areas attractive nesting, resting, and feeding areas for other animals including turtles, terns and
other waterfowl, snakes, fish, amphibians, birds, and other rodents. Muskrats are also predators, keeping the Estuary’s local
food webs in balance.
Known by some as “poor man’s mink,” muskrat can be harvested for its pelt. Historically, muskrats were trapped in the
Estuary’s wetland areas including the New Jersey Meadowlands, where their numbers have improved somewhat in recent
years, likely due to the abandonment of trapping in this highly-developed area.
The muskrat is a stout, semi-aquatic rodent. Full grown, they weigh between 2 and 4 pounds with a body length of 18 to
25 inches and a tail length of 8 to 11 inches. The muskrat’s grayish-brown coat is practically waterproof. Its dense undercoat
is covered by long, brown guard hairs that protect the soft undercoat from wear. Its strong tail is nearly hairless, somewhat
flat along the sides, and covered in scales.
Muskrats are named for their musk gland, located under their tails. Secretions from this gland warn other muskrats
to keep away, signaling a particular territory as “taken.” This cuts down on competition for food and mates, aiding in the
muskrat’s overall survival.
With webbed hind feet acting as paddles and a long tail serving as a rudder, muskrats are good swimmers, capable
of moving at up to 3 miles per hour and even swimming backwards. Their nostrils, shaped like the number seven, allow
the muskrat to inhale remaining oxygen from their previously exhaled breath. This adaptation enables the muskrat to swim
underwater for up to 15 minutes.
Living in or near water for most of their lives, muskrats excavate their homes or lodges in the banks of the Estuary’s
slower moving creeks and streams using their sharp front claws. Most active at dusk, dawn and during the night, muskrats
feed on vegetation including cattails and other aquatic plants but will also eat mussels, frogs and small turtles. They are
eaten by foxes, coyotes and large owls.
The muskrat is an adaptable creature that can do well close to people. It can tolerate poor water quality, and, where
wetland habitat has been eliminated, can make its home in newly constructed canals or irrigation channels. These abilities have
enabled the muskrat to survive and claim a niche for itself in the altered environments of the NY-NJ Harbor Estuary.