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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

How do Landfills Work? (Click Here)

HEP Awards Grants for 4 Stewardship Projects (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.

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.

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/getinvolved.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.

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.


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 & Estuary Program has awarded a total of $11,400 to support community-based 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)
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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.


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