For the past year, the subject of polychlorinated biphenyls in the Hudson River and what should be done about them has been discussed by politicians and residents all over the capital region. Often the top story on the local news, the front page headline of the newspaper, the subject of a special on television, or the reason for a town meeting, dredging has become a much debated topic. With all the information being exchanged and opinions published, it is easy for the average person to become confused. In an attempt to make things clear, the following report defines dredging, PCBs, and presents a short discussion of each side of the Hudson River dredging debate.
Webster’s Dictionary defines polychlorinated biphenyls (PCBs) as any of several compounds that are produced by replacing hydrogen atoms in biphenyl with chlorine, having various industrial applications and are poisonous environmental pollutants that tend to accumulate in animal tissue. They have a high resistance to excessive temperatures and do not disingrate in water. Because of these qualities, they can be useful in paints, lubricants, and most commonly, as a dielectric in capacitors.
Unfortunately, PCBs are hazardous to human and animal health, as well as to the environment. In studies published by the Agency for Toxic Substances and Disease Registry (ATSDR), the following health concerns are related to the ingestion of PCB’s in people:
Reproductive functions may be disrupted by exposure to PCBs.
Neurobehavioral and developmental deficits occur in newborns and through school-aged children who had in utero exposure to PCBs.
Liver disease and diabetes, and effects on the thyroid and immune systems are associated with elevated serum levels of PCBs.
Increased cancer risks, such as non-Hodgkin’s lymphoma, are associated with PCB exposures.
Many companies produced PCBs in the 1930’s and 1940’s and because the chemical does not decompose, PCBs are still present in soil and rivers, subsequently ending up in fish and other wildlife. According to the Environmental Protection Agency (EPA), PCBs build up in the environment, and larger concentrations are found higher in the food chain. Eating contaminated fish is the most likely way for PCBs to get into the human body. In 1997, the EPA banned the production of PCB’s and they were classified as a probable human carcinogen.
Dredging is the removal of soil or material from the bottom of a river, lake or ocean harbor. (Encarta Online 8 Apr 2001). There are two distinctive types of dredging; navigation and construction dredging, and environmental dredging. Navigation and construction dredging are used to remove sediment that has accumulated to a level where the water depth is insufficient to support safe navigation (Huskie 2). Navigation dredging tends to use large open clamshell dredges. Environmental dredging utilizes hydraulic dredges that act as a vacuum to remove contaminated sediments such as PCBs, (“Environmental” Clearwater.org). A representation of these dredges is on the following page courtesy of Keene Engineering (“Environmental” Clearwater.org). A sediment that is toxic or hazardous, once removed, must be placed in an approved hazardous waste landfill or, treated until it is harmless (Huskie 2).
HISTORY OF PCBS AND THE HUDSON RIVER
The following is a version of a timeline published by Clearwater Hudson River Sloop, an organization of volunteers dedicated to preserving the Hudson River. It describes General Electric’s (GE) relationship with PCB’s and the river. It is believed that GE legally dumped over one million pounds of PCBs into the Hudson.
1936: First study revealing major health and safety problems associated with PCBs.
1947: General Electric (GE) starts using PCBs in the manufacture of electrical capacitors at its Ft. Edward plant on the eastern shore of the Hudson River.
1973: Ft. Edward Dam removed from upper Hudson River, causing large amounts of PCBs to flow into the lower Hudson.
1974: An EPA study shows high levels of PCBs in Hudson River fish.
1976: Congress passes the Toxic Substance Control Act banning the manufacture of PCBs and prohibiting all uses except in totally enclosed systems.
2/76: Department for Environmental Conservation (DEC) makes it illegal to fish in the upper Hudson from the FT. Edward Dam to the federal dam at Albany, closes Hudson River commercial fisheries, and warns people about the dangers of eating Hudson River fish.
2/76: Administrative hearing finds that the PCB pollution was GE’s fault.
4/76: The worst flood in 100 years causes large amounts of polluted sediments to flow down river.
9/76: GE stops dumping PCBs into the Hudson River from its Hudson Falls and Ft. Edward plants. GE agrees to spend one million dollars on PCB research and three million dollars to monitor the PCBs in the river, and in return will not be blamed for the pollution by the state.
5/77: EPA makes it illegal to discharge any PCBs into navigable waters under the clean Water Act.
9/83: EPA releases updated Superfund National Priority List, which includes the upper Hudson River.
1984: EPA studies PCB problem: issues a Record of Decision (ROD) calling for NO ACTION.
9/91: Water test in the upper Hudson shows unusually high levels of PCBs (4,539 parts per trillion).
8/92: A test of sediment near an old discharge pipe from the Hudson Falls shows high levels of PCBs.
2/93: DEC releases 1992 fish sampling data showing that PCB levels in Upper Hudson fish increased 300% between 1991 and 1992.
5/93: GE says that PCBs have probably been leaking from the ground at it’s Hudson Falls plant since the early 1980’s.
6/93: Seven GE capacitors filled with PCBs are found in the Hudson River next to the Hudson Falls plant. The capacitors are removed from the river.
7/93: DEC tests an “oily liquid” found seeping into the Allen Mills Structure. It proves to be 72% pure PCBs.
10/93: DEC and GE agree to begin cleanup on the Hudson Falls and Ft. Edward sites.
1996: Scientists discover that PCBs evaporate from the Hudson River water and tide-exposed sediment. Blood tests of Hudson Valley residents reveal elevated levels of PCBs in non-fish eaters.
4/97: US Fish and Wildlife Services releases study showing tree swallows breeding near Hudson Falls have high concentrations of PCBs in their body and eggs. Levels up to 55 ppm were documented, qualifying them as hazardous waste.
9/97: Body of a 16 week old bald eagle is found along the Hudson River with 71 ppm of PCBs in it’s body fat.
It is obvious that PCB levels in the Hudson River are dangerous, and that something needs to be done. The question is, to dredge, or not dredge? There are strong supporters for each argument, with websites publishing their views. The following briefly summarizes both sides.
General Electric has launched an extensive advertising campaign, utilizing television and radio commercials, billboards, newspaper ads and the internet to convey it’s message that dredging will not work. Hudsonvoice.com, the company’s web site regarding the issue, states, “although dredging can remove significant volumes of sediment and associated contaminant mass, dredging inevitably leaves behind residual materials at the sediment surface”.It further explains that this is due to inaccessible areas in the river and the agitation of the dredges in the water releasing contaminants that were previously buried.
Hudsonvoice.com gives Manistique Harbor, Fox River, and St. Lawrence River as three of examples of dredging attempts that not only failed to lower PCB concentrations, but actually raised levels of the carcinogen. Areas of these waterways that were not dredged experienced a decrease in PCB concentrations. GE explains that this decrease in PCB levels is due to a process called sedimentation, in which old PCB deposits become buried by new sediment, thus making them less accessible to fish and other
wildlife (Hudsonvoice.com 2/27/01).
GE believes that there are two types of PCB source that affect fish. There is the sediment deposited by GE decades ago that has been covered by new sediment, and there is the current leakage from old plants. GE argues that this new leakage contains the PCBs that are affecting fish, and therefore dredging will not significantly reduce PCBs levels. Rather, as GE graphically displays in the following two illustrations, allowing the river to naturally clean itself, along with GE’s control of new leakage, will lower PCB concentrations as effectively as dredging will.
The following is a list posted on Hudsonvoice.com describing the actions GE has taken to help clean the river.
GE has successfully removed 139 tons of PCBs from near the Hudson Falls plant site.
GE converted an abandoned paper mill near the Hudson falls’ plant into a system of wells to recover PCBs before they can reach the river. To date, 5,103 gallons (255 tons) of PCBs have been recovered and removed.
GE constructed a water treatment facility at Hudson Falls that has treated more than 153 million gallons of water.
To evaluate the effectiveness of GE’s program, engineers sample Upper Hudson water.
GE’s investment in research and clean-up projects on the Hudson River now exceeds $200 million.
GE is not the only group against dredging, in forums all over the Hudson River area; residents have been voicing strong opposition to dredging. However, there are plenty who believe that dredging is the answer. A survey conducted by Scenic Hudson Inc., an environmental group supporting dredging showed 84 percent of residents surveyed think the EPA should order dredging (Capital Business Review November 16, 2000).
Clearwater River Sloop, one of the most well known supporters of dredging the Hudson, disputes the fact that sedimentation is allowing the river to clean itself. Citing scientific studies, Clearwater states, “less than 10% of PCB mass has been reduced over the past 20 years and PCB’s are most often in the top five inches of sediment” (Clearwater.org 2/21/01).
Although supporters of dredging agree with GE that dredging may cause PCB levels in the river to rise, they argue that it will only occur in localized areas nearest machinery. Precautions such as dredging during low flow periods and constructing silt curtains will further prevent sediments from spreading through the river. The EPA estimates that only 0.2% of the total dredged PCB sediment will be lost (Clearwater.org 2/18/01).
Clearwater River Sloop says that dredging will work, as exemplified by it’s recent success at reducing PCBs by 90% along Lake Champlain and that it may even make the local economy stronger by providing jobs.
The following is an outline of the EPA’s dredging plan (“EPA outlines…plan MSNBC.com)
Approximately 2.65 million cubic yards of sediment will be removed from the Hudson River.
Treated and stabilized sediments will be transported by rail landfills out of the area.
The navigation channel will be dredged as needed to implement the cleanup and to keep existing canal traffic moving during the project.
Environmental dredging techniques will be used to minimize and control the release of sediments.
Dredged areas will be refilled with approximately one foot of clean material to isolate residual PCB contamination and restore habitat.
Monitoring of sediments in dredged and unpremeditated areas will take place.
Water removed from the dredged sediments will be treated and discharged back into the river.
Fish, water and sediments will be monitored to determine when preliminary remediation goals are reached.
Modified fish consumption advisories will continue, as appropriate.
PCBs still entering the river through fractures in the bedrock below GE Hudson Falls plant will be controlled.
The cleanup plan will be reevaluated every five years.
There are many different aspects to consider when examining the Hudson River dredging debate. Is the river cleaning itself? Will dredging cause more harm than good? Is General Electric just trying to avoid paying for the dredging? The capital region as a community has been trying to answer these questions for years.
The EPA will receive public comment until April 17, 2001 and then it will make its final decision about the fate of the Hudson River.
Clearwater. “Environmental Dredging.” 8 April 2001.
Clearwater. “Facts About Dredging Hudson River PCBs.” 8 April 2001.
Clearwater. “Hudson River PCB Pollution Timeline.” 18 Feb 2001.
Clearwater. “PCB Contamination of the Hudson: Is Dredging an Appropriate Cleanup Strategy?” 18 February 2001.
Dredging”. Microsoft Encarta Online Encyclopedia 2001. 8 April 2001.
“EPA outlines dredging plan.” MSNBC. 12 December 00. 25 February 2001. http://www.msnbc.com/local/wnyt/77805.asp
Hudson Voice. “Web Site.” 27 February 2001. http://www.hudsonvoice.com
Huskie, Stephen J. “Dredging channels water courses’ economic, environmental effects.” American City Business Journals Inc. 19 October 1998. 18 February 2001.
“Polychlorinated biphenyls.” Webster’s Dictionary.
“Survey says Hudson Valley residents support dredging of PCBs in river.” Capital District Business Review. 16 November 2000. 26 February 2001.
United States. Agency for Toxic Substances and Disease Registry. Public Health Implications of Exposure to Polychlorinated Biphenyls. 13 August 1999. 18 March 2001.
United States. Environmental Protection Agency. PCBs 101- A PCB Primer.
15 December 2000. 27 February 2001.