340 likes | 810 Views
Pollution Prevention and Management Strategies for Polychlorinated Biphenyls in the NY/NJ Harbor. Report from the Harbor Consortium of the NY Academy of Sciences Summary by: M. L. Anderson. What are PCB’s ?. Polychlorinated Biphenyls
E N D
Pollution Prevention and Management Strategies for Polychlorinated Biphenyls in the NY/NJ Harbor Report from the Harbor Consortium of the NY Academy of Sciences Summary by: M. L. Anderson
What are PCB’s ? Polychlorinated Biphenyls • PCBs were first created in 1881 and commercial manufacture began in 1929. • PCBs were produced worldwide for a variety of institutional uses. • PCB’s are man made chemicals used mainly in electrical equipment. • PCBs are stable compounds that are fire resistant and do not conduct electricity. • Characteristics of PCBs are: chemical inertness; thermal stability and low vapor pressure.
What are PCB’s ? • Synthetic chemicals made by combining two benzene (carbon) rings with 1 to 10 chlorine atoms. (C12H10-nCln) • The basic PCB structure allows for 209 different chlorination patterns, thus 209 recognized PCB compounds with varying levels of toxicity.
What are PCB’s ? • 60 % worldwide and 77% US production of PCBs was used in the production of transformers and capacitors. • Total worldwide production of PCBs from 1929 to 1989 is estimated at 1.5 Million Tons. • Monsanto Chemical Co. commercialized ‘Arodor’ blends of PCBs, used as transformer fluids and solvents.
What is a Transformer? A device that converts power generators low-voltage electricity to higher voltage levels for transmission to the load center (a city). • Then it converts high voltage to low voltage to the end user. • This transfer is achieved through electromagnetic induction but without the use of moving parts. • Transformers generally require some type of dielectric fluid, which is a poor conductor of electricity yet capable of supporting electrostatic fields. • From 1930 to 1977 two types of cooling fluid were used, both containing large amounts of PCBs.
What is a Capacitor? A passive electronic component used to store energy within an intrinsic electrostatic field. • Capacitors may have two conducting plates that are separated by an insulating material known as a dielectric. PCBs were the main dielectric in capacitors through 1977. • PCBs were used in high voltage capacitors operated by utilities. • Low-voltage-power capacitors (in large motors) were installed in: • Institutional and other building compounds • Electric locomotives • Wheel or skid-mounted power centers in mines • The operating live of a large capacitor is at least 20 years. Many PCB capacitors are still in use. The attrition rate is slow.
What products are PCBs found? • Closed applications in transformers, capacitors, circuit breakers, heat transfer systems • Di-electric fluids in transformers and capacitors, public utility companies. • “Askarel”-type PCB transformers at non-utility facilities. (Askarel- the trade name in the US for the commercial blend of PCB and trichlorobenzene) • PCB capacitors from household appliances.
What products are PCBs found? • Paints and other plasticizers • Carbonless copy paper (NCR) • Inks and pigments in paper (both current and historical) • Oil Recycling facilities. Dioxins (PCDDs) and furans (PCDFs) can form from PCB contaminated mineral oil, during combustion unless specific incineration practices are followed. • Scrap tires used as fuel can break down plasticizers during combustion releasing PCBs.
Electrical capacitors Electrical Transformers Vacuum pumps Hydraulic fluids Gas-transmission turbines Plasticizer in resins and rubber Adhesives Wax extenders (including ceramic molds) Inks Lubricants Cutting oil Carbonless copy paper Heat transfer systems Galbestos Pesticide extenders De-dusting agents Sealants / caulking material Monsanto (US) manufactured PCBs under the name “Aroclor”
Closed applications: PCB fluid was totally enclosed within the electrical equipment (transformers, capacitors and small capacitors in refrigerators, air conditioners, microwave ovens and ballasts.) PCBs were used as insulating material, flame-retardant materials or as coolants and lubricants. Semi-open applications: Hydraulic fluids in underground pumps and mining operations. Also as compressors in gas pipelines. A fine mist of PCBs contaminated oils was sprayed in underground metal gas pipes to retard corrosion. More Industrial and commercial usage of PCBs. • Open applications: • Plasticizers, pigments, dyes, pesticide extenders, wood preservatives. • PCB oils were used as a dust control agent and sprayed on roads and open ground surrounding utility work areas and railroad yards.
Environmental Impacts of PCBs 1966 - First study that identified PCBs in the environment. • PCBs accumulate in the fatty parts of organisms. • They are lipophilic and biomagnification occurs up the food chain. • PCBs bio-accumulate in the food chain. • PCBs are persistent chemicals and do not readily break down in the environment. • PCB concentrations are higher in organisms that are higher up the food chain.
What are the Bioaccumulation factors of PCBs? • Aquatic organisms can contain 2000 to more than 1Million times higher PCBs than the concentration in water. • PCB’s interfere with the endocrine system which regulated all biological processes from conception to old age. Development of brain, CNS, reproductive system and metabolism. • PCBs disrupt hormonal systems by mimicking or blocking natural hormones that regulate the essential functions of endocrine glands (thyroid, ovaries, testes). • They can suppress the immune system and induce several types of cancers and endometriosis.
What are the Bioaccumulation factors of PCBs? • PCB exposure is linked to birth defects, tumors, retarded learning, a decline in fertility of fish, birds, amphibians, seals, polar bears and mammals. • The EPA has classified PCBs as “B2 probable human carcinogen”. • Acute effects in humans are seen in occupational exposure or during electrical equipment fires.
Setting for PCB Legislation • Manufacture voluntarily ended • Banned over 25 yrs ago • Extremely complex environmental hazard • The #1 most expensive environmental challenge in NY Harbor is dealing with PCB contaminated sediments • PCB’s continue to be redistributed and dispersed through processes such as disposal, recycling and volatilization.
Myth: Because these materials have not been made in the U.S. for 25+ years, we must know how much was made and where most of them are. • Need for comprehensive reporting on: • the rates of retirements • quantities of proper disposal • PCB concentrations from all PCB-containing equipment and products.
Initial Problems with estimating remaining PCB’s No updated data on: • How much PCB remains in products? • How much has been released into the environment? • How much has been properly disposed of in landfills? • A small quantity of PCB dispersed into the environment, has the potential to generate large amounts of PCB contaminated waste.
Difficult to track and understand how these chemicals move • The molecular weight differences between different PCB compounds affects their toxicity and how they move and behave in the environment. • Types of organisms that are affected and the way they are harmed keeps expanding • PCB’s bind to the products that contain them becoming “PCB containing materials” • Unable to tell how much actual stock PCB material is still ‘out there’ and where it is located.
Regulation Background: Passage of the Clean Water Act 1972 Resulted in: • Permit programs control the major sources of pollution. • Industrial pre-treatment programs reduced industrial discharges of wastes resulting in substantial reductions in loadings of several toxic chemicals.
Regulation Background: Prohibition on production, distribution and commercialization of PCB’s in 1978. • The use of certain products containing PCBs continued to be allowed pursuant to proper maintenance and upkeep of such equipment. • PCB products ware regulated for safe disposal.
Regulation Background: Superfund legislation was enacted to address previously contaminated sites. • 200 miles of the Hudson River bed designated as a superfund site. • Human health advisory (no-consumption) of fish and certain mammals because of PCB concentrations in these organisms.
Regulation Background: In 1976 Congress enacted the Toxic Substances Control Act (TSCA) to identify and control toxic chemical hazards to human health and the environment. • This act constitutes the principal regulatory framework for PCBs. The NRC requires reporting of PCB transformer fires and spills of 1lb. or more.
PCBs are among 12 persistent organic pollutants (POPs) banned by International treaty, the International Stockholm Convention, signed in 2001 and agreed in 2004. This POP Convention requires the following actions: • Immediately eliminate the production of PCPs. • Eliminate the use of PCBs in equipment by 2025 • Eliminate export or import of equipment containing PCBs • Immediately eliminate the recovery of liquids containing PCBs at levels above 50ppm for reuse in other equipment. • Develop inventories of PCBs in use and in stockpiles. • Properly dispose of PCB wastes in such a way that that the persistent organic compound is destroyed or irreversibly transformed. • Develop strategies to identify and remediate PCB contaminated sites.
Goals of the 3rd Harbor project Create a safer environment for the @ 20 million people that live in the watershed adjacent to the Harbor by: • ID pathways of PCB’ into the watershed and Harbor. • ID the best strategies to keep new pollutants form entering the watershed. • Collect data from Input, and output of PCB’s from manufacturing, service industries and households.
Problems Estimating the Damage and Remediation needed • Toxic Chemical Release Inventory (TRI) data includes estimates of PCB contaminated materials from remedial actions however, this data is based on tests on limited samples. • The current reporting system does not distinguish between off-site releases (spills and transfers by industrial facilities, form on-site releases (releases to the land). • Until 2000, the PCB reporting threshold was 25,000lbs/year for manufacturing, processing and 10,000 lbs/year for ‘other’ uses. This leaves a large amount PCBs unreported, un-tracked, and often disposed of improperly. • Of the 127,000 metric tons of PCBs in use nationwide in 1988, only ~11,000 metric tons of PCBs are accounted for today by the TRI database. Yearly monitoring data is riddled with large gaps in tonnage.
Sources of PCBs in the NY/NJ Harbor watershed Sources include: • Manufacturing facilities • Utility and non-utility transformer stations • Regulated and unregulated disposal sites • Other contaminated sites • Industrial sites where PCBs are inadvertently generated by pigment manufacture or use of contaminated products (e.g., ferric chloride) • Recycling sites of PCB contaminated materials (e.g., metals and carbonless copy paper)
Sources of PCBs in the NY/NJ Harbor watershed • Sites where PCBs are still used in ‘closed’ applications such as transformers and capacitors. • PCPs are released into the environment by accidental spills during maintenance, accidental spills, fires or improper disposal. • Electrical equipment may be knocked down in an accident, lightning strike, storm damage. • Spilled PCB can be volatilized or transported during storm events, before clean-up crews arrive. • Release of PCBs from the site of improperly stored or disposed containers. • Conversion of PCBs into furans and trichlorobenzenes into dioxins via combustion during a fire or lightning strike.
Pathways of PCBs in the NY/NJ Harbor watershed Where are the PCBs in Harbor sediments, biota and the atmosphere? • The Containment Assessment and Reduction Program (CARP) is attempting to understand the fate and transport of contaminants discharged into the entire estuary, and the use of this information to take necessary actions. (Study results not yet released) http://www.hudsonriver.org/carp.html • EPA’s Regional Environment Monitoring and Assessment Program (REMAP) gathered data in 1993 & 1998, that included sampling surficial sediments (including PCBs) toxicity, and community structure. http://www.epa.gov/emap/remap/html/docs/nynjharbor/html
Mass Balance Study Undertaken to understand PCB loadings, inputs to the system. • PCBs have an affinity to particles, therefore are transported downriver via particles. • Leaching of PCBs into groundwater and then transport into the harbor is unimportant, as most of the PCBs are expected to remain bound to the solid particles. • 56% of the total loadings are dominated by input at the Newburg Bridge. This includes loadings from the Troy Dam, Mohawk River and lower Hudson River. • PCB inputs at the Troy Dam account for ~ half of the input to the estuary. (1997 EPA)
Mass Balance Study Loadings and losses are calculated by multiplying concentration by flow rate. • Overall input to the system = 444-883 kg/yr • Overall output to the system = 746-1,631 kg/yr. • Loadings = Losses? • The mass balance is closed? No • Losses include sediment that may now be buried. • Much of loss is through volatilization: ~ 400kg/yr of tetra & trichlorobiphenyls that were previously stored in sediments are being lost to the atmosphere, mostly around the Tappan Zee and Haverstraw Bridges. • High MW PCBs are transported into the system by CSO and runoff.
Results of Mass Balance Study • Upper Hudson River is main source of PCBs to NY/NJ Harbor. • Load from storm water runoff is uncertain. More data is needed. • Volatilization is the most important loss process for low-MW PCBs. • Much low-MW PCB is being released to the water column, then to the atmosphere each year. • High MW PCBs enter the estuary primarily through CSO and runoff. • Loading from tributaries other than the Hudson River, are relatively small.
NY/NJ Harbor Report Findings • More than 50% of the Harbor PCB’s originate in the Upper Hudson River including Hudson River Superfund site, and NYS Superfund sites (Hastings, Ft. Edward, Hudson Falls) • Differences in PCB mixtures from Upper Hudson to local input. • 56% of PCB’s to NY/NJ Harbor, originate in the Upper Hudson River • 17% from combined sewer outflows (CFO’s); • 17% from storm water runoff
NY/NJ Harbor Report Findings • Contaminated sites are likely contributors of PCB’s into the Harbor • Di-electric fluids account for ~ 70% of domestic PCB production. Were commonly used in transformers and capacitors. • 70% of Askarel-type PCB transformers were at non-utility facilities. Many were either taken out of service or underreported. • Law requires PCB waste to be properly managed. No regulation exists to test sources with small to moderate amounts of PCBs.
NY/NJ Harbor Report Findings • Small PCB capacitors from household appliances and demolition debris enter the Municipal Solid Waste (MSW) stream each year. No inventories of these units. 20% of MSW in the NY/NJ Harbor region in incinerated. • 5 to 10% of Harbor input is from inadvertently produced PCB’s. (combustion) • US domestic production of PCB’s = half million tons (568,000T) of pure PCB. PCB contaminated bulk waste in the US is estimated at 168 to 600 Million tons.
Recommendations of Harbor Report • Create a regional inventory of PCB electrical equipment, including # of units and amount of PCBs contained in each unit, number of units retired also recording PCB content. • Document # of and amount of PCBs in liquid-filled transformers. • Monitor PCB concentrations at dismantling, fragmentation, recycling, storage and disposal facilities. • Track PCBs from household appliance waste stream. • Monitor inadvertent PCB production at Public Owned Treatment Works (POTWs) by testing sludge / effluent for PCB concentrations. PCBs end up in POTW from industrial processes, treatment plant activities and storm events.