List of Pollutants

      During the March 2011 CAG meeting, LWG gave a presentation, in part, on the issue of what pollutants they have included in the unreleased Feasibility Study (FS).  LWG explained that there is a screening process that began during the Remedial Investigation (RI) phase of the cleanup.  During the RI phase, Chemicals of Interest (COIs) are identified and include all chemicals found on the site. 

Then, COIs are compared to conservative-risk screening levels and those that exceed the screening levels are considered Chemicals of Potential Concern (COPC) and are included in the Risk Assessment (RA).  COPCs that result in potentially unacceptable risk during the site-specific RAs are considered Chemicals of Concern (COCs) and are included in the FS.  Below is a flow chart representing this process made by LWG.  To download it, see the attachment below (COCs.doc) or click here.


     The list of pollutants below is provided to illustrate the array of accumulated contamination in the Portland Harbor.  The list also briefly explains the health and environmental impacts associated with these chemicals.  Links are provided for those interested in further information.


COIs:  The initial COIs are detailed in the Draft Analytical Concentration Goals for Target Analytes in Sediments, Tissues, and Water Samples Report to EPA (Windward and Kennedy/Jenks 2002).  The study identified metals, polycyclic aromatic hydrocarbons, pestides, PCBs, butylins, and dioxin/furans, as well as several miscellaneous semi-volatile and volatile organic compounds.  In a presentation to CAG, Jim Wyatt from LWG/Environmental Law Center indicated that there were 399 COIs, including DDT and TBTs as well as those mentioned above.  For maps of concentrations of DDx, Dioxans, PCBs, and PAHs, click here.

COCs:    According to LWG representative, Barbara Smith, "Each [COC] will likely have a unique final cleanup remedial action level and all remedies will be protective of human health and the environment.  Achieving the final cleanup level for one chemical (e.g., PCBs) will likely also resolve most of the dioxins and pesticides issues (e.g., they are co-located)."


PCBs:  Banned from production in 1977, Polycholrinated biphenols or PCBs (mixtures of up to 209 chlorinated compounds) remain in the environment to this day.  They are known as Persistent Organic Pollutants (POPs) for their ability to remain in the environment years after creation.  Historic sources included manufacture of coolants and lubricants.  These chemicals are known to cause cancer in animals, and may cause observable effects in humans such as immunological and neurological disorders and skin lesions.  For more information on PCBs, click here.


DDx:   DDT, the most well-known of these chemicals, was banned in the United States in 1972 based on observable effects on wildlife, such as bald eagles.  They are known as Persistent Organic Pollutants (POPs) for their ability to remain in the environment years after creation.  Unfortunately, DDx continues to enter the environment because many countries have not banned its use as a pesticide.  DDx compounds are known to have nervous system impacts as well as reproductive complications.  For more information on DDx, click here.


Dioxins/FuransThis group of chemicals is classified as a "known human carcinogen."  Sources of dioxins include paper pulping and bleaching, waste incineration, and chemical and pesticide production.  They are known as Persistent Organic Pollutants (POPs) for their ability to remain in the environment years after creation.  Dioxin is also known to cause reproductive and developmental problems.  For more information on Dioxins/Furans, click here.


Polyaromatic Hydrocarbons (PAHs):  Formed by burning organic material or naturally from thermal geologic activity,  PAHs are often found in heavy fuel, tar, and creosote.  The two PAHs listed below were found at Triangle Park near industries that historically produced these chemicals-- they are known carcinogens.  For more information on PAHs, such as chemical properties and managment/remediation, click here.





EPA originally expressed concern to LWG about the draft Remedial Investigation, the Human Health Risk Assessment (HHRA), and Baseline Ecological Risk Assessment (BERA) because so few chemicals were listed as COCs.  No COCs were added in the revised final documents despite the fact that many more contaminants exceeded EPA risk levels for adverse health effects in the studies.  While EPA has not approved the final HHRA and BERA, LWG believes that by focusing on the abovementioned COCs (PCBs, DDx, Dioxins/furans, and PAHs) and developing cleanup strategies for them, the other contaminants will likewise be remediated because they are "co-located" with the COCs.  Time will tell whether EPA accepts this conclusion.


Other Pollutants:  Many of these contaminants have been the subject of Early Actions.


Heavy Metals

     Hexavalent Chromium (Cr) (subject of early action at Arkema)

BTEX (benzene, toluene, ethylbenzene, and xylenes)



Tar Body



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