Reducing Toxic Substances and Pathogens

The Goal

Reduce contaminants that pose a risk to public health and the Lake Champlain ecosystem.

// In This Section //

• Introduction
• Categories of Contaminants
• Sources of Toxins
• Monitoring Contaminants of Concern
• Toxin Reduction Efforts
• Citations

Introduction

Toxic substances include a diverse group of chemical contaminants, both natural and man-made, that can adversely affect plants, animals, humans, and the overall quality of the Lake Champlain ecosystem. Their impacts may be acute, occurring immediately, or they may be chronic, occurring after a prolonged period of exposure. Exposure to these substances may carry a risk of injury or illness to humans and other organisms. Toxicity varies based on the physical properties, quantity, and persistence of these compounds in the environment. Adverse effects of some substances have been observed in the Lake, but the long-term effects on the ecosystem, aquatic life, and human health of persistent, low-level exposure to many chemicals are not well understood. Even at very low concentrations, certain types of chemicals may affect the reproduction, development, behavior, and survival of aquatic organisms. Pathogens are infectious agents that cause illness, and, where they occur in the waters of the Lake Champlain Basin, they pose a risk to human health.

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Categories of Contaminants

The Lake Champlain Basin Program (LCBP) Toxics Management Workgroup has identified toxic substances of concern, grouped into several categories, and will publish a Lake Champlain Toxic Management Strategy report. More information about each of these substances will be found in the report, anticipated for release in 2011. Other contaminants of concern include pathogens such as E. coli and minerals such as road salt.

Bioaccumulating Toxins

This group includes substances that persist in the environment and increase in concentration with each step up in the food web. Bioaccumulating toxins are incorporated into plankton, which are eaten by fish, in which they may accumulate and become concentrated. Fish that eat these fish then accumulate the toxins in ever higher concentrations. Examples of bioaccumulating toxic substances currently found in the Lake Champlain Basin include mercury, polychlorinated biphenyls (PCBs), and dioxins (from pesticides). These substances are typically found in sediments or are deposited from wind currents on which they are transported from locations outside of the Basin. Mercury is one example of a toxic substance whose source is now predominantly atmospheric deposition. Achieving the reduction targets of the Northeast Regional Mercury TMDL will significantly advance the states toward their goal of reducing mercury levels enough to eliminate fish consumption advisories. In addition, the northeast states filed a §319(g) petition for the US Environmental Protection Agency (USEPA) to convene a management conference of states that are contributing nonpoint source (atmospheric deposition) pollution that is, in part, causing water-quality impairments in our states. Vermont and New York continue to be very active in these mercury-control efforts using Clean Water Act tools for the benefit of Lake Champlain and many other fresh waters in the northeast.

Cyanobacterial Toxins

Two toxins of primary concern in Lake Champlain are anatoxin and microcystin, which are produced by several species of cyanobacteria that form blooms under certain environmental conditions. These cyanobacteria blooms are frequently caused by combinations of excess nutrients present in the water column and warm, calm surface waters. Excess nutrients can come from sources higher up in the watershed that are delivered through the tributary network or from within the Lake’s sediments. More information about these issues can be found in Chapter 4, Reducing Phosphorus Pollution.

Pesticides

This group includes all chemical compounds that are used to control or limit the growth of nuisance plants, animals, and fungi and includes herbicides, lampricides, insecticides, and fungicides. These compounds are found in the Lake, often from runoff from agricultural fields, urban lawns, and golf courses as well as other commercial and residential applications.

Pharmaceuticals and Personal Care Products (PPCPs)

This group includes all forms of medications, fragrances, surfactants, detergents, and antimicrobial additives. This group is an emerging issue; many PPCPs have been detected in the Lake, but the impacts of their presence are still under investigation. Recent research indicates that many PPCPs (hormones, in particular) do impact several forms of aquatic biota, although the short- and long-term effects of most PPCPs on the Lake ecosystem remain unknown. PPCPs typically enter the Lake via wastewater treatment systems as they are washed off or excreted and flushed through the wastewater system.

Trace Elements

This group includes such elements as arsenic, manganese, cadmium, chromium, lead, nickel, silver, zinc, and copper; all of which are persistent in the environment in localized areas (i.e., sediment or fish) at levels above current human and wildlife health guidelines. Sources include historical contamination at industrial sites in the Basin, atmospheric deposition, aquatic nuisance control activities, natural geological formations, and stormwater runoff events.

Other Toxins

This group includes a variety of toxic substances not identified in the groups above, such as chlorinated phenols, polybrominated diphenyl ethers (PBDEs), persistent organics, and solvents.

Pathogens

These disease-causing agents also occasionally pose a health risk in the Lake Champlain Basin. Pathogens – such as bacteria, viruses, and parasites – can create gastrointestinal illness when ingested. Public beaches on the Lake are tested for coliform bacteria because it is an indicator that human or animal waste is in the water. New York, Québec, and Vermont all have their own monitoring protocols for popular beaches during the summer months.

Road Salts

This contaminant group includes sodium chloride and calcium chloride, both of which are used in road deicing during winter months throughout the Basin. Routine monitoring of these salts has indicated that concentrations have increased throughout the Lake and its tributaries during the last decade (LCBP Long-term Monitoring Program, unpublished data).

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Sources of Toxins

Lake Champlain is well studied for some toxic substances (i.e., mercury and PCBs), but only recently have studies been initiated to look at newer types of toxic substances and their sources. Active sources, routes of transport, delivery methods, and quantity of these substances still need to be explored in order for management to be effective. Common sources of toxic substances include: spills, sewage, industry, stormwater runoff, combined sewer overflows, agriculture, landfills, hazardous waste sites, household hazardous materials, and atmospheric deposition. Once toxic substances enter the aquatic environment, they may accumulate in the sediments, remain suspended or dissolved in the water column, or be consumed or absorbed by aquatic organisms and enter the food chain. Some toxic compounds may change form and become different compounds with different properties and toxicities, and the synergistic effects of multiple toxins remains unknown.

Mercury and PCBs remain a significant threat to the Lake and to human health. These substances persist in the environment and accumulate in sediments and aquatic organisms, including fish. Considerable research and management has been undertaken to reduce the level and threat of mercury and PCB contamination, although atmospheric deposition from sources beyond the Lake Champlain Basin remains the primary source of mercury. While new sources of PCBs within the Lake Champlain Basin have been minimized, PCBs continue to persist in the environment and need continued monitoring. Safe consumption of fish remains a top concern for people residing in the Basin; New York, Québec, and Vermont continue to issue fish consumption advisories in order to limit human exposure to mercury and PCBs.

The landscape of toxic contamination in Lake Champlain is changing. New chemicals are being used and introduced into the environment on a daily basis. Continual advances in analytical techniques allow for increased detection of compounds that are released into the environment from domestic, agricultural, and industrial applications. Pesticides, road salts, detergent additives, pharmaceuticals, and personal care products that are used in our daily lives are all compounds of emerging concern for the Lake Champlain ecosystem. Both the extent of contamination and the magnitude of potential effects from these compounds are poorly understood.

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Monitoring Contaminants of Concern

Cyanobacteria, commonly known as blue-green algae, are a normal part of the Lake Champlain ecosystem. However, high densities of algae in blooms can produce toxins that cause gastrointestinal problems, skin irritation, and, in high concentrations, can affect the liver and nervous system. Nearly annual blooms have been observed in some locations in Lake Champlain since 2000. The LCBP has coordinated blue-green algae monitoring in Lake Champlain for the last decade in partnership with the University of Vermont (UVM), the States of Vermont and New York, the Lake Champlain Committee, and the Province of Québec. Monitoring occurs on all sections of the lake. The Québec Ministère du Développement durable, de l’Environnement et des Parcs (Ministry of Sustainable Development and Parks) monitors Missisquoi Bay north of the border and sends regular information to Vermont and New York about conditions in Canadian waters. Monitoring in US waters happens through a partnership that includes citizen volunteers. Weekly testing occurs from July through early September. UVM summarizes the results of this testing and circulates information about Lake conditions to public health officials. Public information about conditions, and any beach closures or public health hazards are posted on the Vermont Department of Health and the LCBP web sites. Public alerts (including a map) direct Lake users to areas that are generally safe and list any areas that contain algae accumulations and should be avoided. This monitoring and alert system has successfully prevented people from adverse exposure to cyanotoxins; since implementation, no documented major illnesses based on exposure to cyanotoxins have been recorded.

A recent study conducted by US Geological Survey (USGS) in the Lake Champlain Basin indicated that domestic and agricultural chemicals and their breakdown products have been detected in Lake Champlain and its tributaries (Phillips and Chalmers 2009). More than seventy different chemicals were identified in the study, including flavorants, fire retardants, plasticizers, pesticides, fragrances, pharmaceuticals, and detergent degradates. Many of these chemicals enter surface water through the wastewater stream. Wastewater treatment facilities remove many types of contaminants, preventing them from entering surface water, but no facility or treatment process is capable of removing all compounds. The highest concentrations of pharmaceuticals and antimicrobials detected in the USGS study were found in the effluent of the wastewater treatment plant that services a hospital. High concentrations were also detected during combined sewer overflow events, when some waste bypasses the treatment plant. However, few contaminants were detected in the waters of Lake Champlain itself.

The co-occurrence of these compounds with caffeine emphasizes the degree to which Basin residents are both the source of and solution to this issue and the heretofore unpredictable fates of these compounds is being clarified by new science outside of the Lake Champlain Basin. For one example, recent literature suggests that dioxin-like compounds found in sediments may be the partial product of waste treatment reactions with the common antibacterial compound triclosan (Buth et al. 2010). Many aspects of emerging contaminants still require assessment in the Lake Champlain Basin (e.g., incidence of agricultural hormones, the effects of exposure to mixtures of very low-level compounds). Management of these compounds relies on personal choice in the products we use and industry response to the public requirement for products with lower levels of toxic compounds. This is exemplified by very significant documented declines in the estrogen-mimicking compound p-nonylphenol due to its removal from detergents by manufacturers (Phillips 2010). Research and management must now focus on these new-generation contaminants.

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Toxin Reduction Efforts

Detection of chemicals in Lake Champlain and its tributaries indicates that management and preventive measures may be necessary to reduce potential threats to the ecosystem and human health. The overall strategy for the management of toxic substances should be guided by a pollution prevention approach and the Precautionary Principle, which states that when there is a suspected health or environmental concern, preventive actions should be considered even without scientific certainty that harm will ensue. The precautionary principle is the central tenet of the European Union’s approach to management of hazardous and toxic substances in conjunction with the Restriction on Hazardous Substances Directive. Management for toxins should be employed at personal, business, municipal, and state levels. Every person living or working in the Basin has the responsibility and ability to minimize toxic substances from reaching the ecosystem.

A new clean-up effort on the Saranac River in Plattsburgh, New York, began in June 2010. Sediments from the river bed are contaminated with coal tar from a former manufactured gas plant. This project, phased over 3 years, involves construction of temporary coffer dams to isolate work areas and provide for natural river flow and fish movement through the site, construction of a temporary water treatment plant, and erection of a structure to process the sediments as they are removed from the river bed and shipped off-site. This project is estimated to remove 40,000 cubic yards of contaminated sediments by project completion in 2012. The project also requires restoration of the river bed to original grades and substrate with clean new materials from a nearby quarry.

Vermont continues to implement the provisions of the 2007 mercury product legislation, which includes reviewing sale restriction exemption applications, updated labeling and notification plans, and maintaining the auto switch collection program. Additions to the law in 2008 established a thermostat collection incentive program with manufacturer-funded recycling and financial incentives. Vermont captured nearly 1,800 pounds of mercury-containing products, 33 pounds of elemental mercury, and 3 pound of mercury from more than 1.2 million fluorescent bulbs in 2008 (the most recent year for which data are completely available).

As part of an earlier project, Vermont’s Agency of Agriculture, Food, and Markets (VAAFM), its municipal solid waste districts, and Department of Environmental Conservation (VTDEC) located, removed, and replaced all known mercury manometers from working and nonworking dairy farms. A total of 180 manometers were removed and 159 non-mercury replacements were installed for a total of 77 pounds of mercury removed from Vermont farms.

Brownfields are also of concern to human health; these are parcels that could be expanded or redeveloped and may be contaminated by hazardous substances from previous uses. Redevelopment projects that are proposed for brownfields parcels are required to survey, clean up, and monitor potential contaminants before the project can occur. Redevelopment of brownfields parcels can help ease development pressure on green spaces and working landscapes, in addition to protecting the environment by mitigating the contaminated site. These projects are overseen by the USEPA Brownfields Program, and EPA grant funding is available for assessment, clean up, revolving loan funds, and job training.

The new framework of Opportunities for Action (OFA) identifies broad objectives designed to help managers better understand the issues and to make efforts to reduce contaminants in the waters of the Lake Champlain Basin more effective. The actions and tasks identified in this chapter will help partners work toward the goal of reducing contaminants that pose a risk to public health and the Lake Champlain ecosystem. Efforts made by all partners, including those listed in this plan, will promote the reduction of toxins, pathogens, and other contaminants of concern.

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Citations

Buth, Jeffrey, Peter O. Steen, Charles Sueper, Dylan Blumentritt, Peter J. Vikesland, William A. Arnold, Kristopher McNeill. 2010. Dioxin photoproducts of triclosan and its chlorinated derivatives in sediment cores. Environmental Science & Technology 44(12): 4545-4551.

Phillips, P. and A. Chalmers. 2009. Wastewater effluent, combined sewer overflows, and other sources of organic compounds to Lake Champlain. Journal of American Water Resources Association 45(1): 45-57.

Phillips, Patrick. 2010. USGS. Personal Communication.

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