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Dredging Decision Fact Sheet

The Truth About Environmental Dredging

The river looks clean, but looks can be deceiving.

Yes, the Hudson River looks clean and is teeming with fish. Improvements in the health of the Hudson River are visible and substantial. Thanks to the federal Clean Water Act and advances in sewage treatment, bacteria and nutrient levels have declined significantly, creating a healthier river environment that has encouraged the return of fish and wildlife. But don't be fooled by pretty pictures. The bottom line is that the PCBs in the river and its sediment are not visible. And the fish and the river bottom on which they depend for food and shelter are contaminated. It's what you can't see that can hurt you.

PCBs are harmful to people's health.

PCBs cause cancer in laboratory animals, are considered a probable cause of cancer in people, and can trigger other serious health problems including low birth weight, thyroid disease and learning, memory, reproductive and immunological problems. Pregnant women and children are especially vulnerable. Major national and international health organizations, including the National Institutes of Environmental Health Sciences, the National Institute of Occupational Safety and Health, the American Cancer Society and the World Health Organization agree with EPA about the toxicity of PCBs.

Eating fish from the Hudson can be dangerous.

For twenty-five years, concerns about PCBs in Hudson River fish have prompted New York State to issue health advisories that recommend limits on eating fish from the river. People should protect themselves by following state fish consumption advisories. Women of child-bearing age and children under age 15 should not eat any fish from the Hudson River, and no one should eat fish caught between the Federal Dam at Troy and Hudson Falls.

People continue to eat fish from the Hudson.

Some say the answer to the PCB problem is "just don't eat the fish." This approach ignores reality. Studies show that people who fish the river – for recreation, cultural practice or subsistence – continue to eat the fish they catch and to bring them home to their families. And accepting that we can't eat Hudson River fish would simply write off this important natural resource.

The Hudson River is not cleaning itself.

PCB levels in river water and fish have declined significantly since 1977, which some people offer as proof that the river is cleaning itself. But, the decline is largely due to the ban on PCB discharges that went into effect that year. When direct discharges of the contaminant were stopped, PCB concentrations in river water and fish logically dropped as well. But many of the PCBs discharged into the river decades ago remain in the river sediment.

PCBs in the sediment are not safely buried.

River sediment is continually redistributed across the bottom by erosion and river flows. This movement exposes PCB-contaminated sediment, making it available to the fish. Elevated levels of PCBs, up to 600 parts per million (ppm), are still found at the surface of the sediment, and 60% of the sediment core samples taken by EPA had PCBs in the top nine inches.

Although PCBs do break down, they remain in the river and are hazardous.

The endurable quality of PCBs, which made them valuable as industrial products, makes them hazardous to the environment. PCBs degrade naturally over time, but the process -- called natural dechlorination -- does not make them harmless. EPA considers all PCBs, regardless of their level of chlorination, to be hazardous to people's health. The PCBs may change, but they don't go away.

PCB levels in fish are no longer going down.

Although PCB levels in fish have decreased over the past twenty years, the downward trend has leveled off. In fact, average PCB levels in the fish of the upper Hudson have not changed significantly in seven years. They are still high enough to pose a risk to people and trigger restrictions on eating fish and a ban on commercial fishing.

PCBs move throughout the river.

A sophisticated scientific technique fingerprinted where the PCBs come from and where they go. It enabled us to track the movement of PCBs from the sediment of the Thompson Island Pool -- the most heavily contaminated section of the river -- through the water, to as far downstream as Kingston, New York, 100 miles south. The fingerprints also reveal that the three-fold increase in PCBs, as water flows through the Thompson Island Pool, comes from the sediment.

Source control alone will not clean up the river.

Each day, about five to six ounces of PCBs enter the river at the top of the Thompson Island Pool through fractures in the bedrock underneath the General Electric (GE) Hudson Falls plant. Samples show that about one to 1-1/2 pounds of PCBs flow out of the Thompson Island Pool every day. It's simple math. The additional PCBs come from the river sediment. By turning off the Hudson Falls spigot, PCB levels in fish should go down somewhat. That's why source control is an important complement to EPA's cleanup plan. But, without targeted dredging, PCBs in the sediment will continue to find their way into fish at unacceptable levels and for an unacceptable length of time.

Letting nature take its course will not protect people who eat fish from the Hudson.

It has been suggested that if no action were taken other than source control, the levels of PCBs in fish will meet the federal Food and Drug Administration (FDA) tolerance level of 2 ppm between 2010 and 2014. FDA standards reflect a "market basket" approach, which assume people eat a variety of fish from a variety of places, purchased at their local market. A PCB level of 2 ppm is not sufficient to protect people who regularly eat fish from the Hudson River. That's why we have developed a risk-based concentration of .05 ppm as our goal for PCBs in fish. That is also the advisory level for unrestricted consumption accepted for the Great Lakes.

The Hudson River can one day be as healthy as it is beautiful. But, it will take the collective will of the thousands of people who cherish the river for its history, its resources and its natural beauty.

For information about this page, contact: kluesner.dave@epa.gov


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