Monday, January 28, 2013

Toxic Chemicals in Chesapeake Bay -Expanding the Pollution Diet

from EPA report

The U.S. Environmental Protection Agency’s Chesapeake Bay Program just released a report that outlines the extent and severity of toxic contamination in the Chesapeake Bay and the Watershed. This report by Scott Phillips (USGS) and Greg Allen (EPA) is based on a review and compiling of water-quality reports from the various Chesapeake Bay watershed states (Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia) and Washington, D.C., and scientific work performed by the U.S. Geological Survey and U.S. Fish and Wildlife Service who have been doing extensive studies on contaminants in surface and groundwater and also the cause of observed impact on fish, plants and wildlife.  The authors of the EPA  report focused on summarizing studies conducted after 2000 with an emphasis on the 2010 water-quality assessment reports from the states to define the extent and severity of occurrence of: polychlorinated biphenyls (PCBs); dioxins and furans; polycyclic aromatic hydrocarbons (PAHs); petroleum hydrocarbons; pesticides; pharmaceuticals; household and personal care products; polybrominated diphenyl ethers (PBDEs); biogenic hormones; and heavy metals in the Chesapeake Bay watershed and ultimately in the source drinking water for millions of people.

This report was issued under the “Strategy for Protecting and Restoring the Chesapeake Bay Watershed” released in May 2010 and is first in a series of actions to control pollution, restore habitat and wildlife, conserve land, and increase public awareness and accountability in the Chesapeake Bay Watershed. The federal ‘Strategy” for the Chesapeake Bay region of the 64,000-square-mile watershed includes using federal regulations to restore clean water, implement new conservation practices on four-million acres of farms, conserve an additional two-million acres of undeveloped land, and restore the habitat for key species such as oysters, black ducks, and brook trout. Under the “Strategy” the states will be held accountable to achieve specific milestones every two years to ensure measurable progress.

While there is overlap between the so called “settlement agreement” and “Strategy,” they are not the same. The settlement agreement resolved the lawsuit brought by former Maryland State Senator Bernard Fowler, the Chesapeake Bay Foundation, Maryland and Virginia watermen’s associations, and others filed against the EPA in January 2009 alleging the Agency failed to fulfill its duties under the Clean Water Act (CWA) and the Chesapeake 2000 Agreement. EPA settled the lawsuit with the “settlement agreement,” which required EPA to:  “Establish and implement a Chesapeake Bay total maximum daily load, TMDL, for nutrients and sediments.”  The TMDL required the creation of watershed implementation plans (WIPs) approved by EPA under threat of  “back step measures” by all of the Chesapeake Bay watershed states and the District of Columbia to ensure they achieve the nutrient and sediment allocations under the TMDL.

The TMDL addresses only pollution from excess nitrogen, phosphorus and sediment. The TMDL does not address toxic, carcinogenic or endocrine disruptors that may be present in the watershed. The excess nitrogen, phosphorus and sediment in the Chesapeake Bay cause algae blooms that consume oxygen and create “dead zones” where fish and shellfish cannot survive, block sunlight that is needed for underwater Bay grasses, and smother aquatic life on the bottom. The result is fish kills and murky water that threaten the aquatic industry and recreational use of the bay. 

The TMDL sets a total Chesapeake Bay watershed limit for the six states and Washington DC of 185.9 million pounds of nitrogen, 12.5 million pounds of phosphorus and 6.45 billion pounds of sediment per year which is a 25% reduction in nitrogen, 24% reduction in phosphorus and 20 %t reduction in sediment from the current levels. The pollution limits are then partitioned to the various states, DC and river basins based on the Chesapeake Bay modeling tools and monitoring data. The estimated cost of implementing the WIPs in Virginia and Maryland were $13.6-$15.7 billion and $14.8 billion respectively. Now EPA is preparing to address the toxic pollutants.

This new report addresses toxic pollutants in the watershed and is the first step in a new round of regulations and requirements for the Chesapeake Bay watershed states and Washington DC. In the Chesapeake Bay watershed, both largemouth and smallmouth bass show signs of feminization (testicular oocytes and vitellogenin in males), skin lesions and impaired immune systems. The scientists of the USGS and Fish and Wildlife discovered that the smallmouth bass have the most impacted with a higher incidence of intersex (male fish with eggs)occurrence and a high incidence of skin lesions and large fish kills in the Potomac and James Rivers. Smallmouth bass may be the most sensitive indicator of environmental health in the Chesapeake Bay watershed. The smallmouth bass have been a warning, but the pollution problems they represent remain beyond our understanding at this time. The USGS and Fish and Wildlife have not succeeded in identifying the cause or causes of the feminization, skin lesions and impaired immune systems.
from EPA report

The EPA report found that PCBs, PAHs, herbicides (primarily atrazine, simazine, metolachlor, and their degradation products), and mercury were widespread throughout the Chesapeake Bay watershed. Other contaminants like dioxins/furans, petroleum, hydrocarbons, some chlorinated insecticides (aldrin, chlordane, dieldrin, DDT/DDE, heptachlor epoxide, mirex), and some metals (aluminum, chromium, iron, lead, manganese, zinc) were known in localized occurrences. Finally, for atrazine, some pharmaceuticals, some household and personal-care products, some PBDEs, and biogenic hormones, the extent and amount of contamination could not be assessed based on the information available.

The Chesapeake Bay Program intends to develop toxic contaminant reduction strategies to be added to the Chesapeake Bay TMDL by 2015, but first more data needs to be gathered to identify the extent of contamination for many of the chemicals. The impact on human life and the ecosystem of these and other emerging contaminants is not understood. As the EPA report and previous work done by the USGS point out we need to determine the impact and fate of these micro pollutants before we implement the watershed cleanup plans to make sure we are implementing the right strategies for the health of the entire ecosystem which may include eliminating the use of certain chemicals, upgrading waste water treatment systems and other actions. 

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