On April 7, a leak was discovered at the Potomac Electric Power Company’s (Pepco) Chalk Point generating station. The oil leak from a pipeline released approximately 126,000 gallons of #2 and #6 oil into a marsh and subsequently into parts of the Patuxent River. The emergency response phase concluded with the containment of the spilled oil from the Chalk Point Generating Station, although cleanup continues and damage assessment and restoration efforts are now under way.

Under the Oil Pollution Act of 1990, Pepco is responsible for restoring injured natural resources to their condition prior to the spill and for compensating the public for the loss of natural resources from the time they are injured until they are restored. The EPA is leading efforts to clean up and minimize the effects of the spilled fuel oil, but other governmental agencies, referred to as natural resource trustees, are advocates for the protection and restoration of injured resources.

Environmental experts from four government agencies, the National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, Maryland Department of the Environment and Maryland Department of Natural Resources, act as natural resource “trustees” on behalf of the public. The natural resource trustees are working cooperatively with Pepco and affected citizens to assess and restore the natural resource injuries caused by the oil spill. The trustee agencies are also responsible for ensuring that Pepco fulfills this obligation. This process is formally called a Natural Resource Damage Assessment (NRDA). It strives to answer the following questions: What resources have been injured? What is the loss to the public? How can the resources be restored? What type and amount of restoration is appropriate?

The trustee agencies are evaluating injuries to marshes and other habitats and impacts to finfish, shellfish, colonial waterbirds and other wildlife, as well as surface waters and sediments in the Patuxent River. Lost recreational uses such as boating, fishing and other activities will also be evaluated. Data collection will continue for several months.

Initial assessments of oil spill damage began as soon as the spill was discovered. The U.S. Fish and Wildlife Service and the Maryland Department of Natural Resources organized shoreline survey teams to locate and report any oiled wildlife in need of rescue. Biologists also collected and documented dead specimens for future NRDA activities. Dead wildlife: ruddy ducks, cormorants, muskrats, diamondback terrapins and water snakes were collected during these surveys as well as gizzard shad and catfish, although the fish mortality may not have been related to the oil spill. Sediment and water samples were also collected to evaluate whether toxic conditions may have been present.

Wetlands and shoreline fringing marshes were the hardest hit by the oil spill, particularly in Swanson, Indian and Trent Hall Creeks. Study areas have been established in lightly to heavily oiled areas as well as in unoiled areas for reference. Wetland experts will assess the impact of oil on the vegetation and wildlife, as well as the time that will be required for these resources to recover.

Other birds, in addition to the ones rescued or collected during initial surveys, may be impacted by the oil spill. These include bald eagles, great blue herons and ospreys. Although no dead adults were found, some oiled birds were seen. Oil is extremely toxic to bird eggs and, as the spill happened during nesting season, there is concern that eggs could be contaminated. The U.S. Fish and Wildlife Service will monitor the hatching and fledging success of osprey, great blue heron and bald eagles nests within the spill zone until the birds leave the nest.

Fish larvae and eggs may also have been affected. The Department of Natural Resources conducted trawls in the Patuxent River to determine what species of fish larvae and eggs were in the river at the time of the spill. Testing on water samples collected from Swanson Creek and dilutions of oil by the Academy of Natural Sciences’ laboratory will determine at what levels the water was toxic. Surface water samples collected for several weeks after the spill will be analyzed for petroleum products. This information will be used to estimate the effect on larval fish and eggs.

Another possible study would look for evidence of impacts to bottom-dwelling (benthic) invertebrate communities. Benthic invertebrates like clams, mussels, shrimp-like crustaceans and worms are important in the diets of many other aquatic wildlife. These animals can be good indicators of environmental conditions because of their low mobility and the fact that they live in bottom sediments where contaminants accumulate.

Information from these and other studies, in combination with input from the public and Pepco, will be used by the trustees to develop a draft natural resource restoration plan. The draft plan will describe assessment activities and natural resource injuries; propose and evaluate restoration alternatives; and identify restoration projects to address injured natural resources. The draft plan will be available for public review and comment. Once finalized, trustees will start restoration projects with funding from Pepco or oversee Pepco’s implementation of these projects.

The ultimate mission of the natural resource trustees is to restore injured natural resources at no cost to the taxpayer. Restoring natural resources benefits people as well as fish and wildlife. By restoring our natural resources, we help to maintain the quality of life for now as well as future generations.