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Chemical Contaminants

The DelawareWatersheds.org website has posted information on contaminants in the Christina River.

The Christina River Watershed has a total of two hundred and fifty-nine sites listed in the Site Investigation and Restoration Section database. There are eighty four Brownfield program sites, seventy-eight sites in the Voluntary Cleanup Program (VCP), seventy-four state-fund lead (HSCA) sites, seventeen sites that have undergone a preliminary assessment / site inspection (PA/SI), four sites listed as a Formerly Used Defense Sites (FUDS) and two National Priorities List (NPL) sites.

Each of the sites is sampled through the programs listed above for a consistent suite of environmental contaminants. These contaminants are broadly classified as Volatile Organic Compounds (VOCs), Semi-Volatile Organic Compounds (SVOCs), Pesticides, Polychlorinated Biphenyls (PCBs) and Metals as listed using USEPA and DNREC defined standards. When sites are adjacent to water bodies sediment samples are collected to assess potential impact from a site on the health of the waters.

In water bodies of the Christina River Watershed, samples have indicated that PCBs, dieldrin and chlordane are present in the environment at levels requiring further attention under the Clean Water Act (1972). The Christina River Watershed is on the 303d list of impaired waters as well as having State of Delaware Fish Consumption Advisories for PCBs, dieldrin and chlordane.

If you would like to view reports for any of the sites in the SIRS program please follow the link the DNREC Environmental Navigator to search by map for the Christina River Watershed.

According to the Delaware Department of Natural Resources website, here is a recent update on chemical contamination in the Christina Watershed.


PCB Mass Loading from Hazardous Substance Release Sites to Surface Waters of the Christina River Basin

A DNREC collaborative environmental report

The Department of Natural Resources and Environmental Control, the Division of Air and Waste Management, Site Investigation and Restoration Section (SIRS) and the Division of Water Resources’ Watershed Assessment Branch (WAB) have collaborated on a regional environmental study of polychlorinated biphenyls (PCBs) in the Christina River Basin in northern New Castle County.The collaborative environmental study analyzed PCB concentrations throughout the Christina River Basin

PCBs are hazardous industrial chemicals that are no longer manufactured in the U.S. but which are nevertheless widespread in the environment as a result of past usage, poor disposal practices, and their slow breakdown. This study compiled information on the presence and levels of PCBs on waste sites within the Christina Basin and then estimated how much PCB on these sites continues to be released to nearby surface waters.

Although the presence of PCBs can pose a potential risk to people and wildlife that visit waste sites, the release of PCBs can result in especially high risks when these chemicals enter adjacent surface waters and bioaccumulate in fish and other aquatic life. Bioaccumulation is the process where a chemical builds up in fish to levels far greater than in the water itself. Once PCBs are in the fish, people who regularly eat the fish are at greater risk of various adverse health effects. In addition, birds that consume fish – such as ospreys, bald eagles, and herons – as well as other fish-eating animals such as otters are also at risk when they consume fish containing PCBs.

Fish consumption advisory sign along the Christina RiverIn Delaware, as with many states, PCBs are a major cause for issuing fish consumption advisories. This is certainly true for the Christina Basin in northern New Castle County, where DNREC and the Department of Health and Social Services (DHSS) advise people to totally avoid eating fish from the tidal portions of the Christina, Brandywine, and White Clay Creeks and to severely limit consumption of fish caught from the non-tidal portions of the Basin. PCBs in the fish are the primary risk driver for these advisories. PCBs are probable human carcinogens and are associated with several other adverse health effects. They are able to pass from mothers to unborn children and are believed to contribute to subtle yet lasting mental deficits in children after birth.

The DNREC collaborative study is a key and integral component of a much larger project that aims to link upland sources of PCBs with their primary impact in surrounding waterways. Because this project considers all sites known to be contaminated to one degree or another with PCBs, the information gathered will allow DNREC to look at the cumulative impact of PCBs in the area. This brings a new and more holistic perspective to the problem, which in turn could lead to innovative management solutions. Looking at all sites at once will also allow the Department to prioritize sites for remediation based on their relative impact. It is DNREC’s goal to systematically clean up these sites so these properties are useful and so that they no longer release PCBs to area surface waters. In so doing, PCB levels in the fish will slowly improve over time and people will once again enjoy the health benefits of consuming fish.

Link to complete DNREC environmental report.