Yadkin – Pee Dee Reservoirs PCB Sampling



In 2011 through 2013, the North Carolina Division of Waste Management (DWM), the North Carolina Division of Public Health (DPH), the North Carolina Division of Water Quality (DWQ) and the US EPA Region 4 Superfund Division (EPA) conducted a joint project to investigate polychlorinated biphenyls (PCBs) in sediment and fish tissue in the Yadkin-Pee Dee River system. The study area includes High Rock Lake, Badin Lake, Lake Tillery, and the uppermost reaches of Blewett Falls Lake.

Study sample methods and locations were designed to complement the body of PCB data for fish and sediment collected in Badin Lake prior to 2011. While focused on identifying any potential risks to human health due to PCBs in the River system, the study provided data for comparison to PCB analyses from other river basins in the State and guide decisions about any need for further ecological risk assessments in the River system.

In April 2011, EPA and DWM staff collected 21 sediment samples. Sample locations are noted with red circles on the project summary map. Approximately half of these samples were collected from locations where direct contact is likely to occur at beaches and boat ramps; the other half of the samples were collected near the center channel, in order to better characterize PCB levels in sediment moving through the Yadkin River system.

DWQ collected approximately 100 fish tissue samples in High Rock Lake and Lake Tillery in August through November 2011 to determine the risks to human health associated with ingestion.  Fish were collected during those months to maximize characterization of potentially elevated PCB concentrations in fish tissue.  Fillet samples were prepared from bottom feeder, middle and upper trophic level fish fillet tissue. Sample locations are marked with fish symbols on the project summary map.

In April 2012, the joint working group received confirmation that EPAs laboratory would be able to analyze additional sediment and fish tissue samples.  The working group collected these samples from Falls Reservoir, located between the Narrows Dam and Falls Dam, between the south end of Badin Lake and the northern end of Lake Tillery. DWQ collected fifteen fillet samples from bottom feeder, middle and upper trophic level fish fillet tissue in August 2012. DWM collected a total of twelve sediment samples from center channel and near bank locations in September 2012 (see Falls Reservoir detail map).

EPA conducted all analyses at their Athens, Georgia lab.  Sediments were analyzed for Aroclor PCBs. EPA analyzed more than 100 fish tissue samples for all 209 PCB congeners (the different PCB formulations). The DPH compared concentrations of PCBs in the fish tissue samples to existing PCB consumption advisory action levels (DPH, May 2007) for the potential to cause adverse health effects to persons who eat PCB-contaminated fish on a daily basis over many years. DPH issued a fish consumption advisory to provide the best available analytical techniques approved by EPA for PCB analysis. The fish tissue and sediment information will also serve as an initial screen to determine the need for and direction of future studies that may be needed to evaluate potential adverse human health or ecological effects in the Yadkin River basin.

What are the study results?

DPH advises that health effects are not expected from contact with sediments in the study area.  Some catfish more than 18 inches in length had PCB concentrations above the N.C. Department of Health and Human Services action level. DPH recommends that people follow the statewide advice for mercury in fish. The statewide mercury advisory already includes restrictions for catfish and will protect people from exposure to the levels of PCBs found in High Rock Lake, Badin Lake, Falls Reservoir and Lake Tillery. A summary of DPH recommendations can be found here:

 

DPH Reports can be found through the following links:

Other documents related to the study can be found through the following links: 

Analytical Data Fish Tissue

Fish and Sediment Sampling Plans

Photos

Sediment Sampling Reports