Perflourochemical Contamination of Biosolids Near Decatur, Alabama

EPA has worked with several federal and state agencies,the City of Decatur and local industries to address elevated levels of perfluorochemicals (PFCs) in Decatur, Alabama.

For 12 years (1996 to2008), treated sewage sludge (biosolids) containing PFCs from Dry Creek Wastewater Treatment Plant (Decatur Utilities) were applied and used as a soil amendment on 5000 acres of privately owned agficultural fields in Lawrence, Morgan, and Limestone Counties (see map).

Decatur Utilities receives wastewater from numerous industrial sources, including facilities that manufactured or used PFCs, such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). After learning of the PFC levels in its biosolids, Decatur Utilities voluntarily stopped distributing them in November 2008.

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Environmental Studies

In September, 2007, EPA began sampling for PFCs in and around the areas where the biosolids from Decatur Utilities had been applied. This initial sampling conducted through May 2012 by EPA, other federal and state agencies, Decatur Utilities and a group of local businesses identified PFCs in the environment, including:

Biosolids and the soil that received the biosolids

None of the soil samples exceeded EPA's soil screening values for PFOA and PFOS (PDF, 11 pp, 456K) to protect children's health (which are also protective of adult health).

Public drinking water systems

None of the community water systems had PFC levels in finished water above EPA's provisional health advisory levels for drinking water.

Private drinking water systems

Three of the 19 wells tested had PFC levels above EPA's provisional health advisory levels for drinking water (0.4 ppb for PFOA and 0.2 ppb for PFOS). Two of the wells were sampled by EPA between January and March 2009 and had PFOA levels of 2.2 ppb and 0.6, respectively. The other well was sampled by a group of local industries between February and March 2010 and had PFOS levels of 0.339 ppb and 0.365 ppb (duplicate sample). These three residences were provided with bottled water and connected to public drinking water. Two additional residences with private wells that did not have elevated levels of PFCs were also connected to public drinking water.

Agricultural wells and surface water

PFCs were detected in 12 agricultural wells, 32 farm ponds and one stream. EPA has not yet established provisional health advisory levels for water that is used for purposes other than human consumption and is therefore unable to determine what, if any, health or environmental risk may be posed by these sources.

Vegetation

A limited number of plants from several fields where biosolids had been applied were collected and analyzed to determine whether they uptake PFCs. Varying levels of PFCs were detected in these samples, however, EPA has not yet established screening or health advisory values for PFC levels in vegetation.

Local cattle

The U.S. Department of Agriculture (USDA) and the Food and Drug Administration (FDA) tested for PFCs in blood, tissue and milk samples from local cattle grazed on farms where biosolids from Decatur Utilities were applied. The agencies concluded these is "no reason to believe there are human health concerns with consuming the meat processed from cattle grazed on lands receiving these biosolids." There were no PFOA of PFOS in the mild sample from the single cow that was tested and a very low level of PFOS was detected in a bulk milk sample. In addition, retail milk samples were collected throughout the U.S. to determine background levels for PFCs in milk. No PFCs were found in any of the additional raw or retail milk samples tested.

Locally-caught fish

PFCs, including both PFOA and PFOS, were detected in fish tissue samples taken from catfish and large-mouth bass in the Tennessee River near Decatur. The PFOA analytical results averaged approximately 0.74 ppb and the PFOS anlytical results averaged approximately 806.06 ppb. Based on the PFOS results, the Alabama Department of Public Health has issued a 'no consumption' fish advisory for all species of fish in the baker's Creek embayment of Wheeler Reservior. Future testing will determine if this advisory needs to be expanded.

More detailed information about all of the environmental studies, including results, can be found here.

Human Health Study

In addition to the environmental sampling described above, the Agency for Toxic Substances and Disease Registry (ATSDR) tested the concentration of PFCs in the blood of 155 residents in the Decatur area during April 2010. ATSDR's investigation targeted residents who were potentially exposed to PFCs in soils where biosolids were applied or in local drinking water sources. In February 2011, ATSDR provided the confidential results to each individual whose blood was tested.

Participants were informed of whether their test results indicated PFC levels below or above the average of most people in the United States population, as referenced in the Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey for PFOA and PFOS

Investigation results were released in April 2013, and are available online

Actions Taken

Industries in the Decatur area have made significant progress over the last few years to reduce and prevent the release of PFCs. The industries have stopped manufacturing PFOS and are phasing out PFOA. The city and state have investigated industrial and domestic sources of PFCs to the wastewater treatment plant. After learning of the PFC levels in its biosolids, Decatur Utilities made the decision to voluntarily stop distributing the biosolids as a soil amendment in November 2008.

Future Activities

EPA has completed its monitoring of PFCs in soil and water in the Decatur area. We continue to coordinate with ATSDR, ADPH, and ADEM on activities being conducted by these agencies and to determine what, if any, additional future actions may be needed to address the PFC releases and potential impacts on people's health and the environment in Decatur.

Background Information

PFC Contamination from Biosolids In Decatur, Alabama:

Map
Fact Sheet (PDF, 6pp, 282K)
FAQs (PDF, 2pp, 106K)

General:

For information about the contents of this page please contact Lee Thomas (thomas.lee@epa.gov)