DEQ-CFW_00073750

Update on APFO Investigations at DuPont -Fayetteville Facility
EPA ID # NCD 047 368 642
April 18, 2006
I. Introduction
On September 23, 2005, Dexter Matthews, who is director of the Division of
Waste Management, issued a letter stating that releases of APFO to soil and groundwater
would be addressed under DuPont-Fayetteville's existing Hazardous Waste Management
Permit. From that time forward, APFO investigations have been be part of the on -going
RCRA Facility Investigation (RFI) process and have been conducted under Division of
Waste Management oversight.
Prior to this, DuPont had been investigating APFO through a Letter of Intent. The
letter is addressed to EPA -Headquarters and is from the domestic manufacturer and users
of APFO. This Letter of Intent is still in place.
As of September 2005, DuPont had sampled nineteen monitoring wells for APFO.
The facility had also collected surface water samples at five locations, including the
facility's main discharge at Outfall 002. Nearly all the monitoring wells are located in
the Nafion manufacturing area. The highest concentration reported for these wells is 1.5
parts per billion (ppb).
II. Investigations Performed as Part of the RCRA Facility Investigation (RFI)
A. First Addendum to Existing Phase II RFI Work Plan
On September 30, 2005, the Division approved an addendum to DuPont-
Fayetteville's existing Phase II RFI work plan. A major objective of the addendum was
to expand the APFO investigation to the area around the APFO manufacturing unit. Six
monitoring wells were installed in the vicinity of the APFO unit. Surface soil samples
were also collected at these well locations.
Analytical results from one well, which is located immediately north of the APFO
unit, showed APFO at a concentration of 147 ppb in groundwater. (This well was
sampled again in December 2005. The APFO concentration was 765 ppb.) APFO was
also detected in groundwater at a second well located about 500 feet north of the APFO
unit. The concentration in this well was 2.5 ppb. (The next highest groundwater
concentration reported for APFO was 0.22 ppb.)
The highest concentration in the soil samples was 8 ppb. Another soil sample
collected in December showed a concentration of 41 ppb.
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In addition, four surface water sample locations were re -sampled and analyzed for
APFO. The surface water sample locations were in the Nafion area, and the analytical
results were similar to what is usually seen in groundwater in this area of the plant (i.e.,
less than 0.5 ppb).
B. Second Addendum to Existing Phase II RFI Work Plan
On January 4, 2006, the Division approved a second addendum to DuPont's Phase
II RFI work plan. Investigations for APFO included the installation of five monitoring
wells and two piezometers. The monitoring wells were installed near the Cape Fear
River, and the two piezometers were installed north of the APFO unit near the facility
property boundary. Six samples of surface water from the Cape Fear River were also
collected and analyzed for APFO. In addition, DuPont sampled twenty-three existing
monitoring wells and piezometers, including two piezometers located near the plant's
Teflon unit, for APFO.
Field activities for this phase of the investigation were completed in early March
and, except for the samples collected from the Cape Fear River, analytical results are not
available. Dupont -Fayetteville reported the analytical results for the river samples to the
Division of Water Quality and the Division of Waste Management in early April. The
concentrations of APFO range from 0.101 ppb to 0.140 ppb, with the higher
concentrations upstream of the facility.
I11. Additional Field Activities Conducted Under the RCRA Permit
In October 2005, the Division asked EPA -Region 4 for assistance with media
sampling and analysis. On January 24 and 25, Region 4-SESD split five ground water
samples from monitoring wells, six samples from potable wells, two surface water, and
two sediment samples with DuPont field investigators.
In a letter dated March 14, 2006; DuPont -Fayetteville reported their analytical
results for the six potable wells. There were no detectable amounts of APFO in five of
the six wells. The result for the other water well showed less than a quantifiable amount
of PFOA. In this case, the APFO concentration was less than 0.012 ppb.
The DWM received EPA's final results on April 17, 2006. The six potable wells
were nondetect for APFO. The results for groundwater monitoring wells were similar to
DuPont's split samples and to the historical results for monitoring wells that had been
sampled previously. The two surface water samples were also reported as nondetect, as
was one of the sediment samples. APFO was detected in the other sediment sample,
sample Outfall 002-SED, but the concentration was below quantification limits.
In November 2005, DuPont sampled two private drinking water wells located
about a mile north of the facility's APFO unit. One sample was collected from the Point
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East Subdivision and the other from the Marshwood Lake community. Both samples
were analyzed for APFO at two different commercial laboratories. Both labs reported
non -detect for the Point East sample. Samples from Marshwood Lake were reported as
"not quantifiable" by one laboratory. The second lab reported a concentration of 0.011
ppb for APFO.
IV. Toxicological Studies Performed by DWM
Since September, 2005, the Hazardous Waste Section has attended several
meetings with DuPont and with the C-8 Working Group. Susan Goldhaber, the Section's
toxicologist, started reviewing the available toxicological information in September and
has stayed up-to-date on C8 issues. The U.S. EPA has a draft document on the health
effects of C8. The document concluded that there are no known health effects from
exposure to C8 in people. However, there have been health effects seen in animal studies
(studies in rats and mice), such as effects on the liver and an increase in certain types of
tumors.
The U.S. EPA does not have a regulation for the allowable amount of C8 in water.
In January 2005, per the Director of the Division of Waste Management's (Dexter
Matthews) request, she prepared a summary report with a recommended water screening
level for C8 and a recommended soil screening level to protect groundwater as a drinking
water source for C8. The report was forwarded to the Division of Public Health, North
Carolina Department of Health and Human Services for their toxicologist to review and
comment. The recommended values are 2.1 ppb for a water screening level and 2.2
mg/kg for a soil screening level to protect groundwater as a drinking water source. Susan
then prepared recommended residential and industrial soil levels, which do not consider
groundwater as a source. These recommended values are 150 mg/kg for residential
exposure for an adult, 18 mg/kg for residential exposure for a child, and 127 mg/kg for
industrial exposure for a worker.
North Carolina's water screening level of 2 ppb is the lowest allowable level of
C8 (the most conservative) of the States that have levels for the compound: West Virginia
and Ohio both use a water screening level of 150 ppb; Minnesota's level is 7 ppb, and
New Jersey has a level of 5 ppb.
V. Future Investigations
DuPont -Fayetteville will submit a Phase II RFI report in May 2006, and DWM
will review this report. The DWM and Dupont -Fayetteville have discussed potential data
gaps and investigation of these, and other data gaps that may arise from the review of the
Phase II RFI report, will be implemented through a third phase of the RFI. Additional
detailed subsurface work, such as installation of additional monitoring wells and surface
geophysical investigations, has been discussed.
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DuPont plans a stack test at the APFO unit, and the Division of Air Quality will
oversee the test. DuPont has a contract with an engineering firm to develop a protocol
for the test. DuPont has also conducted air monitoring at the APFO unit.
EPA -Region 4 has proposed sampling additional private wells in the vicinity of
the DuPont -Fayetteville facility. Region 4 will develop a sampling plan based on the
results of the EPA/DuPont split sampling program conducted in January 2006.
VI. Conclusion
Multiple government environmental agencies are involved in investigation and
oversight at the DuPont -Fayetteville facility. Even this brief summary has mentioned the
NC Division of Waste Management, NC Division of Water Quality, NC Division of Air
Quality, US EPA Region 4, and US EPA Headquarters. These agencies have acted
proactively to protect human health and the environment and will continue to do so.
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