NC0000892_Other Agency Documents_20230322

Responses to the SELC Comments
Arclin Permit NC0000892
March 22, 2023
Arclin discharges PFAS, a class of chemicals known to cause harm to human
health and the environment.
II. Arclin's pollution threatens downstream drinking water supplies.
In 2019, the Department instructed Arclin to collect samples of its wastewater to determine if
the company released PFAS.6 The results of that sampling, collected in early 2020, confirm that
Arclin discharges PFAS at concentrations as high as 153 parts per trillion (11ppt").7
In early 2020, Arclin reported that it discharges PFAS at concentrations ranging between 111.9
ppt and 153.5 ppt.26 Arclin's wastewater contains PFOA and PFOS thousands of times higher
than what EPA considers safe. PFOA was detected at concentrations of 13 ppt and PFOS was
detected at concentrations of 15 ppt.l These levels are high when one considers how toxic these
chemicals are even in small amounts. At 13 ppt, Arclin's PFOA concentrations are 3,250 times
the healthy advisory level, and at 15 ppt, Arclin's PFOS concentrations are 750 times the
health advisory level. The company's wastewater contains other PFAS including
perfluorobutanoic acid ("PFBA" ), perfluorobutanesulfonic acid ("PFBS"), perfluoroheptanoic acid
("PFHpA"), perfluorohexanesulfonic acid ("PFHxS"), perfluorohexanoic acid (PFHxA"), and
perfluoropentanoic acid ("PFPeA").
Response:
Currently, neither EPA nor NC DEQ has water quality criteria/standards for PFAS compounds.
We can use the MCLs proposed by EPA for PFOA/PFOS (4 ng/L) and EPA GenX health goal (10
ng/L) to evaluate potential impact on the downstream drinking water.
Calculation indicates that the allowable discharge concentrations for PFOA/PFOS would be
1,036 ng/L and for GenX would be 2,590 ng/L. At these levels, the instream concentrations of
PFOA/PFOA and GenX would not exceed the MCLs and health goal proposed by the EPA. The
detected effluent concentrations of 3 indicator parameters (PFOA, PFOS, and GenX) are far
below the allowable levels. Therefore, current discharges of PFAS compounds by Arclin do not
represent threat to the downstream communities.
III. The Department must control Arclin's PFAS pollution in its renewal permit.
a. The Department must require Arclin to update its permit application to disclose its PFAS pollution.
Response:
Although, the renewal application did not contain effluent PFAS data, the facility submitted PFAS data
separately on several occasions. SELC is using these data in the comment letter.
In addition, the DEQ is imposing additional PFAS monitoring on the facility in accordance with the EPA
MEMO.
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b. The Department must impose effluent limits to control Arclin's PFAS pollution.
Response:
Development of the BPJ TBELs is extremely complicated and difficult procedure. Currently, the
DWR has no institutional capacity to develop their own BPJ BAT in according with the EPA
guidance. This effort would be enormous in nature and will require full time commitment from
numerous existing staff members, it will also require an expertise in economics beyond what
exists in the DWR. For example, EPA has the Engineering and Analysis Division that employs
approximately 40 experts, these experts develop Effluent Guidelines. Recently, this EPA
Division spent 10 years to develop the latest update to the Power Plant Guidelines and then an
additional 5 years to make subsequent adjustments to the Final Rule.
In 2014, the DWR attempted to develop their own BPJ BAT for Duke Energy Riverbend permit
by using a very simplified procedure. SELC was critical of DWR's effort for not adhering to the
EPA guidance. Nevertheless, SELC now suggests that we use the same simplified procedure,
which they strongly criticized previously.
Furthermore, the use of simplified procedure is not likely to withstand legal challenges because
it omits numerous important components, including economic evaluation, robust statistical
analysis, comparison with similar facilities that successfully install and operate treatment
technologies, public notification and comment period, etc.
In addition, the EPA is currently developing effluent guidelines for PFAS manufacturers and
updating effluent guidelines for OCPSF facilities. It is not prudent to devote limited DWR
resources to duplicate EPA efforts.
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