2022.05.02_CCO.p19-24_DEQresponseToChemoursApril1LCFR-V2samplingplan

May 2, 2022

Ms. Dawn Hughes
Plant Manager
Chemours Fayetteville Works
22828 NC Highway 87 W
Fayetteville NC 28306

RE: Notice Regarding Chemours’ Obligations Under Consent Order and 15A NCAC
02L .0106 - Offsite Groundwater Assessment and Provision of Replacement
Drinking Water Supplies.

Dear Ms. Hughes:

The North Carolina Department of Environmental Quality (DEQ) has reviewed the updated
April 1, 2022 documents from Chemours in response to our November 3, 2021 Notice
Regarding Chemours’ Obligations Under Consent Order and 15A NCAC 02L .0106 - Offsite
Groundwater Assessment and Provision of Replacement Drinking Water Supplies.
Chemours’ response included a cover letter, the Framework to Assess Table 3+ PFAS in
New Hanover, Brunswick, Columbus, and Pender Counties, and the Interim Four Counties
Sampling and Drinking Water Plan (“Interim Plan”).

Recently, DEQ has collected additional groundwater data from the lower Cape Fear Region,
provided as Appendix 1 to this letter. These data show the presence of Attachment C PFAS
in a number of non-water supply wells. Chemours should update the Interim Plan to
incorporate these data and address the comments below. As around the Chemours facility,
the priority in the Lower Cape Fear counties is to identify impacted drinking water wells
with these PFAS and to provide alternate drinking water as required by the Consent Order.

The April 1 submittal incorporates many of the comments NC DEQ provided in the March 2
response. In addition to those changes, NC DEQ directs Chemours to do the following:

• Prioritize the identification and expeditious sampling of private wells within ¼ mile
of public water distribution lines and sanitary sewer network;
• Prioritize the identification and expeditious sampling of private wells within ¼ mile
of the detections shown in monitoring data provided by NC DEQ;
• Provide a detailed description of the representative sampling methodology,
including justification for any exclusionary criteria;

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• Provide a timeline to expeditiously complete sampling in the four counties; and
• Increase reporting on the sampling activities from quarterly to monthly until
advised otherwise.

1. Incorporation of new groundwater data. In DEQ’s March 2, 2022 letter, DEQ
directed Chemours to expand the eligibility criteria described in Section 2.1.3 of the
Interim Plan to include, among other things, wells located in the vicinity of areas
where existing data shows the presence of PFAS associated with the Fayetteville
Works Facility, and conduct representative sampling of wells meeting these criteria
that is not limited to individuals who have requested sampling. In its April 1, 2022
response, Chemours agreed to expand the PFAS eligibility criteria to include private
wells within a quarter-mile radius of known Attachment C PFAS concentrations in
private and non-private wells exceeding CO-criteria.

NC DEQ previously provided Chemours with PFAS sampling data collected from
2019-2021 at private water supply wells, public water supply wells, and non-water
supply wells located in New Hanover County. These data indicate known locations
of Attachment C PFAS compounds. As shown in Appendix 1, NC DEQ has collected
additional PFAS data from non-water supply wells in 2022 in Brunswick, Pender
and Columbus counties. These data again indicate known locations of Attachment C
PFAS compounds and are consistent with the theory that wastewater collection
lines and/or water distribution lines are a likely source of groundwater
contamination in the four counties.

Based on this information, Chemours shall incorporate the data provided with this
letter into Section 2.1.1 of the Interim Plan to inform the eligibility criterion of
proximity to Consent Order exceedances. DEQ further directs Chemours to
prioritize identification of private wells and expeditiously conduct sampling within
¼ mile of the detections shown in DEQ’s data as well as public water distribution
lines and sanitary sewer networks.

2. Representative sampling. While Chemours has agreed to expand the sampling
eligibility criteria and perform representative sampling in the future, Chemours has
indicated that further data is required before representative sampling can proceed.
Chemours proposes to contact properties by mail and proceed to sample responsive
properties. Chemours further states that “Based on the analytical results from the
sampling described above, additional private wells will be sampled within a quarter
mile radius of Attachment C PFAS concentrations exceeding CO criteria.”

It is unclear from this response to what extent and how quickly Chemours proposes
to conduct representative sampling that is not limited to those that have requested
sampling.

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Within 30 days of receipt of this letter, Chemours shall revise the Interim Plan as
follows:

o Provide a detailed description of the methodology to be used to identify
properties for sampling outside of direct mailings to residents. Include in
your response, any specific data gaps that Chemours claims will prevent the
identification of wells that meet eligibility criteria and commencement of
representative sampling. Additionally, please update the maps in the
Appendices of the Interim Plan to show the public water service area for each
county. Currently, only the Brunswick County and Pender County
appendices display this information;
o Provide a detailed description of the methodology Chemours proposes to use
to conduct representative sampling of wells not limited to properties that
have requested sampling and an expeditious timeline for conducting such
sampling;
▪ Water supply wells located closest to the wells with known
Attachment C PFAS concentrations should be prioritized for sampling.
▪ This should include water supply wells with the closest horizontal
distance, but also may include the closest water supply wells screened
in the same aquifer as known detections, even if these wells are not
the closest lateral distance
o Chemours should commence representative sampling as soon as possible
and mobilize sufficient resources to respond to sampling requests within 48
hours with projected scheduled for sampling to be included in the monthly
reporting.
o In addition to the phone and mail options, Chemours should provide an email
or online form for residents to submit sampling requests.

3. Monthly reporting. DEQ directs Chemours provide a written monthly update
regarding residents who respond to Chemours’ mailings, including (1) the date and
number of responsive residents (2) the number of residents who meet one or more
of the eligibility criteria, including which eligibility criterion has been met; (3) the
projected date of sampling for those who meet one or more eligibility criteria; (4)
the number of residents who do not meet any eligibility criteria, including for each
ineligible resident, a brief explanation of why the resident does not meet any
eligibility criteria; (5) the number of residents sampled; and (6) the results of the
sampling.

We appreciate your attention and prompt response in this matter. If you have any
questions, please feel free to contact me at [phone].

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Sincerely,

Sushma Masemore, P.E.
Assistant Secretary for the Environment

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Appendix 1

Site Name Well Type Aquifer County Collection Date Total Attachment C PFAS (ng/L)Total PFAS (ng/L)Total Attachment C PFAS:Total PFAS (%)
Calabash #7 DWR Monitoring Well Surficial (S)Brunswick 2/23/2022 741.54 1001.60 74
Southport RS 4 #6 DWR Monitoring Well Surficial (S)Brunswick 2/23/2022 463.67 628.45 74
Southport RS 4 #5 DWR Monitoring Well Castle Hayne (Tch)Brunswick 2/17/2022 135.55 153.25 88
Topsail Beach #5 DWR Monitoring Well Surficial (S)Pender 2/15/2022 100.25 108.34 93
Stanbury #3 DWR Monitoring Well Surficial (S)Brunswick 2/23/2022 71.78 89.79 80
Topsail Fire Tower #1 DWR Monitoring Well Surficial (S)Pender 2/15/2022 54.42 99.70 55
Bolivia #1 DWR Monitoring Well Surficial (S)Brunswick 2/17/2022 31.09 32.92 94
Waccamaw School #8 DWR Monitoring Well Surficial (S)Brunswick 2/23/2022 21.29 153.96 14
Topsail Beach #4 DWR Monitoring Well Castle Hayne (Tch)Pender 2/15/2022 12.60 13.79 91
Long Creek #1 DWR Monitoring Well Surficial (S)Pender 3/1/2022 6.46 8.10 80
Bladenboro #1 DWR Monitoring Well Surficial (S)Bladen 3/1/2022 BDL BDL N/A
Bladenboro #4 DWR Monitoring Well Peedee (Kpd)Bladen 3/1/2022 BDL 3.40 0
Dublin #1 DWR Monitoring Well Upper Cape Fear (Kucf)Bladen 3/1/2022 BDL 5.77 0
Dublin #2 DWR Monitoring Well Black Creek (Kbc)Bladen 3/1/2022 BDL BDL N/A
Dublin #3 DWR Monitoring Well Upper Black Creek (Kubc)Bladen 3/1/2022 BDL 2.54 0
Dublin #4 DWR Monitoring Well Surficial (S)Bladen 3/1/2022 BDL 2.73 0
Dublin #5 DWR Monitoring Well Surficial (S)Bladen 3/1/2022 BDL 7.69 0
Kelly #3 DWR Monitoring Well Peedee (Kpd)Bladen 3/1/2022 BDL BDL N/A
Kelly #4 DWR Monitoring Well Surficial (S)Bladen 3/1/2022 BDL 0.93 0
Kelly #5 DWR Monitoring Well Black Creek (Kbc)Bladen 3/1/2022 BDL BDL N/A
Kelly #6 DWR Monitoring Well Upper Cape Fear (Kucf)Bladen 3/1/2022 BDL BDL N/A
Smithfield McNair House #1 DWR Monitoring Well Black Creek (Kbc)Bladen 3/8/2022 BDL BDL N/A
Smithfield McNair House #2 DWR Monitoring Well Upper Cape Fear (Kucf)Bladen 3/8/2022 BDL BDL N/A
Bear Pen #3 DWR Monitoring Well Peedee (Kpd)Brunswick 3/15/2022 BDL 5.43 0
Boiling Springs RS 1 #1 DWR Monitoring Well Surficial (S)Brunswick 2/17/2022 BDL 3.13 0
Boiling Springs RS 2 #1 DWR Monitoring Well Peedee (Kpd)Brunswick 2/17/2022 BDL 8.42 0
Boiling Springs RS 2 #2 DWR Monitoring Well Surficial (S)Brunswick 2/17/2022 BDL 0.88 0
Long Wood #5 DWR Monitoring Well Surficial (S)Brunswick 2/23/2022 BDL 0.86 0
Maco #2 DWR Monitoring Well Peedee (Kpd)Brunswick 2/24/2022 BDL 2.68 0
Maco #5 DWR Monitoring Well Surficial (S)Brunswick 2/24/2022 BDL BDL N/A
Shallotte #4 DWR Monitoring Well Peedee (Kpd)Brunswick 2/23/2022 BDL BDL N/A
Southport RS 4 #4 DWR Monitoring Well Peedee (Kpd)Brunswick 2/23/2022 BDL 19.30 0
Sunset Harbor North #6 DWR Monitoring Well Peedee (Kpd)Brunswick 2/17/2022 BDL 2.51 0
Sunset Harbor North #7 DWR Monitoring Well Surficial (S)Brunswick 2/17/2022 BDL BDL N/A
Carver Moore #1 DWR Monitoring Well Surficial (S)Columbus 3/15/2022 BDL BDL N/A
Carver Moore #4 DWR Monitoring Well Upper Black Creek (Kubc)Columbus 3/15/2022 BDL BDL N/A
Clarendon #1 DWR Monitoring Well Surficial (S)Columbus 2/24/2022 BDL 18.52 0
Clarendon #3 DWR Monitoring Well Upper Cape Fear (Kucf)Columbus 2/24/2022 BDL BDL N/A
Clarendon #4 DWR Monitoring Well Black Creek (Kbc)Columbus 2/24/2022 BDL 1.90 0
Lake Waccamaw #6 DWR Monitoring Well Peedee (Kpd)Columbus 2/24/2022 BDL 3.44 0
Lake Waccamaw #8 DWR Monitoring Well Black Creek (Kbc)Columbus 2/24/2022 BDL BDL N/A
Lake Waccamaw #9 DWR Monitoring Well Upper Cape Fear (Kucf)Columbus 2/24/2022 BDL 1.43 0
Nakina #2 DWR Monitoring Well Surficial (S)Columbus 3/15/2022 BDL 0.85 0
Nakina #4 DWR Monitoring Well Peedee (Kpd)Columbus 3/15/2022 BDL 3.49 0
Burgaw #3 DWR Monitoring Well Peedee (Kpd)Pender 3/15/2022 BDL 94.09 0
Burgaw #7 DWR Monitoring Well Black Creek (Kbc)Pender 3/15/2022 BDL 2.83 0
Holly Shelter #1 DWR Monitoring Well Surficial (S)Pender 3/15/2022 BDL BDL N/A
Holly Shelter #3 DWR Monitoring Well Peedee (Kpd)Pender 3/15/2022 BDL BDL N/A
Long Creek #3 DWR Monitoring Well Peedee (Kpd)Pender 3/1/2022 BDL 5.08 0
Topsail Fire Tower #2 DWR Monitoring Well Castle Hayne (Tch)Pender 2/15/2022 BDL BDL N/A
Topsail Fire Tower #4 DWR Monitoring Well Peedee (Kpd)Pender 2/15/2022 BDL BDL N/A
2022 Groundwater PFAS Results from Bladen, Brunswick, Columbus and Pender Counties

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