IH3730_20240416_Review Letter

April 15, 2024

Ms. Tammy Hall
TE Connectivity Corporation
PO Box 3608, MS 140-005
Harrisburg, Pennsylvania 17105-3608

Re: General Instruments Corp.
1396 Charlotte Highway
Fairview, Buncombe County
IHSB # NCD003163730

Dear Ms. Hall:

The North Carolina Department of Environmental Quality, (DEQ), Division of Waste Management
(Division), Inactive Hazardous Site Branch (Branch), has received and reviewed historical reports
and the following recently submitted reports:
• HRP Associates, Inc., 2023. 2022 Annual Water Quality Monitoring Report. September 5,
2023;
• HRP Associates, Inc., 2024. 2023 Annual Water Quality Monitoring Report. March 19,
2023.

We appreciate the efforts and continued cooperation of TE Connectivity Corporation to address
affected groundwater at the subject Site1. Within 30-days of receiving this letter, the Branch is
requesting TE Connectivity Corporation to respond in writing to this letter and begin
implementation of activities detailed below.
1) At the end of the reporting period for the 2023 Annual Water Quality Monitoring Report,
the groundwater plume capture/containment pump and treatment system (system)
operated for 77-days over the previous 16 months: approximately 15% of the time.
Although, it is our understanding that the recovery wells and system are currently
operating. Provide a written description of the issues relating to the inoperability of the
system, and the actions completed, or planned, to improve the continued operation of
the system;
2) Per the Administrative Order on Consent, the Division is to be notified prior to
modifications to the system, prior to field work, and when there is a delay in performance

1 Formerly known as Communications Instruments Inc. (CII)
General Instruments Corp.
April 16, 2024
2
such as a system shutdown. Notifications shall continue to be made to the Branch prior
to a planned, or unexpected, shutdown event, repair, or modification to the system;
3) Breakthrough of contaminant mass was detected in the 4th Quarter 2023 treatment
system effluent (trichloroethene 163 micrograms per liter [µg/L], and tetrachloroethene
9.5 µg/L), and was discharged to Cane Creek (outfall 004). Resampling of the system
effluent shall be completed to demonstrate system effectiveness at removing site-related
contaminants. Samples of the system influent, and post air-stripper samples, could also
be sampled to a) document mass removal, and b) estimate contaminant mass loading of
the granular activated carbon beds to prevent breakthrough. Samples should be analyzed
for the site-related compounds listed in 15A NCAC 02L .0202 Groundwater Quality
Standards (2L), and interim maximum allowable concentrations (IMACs);
4) Collect a one-time system influent sample for each of the compounds listed in 2L and
IMACs, using the specified Environmental Protection Agency analytical methods:
a. Volatile organic compounds (VOCs), including 1,4-dioxane, by EPA Method 8260,
b. 1,4-dioxane, by EPA Method 8260 selected ion method (SIM), and
c. Perfluorooctanoic Acid (PFOA), Perfluorooctyl Sulfonate (PFOS) by EPA Method
1633;
5) The site plans presented in the progress reports dated February 8, and July 29, 2010,
depict different alignments for the plant wastewater treatment system effluent (outfall
001), and the groundwater treatment system effluent (outfall 004). Confirm the location
of outfalls 001 and 004, and provide location coordinates in decimal degrees;
6) Provide quarterly reports until the groundwater plume capture/containment pump and
treatment system is demonstrated to be operational and functioning as designed, and to
document the items listed above;
7) The results of the November 2023 surface water samples indicate that there has been a
corresponding increase in concentrations of chlorinated compounds detected in Cane
Creek. Of note are the concentrations of tetrachloroethene above Title 15A of the North
Carolina Administrative Code (NCAC) Subchapter .02B standards, and the concentrations
detected at SW-4 located approximately 2,200 feet downstream of the confluence of the
unnamed tributary emanating from the Duck Pond and Cane Creek. Please recollect the
surface water samples SW-3, SW-6, SW-7, and an additional sample located behind, the
residence located at 1442 Charlotte Highway (PIN 9686-72-2470). Samples should be
analyzed for the site-related 2L and IMAC compounds. Data collected shall be imported
into the DEQ’s Risk Calculator for assessment of the recreator/trespasser surface water
scenario;
8) The property to the south (PIN 9686-72-5156), adjacent to the residence located at 1442
Charlotte Highway, has a spring house (noted as reservoir on Buncombe County Plat Book
140 Page 161) which was listed as Spring #3 in previous reports. It was reported Spring #3
is not hydraulically connected to site groundwater2 but supporting information was not
2 Altamont Environmental, 2014. Downgradient Investigation Work Plan. January 7, 2014.
General Instruments Corp.
April 16, 2024
3
provided. In 2014, a sample was proposed to be collected from Spring #3, but it was not.
The owner stated that the Spring #3 no longer supplies water to the residence, water is
visible in the spring house, Spring #3 has artesian conditions, and the discharge was piped
to Cane Creek when Charlotte Highway was widened. Please collect a sample of the water
in the spring house and if Spring #3 is discharging collect a surface water sample from
Cane Creek in the downstream direction of the outfall. Samples shall be analyzed for the
site-related 2L and IMAC compounds;
9) Groundwater data collected, on November 16, 2024, from PZ-S4 was imported into the
DEQ’s Risk Calculator for the residential groundwater to indoor air exposure scenario. The
cumulative cancer risk was acceptable, but the non-carcinogenic hazard quotient (220)
was more than the acceptable value (1.0). Evaluate the potential for vapor intrusion at
the off-site residences, including 9, 14, 15, 19, 27 Miller Road, and 1442 Charlotte
Highway. Prepare a work plan for field sample collection and reporting. Regular
observations of the vapor intrusion mitigation systems at 6, 8, and 10 Miller Road shall be
made to verify the VI systems are properly operating and functional;
10) Complete a field-verified receptor survey to identify water supply wells3 within a 3,000-
foot radius of the site, with particular attention to downstream and down gradient, and
along fracture/foliation strike and dip, and provide a list of water supply wells to be
sampled;
11) Due to the length of time the system was not operational, perform a groundwater
monitoring event in May, or as reasonable possible. Groundwater wells in the down-
gradient direction of the site and near residences shall be sampled, including MW-22,
MW-29, MW-30, MW-34S, MW-35D, MW-38S, MW-38M, and MW-38D, MW-42, MW-43,
PZ-S1, PZ-D1, PZ-S4, and PZ-D4. Each groundwater monitoring and recovery well shall be
accessed, fluid levels and depth to bottom gauged, and groundwater samples be
collected. Samples shall be analyzed for the site-related 2L and IMAC compounds;
12) Submit a semiannual groundwater monitoring report to document the activities listed
above.
13) All analytical and field measurements shall be submitted to the Branch using the DEQ
Electronic Data Deliverable (EDD) format. Information regarding the NCDEQ EDD format
and additional information can be located at the following earthsoft web page:
https://earthsoft.com/products/edp/ncdeq-edp-format/;
14) Historical reports4,5 indicate that there is/was a stream gauge located on a tree on the
western bank of Cane Creek near groundwater monitoring wells MW-7 and MW-31.
Additional stream gauges could be installed in Cane Creek (i.e., near MW-38), the duck
pond, the unnamed tributary (i.e., near SW-6, Spring #1, or MW-29) to better understand
the groundwater/surface water interaction, and head relationships.

3 Numerous wells were identified by the Branch, south of the Site, and along Noble Road 4 Altamont Environmental, 2008. Semi-Annual Progress Report. May 8, 2008. 5 Altamont Environmental, 2009. Pilot Test Work Plan. December 23, 2009.
General Instruments Corp.
April 16, 2024
4
As reported in the 2020 Annual Progress Report, Trichloroethene (TCE) concentrations detected
in groundwater monitoring wells MW-48 (Deep Regolith: 67,000 micrograms per liter – µg/L),
MW-47 (Bedrock: 147,000 µg/L), and MW-46 (Deep Bedrock: 261,000 µg/L) were 6%, 13%, and
24% the solubility of TCE, respectively. Concentrations of 1% or more of the effective solubility
are indicative of the presence of pure-phase TCE which is a dense nonaqueous phase liquid.
Reportedly, the on-site disposal pit was used between 1961 and the mid-1970’s6; up to 63 years
before present.

The existing groundwater plume containment/capture and treatment system was originally an
Interim Remedial Action because of the immediate need to reduce off-site migration of
chlorinated solvents in groundwater to Cane Creek. Cane Creek was classified as a water supply
(WS-IV) in the French Broad River Basin at that time; currently Cane Creek is classified as a Class
C, Trout designated, surface water body.

Based on the reporting provided, contaminant concentrations in groundwater are not delineated
and are migrating off-Site. The groundwater plume containment/capture and treatment system,
started in 1997, has operated for approximately 27 years. Two rounds of sodium permanganate
in-situ chemical oxidization (ISCO) pilot tests were conducted in 2010 and 2017 with varied or
limited success.

The recommendations provided in the previous 5-years of reporting were reviewed. The
following recommendations are urged to be completed, to reduce groundwater concentrations
and shorten active remedial timeframes.
I. The annual sampling data and the results of the sodium permanganate pilot test will be
used to develop an approach for additional source area injections of sodium
permanganate.
II. Evaluate data gaps that may be filled to refine the existing conceptual site model,
delineate the downgradient VOC plume extent, and further characterize the potential
risk, if any, to downgradient receptors.
III. Collect surface water samples along Cane Creek to delineate the reach(es) where the VOC
plume discharges to surface water.
IV. Collect groundwater samples from three downgradient domestic water supply wells.
V. Develop a groundwater flow model.
VI. Additional data gathering to verify the absence of a completed exposure pathway
between the VOC plume and domestic water wells.
VII. Continue to analyze for various natural attenuation parameters.
VIII. Renovation of the system building and its components to maximize groundwater recovery
and constituent treatment.
6 Tighe & Bond, Inc., 1993. Site Assessment of the Communications Instruments, Inc., Facility. May 10, 1993.
General Instruments Corp.
April 16, 2024
5
IX. Incorporate system influent sample requirements into future sampling events to begin
calculating accurate mass removal values moving forward.
The Branch also encourages TE Connectivity Corporation to also complete the following:
A. Annual groundwater monitoring reports be prepared and submitted to the Branch in
conformance with current Branch guidelines, and submitted no more than 45-days of
receiving analytical results. Reporting include, but not limited to, the following
components:
i. Samples analyzed for the site-related 2L and IMAC compounds,
ii. Calculations of vertical and horizontal groundwater gradients,
iii. Calculations of groundwater seepage velocity,
iv. A description and depiction of the vertical and horizontal extent of groundwater
contaminant concentrations,
v. Cross sections coincident, and transverse, with groundwater flow,
vi. A trend analysis of contaminant concentrations,
vii. A discussion and list of known or potential receptors,
viii. Analysis and discussion of water quality parameters (e.g., temperature, pH,
dissolved oxygen, oxidization-reduction potential or Eh, conductivity, and
turbidity),
ix. A discussion of the monitoring and continued analyses of contaminant
degradation (i.e., daughter products, terminal electron acceptors, alkalinity,
methanogenesis, etc.),
x. A complete set of historical groundwater and surface water analytical data;
B. TE Connectivity Corporation shall provide, or make available, historical reporting and
analytical data, for the treatment system and groundwater monitoring, to its contractor
(HRP Associates, Inc.) for their use7;
C. Perform a desktop fracture and lineament analysis, and a fracture analysis of the borehole
data collected in 2020 during the installation of MW-46 and MW-49, to better
understand/predict preferential migration of contaminants;
D. Prepare a work plan to address potential data gaps and to collect information necessary
to prepare a Remedial Investigation Report Addendum, with a Conceptual Site Model,
and a Feasibility Study;
E. Perform a data gaps evaluation, develop a groundwater flow model as recommended in
the 2020 Annual Progress Report, and evaluate the need to utilize RW-6 and RW-7 or
augment the system with additional recovery wells;
F. Based on the Feasibility Study, a Remedial Action Plan shall be prepared, and submitted
to the Branch.

If TE Connectivity Corporation, has any questions, please contact me at [phone] or via e-
mail at [e-mail].
7 “HRP began managing the Site in June 2022. Operational data prior to this date is unavailable.”
General Instruments Corp.
April 16, 2024
6

Sincerely,

Brett Engard, P.G.
Hydrogeologist
Inactive Hazardous Sites Branch

cc. Mr. Samuel Muller, Senior Consultant, HRP Associates, Inc.

Attachments:
DEQ’s Risk Calculator, November 2023 PZ-S4 data
Version Date:
Basis:
Site Name:
Site Address:
DEQ Section:
Site ID:
Exposure Unit ID:
Submittal Date:
Reviewed By:
4/12/2024
Prepared By:B. Engard
IHSB
PZ-S4
North Carolina Department of Environmental Quality
Risk Calculator
General Instrument
1396 Charlotte Highway, Fairvew, NC
IHSB
NCD003163730
February 2024
November 2023 EPA RSL Table
North Carolina DEQ Risk Calculator
DEQ Risk Calculator - Vapor Intrusion - Resident Groundwater to Indoor Air
Version Date: February 2024
Basis: November 2023 EPA RSL Table
Site ID: NCD003163730
Exposure Unit ID: PZ-S4
CAS # Chemical Name:
Groundwater
Concentration
(ug/L)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non-
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non-
Carcinogenic
Hazard
Quotient
75-71-8 Dichlorodifluoromethane 1.3 - 2.1E+01 1.7E-01
156-59-2 Dichloroethylene, cis-1,2- 12.8 - 8.3E+00 5.1E-02
127-18-4 Tetrachloroethylene 63.7 1.1E+01 8.3E+00 4.3E-06 1.1E+00
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2- 54.5 - 1.0E+03 2.2E-01
79-01-6 Trichloroethylene 108 4.8E-01 4.2E-01 9.1E-05 2.1E+01
Cumulative: 9.5E-05 2.2E+01
Groundwater concentrations are in u /L. Air concentrations are in u /3.
Output Form 3A
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor
intrusion risk, no risk values are calculated for these chemicals.
North Carolina DEQ Risk Calculator