DWQ-2024-008290

Hand Delivered
November 25,2024
Mr. John Mackey, Director
Utah Division of Water Quality
Department of Environmental Quality (DWQ)
1950 West North Temple
Salt Lake City, UT 84119
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No\/ 25 2024|'X- v6''o'r*r
or**.ut*Re: Ammonia Discharge Compliance Update Report
Hexcel Corporation - Salt Lake City Operations
UPDES Permit UT0025305
Dear Mr. Mackey,
In accordance with condition I.C.3.a of Hexcel Corporation's (Hexcel) Utah Pollutant Discharge
Elimination System (UPDES) Permit, dated May 1, 2024, Hexcel is submiuing this Ammonia
Discharge Compliance Update Report. This progress report, due December 1, 2024, as required
by the permit, provides an update of Hexcel's progress to attain and maintain compliance with the
final effluent limits in Hexcel's UPDES Permit, effective January l, 2026. As required by the
permit, this report evaluates the sources of the ammonia in the effluent, our plan to attain
compliance, and a description of Hexcel's efforts to attain compliance by December 31, 2025.
Hexcel is in compliance with the limits defined in the UPDES Permit. The permit-mandated
ammonia discharge limits vary by season, with the winter months (January through March) being
the most restrictive. Data through October is summarized in Table 1, below. Due to the wide range
of results, Hexcel remains concerned with permit limits for the restrictive winter months, as
previously communicated to DWQ. Hexcel will continue to monitor the ammonia concentration
in the effluent through the2025 winter season.
Table l:2024 Ammonia Concentration in Effluent
Month Hexcel Result
(ms/L)
Chronic Limit
(ms/L)
Acute Limit
(me/L)
Season
(me/L)
January 5.94 6.6 2r.68 Winter
February 5.94 6.6 2L68 Winter
March 0.64 6.6 21.68 Winter
April 3.03 41.53 94.79 Sprine
May 4.04 41.53 94.79 Sprine
June 6.41 41.53 94.79 Sprine
July t7 45.15 r5t.67 Summer
Ausust 15.8 45.15 151.67 Summer
September 20 45.15 r51.67 Summer
October 8.61 53.64 119.58 Fall
Hexcel Corporation, PO Box 18748, Salt Lake City, UT 841,l8, USA
HH'(CE
Evaluation of Ammonia Sources
The source of ammonia in the site effluent is primarily generated from the carbon fiber rinse water
process where ammonia bicarbonate is removed during manufacture. There are thirteen (13)
different fiber line locations where ammonia bicarbonate baths are used. This collected rinse water
is mixed with water from other streams, including, reverse osmosis reject water, pump seal cooling
water, cooling tower blow down, steam condensate and non-contact cooling water, before being
discharged off site.
Hexcel implemented an elaborative sampling campaign in June to better understand how ammonia
concentrations from each rinse water bath differ and its impact to the water discharge stream.
Based on sampling data, the ammonia concentration in the effluent seems consistent within each
fiber line, however, the concentrations differ between fiber lines due to the different products being
produced. Different properties are needed based on customer specifications and qualifications,
which can include rinse water temperature, and the mass of the carbon fiber produced. Hexcel
gathered data from nine (9) fiber lines to date, since the other four carbon fiber lines were not
running at the time of the sampling.
Hexcel has made significant progress in understanding the souroe of ammonia within the
processes, however, additional evaluation is needed. Further sampling is planned to better
understand all the mechanisms impacting the effluent, and we are in the process of purchasing
additional analytical equipment to obtain more real time results to assist in this evaluation.
Plan to Attain Compliance
Hexcel's plan to attain compliance is 1.) understand the various ammonia sources on the site as
explained above. Significant progress has been made and additional cvaluations will be conducted;
2.) following the analysis, alternative solutions will be evaluated to reduce ammonia
concentrations in the effluent without compromising product quality; and 3.) Hexcel will closely
monitor ammonia concentra.tions in the elischarge stream to determine any necessary intervention.
and work to find a potential engineering solution to control the ammonia values below the required
limits.
Other Efforts to Date
In conjunction with the source evaluations, Hexcel has engaged with a nationally reputed water
treatment specialist engineering firm (Anguil) to evaluate other solutions for reducing effluent
volumes, as well as solutions to treat and/or manage the effluent. This evaluation is currently in
the early stages and requires the additional analysis before controls can be pursued.
Further information on the sampling campaign and engineering efforts will be provided in the next
update report, which is due June 1, 2025.
If you have any questions or would like to discuss further, please let me know.
HexcelGorporation, PO Box 18748, Salt Lake City, UT 84118, USA
HExcEr&
Thank you..#
..t! "3^/' 1'U
Tyson Hone
Salt Lake City Site Environmental Manager
Hexcel Corporation
Tyson. Hone@Hexcel. com
(38s) 831-3472
cc Drew Patterson, Hexcel Salt Lake City Fibers Plant Manager
Hexcel CorporaUon, PO Box 18748, Salt Lake City, UT 84llB, USA