NC0026123_Comments_20230130

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WADE R.FOWLER,JR.,COMMISSIONER
FAYETTEVILLE PUBLIC WORKS COMMISSION
EVELYN O.SHAW,COMMISSIONER �,�► ,' / / 955 OLD WILMINGTON RD
RONNA ROWE GARRETT,COMMISSIONER P.O.BOX 1089
DONALD L.PORTER,COMMISSIONER H/ OWN UTILITY FAYETTEVILLE,NORTH CAROLINA 28302-1089
MARION J NOLAND,INTERIM CEO/GENERAL MANAGER R E C ENEB.-cutoomi
January 24, 2023
JAN 3 0 2023
Via US Mail and Email ( iick.cocoAncdenr.gov)
North Carolina Department of Environmental Quality NCDEQ/DWR/NPDES
NPDES Municipal Permitting Unit
Attn: Nick Coco, PE
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Comments on Draft NPDES Permit NC0026123
Asheboro WWTP, Lee County, North Carolina
Facility Grade IV Biological WPCS, SIC Code 4952
Dear Mr. Coco:
Fayetteville Public Works Commission (PWC) has reviewed the draft NPDES permit for
the Asheboro WWTP (the "Draft Permit"), located in Randolph County and discharging into the
Deep River within the Cape Fear River Basin (the "Basin"). The Asheboro WWTP is upstream of
PWC's drinking water intake, and as such, it is in PWC's customers' best interests for PWC to
take an active role in protecting water quality throughout the Basin.
PWC also provided comment on the draft NPDES permit issued in 2018. PWC
appreciates DWR including all comments and responses to those comments in this publicly
available draft permit. PWC offers the following additional comments on Asheboro's current
Draft Permit.
More Frequent Effluent Monitoring for Emerging Contaminants is Necessary
PWC appreciates DWR's efforts to lower the presence of 1,4-dioxane and PFAS
compounds in the Basin. As DWR acknowledges in the cover letter for the Draft Permit, these
compounds do not break down once discharged into the environment. Each upstream
discharge increases the mass of these compounds present in the river downstream. Because
these substances are not removed through the normal drinking water treatment process,
upstream discharges typically end up in the drinking water of downstream customers.
Furthermore, discharges of these substances are not consistent from one day to the
next. As the 2022 example of 1,4-dioxane discharges from Greensboro's T.Z. Osborne WWTP
demonstrates, discharges of these emerging contaminants are frequently of a periodic or"slug"
nature. Therefore, regarding 1,4-dioxane, PWC supports the weekly effluent monitoring
requirement included in the Draft Permit.
However, regarding PFAS effluent monitoring (once there is an approved method for
sampling PFAS in wastewater), quarterly sampling for these compounds is insufficient. In 2019,
three rounds of sampling of Asheboro's effluent indicated the range of concentrations for PFOA
BUILDING COMMUNITY CONNECTIONS SINCE 1905
AN EQUAL EMPLOYMENT OPPORTUNITY EMPLOYER

was between 9.47 and 11.7 ng/L (more than three orders of magnitude greater than EPA's
drinking water health advisory standard). The sample results also indicated the range of
concentrations for PFOS in Asheboro's effluent was between 18.8 and 19.8 ng/L (over four
orders of magnitude above the EPA health advisory standard). Given the limited data set
available for Asheboro's effluent, PWC believes that weekly PFAS effluent monitoring is
warranted. Quarterly effluent sampling for PFAS will not be sufficiently frequent to determine
whether the concentrations of PFOA and PFOS in Asheboro's wastewater represent a
consistent load into the Basin or if they are the product of"slug discharge" events from
Asheboro's WWTP.
In-Stream Monitoring for PFAS and 1,4-dioxane throughout the Basin is Necessary
As noted above, discharges of PFAS and 1,4-dioxane do not break down in the
environment, and each source of these discharges contributes to an overall higher downstream
concentration. Pursuant to 15A NCAC 02B.0203, DWR "shall" develop water quality based
effluent limits (WQBEL) such that downstream water quality and usage "will not be impaired."
(emphasis added). The key to satisfying DWR's obligation in this regard is developing the data
set that is necessary to understand how PFAS and 1,4-dioxane concentrations change as water
moves downstream in the Basin.
Thus, PWC believes that DWR should require weekly in-stream monitoring for PFAS
and 1,4-dioxane at Asheboro's downstream monitoring point if there is a reasonable potential
for a violation of water quality standards. Continuing to rely on a simple mass-balance
calculation at a permittee's outfall to develop WQBELs for PFAS and 1,4-dioxane is inconsistent
with how they are known to behave in the environment as well as the requirements of 15A
NCAC 026.0203. DWR must begin the process of addressing these substances in a manner
that is consistent with the science. Regular and frequent in-stream monitoring for them is the
first step.
PWC also notes that a network of ongoing in-stream monitoring points will provide an
additional opportunity to detect "slug discharges" of PFAS and 1,4-dioxane into the Basin.
These data may afford downstream utilities an opportunity to reduce the concentration of these
substances in their customers' drinking water. To facilitate these efforts, PWC suggests that
DWR provide all drinking water utilities in the Basin with expected travel times between each
permitted outfall subject 1,4-dioxane and PFAS monitoring and each drinking water intake within
the Basin.
Finally, PWC believes that instream sampling should occur on the same day an effluent
sample is collected.
DWR's Approach for Developing Water Quality Based Effluent Limits for 1,4-Dioxane
PWC supports DWR's application of 15A NCAC 02B.0206 and the use of chronic risk
levels and average annual flow in the Deep River at the next downstream water supply
watershed boundary for development of site-specific water quality based effluent limits
(WQBEL) for 1,4-dioxane. However, in order to comply with 15A NCAC 02B.0203, PWC
believes DWR must develop WQBELs for 1,4-dioxane that account for the cumulative effect of
all upstream 1,4-dioxane discharges on downstream water supply surface waters
Schedule of Compliance for 1,4-Dioxane Limits is Too Lenient
On May 31, 2018, after receiving the results of at least five monthly effluent sampling
events for 1,4-dioxane between December 2017 and April 2018, Asheboro submitted its
comments to DWR regarding a prior draft NPDES permit for the Asheboro WWTP. Therein,
Asheboro stated, "Asheboro staff is aware of the concern with 1,4-dioxane." It continued, "We

feel identifying the sources of this contamination is crucial," and that "Asheboro believes after
the sources are identified, then a set of standards should be developed and limits applied."
Letter from Michael D. Rhoney, P.E. to Gary Perlmutter (May 31, 2018) (included in Fact Sheet
for Draft Permit at 89-90 [hereinafter, the "Fact Sheet"]).
Asheboro's subsequent investigation into "the sources of this contamination," however,
appears to have been less robust than its 2018 comments suggested. Indeed, during the period
between December 2017 and April 2021, the Fact Sheet suggests Asheboro identified only one
source of 1,4-dioxane discharges into its collection system — an entity known as Starpet. The
only other source identification efforts undertaken by Asheboro and described in the Fact Sheet
was sampling of landfill leachate originating from the Carolinas Great Oak Landfill between April
and July of 2021. PWC questions why Asheboro delayed its source investigation for as long as
it did — especially when a simple dilution calculation reveals that Starpet's discharges of 1,4-
dioxane were not the only source of releases into the Asheboro WWTP.
The Fact Sheet indicates the average concentration of 1,4-dioxane in Asheboro's
effluent between 2018 and 2022 was 116 ug/L and that Asheboro's average daily discharge
volume was 4.05 MGD. Asheboro's annual pretreatment reports to DWR between 2018 and
2021 indicate that Starpet's maximum permitted discharge volume to the Asheboro WWTP was
70,000 gallons per day. Therefore, even assuming Starpet discharged the maximum
permissible volume of wastewater every day during this period, the average daily concentration
of 1,4-dioxane in Starpet's effluent would have needed to be 6,711 ug/L to produce an average
concentration of 116 ug/L from the Asheboro WWTP. Because Starpet's average daily effluent
concentration of 1,4-dioxane was nowhere near this level, Asheboro should have begun an
investigation into other sources much sooner.
Nonetheless, the Draft Permit proposes to give Asheboro five more years (and more
than 10 years since Asheboro first became aware of this issue) to achieve compliance with
DWR's 1,4-dioxane WQBELs in the Basin. PWC believes that DWR should not allow Asheboro
to benefit from its lack of diligence in this matter and that a compliance schedule of three years
is more appropriate. A shorter timeline to achieve compliance with the stepped-down limits in
the Draft Permit will provide a stronger incentive for Asheboro to identify the sources of 1,4-
dioxane quickly and require them to implement reductions expeditiously.
Daily Conductivity Monitoring Should Remain in the Permit
PWC requests that DWR keep the daily conductivity monitoring requirement in the
permit. Conductivity data provides a mechanism to detect changes in wastewater quality from
manufacturing operations at existing industrial users' facilities. Continuing this monitoring
provides a simple "red-flag" test to alert the Asheboro WWTP that other changes in its influent
may have occurred.
Bromodichloromethane Reductions in the Watershed
PWC remains concerned about the levels of bromide in the watershed and appreciates
DWR's inclusion of a bromodichloromethane limit in this draft permit. Trihalomethanes (THMs)
are regulated in PWC's drinking water, and the presence of compounds including
bromodichlormethane and bromides in the source water affect PWC's treatment processes and
ability to limit the formation of disinfection byproducts in its finished water. Data also show that
concentrations of bromide go down as river flows go up, indicating point sources of bromide.
However, the 2022 average of 0.215 mg/L (with a maximum of 0.489 mg/L) was higher than the
averages in 2021 and 2020.
PWC continues to monitor bromide carefully and while not currently monitoring
bromodichloromethane in our source water, these parameters impact the potential for formation

of disinfection byproducts. PWC seeks to better understand the sources and therefore the
potential opportunities to reduce the potential of THMs in its drinking water. Asheboro stated in
2018 that the facility can comply with a bromodichloromethane limit and PWC expects the
facility's exceptional performance record to include this limit as well.
As stewards of the Cape Fear River water supply for our customers, PWC appreciates
the opportunity to submit these written comments. PWC believes that a public hearing is
appropriate to fully inform all stakeholders within the basin and to gather additional public
comment before issuing the final NPDES permit. PWC therefore request a public meeting. If
additional information is needed, please contact me at mick.nolandfaypwc.com.
Respectfully submitted,
Fayetteville Public Works Commission
By:
Mi Noland, nterim CE /General Manager