NC0020737_Comments_20240325

SOUTHERN 48 Patton Avenue,Suite 304 Telephone [phone]
ENVIRONMENTAL Asheville,NC 28801 Facsimile 828-258-2024
LAW
CENTER
March 22, 2024
Via Mail and Electronic Submission REC�����
Nick Coco MAR 2 5 202�¢
Environmental Engineer
NCDEQ-DWR NCDEQ/D vn NPDES
Water Quality Permitting Section
1617 Mail Service Center
Raleigh,NC 27699-1617
Re: Comments on NPDES Wastewater Permit NC0020737 Pilot Creek WWTP
Dear Mr. Coco,
Thank you for providing another opportunity to comment on the draft NPDES Wastewater
Permit NC0020737 (the "Draft Permit") for the Pilot Creek Wastewater Treatment Plant ("Pilot
Creek WWTP").We submit these comments on behalf of the Southern Environmental Law Center
("SELC"),MountainTrue, and the Broad Riverkeeper.
We appreciate the corrective actions DEQ took in response to our previous comments,
including its decisions to impose a chronic silver limit, align the permit with current selenium
standards, and add a selenium limit across all flow tiers. These changes will result in a more
protective permit and improved water quality in the Buffalo Creek watershed.
That said, we remain concerned that other portions of the Draft Permit do not do enough
to protect the existing uses of Buffalo Creek, as well as downstream environmental justice
communities. These shortcomings must be addressed in a second revised permit.
I. DEQ must account for background conditions.
As we explained in our previous comments, binding federal regulations require DEQ to
determine if a discharge "will cause, have the reasonable potential to cause, or contribute to an
excursion above any State water quality standard, including State narrative criteria for water
quality."' This means DEQ must analyze"whether a discharge,alone or in combination with other
sources of pollutants to a waterbody . . . could lead to an excursion above an applicable water
quality standard."2 To determine whether an excursion is likely,EPA has explained that DEQ must
first"determine the critical background concentration of the pollutant of concern in the receiving
'40 C.F.R.§ 122.44(d)(1)(i)(emphasis added);see also 15A N.C.Admin.Code 02B .0203(requiring DEQ to
design"[w]ater quality based effluent limitations and management practices for direct or indirect discharges of
waste.. .such that the water quality standards and best usage of receiving waters and all downstream waters will
not be impaired").
2 U.S.EPA,NPDES Permit Writers'Manual at 6-23(2010)[hereinafter"Permit Writers'Manual"];see also 40
C.F.R. § 122.44(dx 1 Xii)(requiring DEQ to"account for existing controls on point and nonpoint sources of
pollution"in the waterbody when conducting a reasonable-potential analysis).
Charlottesville Chapel Hill Atlanta Asheville Birmingham Charleston Nashville Richmond Washington,DC

water before the discharge . . .to ensure that any pollutant limitations derived are protective of the
designated uses"for those waters.3
In its response to comments, DEQ expressly disclaims this responsibility. Instead, it
observes that DEQ's "typical" practice "for all NPDES permits written in North Carolina" is to
assume "that the background concentrations are zero."4 Respectfully, we fail to understand how
this observation resolves the problem. The fact that DEQ is consistently failing to meet a
requirement of the Clean Water Act does not nullify that requirement. The Clean Water Act
requires DEQ to consider background conditions on Buffalo Creek. DEQ cannot avoid this
requirement by observing that it fails to heed it as a matter of course.
In response, DEQ seems to suggest that it indirectly considers background conditions by
looking at stream impairments identified in the most recent 303(d) list. But that approach
effectively flips the statutory scheme on its head.The overriding goal of the Clean Water Act is to
"eliminate[]"the discharge of pollutants into navigable waters.5 Under DEQ's"typical"practice,
however, it declines to consider whether NPDES permittees are cumulatively contributing to
excursions of state water quality standards until those water quality standards are already being
exceeded. In effect, DEQ is waiting for a water body to be "polluted enough" before it begins
considering the cumulative effects of background pollution. This wait-and-see approach is
contrary to the Clean Water Act and its implementing regulations.
What's more, looking at the most recent 303(d) list is not a substitute for a true analysis of
background conditions. The 303(d) list only identifies waters that are currently impaired. It does
not identify waters that are on the cusp of being impaired,or that could become impaired if a new
or modified pollution discharge is added to the receiving waters.As a result,the 303(d)list cannot
reliably answer the question the Clean Water Act requires DEQ to wrestle with: is this new or
modified permit likely to contribute to an exceedance of state water quality standards?
Analyzing background conditions during permit issuance is not only consistent with the
Clean Water Act, but would also help DEQ keep more waterbodies off the 303(d) list. Under
DEQ's current approach, it is effectively flying blind, approving pollution discharges that may or
may not contribute to exceedances of water quality standards depending on background conditions.
Consistently analyzing these background conditions at the outset will allow DEQ to tailor its
permit limits to avoid exceedances before they happen,thereby helping it avoid the hassle of listing
and managing waters after they become impaired.
In sum,we strongly recommend that DEQ redo its reasonable-potential analyses to account
for background pollution levels.
II. DEQ should consider moving its upstream sampling site closer to the outfall.
According to DEQ,it mistakenly flipped upstream and downstream temperature data in its
initial draft permit. The true data reveal that upstream temperatures were 1.5 °C warmer than
3 Permit Writers'Manual at 6-19.
4 Fact Sheet Addendum at 1.
5 33 U.S.C.§ 1251(aX1)(emphasis added).
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downstream temperatures, on average. This is somewhat surprising, as stream temperatures
typically increase as waters flow downstream.6 The fact that this is flipped in the Buffalo Creek
watershed near the discharge suggests something is altering this typical pattern. We suspect that
this is an artifact of DEQ's selected upstream sampling site.
According to the Draft Permit,the upstream sampling site is located"100 yards above the
outfall."7 But according to the map provided in the permit,the upstream sampling site is actually
located 1.2 miles upstream of the outfall,just below the Kings Mountain Reservoir Dam. Dams
can dramatically influence the temperature of the waters below them.8 Given the anomalously
warm temperatures recorded below the reservoir dam, it seems likely that the dam is increasing
water temperatures at the upstream sampling site. These aberrantly high numbers may be
obscuring the true effects of the Pilot Creek WWTP discharge on water temperature, as well as
dissolved oxygen and conductivity.
We recognize that the location of the upstream sampling site may be a matter of
expediency. The current upstream dam sampling site is easily accessible off Oak Grove Road.
However, expediency should not be the sole factor in selecting a sampling site. If DEQ wants an
accurate picture of how the Pilot Creek WWTP is impacting instream temperature, dissolved
oxygen, and conductivity, it should adhere to the 100-yard distance described in the permit—or at
least find a sampling site somewhere in the near vicinity. Alternatively, DEQ must explain why
finding a closer upstream sampling site was infeasible,and amend its permit language to accurately
describe the upstream sampling site's location.
III. DEQ should reevaluate its approach to total residual chlorine.
As we explained in our previous comments,North Carolina's acute limit for total residual
chlorine is 17 ug/L.9 The Draft Permit acknowledges this limit and sets a daily maximum limit of
28 ug/L across all flow levels to protect against acute toxicity.10 However,the Draft Permit goes
on to say that DEQ "shall consider all effluent total residual chlorine values reported below 50
ug/L to be in compliance with the permit."11
DEQ argues this more capacious language is needed because of"analytical issues" with
analyzing chlorine levels below 50 ug/L.12 But as we pointed out in our comments, those
"analytical issues" may be a thing of the past. Scientists have recently developed numerous
technologies to better assess chlorine concentrations and eliminate analytical interference.
13
6 U.S.EPA,Spatial and Temporal Patterns of Stream Temperature(2001).
Draft Permit at 4.
8 U.S.EPA,Temperature,https://www.epa.gov/caddis/temperature.
9 15A N.C.Admin.Code 02B.0211(3).
10 Draft Permit at 3,5,7.
"Id. at4,6,8.
12 Fact Sheet at 5;see also N.C.Dep't of Env't&Nat.Res.,Total Residual Chlorine 50 ug/L Compliance Level
(May 1,2008),https://www.deq.nc.gov/coastal-managementlgis/data/esmp-data/2010/july/npdes/trccomplevel-
20090710-dwq-swp-npdes/download.
13 See,e.g.,Robert Wilson et al.,Continuous Chlorine Detection in Drinking Water and a Review of New Detection
Methods,63 Johnson Matthey Tech.Rev. 103(2019);Peng Li,Concise Review on Residual Chlorine Measurement:
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In its response to comments,DEQ claims that its more generous 50 ug/L limit is still needed
to "account for analytical variability."14 But as we explained in our comments, newer and more
accurate technologies obviate the need for such wiggle room. DEQ does not address these
technologies or acknowledge whether they are already being deployed by the Pilot Creek WWTP
or could be deployed in the future. While we appreciate DEQ's promise to assess this issue"in the
future in collaboration with the Water Sciences Section,"15 we wish to emphasize that DEQ lacks
the authority to issue NPDES permits that do not ensure compliance with water quality standards,
including the total residual chlorine standard 16—regardless of whether that is the agency's
"typical"practice.17
IV. DEQ should consider the environmental justice impacts of the Draft Permit.
DEQ should reconsider the environmental justice impacts of the Draft Permit. According
to the state's community mapping tool, two environmental justice communities are located
downstream of the outfall.18 Both of these communities have significantly higher rates of cancer,
heart disease, and child mortality than the state average.19
In previous comments on this Draft Permit, we reminded DEQ that Governor Cooper's
Executive Order 292 requires additional consideration of environmental justice and public health
impacts by the agency"in their permitting,policy actions,and agency programs."20 This additional
consideration must extend "to the furthest extent permissible by law."21 DEQ responded by
asserting that no environmental justice consideration is necessary for this Draft Permit because it
is a"renewal of an existing permit and not an expansion or a new permit"22 This is illogical and
inaccurate.
First, new information which may impact environmental justice communities is likely to
be available at the permit renewal stage. In the time between a permit's original approval and the
permit's renewal, additional dischargers may have been permitted in the same watershed,
advancements in the scientific understanding of certain pollutants or their cumulative impacts may
have been discovered, and demographic shifts downstream of a facility may have taken place. It
would be illogical and irresponsible for DEQ to ignore this additional data when exercising the
Interferences and Possible Solutions,323 J.of Cleaner Prod.(2021);Peng Li.et al.,Micro particles as Interfering
Substances in Colormetric Residual Chlorine Measurement,207 Ecotoxicology&Env't Safety(2021);Vt.Dep't of
Env't Conservation,Chlorine Residual,
https://dec.vermont.gov/sites/dec/files/wsm/wastewater/docs/Section%209_Total%20Residual%20Chlorine.pdf
(describing low-range colorimetric analyses with a range of 2 to 500 ug/L).
14 Fact Sheet Addendum at 1.
15Id
16 See 33 U.S.C.§ 1311(b)(1XC)(requiring NPDES permits to include limitations"necessary to meet water quality
standards");40 C.F.R. § 122.44(d)(1)(same).
17 Fact Sheet Addendum at 1.
'8 See N.C.Dep't of Env't Quality,Community Mapping System,
https://ncdenr.maps.arcgis.com/apps/webappviewer/index.html?id=1 eb01be2bctb4cccb3cc212af8a0b8c8.
19 Id
20 Exec.Order 292(Oct.24,2023).
21 Id
22 Fact Sheet at 26.
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agency's responsibility to evaluate impacts of a permitting decision on environmental justice
communities. DEQ is expected to ensure that permits still comply with the Clean Water Act at the
permit renewal stage irrespective of whether an expansion or new permit is at issue.23 DEQ owes
this same duty to reassess risks to environmental justice communities.
Additionally, DEQ's statement that the Draft Permit is already consistent with state and
federal requirements is inaccurate. As explained above,the Draft Permit is inconsistent with state
and federal law in several ways. And even if it had complied with these requirements, DEQ has
still failed to comply with Executive Order 292.Since the agency has not undertaken any additional
analysis regarding environmental justice communities, DEQ has not yet followed the Executive
Order's directive to consider environmental justice implications of this permitting action to the
maximum extent permissible by law. Because environmental justice communities like those
downstream of the Pilot Creek WWTP are often disproportionately affected by pollution,
Executive Order 292 requires DEQ to carefully assess whether its permit limits are acting as
cumulative stressors.At the very least,this means the agency must analyze background conditions,
as explained above, and err on the side of caution when setting permit limits.
These errors should be rectified in a revised draft permit, which should include a more
thorough investigation of background conditions and environmental justice impacts.
V. Conclusion
We appreciate DEQ's amendments to the previous draft permit. However, for the reasons
explained above, DEQ must further revise the Draft Permit and reissue it for public comment.
Thank you for consideration of this letter. Please contact or Alyson Merlin (828-258-2023;
[e-mail]), or Spencer Scheidt (828-258-2023; [e-mail]) if you have any
questions regarding these comments.
Sincerely,
Alyson Merlin,Associate Attorney
Southern Environmental Law Center
47ree-r',
Spencer Scheidt,Associate Attorney
Southern Environmental Law Center
David Caldwell, Broad Riverkeeper
MountainTrue
23 See Upper Blackstone Water Pollution Abatement Dist. v. U.S. E.P.A.,690 F.3d 9,22(1st Cir.2012)(stating that
the regulatory term limit on permits"requires the EPA or state permitting authority to re-ensure compliance with the
Act whenever a permit expires and is renewed");see also 40 C.F.R. § 122.46(a),40 C.F.R.§ 123.25(a)(17).
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