Durham County Comments on NCG11

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Engineering and
7 Environmental Services
Utilities Division
May 17, 2023
Submitted via Email (brittan. .cookkncdenr.gov)
Ms. Brittany Cook
Division of Energy, Mineral, and Land Resources (DEMLR)
Stormwater Program
1612 Mail Service Center
Raleigh,North Carolina 27699-1612
Re: General Permit NCG110000 NPDES Permit to Discharge Stormwater
Dear Ms. Cook:
Durham County appreciates the opportunity to comment on the proposed draft General Permit
NCG110000 for Treatment Works. Please see our comments below.
1. Spill Prevention and Response Procedures (13-9.0
Durham County does not see,nor can find where DEMLR has the authority to require that
POTWs keep a "signed and dated acknowledgement in which staff members accept
responsibilities for the Spill Prevention and Response Procedures". Durham County
request this be deleted from the draft general permit.
2. Solvent Management Plan (B-10)
DEMLR has added a requirement for a Solvent Management Plan to be incorporated into
the Stormwater Pollution Prevention Plan (SWPPP). EPA's Multi Sector General Permit
(MSGP) does not include solvent management planning. Solvents are already a part of the
definition of"significant materials,"making this section unnecessary. The language would
require Durham County to certify on the discharge monitoring report(DMR)that there has
not been a "leak, spill, or dumping of concentrated solvents into the stormwater or onto
areas which are exposed to rainfall or stormwater runoff'since the last DMR was filed and
that we are following our solvent management plan. Durham County objects to these
requirements,which are not included in federal law. There are spill reporting requirements
in both state and federal law, but this requirement even exceeds those. Durham County
request the entire Solvent Management Plan section be deleted from the draft general
permit.
3. Preventative Maintenance and Good Housekeeping Program (B-11)
In the current general permit, the timeframe states "Timely compliance ..." but the
proposed general permit states to be completed on a quarterly basis. No violation has
occurred based on conducting inspection, maintenance, and housekeeping at our current
intervals. Durham County request this timeframe be deleted from the draft general permit.
5926 NC Highway 55 East,Durham,North Carolina 27713
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4. Employee Training Requirements (B-12)
The draft general permit requires annual employee training that includes specific topics.
Some of these topics are not applicable to stormwater at Durham County. Requiring us to
cover certain irrelevant topics is time consuming and cuts into the time available to discuss
topics that are pertinent to staff. Durham County request specific topics listed in (a)
through (1)be deleted from the draft general permit.
5. Residuals Management(C-3)
The draft general permit includes a new requirement to manage residuals "in accordance
with applicable standards and in a manner such as to prevent any pollutants from such
materials from entering waters of the state or navigable waters of the United States." This
requirement is not necessary as we are already required to manage residuals per our
individual NPDES permit(NC0026051) and in accordance with the law.Also, including it
in the draft general permit subjects the County to potential double jeopardy from
enforcement under two permits,instead of one, for the same requirement. Durham County
request that DEMLR delete Residuals Management section in its entirety from the draft
general permit.
6. Oualitative Monitoring of Stormwater Discharges (Part D)
Qualitative monitoring is at a frequency of semi-annual in the general permit,but the draft
general permit proposes increasing the frequency to quarterly. DEMLR list no justification
for the change. Durham County request the frequency remain semi-annual in the general
permit.
7. Analytical Monitoring of Stormwater Discharges (Part E)
Durham County objects to the benchmarks for Treatment Works in this draft general
permit. The draft general permit goes beyond EPA's 2021 MSGP. EPA does not require
that Sector T - Treatment Works conduct benchmark monitoring but has made this
monitoring "Report Only", with no thresholds or baseline values for the following
parameters: Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and pH.
EPA does not require indicator monitoring for fecal coliform nor does it impose any
escalating response requirements as a result of permittee indicator monitoring. DEMLR
has provided no basis for requiring these more stringent requirements than EPA imposes
in the MSGP.
While there may be some detectable fecal coliform levels in outfalls authorized under the
general permit, our experience is that these levels are typically attributable to non-human
sources. DEMLR's Fact Sheet notes that bacteria hits have occurred at "industrial,
commercial, or municipal"plants—leaving it uncertain as to whether there have been any
levels of concern from any POTW's stormwater discharges statewide. Durham County
believes these are site specific issues and should be handled as such. DEMLR also provides
no basis for pH and TSS monitoring. There is little we can do about pH levels and do not
believe pH is a water quality issue associated with wet weather discharges regulated under
the general permit. Durham County request keeping the qualitative monitoring
requirements currently under the existing general permit.

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If DEMLR decides not to remove analytical monitoring then they should revise the
requirement for a sample to be taken"within the first 30 minutes of discharge and continue
until all outfalls that are discharging are sampled"to read"to the extent practicable,within
the first 30 minutes of discharge and continue until all outfalls that are discharging are
sampled." Sampling will take staff away from plant operations during times of high flow,
when they are most needed. These requirements will further impair our staff shortages and
could not come at a worse time. Durham County notes that while the sampling is limited
to a facility's "normal operating hours" we operate 24/7 and, without a clarification that
after-hours sampling is not required, may have to send staff out in the evening and night
shifts. We object to this requirement due to staffing and safety concerns as often these
shifts consist of only one operator. Also, if we are being asked to sample after business
hours, this will result in certified laboratory staff coming in after hours to comply with the
fecal coliform 8-hour hold time,resulting in additional cost to the County.
If these requirements remain in the draft general permit, Durham County request DEMLR
to allow representative sampling of certain outfalls to enable our staff to avoid outfalls
which present access, safety, or other obstacles to the sampling requirement. We will need
a way to exempt from sampling outfalls that rarely discharge and multiple outfalls in close
proximity to each other to remain in compliance.
The prohibition against taking samples that are closer than 30 days apart is unnecessary
and sees no logical reason for the restriction. Durham County request this be removed
from the draft general permit.
8. PFAS Monitoring (E-3)
DEMLR is proposing to require permittees to"monitor for emerging contaminants such as
Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) in accordance with written
notification."As with benchmarks,EPA's MSGP does not include PFAS monitoring. This
requirement violates N.C.G.S. §15013-19.3. Durham County objects to PFAS monitoring
because we do not manufacture any PFAS chemicals and as such, PFAS chemicals are not
expected to be in runoff from our facility in amounts of interest or concern. PFAS sampling
is expensive and there are currently no approved wastewater/stormwater sampling
methods. We also object because the provision in question essentially forces us under the
general permit to agree to HAS monitoring now without knowing which PFAS must be
monitored, methods to use, and at what frequency. Durham County request that PFAS
monitoring requirements be removed from the draft general permit.
9. Reports Required if More Frequent Monitoring Has Occurred (F-6)
This section states that for the purpose of benchmark monitoring, the first analytical result
for each parameter should be used rather than an average of data over the monitoring
period. Durham County maintains our objection to benchmark monitoring(see#7 above),
and question why DEMLR would not allow the use of an average value, which provides
more representative information, rather than the first result.

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10. General Water Ouality Standards Should Not Be Imposed (Pate 2)
The general permit specifies that"The discharges allowed by this General Permit shall not
cause or contribute to violations of Water Quality Standards. Discharges allowed by this
permit must meet applicable wetlands standards....". This general water quality standard
language is inappropriate because it deprives Durham County the opportunity to comment,
appeal, and request a compliance schedule of the allowable levels of a pollutant which can
be discharged. Durham County request the language be removed from the draft general
permit or at a minimum, qualified with "To the extent required by pplicable law, the
discharges allowed by this General Permit shall not cause or contribute to violations of
Water Quality Standards."
If there are any questions pertaining to the comments above, contact me at sbrixeykdconc.gov.
Sincerely,
Docu Signed by:
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`9fe$'ffari1`e--Brixey
Deputy Director of E&ES/POTW Director
Cc: Amy Moore, Compliance Manager