NC0072699_Fact Sheet_20180209

DEQ/DWR
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NCO072699
Facility Information
Applicant/Facility Name: Town of Beaufort/Pine Street Water Treatment Plant
Applicant Address: PO Box 390, Beaufort, North Carolina 28516
Facility Address: 910 Pine Street, Beaufort, North Carolina 28516
Permitted Flow: Not limited
Tvpe of Waste: Filter backwash and Ion Exchange regeneration
Facility/Permit Status: Renewal
Facility Classification PC -1
County: Carteret
Miscellaneous
Receiving Stream:
UT to Town
Creek, White Oak
RB
Regional Office:
Wilmington
Stream Classification:
SC
USGS TooQuad:
Beaufort
303(d) Listed?
No
Permit Writer:
Brianna Young
Subbasin:
03-05-03
Date:
2/9/2018
HUC
0302030104
J
•
Drainage Area mit :
N/A
Summer 7Q10 cfs
Tidal
Winter 7Q 10 cfs :
Tidal
30Q2 cfs
Tidal
Average Flow cfs :
Tidal
IWC (%):
100% capped at
90% for WET
Primary SIC Code:
N/A
SUMMARY
The Beaufort Pine Street WTP is an Ion Exchange (Softener) Water Treatment Plant to treat
ground water drawn from two wells. The facility is designed to provide 0.60 MGD of treated
potable water. After softening, the water is treated by gaseous chlorination and
hydrofluorosilicic acid. The backwash and softener regeneration wastewater is estimated to be
0.010 MGD average at plant capacity of 0.60 MGD potable water. Recent (March 2014 — April
2017 operating data) shows a monthly average discharge flowrate of 0.0065 MGD with a
maximum of 0.0156 MGD. The facility discharges the backwash wastewater after
dechlorination with sodium bisulfate (30/40%) to an unnamed tributary to Town Creek in the
White Oak River Basin. The discharge is to a dry ditch with no normal flow except the
discharge and storm water. Instream samples have been collected from the ditch; instream
sampling discontinued as discharge is to a dry ditch used as a stormwater conveyance.
The receiving stream (Town Creek) is classified SC waters in the White Oak River Basin. This
reach is not listed on the 2014 303(d) list.
Monitoring violations for TRC (1 NOV; many instances of BPJ as concentration <50 µg/1), 1
NOD each for frequency violation for chloride, total iron, total manganese, DO, and temperature.
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NCO072699 Renewal
Page 1

PermittingStrategy:
Permitting Strategy for Ion Exchange Water Treatment Plants is followed for this facility except
where noted below.
Discharge Data Review and RPA
DMR data for October 2012 through April 2017 was reviewed. RPA was performed for copper,
zinc, and lead. Copper, Zinc, and Lead all have reasonable potential to exceed water quality
standards.
Ammonia nitrogen monitoring maintained at monthly monitoring as concentrations were found
to be greater than 1 mg/L on several dates.
Whole Effluent Toxicity Testing
The facility currently performs Quarterly Acute Toxicity monitoring using Mysid Shrimp at
90%. The facility has passed all 12 previous WET tests.
Chanes from previous permit to draft:
• Address on cover page updated per renewal application
• Updated language on Supplement to Permit Cover Sheet to match current formatting
used
• Updated components list per renewal application
• Updated outfall map
• Added regulatory citations
• Added parameter codes
• Expiration month changed to allow full 5 -year permit cycle
• Added eDMR language in A(1) and added Section A(5)
• Added flow footnote about log books in A(1) per 2012 WTP strategy
• Flow monitoring changed from weekly to 2/month and sample type from estimate to
Instantaneous per 2009 WTP strategy (discharge frequency is intermittent so
instantaneous flow monitoring is required; the monitoring frequency is as frequent as
the minimum frequency of monitoring for any parameter listed)
• TRC limit changed from daily max to both daily max and monthly average per 2009
WTP strategy
• The facility does discharge Fluoride, but there is no water quality standard for
fluoride in saltwater (per 2012 WTP strategy), so no monitoring is required
• Limits added for copper, lead, and zinc based on RPA and monitoring changed to
monthly
• Sample type for all parameters except flow changed from grab to composite based on
conversation with WiRO (see comments below)
o Compliance schedule to install composite sampler added as well based on e-
mail from WiRO (see comments below)
• Footnote added to A(1) stating that composite sample should be made of equal
volume collected every 15 mins during recharge cycle (per WiRO comments below)
• Removed requirement that monitoring for toxicity shall coincide with monitoring for
metals and TRC as this is no longer required
• Updated language in A(2) to most recent tox language
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NC0072699 Renewal
Page 2

Changes from draft to final:
• Hydrofluorosilicic acid has been defined to be for fluoride addition on supplement to
permit cover sheet (per permittee's comments below)
• Discharge description updated on Supplement to Permit Cover Sheet and in Section
A. (1) (per permittee's comments below)
• Footnote concerning composite sampling has been moved to become Section A. (3)
for clarity (per WIRO comments below)
• Compliance schedule added as Section A. (4) for total copper, total lead, and total
zinc (per permittee's and WiRO comments below)
• TRC put back as a daily max limit in A(1); erroneously changed
• Monitoring for pH, turbidity, and TRC changed back to grab samples per 2009 WTP
strategy; mistakenly changed to composite with other parameters, but these require
grab sampling in order to be accurate (per 2009 WTP strategy)
PROPOSED SCHEDULE FOR PERMIT ISSUANCE:
Draft Permit to Public Notice: November 1, 2017
Permit Scheduled to Issue: February 14, 2018
STATE CONTACT:
If you have any questions on any of the above information or on the attached permit, please contact
Brianna Young at [phone], or by email at [e-mail].
REGIONAL OFFICE COMMENT FOR DRAFT:
Per phone call (7/20/17) with Jim Gregson and Dean Hunkele in WiRO and John Hennessy and
Brianna Young in CO:
• Sample type for all parameters (except flow) has been changed from grab to composite
and a footnote added to A(1) regulating when samples should be collected based on
feedback received from Frank Sansone (ORC) that he samples only during the 1 st rinse
cycle of recharge cycle (process involves 20 min rinse, 50-55 min brine recharge, 20-30
min rinse; Entire cycle totals —2 hrs)
• Compliance schedule of 2 months added to install composite sampler or have another
method approved by WiRO in accordance with 15A NCAC 02B .0503 (4) (per Jim
Gregson's e-mail 10/19/17)
Per e-mail from Dean Hunkele 10/27/17 on Draft
• We just got the permit for the Laurel Rd WTP NCO086975 issued by Joe Corporon
whereby metal limits were given, but he gave them a permit cycle to figure out how to
meet them. Is that supposed to be in these as well?
o DWR Response: If concerns are raised about the facility meeting the new metals
limits, those concerns can be reviewed and the inclusion of a compliance schedule
in the final permit can be considered.
COMMENTS RECEIVED FROM PERMITTEE (VIA EMAIL 11/30/17; MAILED COPIES RECEIVED 12/6/17
• The Town is amenable to the changes identified by the first eight bullets with only three
comments; please see sixth and eight bullets regarding "Supplement to the Cover Sheet."
• Sixth bullet (from draft cover sheet):
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NCO072699 Renewal
Page 3

o Bullet states: Components list has been updated on the Supplement to Permit
Cover Sheet per the permit renewal application.
o Permittee response: The component we are using for addition of fluoride is
Hydrofluorosilicic Acid.
o DWR response: Hydrofluorosilicic acid has been defined to be for fluoride
addition.
• Eighth bullet (from draft cover sheet):
o Bullet States: Language has been updated on the Supplement to Permit Cover
Sheet based on current NPDES permit formatting.
o Permittee response: We suggest the discharge description on Page 2 of 8 and Page
3 of 8 be the same. On Page 2, one could state as "discharge of water softener
regeneration -backwash wastewater from Ion Exchange Units." On Page 3 one
should delete the phrase "filter backwash and" and state as "discharge water
softener regeneration -backwash from Outfall 001."
■ WiRO comments (Dean Hunkele via email 12/7/17): I do not know
enough about their system to comment but seems reasonable to me. The
word "filter" has been present going back to at least the 2003 issuance and
was probably a carryover from a shell document or a permit for another
water permit they borrowed from.
■ DWR response: The Supplement to Permit Cover Sheet has been updated
to state "water softener regeneration -backwash wastewater" and Section
A. (1) has been updated to remove "filter backwash and softener
regeneration backwash" and references only "backwash."
o Permittee response: On Page 2, Item 1 speaks of "a design potable flowrate of
0.60 MGD and a maximum, monthly average wastewater discharge of 0.0156
MGD". The previous permit states a maximum monthly average {wastewater
discharge} of 0.0176 MGD. These numbers do not seem relevant to data
covering the most recent 22 months which indicates an average daily flow of
0.0054 MGD and a maximum monthly average of 0.0094 MGD. These numbers
are dependent on a varying data -set, and the permit does not include a flow limit.
We would suggest deleting the reference to maximum daily average wastewater
discharge from "Supplement to the Cover Sheet."
■ DWR response: The language used in the Supplement to Permit Cover
Sheet is standard language used in all water treatment plant NPDES
permits. The maximum monthly average referenced in the draft permit is
based on data in the Division's database from November 2015. Per the
Division's water treatment plant guidance, this language will remain in the
permit for consistency of water treatment plant NPDES permits across the
state.
• The Town is unsure of intent and has concern regarding the ninth and tenth bullet.
o Ninth bullet (from draft cover sheet): A footnote in Section A. (1) concerning
logbooks has been added for flow monitoring.
o Tenth bullet (from draft cover sheet): Flow monitoring in Section A. (1) has been
reduced to 2/month and the sample type has been changed to instantaneous per
the current water treatment plant strategy.
o Permittee response: Footnote 2 refers to Effluent Characteristic — "Flow" with
Sample Type — "Instantaneous" and Sample Location — "Effluent". The Town is
unsure of intent for changes to flow monitoring. All of the softener backwash -
regeneration flow into the softeners passes through a meter; all of the softener
backwash -regeneration flow exits the softeners as effluent; the effluent flows
reported on the DMRs are based on those meter readings for flow into the
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NCO072699 Renewal
Page 4

softeners and subsequently out of the softeners to Outfall 001. The Town believes
its current method of measuring softener regeneration -backwash flow with the
meter in-place has an appropriate degree of accuracy and should be acceptable
without change.
o WiRO comments (Dean Hunkele via email 12/7/17): I have no idea where they
came up with limiting how flow can be measured or reported for any facility
unless continuous & recording is required. The old permit said "Estimate" which
I am guessing was based on the use of the meters but being an estimate wouldn't
require annual calibration. However, it could be calculated estimate as well based
on cycle time and pump rate. Instantaneous measurement typically requires a
weir and use of a staff gauge to measure water height to get a flow rate at that
instant, both of which they don't have and not sure how they would go about
it. Now I guess they could use the metered flow total for a single cycle and use
the cycle time to get at a calculated "instantaneous" flow value for that single
event if that is what permitting is looking for or just use the flow meters to give a
total for the 24 -hr period.
o Permittee response to flow meter clarification request (via email 1/16/18): We
have spoken with Frank Sansone, Water ORC — Town of Beaufort; Frank
provided clarification by explaining that during softener backwash -regeneration
(recharge), all of the water used during softener backwash -regeneration
{recharge is measured by a meter. The brine solution used during softener
backwash -regeneration {recharge) is not measured by a meter. Frank utilizes
meter readings for water used during recharge to calculate the number of
recharge events and total softener backwash -regeneration flow from the water
treatment plant. The meter measuring water used for backwash and fast rinse is a
11/z -inch turbine meter manufactured by Neptune/Trident.
o WiRO comments (Tom Tharrington phone call 2/1/18): Tom felt the meter they
have in place is appropriate for now to do instantaneous monitoring. DWR will
assume the meter is appropriate for now unless it is deemed inappropriate in the
future. The meters are usually very accurate when used with clean water, which
is why they can be used in WTPs but not WWTPs.
o DWR response: As discharge from the facility is intermittent, the sample type,
per the current water treatment plant strategy, should be defined as instantaneous.
After speaking with staff in the Wilmington Regional office, the flow meter in
place is acceptable.
• Eleventh bullet (from draft cover sheet):
o Bullet states: The total residual chlorine has been changed to both a daily
maximum and monthly average in Section A. (1).
o Permittee response: All things considered, the Town has no immediate concern
regarding the eleventh bullet. We believe appropriate the footnote stating, "The
Division shall consider all effluent TRC values reported below 50 PPB to be in
compliance with the permit."
• Twelfth bullet (from draft cover sheet):
o Bullet states: Limits have been added for Total Copper, Total Lead, and Total
Zinc based on a reasonable potential to exceed water quality standards and
monitoring has been changed to monthly.
o Permittee response (paraphrased): The Town is opposed to monitoring and limits
for total copper, total lead, and total zinc. Request to know how analysis done to
determine a reasonable potential to exceed water quality standards and how
determination made for value of numerical limits. Town believes there is
insufficient data to determine capability to comply with total copper limits but
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NCO072699 Renewal
Page 5

sufficient data to support discontinuance of limits and monitoring for Total Lead.
Town asks to do no more than monitor Total Copper and neither monitor nor set
limits for Total Lead and Total Zinc. Additional information provided in written
comments. Per permittee: "To continue sampling and testing the softener
regeneration -backwash discharge for metals that appear to be present only at very
low levels should not be a requirement of the permit issued to the Town of
Beaufort."
o DWR response: A compliance schedule has been added to the permit as Section
A. (4) for Total Copper, Total Lead, and Total Zinc. Monitoring will remain for
all 3 parameters with a measurement frequency of monthly. Please note that the
practical quantitation limits (PQLs) for Total Copper and Total Lead are 2 gg/L,
and the PQL for Total Zinc is 10 µg/L (per the Inorganic Chemistry Branch of the
Division of Water Resources Water Sciences Section) and monitoring data should
be reportable down to these levels. Per North Carolina 15A NCAC 02B Water
Quality Standards for Surface Waters, the current limits for class SC waters for
copper are 4.8 gg/L (acute) and 3.1 gg/L (chronic), for lead are 210 µg/L (acute)
and 8.1 gg/L (chronic), and for zinc are 90 gg/L (acute) and 81 gg/L (chronic).
Limits for water treatment plants are determined by evaluating DMR data
submitted to the Division, along with a dilution factor (if applicable) and the
maximum monthly average flow reported in the previous 3 years at the time the
review is completed.
■ WiRO comments (Dean Hunkele via email 12/7/17): Dean concurs with
the compliance schedule being added.
• Thirteenth bullet (from draft cover sheet):
o Bullet states: The sampling type for all parameters, other than flow, has been
changed from grab to composite in Section A. (1), and an associated footnote has
been added.
o Permittee response: The Town would prefer no change from grab to composite
sampling of the small discharge at the Pine Street WTP. However it understands
position of the NPDES Unit and would ask for assistance in making transition.
Beaufort is requesting that it not be required install a composite sampler within
two (2) months of the date of permit issuance. Instead the Town would request
twelve (12) months to utilize hand sampling as described by draft while
determining and evaluating "another method approved by Wilmington Regional
Office" as compared to installing a composite sampler. If evaluation determines it
best to install a composite sampler, time for planning and design will be needed to
ensure having a workable composite sampler for the old Pine Street WTP. It is not
a simple plug -in -play exercise. [additional information provided in letter]
o WiRO comments (Dean Hunkele via email 12/7/17): That whole Footnote is
confusing. Being an intermittent discharger, they could either use a sampler to
collect OR we can approve/accept them creating their own composite via multiple
grabs of at least 120 mL at a frequency of every 15 mins or less for the enter cycle
including recharge. They just need to make sure they collect enough sample for
all the required analyses. We can assist them with the latter method and shouldn't
take but any longer than 2 months. I agree it may take a little more discussion or
thought to install a composite sampler and sampling location and may include
adding a take to comingle the waste streams for sampling.
o DWR response: Composite sampling will remain in the permit. The language
concerning this has been moved from the footnotes in Section A. (1) into the new
Section A. (3). The Division has determined that two (2) months from the permit
effective date is sufficient time to complete the requirement.
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NCO072699 Renewal
Page 6

• The Town is amenable to the changes identified by the fourteenth bullet and fifteenth
bullet.
o Fourteenth bullet (from draft cover sheet): The footnote for aquatic toxicity
monitoring has been updated in Section A. (1). Monitoring for toxicity in
conjunction with metals and total residual chlorine is no longer required.
o Fifteenth bullet (from draft cover sheet): Language in Section A. (2) has been
updated.
Town of Beaufort, Pine Street WTP Fact Sheet
NPDES Permit NCO072699 Renewal
Page 7