NC0072702_Fact Sheet_20180209

DENR/DWQ
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NCO072702
SUMMARY
The Beaufort Glenda Drive 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 hydrofluosilicic
acid. The backwash and softener regeneration wastewater is estimated to be 0.005 MGD average
at plant capacity of 0.6 MGD potable water. Recent operating data (April 2014 — May 2017)
show a maximum monthly average discharge flowrate of 0.0258 MGD. The facility discharges
the backwash wastewater after dichlorination with sodium bisulfite to an unnamed tributary to
Turner Creek in the White Oak River Basin. The discharge is to a dry ditch with no normal flow
except the discharge and storm water.
The receiving stream (Turner Creek) is classified SA, HQW PNA waters in the White Oak River
Basin. This reach is listed on the 2014 303(d) list — Shellfish growing area Conditionally
approved closed (Fecal, SH, SA) (see below).
21-35-1-11-1 Turner Creek 51.8 S Acres SA;HQW
From source to Davis Bay
IRCategory: ACS: Parameter Of Interest: Collection Year: 303(d) yr:
5 EC Shellfish Growing Area -Conditionally Approved Closed (Fecal, SH, SA) 2010 2002
Town of Beaufort, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 Renewal
Page 1
Facility Information
Applicant/Facility Name:
Town of Beaufort/ Glenda Drive Water Treatment Plant
Applicant Address:
PO Box 390, Beaufort, North Carolina 28516
Facility Address:
412 Glenda Drive, Beaufort, North Carolina 28516
Permitted Flow
Not limited. Design capacity
is 0.005 MGD.
Type of Waste:
Filter backwash and Ion Exchange regeneration
Facility/Permit Status:
Renewal
Facility Classification
PC -1
County:
Carteret
Miscellaneous
Receiving Stream:
UT to Turner Creek, White
Oak RB
Regional Office:
Wilmington
Stream Classification:
SA, HQW, PNA
USGS Topo
Quad:
Beaufort
303(d) Listed?
Yes; See below
Permit Writer:
Brianna Young
Subbasin:
03-05-04
Date:
2/9/2018
HUC
0302030105
Drainage Area mit :
N/A
Summer 7Q 10 cfs
Tidal
Winter 7Q10 cfs :
Tidal
30Q2 cfs
Tidal
Average Flow cfs):
Tidal
IWC (%):
100% capped at 90% for
WET
Primary SIC Code:
N/A
SUMMARY
The Beaufort Glenda Drive 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 hydrofluosilicic
acid. The backwash and softener regeneration wastewater is estimated to be 0.005 MGD average
at plant capacity of 0.6 MGD potable water. Recent operating data (April 2014 — May 2017)
show a maximum monthly average discharge flowrate of 0.0258 MGD. The facility discharges
the backwash wastewater after dichlorination with sodium bisulfite to an unnamed tributary to
Turner Creek in the White Oak River Basin. The discharge is to a dry ditch with no normal flow
except the discharge and storm water.
The receiving stream (Turner Creek) is classified SA, HQW PNA waters in the White Oak River
Basin. This reach is listed on the 2014 303(d) list — Shellfish growing area Conditionally
approved closed (Fecal, SH, SA) (see below).
21-35-1-11-1 Turner Creek 51.8 S Acres SA;HQW
From source to Davis Bay
IRCategory: ACS: Parameter Of Interest: Collection Year: 303(d) yr:
5 EC Shellfish Growing Area -Conditionally Approved Closed (Fecal, SH, SA) 2010 2002
Town of Beaufort, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 Renewal
Page 1

Permitting Strategy
Permitting Strategy for Ion Exchange Water Treatment Plants is followed for this facility.
Discharge Data Review and RPA
The maximum Monthly Average flow was 0.025814 MGD in October 2016 (data from April
2014 to May 2017). RPA was performed for copper, zinc, and lead (data from October 2012 to
May 2017). Copper and Zinc have RP, limits added with monthly monitoring. Lead showed no
RP (no detects); monitoring retained as previous permit showed RP but reduced to quarterly.
Whole Effluent Toxicity Testing
The facility currently performs Quarterly Acute Toxicity monitoring using Mysidopsis Bahia
(Mysid shrimp) at 90% as required by the current permit. The facility has passed the previous 11
of 12 WET tests. WET testing should continue as Acute monitoring only with mysid shrimp at
90%. The WET testing language [A. (2.)] has been updated.
303(d) language for Draft/Final Cover Letters: "Please note that the receiving stream is listed as
an impaired waterbody on the North Carolina 303(d) Impaired Waters List. Addressing impaired
waters is a high priority with the Division, and instream data will continue to be evaluated. If
there is noncompliance with permitted effluent limits and stream impairment can be attributed to
your facility, then mitigative measures may be required".
Chanes from the previous permit to draft:
• Updated outfall map
• Added regulatory citations
• Added parameter codes to effluent table in A(1)
• Expiration month changed to allow full 5 -year permit cycle
• Added eDMR language in A(1) and added section A(5)
• Updated language on Supplement to Permit Cover Sheet per 2012 WTP guidance
• Moved pH limits from footnote to effluent table in A(1)
• Flow sample type changed from estimate to instantaneous and measurement frequency
changed to 2/month per 2009 WTP strategy since discharge is intermittent
• Limits added for copper and zinc based on RPA and monitoring changed to monthly
• Limits for lead removed since no RP to exceed water quality standards; monitoring
reduced to quarterly
• Sample type for all parameters except flow changed from grab to composite based on
feedback received from WiRO (see below)
o Compliance schedule 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
• Changed TRC limit from just daily max to daily max and monthly average per 2009
WTP strategy
• Updated tox footnote in A(1) — removed "Monitoring for Toxicity shall coincide with
monitoring for metals and TRC."
• Updated TRC footnote
• Flow footnote added in A(1)
• Updated tox language in A(2)
Town of Beaufort, Glenda Drive WTP Fact Sheet
NPDES Permit NC0072702 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)
• Compliance schedule added as Section A. (4) for total copper and total zinc (per
permittee's and WiRO 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)
• 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:
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 has been changed from grab to composite based on
feedback received from Frank Sansone (ORC) that he samples only during 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
• 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.
DMF COMMENT:
JD Potts stated no comments via email 11/2/17
Town of Beaufort, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 Renewal
Page 3

COMMENTS RECEIVED FROM PERMITTEE (VIA EMAIL 11/30/17)
• The Town is amenable to the changes identified by the first six bullets with only three
comments; please see fifth bullet regarding Supplement to the Cover Sheet.
o Fifth bullet (from draft cover sheet): The Supplement to Permit Cover Sheet has
been updated per the current water treatment plant guidance.
o Permittee response: On Page 2 of 8, the component we are using for addition of
fluoride is Hydrofluorosilicic Acid.
■ DWR Response: Hydrofluorosilicic acid has been added to the
components list and defined to be for fluoride addition.
o Permittee response: On Page 2 of 8 and 3 of 8 we suggest the discharge
description 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 0.0258
MGD". This number does not seem relevant to data covering the most recent 22
months which indicates an average daily flow of 0.0044 MGD and a maximum
monthly average of 0.0057 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 October 2016. 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 seventh bullet and twelfth
bullet (from draft cover sheet).
o Seventh bullet (from draft cover sheet): The flow sample type has been changed
to instantaneous and the measurement frequency changed to 2/month per the
current water treatment strategy.
o Twelfth bullet (from draft cover sheet): Footnote for flow has been added in
Section A. (1) concerning log books.
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, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 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
11/2 -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.
All things considered, the Town has no immediate concern regarding the eighth bullet.
o Eighth bullet (from draft cover sheet): The limits for pH have been moved from
the footnotes to the effluent table in Section A. (1).
In regard to ninth bullet and the tenth bullet, the Town requests explanation regarding
addition of limits for Total Copper and Total Zinc.
o Ninth bullet (from draft cover sheet): Limits have been added for Total Copper
and Total Zinc in Section A. (1) based on a reasonable potential to exceed water
quality standards. Associated monitoring has been changed to monthly.
o Tenth bullet (from draft cover sheet): Limits have been removed from Total Lead
and monitoring has been reduced to quarterly in Section A. (1) as there is no
longer a reasonable potential to exceed water quality standards based on
submitted DMR data.
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
Town of Beaufort, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 Renewal
Page 5

sufficient data to support discontinuance of limits and monitoring for Total Lead
and Total Zinc. Town asks to do no more than monitor Total Copper, neither
monitor nor set limits for Total Zinc, and not monitor for Total Lead. 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 and Total Zinc. Monitoring will remain for both
parameters with a measurement frequency of monthly. Please note that the
practical quantitation limit (PQL) for Total Copper is 2 µg/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 SA waters for
copper are 4.8 µg/L (acute) and 3.1 ttg/L (chronic), and for zinc are 90 µg/L
(acute) and 81 ttg/L (chronic). However, the High Quality Waters (HQW)
designation of the receiving stream decreases the limits of the water quality
standards. 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.
• All things considered, the Town has no immediate concern regarding the eleventh,
thirteenth and fifteenth bullet
o Eleventh bullet (from draft cover sheet): The limit for Total Residual Chlorine in
Section A. (1) has been changed to both a daily maximum and monthly average.
o Thirteenth bullet (from draft cover sheet): Footnotes for total residual chlorine
and aquatic toxicity have been updated in Section A. (1).
o Fifteenth bullet (from draft cover sheet): Language in Section A. (2) has been
updated.
o Permittee response: 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."
• Fourteenth bullet (from draft cover sheet):
o Fourteenth bullet (from draft cover sheet): The sampling type for all parameters,
except flow, have been changed from grab to composite in Section A. (1), and an
associated footnote has been added.
o Permittee response: Beaufort is requesting that it not be required to 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
Glenda Drive WTP. It is not a simple plug -in -play exercise. [additional
information describing challenges provided in written comments]
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
Town of Beaufort, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 Renewal
Page 6

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, Glenda Drive WTP Fact Sheet
NPDES Permit NCO072702 Renewal
Page 7