NC0037508_Speculative Limits_19990120

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Hobbs, Upchurch & Associates, P.A.
Consulting Engineers
I Vj 290 S.W. Broad Street @ Post Office Box 1737 • Southern Pines, NC 28388
January 20, 1999
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Mr. Steve Pellei VrbENAA AX \TXcz OPEC - t�-1R Ne w
NPDES Unit `�
Water Quality Section 1J 0
Post Office Box 29535
Raleigh, North Carolina 27626-0535
RE: Clarification of Speculative Limits
NPDES No. NC0037508
Moore County Regional WWTP
Moore County
Dear Mr. Pellei:
Le
Hobbs, Upchurch & Associates, P.A. is in the process of preparing a 201 Facilities Plan
Update for the Moore County Regional Wastewater Treatment Plant. As part of this
process we submitted a request for speculative limits to Mr. David Goodrich. In his letter
dated January 12, 1999, Mr. Goodrich outlined the speculative limits and identified
concerns regarding expansion of the Moore County Regional Wastewater Treatment Plant.
After reviewing Mr. Goodrich's letter we would like to request clarification of the basis for
assigning more stringent effluent requirements to the expanded Moore Regional WWTP
discharge. In addition, we would like to request clarification of expected impacts to
Drowning Creek.
i
It is our understanding based on the current Lumber River policy and based on 15 NCAC 00,
2B .0201d(1)(C) that existing NPDES wastewater discharges will be allowed to expand
with no increase in permitted pollutant loading. The rules require more stringent limits for
disc'.raraes in High Quality Waters. however the Moore County Regional WWTP -
discharges to Aberdeen Creek, which is a Class C water.
The letter seems to indicate that the speculative limits were assigned based on model
results that predicted the increased discharge will violate the instream dissolved oxygen
standard of 5 mg/1. Did the model predict the violation in Aberdeen Creek or Drowning 0 Cf-V,
Cr`ek' Also, did the expected increase in the County's instream waste concentration
contribute to the more strict effluent limitations? It is our understanding that the 50% IWC
limit does not apply to Aberdeen Creek because it is not classified as HQW. c,wtr IT was "IT Opf'. d
The letter raises concerns about the 7Q10 of Drowning_ Creek. Does the model that was
used to set the speculative limits examine the IWC of Drowning Creek? If so, what impact
does the igcreased_discharge have? Also, the Town of Southern Pines has received permits
Southern Pines, NC • Telephone [phone] * Fax [phone] • e-mail: huamain®pinehurst.net
Myrtle Beach • Kill Devil Hills • Raleigh

Mr. Steve Pellei
Speculative Limits — Moore County Regional WWTP
January 20, 1999
Page 2
to expand the water plant to 8 MGD. The expansion will be phased with the initial
expansion to 5 MGD occurring in 1999 and the remaining expansions taking place as
dictated by system demand. Will the expansion of the Southern Pines Water Treatment VO M
Plan impact the speculative limits that were provided in Mr. Goodrich's letter?
Thank you very much for your assistance in this matter. If you have any questions or if
you require additional information please feel free to call Michael Wicker or me at (910)
692-5616.
Sincerely,
'L;riLJRCt & ASSOC!WFES, P.A.
Stephanie Closson, E.I.T.

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
January 12, 1999
Mr. Gary Frick
County of Moore
P.O. Box 905
Carthage, North Carolina 28327
NCDENR
Subject: Request for Speculative Limits
NPDES No. NCO037508
Moore County Regional WWTP
Moore County
Dear Mr. Frick:
Reference is made to the November 16, 1998 request submitted by Stephanie Closson of Hobbs,
Upchurch & Associates, for speculative effluent limits for the Moore County Regional WWTP. The
Moore County Regional WWTP currently has a permit to discharge 6.7 MGD of treated wastewater to
Aberdeen Creek in the Lumber River Basin. The requested speculative limits were for flows at 10.0
MGD and 15.0 MGD and are reflective of the County's 20-year flow projection.
The Division has reviewed the request, and provides the following responses.
Discharge to Aberdeen Creek in the Lumber River Basin
Moore County's current permit allows a discharge of 6.7 MGD with summer limits for BOD5 and NH3 as
N of 22 and 17 mg/1 respectively. The 7Q 10 flow at the discharge location in Aberdeen Creek is 15.2 cfs
and the average stream flow is 47.2 cfs. The Moore County WWTP effluent is a large part of the stream
flow with the current discharge constituting 41 % of the instream waste concentration (IWC).
Aberdeen Creek is approximately 1.4 miles upstream of Drowning Creek. Any discharges from the
Moore County WWTP will likely have a significant impact on the water quality in Drowning Creek.
There are several issues you should be aware of pertaining to any expansion.
1) Based on the 1994 Lumber River Basinwide Water Quality Management Plan, Drowning Creek is
designated as HQW (high quality waters) from its source to the Lumber River. This designation
identifies Drowning Creek as water of high resource value or a biologically sensitive water. The
HQW classification provides greater protection through more stringent point source and nonpoint
source pollution controls than do basic water quality classifications. Protection of these waters is a
basic responsibility of the state's water quality program and a primary goal of the basinwide
management.
2) Most of the tributaries in the Lumber River are classified as swamp waters. Areas in and around
Aberdeen Creek may be characterized by slow moving swamp -like waters that do not flush well.
Swamp -like waters tend to trap nutrients, cause localized eutrophication, promote algal blooms, and
add to existing basinwide problem of low dissolved oxygen. This can be attributed to long
detention times and low re -aeration constants that are characteristic of the swamp -like waters.
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled / 10% post -consumer paper

Moore County 11/16/98 request
Speculative Limits
Page 2
3) Moore County draws water from Drowning Creek near Highway 1. They are currently permitted
to withdraw up to 8.0 MGD, but have made plans for withdrawing up to 14.0 MGD. Earlier
modeling analysis did not include any upstream withdrawal considerations, which would have
altered the 7Q 10 flows. Increased withdrawal result in a decreased ability of the receiving stream
to effectively assimilate point source discharges and nonpoint source wastes.
Expansions to 10.0 and 15.0 MGD
The Division has concerns whenever a discharge comprises a large percentage of the receiving stream.
Expansions to 10.0 and 15.0 MGD will increase the respective IWCs to 50% and 60% of Aberdeen
Creek. In addition, future withdrawals from Drowning Creek will decrease the amount of stream flow
available for waste assimilation downstream.
Results of an evaluative model predicted dissolved oxygen concentrations less than the water quality
standards using existing loading from your W WTP. According to model predictions, current loads at
flows of 10.0 and 15.0 MGD will violate the instream water quality standard of 5.0 mg/l.
Based on the current permitted loads, there is insufficient assimilative capacity to maintain dissolved
oxygen levels above the state's water quality standards. For this reason the Division can only allow an
expansion of the Moore County Regional W WTP at reduced loads.
To meet the minimum water quality standard of 5.0 mg/I advanced tertiary treatment would be required.
Therefore, the Division must limit expansions at 10.0 MGD and 15.0 MGD to summer BOD5 and NH3 as
N of 5.0 and 1.0 mg/I respectively. Speculative effluent limits for these expansions are attached. Please
note any differences when compared to existing limits.
Future Considerations
The speculative limits presented here are based on our understanding of the proposal and of present
environmental conditions. Over time these conditions may change. The Division of Water Quality
(DWQ) cannot guarantee that it will issue the County an NPDES permit to expand its discharge of treated
wastewater into waters of the State. Nor can we guarantee that the effluent limitations and other
requirements included in any permit will be exactly as presented here. Final decisions on these matters
will be made only after the Division receives and evaluates a formal permit application for the County's
proposed discharge.
Environmental Assessments of New Projects and Expansions
The County will have to evaluate this project for environmental impacts before applying for a permit
modification. Anyone proposing to construct new or expanded waste treatment facilities using public
funds or public (state) lands must first prepare an environmental assessment (EA) when wastewater flows
(1) equal or exceed 0.5 MGD or (2) exceed one-third of the 7Q10 flow of the receiving stream. The
Division will not accept a permit application for a project requiring an environmental assessment until the
Division has approved the EA and sent a Finding of No Significant Impact (FONSI) to the state
Clearinghouse for review and comment.
The Environmental Assessment should contain a clear justification for the expanded flow. It should
provide a comprehensive analysis of potential alternatives to expansion, including a thorough evaluation
of non -discharge alternatives. Nondischarge alternatives to expansion, such as spray irrigation, water

Moore County 11/16/98 request
Speculative Limits
Page 3
conservation, and inflow and infiltration reduction are considered to be environmentally preferable to a
surface water discharge.
In accordance with the North Carolina General Statutes, the preferred alternative must be the practicable
waste treatment and disposal alternative with the least adverse impact on the environment is required to
be implemented. If the EA demonstrates that the project may result in a significant adverse effect on the
quality of the environment, you must then prepare an Environmental Impact Statement. Gloria Putnam of
the Water Quality Planning Branch can provide additional information regarding the requirements of the
N.C. Environmental Policy Act. You can contact Ms. Putnam directly at [phone], ext. 567.
I trust this response offers sufficient guidance for the city's proposed expansion. If you have any
additional questions about the speculative limits, feel free to contact Steve Pellei at [phone],
extension 516.
Sincerely, // o
David A. Goodrich
Supervisor, NPDES Unit
Water Quality Section
cc: Stephanie Closson, Hobbs, Upchurch & Associates
P.O. Box 1737 Southern Pines, NC 28388
Fayetteville Regional Office, Water Quality Section
Central Files
NPDES Permit Files

A (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS Speculative
Permit No. NC0037508
During the period beginning upon expansion above 6.7 MGD and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial
number 001. Such discharges shall be limited and monitored by the Permittee as specified below:
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REV111:1RE11TEATS
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Measurement Frequency
Type•EZ
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Notes:
` Sample lo6yie s: E Effluer.dun
nt, - U am at least 100 feet from outfall, D1 - Downstream at NCSR 1225. Stream samples shall be
collected three es er weonths of June, July, August, and September and once per week during the remaining months of the year.
I The monthlKave age (fluent and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85% removal).
2 The daily avbrag diss Ived oxygen effluent concentration shall no be less than 6.0 mg/l.
3 The pH shall no a less than 6.0 standard units nor greater than 9.0 standard units.
Total Residua hlodne shall be monitored only if chlorine is added as part of the treatment process.
5 Limits for this parameter may be instituted at a future date.
6 Chronic Toxicity (Ceriodaphnia) P/F at 50%; March, June September and December, See Part I, Section A, Special Condition.
7 Limits and monitoring for these parameters will be determined upon evaluation of effluent data.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS Speculative
Permit No. NC0037508 •
During the period beginning upon expansion above 6.7 MGD and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial
number 001. Such discharges shall be limited and monitored by the Permittee as specified below:
C••— • •
III rol\ 1 k 1501• 41 -1 ml r I a \ III
Monthly
Average
Veekly
Zerage
Daily
1 Maximum
flleasuremenll!—'�
Frequency
Total Suspended Residue,
- _ • • . -. --ric mean)��IU1`[III]711��Ii11��11
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WMEM
Notes:
Sample IoraY'e s: E Effluent I - Influent, U am at least 100 feet from outfall, D1 - Downstream at NCSR 1225. Stream samples shall be
collected three es er wee dun g t onths of June, July, August, and September and once per week during the remaining months of the year.
I The monthlXg ave ge ffluent B and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85% removal).
2 The daily avbrag diss Ived oxygen effluent concentration shall no be less than 6.0 mg/l.
3 The pH shall no a less than 6.0 standard units nor greater than 9.0 standard units.
° Total Residua hlorine shall be monitored only if chlorine is added as part of the treatment process.
5 Limits for this parameter may be instituted at a future date.
6 Chronic Toxicity (Ceriodaphnia) P/F at 60%; March, June September and December, See Part I, Section A, Special Condition.
7 Limits and monitoring for these parameters will be determined upon evaluation of effluent data.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

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(1.) Facility Name:
Moore County Regional WWTP
(2.) Permitted Flow (MGD):
6.7 to Aberdeen Crk
(5.) County:
Moore
(3.) Facility Class:
IV
(6.) Regional Office:
FRO
(4.) Facility/Permit Status:
Speculative Req
(7.) USGS Topo Quad:
G 21 SW
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(1.) Receiving Stream:
Aberdeen Creek in the
Lumber Basin
(2.) Stream Classification:
C
(6.) Winter 7Q 10 (cfs):
28.7
(3.) Subbasm:
030750
(7.) 30Q2 (cfs):
(4.) Drainage Area (mi2):
36.3
(8.) Average Flow (cfs):
47.2
(5.) Summer 7Q 10 (cfs)
15.2
1 (9.) IWC (%):
41 %
i 3• � s••i�^4--c f�' •'i = � € :: ...... 7t ,��,t:c-:a � 7 ti tt _ i c . i :�t:r . ,:;tu-r v-' i �+ :;}.:.
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1 •P'7 !!7 �t [•'� z t 1. a.. c .. ._,= Y . a �' �� 7 -Ka# ,a; T tt
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(1.) Flow:
10.0 MGD
(1.)
IWC (%):
50%
(2.) Flow:
15.0 MGD
(1.)
IWC (%):
160%
Please see attached letter for the Division's response.
Background:
These speculative limits are in response to the Moore County's request for limits for expansions as outlined in
the 11/16/98 letter from Hobbs, Upchurch & Associates. To accommodate their 20-year flow projection
requested limits for two scenarios: Expansion to 10.0 MGD and to 15.0 MGD at the existing location.
Investigations:
The specific management strategy for 030750 is to hold expanders to existing mass loads unless adverse
impacts are anticipated.
A model run by F. Keogh was constructed to reflect increased water withdrawals that can be expected from
Moore County on Drowning Creek near Highway 1. The model was run at five different scenarios and
predicted DOs below 5.0 mg/1 for four of the scenarios. The last scenario was run for a withdrawal of 14.0
MGD and a discharge of 10.0 MGD. This run predicted protection of instream standards with the following
summer limits:
BOD5 5 mg/l
NH3 2 mg/l
DO 6 mg/1
The ammonia limits given in this speculative effluent page are 1.0 and 2.0 (summer/winter) as these limits are
Bat for this size facility.
DMR instream data for DO showed no significant difference from upstream values to downstream. All values
were above the standard of 5.00 mg/l. Effluent data also looked good.
Expansion at the existing location in Aberdeen Creek
Moore County's current permit allows a discharge of 6.7 MGD with summer limits for BOD5 and NH3 as N
of 22 and 17 mg/l respectively. The 7Q 10 flow at the discharge location in Aberdeen Creek is 15.2 cfs and the
average stream flow is 47.2 cfs. The Moore County WWTP effluent is a large part of the stream flow with the
current discharge constituting 41 % of the instream waste concentration (IWC).
Aberdeen Creek is approximately 1.4 miles upstream of Drowning Creek. Any discharges from the Moore
County WWTP will likely have a significant impact on the water quality in Drowning Creek. Expansions to
10.0 and 15.0 MGD will increase the respective IWCs to 50% and 60% of Aberdeen Creek. In addition,
future withdrawals from Drowning Creek will decrease the amount of stream flow available for waste
assimilation downstream.

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Hobbs, Upchurch & Associates, P.A.
Consulting Engineers
290 S.W. Broad Street • Post Office Box 1737 • Southern Pines, NC 28388
November 11, 1998
Mr. Steve Zoufaly
NC Division of Water Quality — Planning Branch
Post Office Box 29535
Raleigh, North Carolina 27626-0535
RE: Scoping Letter
North Carolina 201 Facilities Plan Update
Moore County
HUA No. M09804
Dear Mr. Zoufaly:
Moore County intends to update its 201 Facilities Plan, including an Environmental
Assessment, for the existing County -owned 6.7 million gallon per day (mgd) wastewater
treatment facility. The facility discharges to Aberdeen Creek, a Class C water in the
Lumber River Basin. The attached Pinebluff Quadrangle map shows the location of the
treatment facility. The Moore County wastewater treatment plant is a regional facility,
and currently receives waste from the Towns of Aberdeen, Carthage, Pinebluff,
Pinehurst, Southern Pines, and Pinebluff Manufacturing.
The 201 Facilities Plan will evaluate the alternatives open to the County for treating the
wastewater from the existing regional service areas. The plan will examine potential
annexation and ETJ areas for the service areas for the next 20 years. Discharge and non -
discharge options will be evaluated. The County has requested speculative limits from
the Division of Water Quality (DWQ) for expanded NPDES permit flows of 10 and 15
mgd. Speculative limits have not been provided to date, however it is likely that it will
be necessary to follow the existing Lumber River policy requiring no increase in pounds
per day pollutant loads. The current permit levels for BOD, TSS, and Ammonia are 22.0
mg/l, 30 mg/I, and 17 mg/l, respectively. Based on that policy, the anticipated
speculative limits for a 10 mgd facility will be approximately 14.7 mg/l BOD, 20.1 mg/1
TSS, and 11.4 mg/1 Ammonia. The anticipated speculative limits for a 15 mgd facility
are approximately 9.9 mg/1 BOD, 13.5 mg/I TSS, and 7.7 mg/I Ammonia. It is
anticipated that the site of the existing wastewater treatment plant can accommodate the
construction of additional facilities for the increased discharge options. Non -discharge
options would require the acquisition of off -site lands for the purposes of land
application.
Southern Pines, NC • Telephone [phone] * Fax [phone] • e-mail: [e-mail]
Myrtle Beach • Kill Devil Hills • Raleigh

Mr. Steve Zoufaly
NC Division of Water Quality — Planning Branch
Page 2 of 2
November 11, 1998
In addition to increasing the capacity of the existing regional wastewater treatment
facility, the 201 Facilities Plan will include an upgrade of the Southern Pines #4 lift
station. It is anticipated that the existing lift station site will be adequate to accommodate
the planned upgrade. The attached Southern Pines Quadrangle map shows the location of
the lift station.
The completed 201 Plan will require an Environmental Assessment, which will be
circulated through the State Clearinghouse. The purpose of this scoping letter is to solicit
your comments and constructive guidance during the development of the plan to avoid
unforeseen problems and expedite the evaluation process. We request that your
comments be forwarded to this office by December 31, 1998 so we will have time to
address issues prior to submittal.
If you have any questions about this matter please contact me at [phone].
Sincerely,
Hobbs, Upchurch
Associates, P.A.
C�-
Stephanie F. Closs
n
Enclosure