NC0071773_Permit Modification_20071231

f�'
NCDENR
North Carolina Department of Environment and
Division of Water Quality
Michael F. Easley, Governor
December 31, 2007
Mr. Donald Hawks
Yadkin County Board of Education
121 Washington Street
Yadkinville, N.C. 27055
Natural Resources
William G. Ross, Jr., Secretary
Coleen H. Sullins, Director
Subject: Modification of NPDES Permit NC0071773
Forbush High School WWTP
Yadkin County
Dear Mr. Hawks:
Division personnel have reviewed and approved your request to modify the subject permit. This
modified permit is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and
the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency
dated October 15, 2007 (or as subsequently amended).
If any parts, measurement frequencies or sampling requirements contained in this permit are
modification unacceptable to you, you have the right to an adjudicatory hearing upon written request within
thirty (30) days following receipt of this letter. This request must be in the form of a written petition,
conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of
Administrative Hearings (6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such
demand is made, this decision shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Quality or permits
required by the Division of Land Resources, the Coastal Area Management Act or any other Federal or Local
governmental permit that may be required.
If you have any questions concerning this permit, please contact Dr. Sergei Chernikov at telephone
number [phone], extension 594.
Sincerely,
/ W
n: Coleen H. Sullins
cc: Central Files
Asheville Regional Office/Surface Water Protection
NPDES Unit
John F. Phillips / Diehl & Phillips [219 East Chatham Street, Cary, NC 275111
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
512 North Salisbury Street, Raleigh, North Carolina 27604 NorthCarolina
Phone: [phone] / FAX [phone] / Internet: www.ncwaterquality.org �l//�
An Equal Opportunily/Atfirmative Action Employer— 50% Recycled/10% Na��N
Post Consumer Paper L

Permit NCO071773
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provisions of North Carolina General Statute 143-215.1, other
lawful standards and regulations promulgated and adopted by the North Carolina
Environmental Management Commission, and the Federal Water Pollution Control Act, as
amended, the
Yadkin County Board of Education
is hereby authorized to discharge wastewater from a facility located at
Forbush High -School
1525 Falcon Road
East Bend
Yadkin County
to receiving waters designated as Forbush- Creek in subbasin 03-07-02 of the
Yadkin -Pee Dee River Basin in accordance with effluent limitations, monitoring
requirements, and other conditions set forth in Parts I, II, III and IV hereof.
This permit shall become effective February 1, 2008.
This permit and authorization to discharge shall expire at midnight on December 31, 2008.
Signed this day December 31, 2007.
4en H. Sullins, Director
Ision of Water Quality
Authority of the Environmental Management Commission

Permit NCO071773
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of this permit
issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive authority to operate
and discharge from this facility arises under the permit conditions, requirements, terms, and provisions included herein.
The Yadkin County Board of Education hereby authorized to:
1. Continue to operate an existing wastewater treatment system that includes the
following components:
➢ 8,000-gallon equalization basin
➢ two (2) 13,000-gallon aeration basins
➢ two (2) 3,250-gallon clarifiers
➢ UV disinfection system capable of treating peak flows of up to 65,000 GPD
➢ 1,500-gallon backup tablet chlorination/dechlorination unit
This facility is located at Forbush High School, off Falcon Road southwest of East
Bend in Yadkin County.
2. After receiving an Authorization to Construct permit from the Division, construct
wastewater treatment facilities not to exceed 0.026 MGD design flow.
3. Discharge treated wastewater from said treatment works at the location specified
on the attached map into Forbush Creek (via outfall 001), currently classified
WS-IV waters in the Yadkin -Pee Dee River Basin.

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Latitude: 360829
Longitude: 803344
USGS Quad#: C 16NE N
River Basin#: 030702 Yadkin
Receiving Stream: Forbush Creek
Stream Class: WS-1V
0
Yadkin County Schools
Forbush High School
NC 0071773
Yadkin County

Permit NC0071773
A. (l.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[0.015 MGD]
During the period beginning on the effective date of this permit and lasting until expansion
or expiration, the Permittee is authorized to discharge from outfall 001. Such discharges
shall be limited and monitored by the Permittee as specified below:
PARAMETER
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location
Flow
0.015 MGD
Weekly
Instantaneous
Influent or
Effluent
BOD, 5-day (202C)
30.0 mg/L
45.0 mg/L
Weekly
Grab
Effluent
Total Suspended Solids
30.0 mg/L
45.0 mg/L
Weekly
Grab
Effluent
NH3 as N
2/Month
Grab
Effluent
Fecal Coliform
(geometric mean
200/100 mL
400/100 mL
Weekly
Grab
Effluent
Total Residual Chlorine (TRC),
28ug/L
2/Week
Grab
Effluent
Temperature (4C)
Weekly
Grab
Effluent
Total Nitrogen (TN)
Quarterly
Grab
Effluent
Total Phosphorus (TP)
Quarterly
Grab
Effluent
pH
> 6.0 and < 9.0 standard units
2/Month
Grab
Effluent
Footnotes:
1. TRC limit and monitoring requirements apply only if chlorine is added to the treatment
system.
There shall be no discharge of floating solids or visible foam in other than trace amounts

TIM
Permit NCO071773 1
A. (2.) EFFLUENT MUTATIONS AND MONITORING REQUIREMENTS
[0.026 MGD]
During the period beginning upon expansion and lasting until expiration, the Permittee is
authorized to discharge from outfall 001. Such discharges shall be limited and monitored
by the Permittee as specified below:
PARAMETER
LIMITS
MONITORING REQUIREMENTS
Monthly
Average—
Daily
Maximum
Measurement
Frequency
Sample Type
Sample
Location
Flow
0.026 MGD
Weekly
Instantaneous
Influent or Effluent
BOD, 5-day (202C)
30.0 mg/L
45.0 mg/L
Weekly
Grab
Effluent
Total Suspended Solids
30.0 mg/L
45.0 mg/L
Weekly
Grab
Effluent
NHs as N
2/Month
Grab
Effluent
Fecal Coliform
(geometric mean
200/100 mL
400/100 mL
Weekly
Grab
Effluent
Total Residual Chlorine (TRC)1
28 pg/L
2Meek
Grab
Effluent
Temperature (°C)
Weekly
Grab
Effluent
Total Phosphorus (TP)
Quarterly
Grab
Effluent
Total Nitrogen (TN)
Quarterly
Grab
Effluent
pH
> 6.0 and < 9.0 standard units
2/Month
Grab
Effluent
Footnotes:
1. TRC limit and monitoring requirements apply only if chlorine is added to the
treatment system.
There shall be no discharge of floating solids or visible foam in other than trace amounts

" State of North Carolina
Department of Environment,
• : '
and Natural Resources
Division of Water Quality NOV 0 0 2D07
James B. Hunt, Governor
NCDENR
Bill Holman, Secretary
Kerr T. Stevens, Director
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
November 7, 2007
MEMORANDUM
li
To: Lee Spencer
—RR—__y_,z
l Ily
NC DENR / DEH / Regional Engineer
r, L IS
Winston-Salem Regional Office
I
From: Sergei Chemikov
i
j JAN _
8 2008 -
NPDES-West
Subject: Review of Draft NPDES Permit NCO071773
j
Yadkin County BOE — Forbush High School
— —
Yadkin County
Please indicate below your agency's position or viewpoint on the draft permit and return this form by
December 10, 2007. If you have any questions on the draft permit, please contact me at the telephone
number or e-mail address listed at the bottom of this page.
RRRRaRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRaR
RESPONSE: (Check one)
one with the issuance of this permit provided the facility is operated and maintained properly, the stated
effluent limits are met prior to discharge, and the discharge does not contravene the designated water quality
standards.
❑ Concurs with issuance of the above permit, provided the following conditions are met:
❑ Opposes the issuance of the above pemtit, based on reasons stated below, or attached:
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 919 733-5083, extension 538 (fax) 919 733-0719
VISIT US ON THE INTERIET@http://h2o.encstate.ne.us/NPDES [e-mail] JAN 0 7 , .3

PUBLIC NOTICE
STATE ' OF NORTH
Nf--b 4` N
CAROUNA
ENVIRONMENTAL MAN-
AtEMENT COMMIS-
/ Q
SIGN/NPDES UNIT
1617 MAIL SERVICE
CENTER
RALEIGH. NC
27699-1617
NOTIFICATION OF
Publisher's
Affidavit
TENT TO ISSUE A
NPDES WASTEWATERER
PERMIT
On the basis of thorough stall review and applica-State of North Carolina, Yadkin County, ss:
tion of NC General Statute
143.21, Public law 92-500
and other lawful standards
and regulations, the North
Carolina Environmental
Management Commission )ally appeared before me the undersigned Ty Ransdell, publisher of THE YADKIN
proposes to issue a Na-
tional Pollutant Discharge E, a public newspaper, of general circulation, printed and published in Yadkinville, in
Elimination System inty aforesaid who, being duly sworn, upon his oath, sayeth that the notice of which
(NPDES) wastewater dis-
charge permit to the per- ached is a true copy, was duly published in
son(s) listed below effec-
tive 45 days from the pub-
lish date of this notice.
Written comments regard- aper on
ing the proposed permit
will be accepted until 30
days after the publish date
of this notice. All com-
ments received prior to
that date are considered in
the final determinations re-
garding the proposed per-
mit. The Director of the cation
NC Division of Water
Quality may decide to hold
a public meeting for the
proposed permit should
the Division receive a sig-
nificant degree of public in-
terest.
Copies of the draft and
other supporting informa-
tion on file used to deter-
mine conditions present in
the draft permit are avail-
able upon request and
payment of the costs of re-
production. Mail com-
ments and/or requests for
information to the INC Divi-
sion of Water Quality at
the above address or call
Dina Sprinkle (919)
733-5083, extension 363
at the Point Source
Branch. Please include
the NPDES permit number
(attached) in any commu-
nication. Interested per-
sons may also visit the Di-
vision of Water Quality at
512 N. Salisbury Street,
Raleigh, NC 27604-1148
between the hours of 8:00
a.m. and 5:00 p.m. to re-
view information on file.
Yadkin County Board of
Education, 121 Washing-
ton St., Yadkinville, NC
27055, has applied for a
modification of its permit
NC0070459 for the Star -
mount High School
WWTP. The Board
wishes to expand the
wastewater flow to 0.026
MGD, with a continued
discharge of treated
wastewater into an un-
named tributary to South
the following dates: November 15, 2007
Fee: $119.04
Ty Rao I
Publisher
Subscribed and
Deep Cree - in the
Yadkin -Pee Dee River Ba-
sin. Currently, BOD, TSS,
ammonia, and TRC are
water quality -limited. This
discharge may affect fu-
ture allocations in this por-
tion of the receiving
stream.
Yadkin County Board of
Education in North Caro-
lina has applied for a
modification of NPDES
permit NC0071733 for the
Forbush High School
WWTP in Yadkin County.
The Board wishes to ex-
pand the wastewater per-
mit to 0.026 MGD, with a
continued discharge of
treated wastewater to For-
bush Creek in the
Yadkin -Pee Dee River Ba-
sin. Currently BOD, TSS
and TRC are water quality
limited. This discharge
may affect future alloca-
tions in this portion of the
watershed.
to beforr{e-9 me Novembst' 26, 21107 4�
9 D
dams,'
Notary Public­l c
i. n ke1/Q +
My Commission expires March `i ;2iryl NG
Publish: November 15,
2007

DENR/DWQ
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NCO071773
Facilitv Information
Applicant/Facility Name:
Forbush High School WWTP
Applicant Address:
121 Washington St., YadkinviIle, North Carolina 27055
Facility Address:
1525 Falcon Drive, East bend, North Carolina 27055
Permitted Flow:
0.026 MGD
Type of Waste:
100% Domestic.
Other Permits :
N/A
Facili /Permit Status:
Class II / Major Modification
County:
Yadkin County
BACKGROUND:
Forbush High School WWTP is a Class II, 100% domestic wastewater treatment system that
treats waste from a high school. The Yadkin county is planning increase in enrollment at the high
school and also construction of a new middle school on the adjacent property. The wastewater
from the new middle school will be treated at the Forbush High School WWTP. The EEA for
this expansion has been approved on October 10, 2007 and Model B was completed on October
19, 2007. Effluent limitations are based on the results of modeling.
PROPOSED SCHEDULE FOR PERMIT ISSUANCE:
Draft Permit to Public Notice: November 7, 2007 (est.)
Permit Scheduled to Issue: January 17, 2008 (est.)
NPDES CONTACT:
If you have questions regarding any of the above information or on the attached permit, please
contact Sergei Chernikov at [phone] ext. 594.
REGIONAL OFFICE COMMENTS:
Fact Sheet
NPDES NCO071773
Page 1

Forbush High School/Yadkin Board of Education jmn
NCO071773 A/ / ° taa�j
Forbush Creek Class WS-IV 030702 1
Yadkin BOE is requesting expansion flow for existing discharger to Forbush Creek.
The flow would increase from 0.015 MGD, to 0.026 MGD. The expansion is to serve a
new middle school that will be built adjacent to Forbush High School. The additional
0.011 mgd of wasteflow will be 100% domestic.
The estimated drainage area and flows at Forbush High School discharge point, per email
from Curtis Weaver of USGS:
DA = 21.6 mi2
QA = 22 cfs
s7Q 10 = 2.1 cfs
w7Q10=6.7cfs
30Q2 = 7.1 cfs
There are no other existing dischargers to this segment of Forbush Creek.
Model results:
A Level B model using a summer 7Q 10 flow of 2.1 cfs was run with inputs for secondary
limits (30 mg/1) for BOD5 and no NH3 or effluent DO limits. The model length was
approximately 2.1 miles downstream of the outfall. The summer model results predict a
DO minimum of 7.3 mg/l at the milepoint 0.0 (the outfall). Based on this result, it was
determined that secondary BOD5 limits would also protect the DO standard under winter
7Q 10 flow conditions.
■ Summer and winter BOD5 limits of 30 mg/1 will protect the instream DO
standard of 5 mg/l.
■ Neither oxygen consuming nor toxicity limits must be applied for NH3 at the
expansion flow of 0.026 MGD. There is sufficient dilution in the stream to
protect the DO and instream toxicity standards.
■ Should apply limits for fecal coliform = 200/100ml
■ TRC = 28 ug/1
■ pH = 6-9 SU

`
SUMMER
MODEL
W/ EXP.
TO 0.026
MGD
BOD=301
NO NH3, NO DO
LIMIT
---------- MODEL RESULTS ----------
Discharger
:
FORBUSH HIGH SCHOOL
Receiving Stream :
FORBUSH CREEK
----------------------------------------------------------------------
The End
D.O.
is 7.76
mg/l.
The End
CBOD
is 2.12
mg/l.
The End
----------------------------------------------------------------------
NBOD
is 1.70
mg/l.
WLA
WLA
WLA
DO Min
CBOD
NBOD
DO Waste Flow
(mg/1)
Milepoint Reach #
(mg/1)
(mg/1)
(mg/1)
(mgd)
Segment
1
7.30
0.00 1
Reach
1
45.00
90.00
0.00
0.02600
Reach
2
0.00
0.00
0.00
0.00000
Reach
3
0.00
0.00
0.00
0.00000

`' *** MODEL SUMMARY DATA ***
Discharger : FORBUSH HIGH SCHOOL Subbasin 030702
Receiving Stream : FORBUSH CREEK Stream Class: WS-IV
Summer 7Q10 : 2.1 Winter 7Q10 : 7.1
Design Temperature: 25.0
GTI
SLOP
VELOCITY
Dft�I
K
Kd
Ka
I
Ka
I
------------
ILmileHl
-------------------------------------------------------------------
ft/m$I
fps
designl
@200
designl
@200
designl
Segment
i
I 0.90I
10.80I
0.149
10.99
10.30 10.24
13.22 I
2.89I
0.44
Reach
--------------------------------------------------------------------------------
1
Segment
1
I 0.25)
10.80I
0.151
11.00
10.30 10.24
13.27 I
2.93I
0.44
Reach
--------------------------------------------------------------------------------
2
Segment
1
I 1.00I
10.801
0.153
11.02
10.30 10.24
13.32 I
2.981
0.44
Reach 3
Flow
CBOD
NBOD
D.O.
cfs
mg/l
mg/1
mg/1
Segment 1
Reach 1
Waste
0.040
45.000
90.000
0.000
Headwaters 2.100
2.000
1.000
7.440
Tributary
0.000
2.000
1.000
7.440
* Runoff
0.060
2.000
1.000
7.440
Segment 1
Reach 2
Waste
0.000
0.000
0.000
0.000
Tributary
0.070
2.000
1.000
7.440
* Runoff
0.060
2.000
1.000
7.440
Segment 1
Reach 3
Waste
0.000
0.000
0.000
0.000
Tributary
0.090
1
2.000
1.000
7.440
* Runoff
0.060
2.000
1.000
7.440
* Runoff flow is in cfs/mile

`
SUMMER
MODEL W/
EXP. TO 0.026 MGD
BOD=30,
NO NH3, NO DO LIMIT
Seg #
Reach #
Seg Mi
D.O.
CBOD (
NBOD
Flow
1
1
0.00
7.30
2.81
2.68
2.14
1
1
0.09
7.34
2.78
2.63
2.15
1
1
0.18
7.37
2.74
2.58
2.15
1
1
0.27
7.41
2.71
2.54
2.16
1
1
0.36
7.44
2.68
2.49
2.16
1
1
0.45
7.46
2.65
2.45
2.17
1
1
0.54
7.49
2.62
2.40
2.17
1
1
0.63
7.51
2.59
2.36
2.18
1
1
0.72
7.53
2.56
2.32
2.18
1
1
0.81
7.55
2.53
2.28
2.19
1
1
0.90
7.57
2.50
2.24
2.19
1
2
0.90
7.57
2.49
2.20
2.26
1
2
0.92
7.57
2.48
2.19
2.27
1
2
0.95
7.58
2.47
2.18
2.27
1
2
0.97
7.58
2.46
2.17
2.27
1
2
1.00
7.59
2.46
2.16
2.27
1
2
1.02
7.59
2.45
2.15
2.27
1
2
1.05
7.60
2.44
2.14
2.27
1
2.
1.07
7.60
2.43
2.13
2.27
1
2
1.10
7.61
2.42
2.12
2.28
1
2
1.12
7.61
2.42
2.11
2.28
1
2
1.15
7.62
2.41
2.10
2.28
1
3
1.15
7.61
2.39
2.06
2.37
1
3
1.25
7.63
2.36
2.02
2.38
1
3
1.35
7.65
2.34
1.98
2.38
1
3
1.45
7.67
2.31
1.94
2.39
1
3
1.55
7.68
2.28
1.91
2.39
1
3
1.65
7.70
2.25
1.87
2.40
1
3
1.75
7.71
2.23
1.84
2.41
1
3
1.85
7.72
2.20
1.80
2.41
1
3
1.95
7.74
2.17
1.77
2.42
1
3
2.05
7.75
2.15
1.74
2.42
1
3
2.15
7.76
2.12
1.70
2.43
Seg #
Reach #
Seg Mi
D.O.
CBOD
NBOD
Flow

Forbush High School exp. to 0.026 mgd
Residual Chlorine
Ammonia as NH3
(summer)
7Q10 (CFS)
2.19
7Q10 (CFS)
2.19
DESIGN FLOW (MGD)
0.026
DESIGN FLOW (MGD)
0.026
DESIGN FLOW (CFS)
0.0403
DESIGN FLOW (CFS)
0.0403
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
UPS BACKGROUND LEVEL (1
0
UPS BACKGROUND LEVEL
0.22
IWC (%)
1.81
IWC (%)
1.81
Allowable Concentration (ugi
940.82
Allowable Concentration (m
43.39
Ammonia as NH3
(winter)
7Q10 (CFS)
6.6
Fecal Limit
200/100ml
DESIGN FLOW (MGD)
0.026
Ratio of 54.3 :1
DESIGN FLOW (CFS)
0.0403
STREAM STD (MG/L)
1.8
UPS BACKGROUND LEVEL
0.22
IWC (%)
0.61
Allowable Concentration (m
260.56
10/11/2007

Facility: Forbush High School
NPDES#: NCO071773
Receiving Stream: Forbush Creek
Comment(s):
Low Flow Record Station Number:
Hydrologic Area Number:
Drainage Area Low Flow Record Station:
Qave Low Flow Record Station:
s7Q10 Low Flow Record Station:
w7Q10 Low Flow Record Station:
30Q2 Low Flow Record Station:
02.1155.0000
HA10
22.10 miles squared
22.10 cfs
2.20 cfs
6.80 cfs
7.30 cfs
must be < 400 sq. miles
Drainage Area New Site:
21.60 sq. miles
MAR New Site:
1
Qave per Report Equation:
22 cfs
s7Q10 per Report Equation:
3.45 cfs
w7Q10 per Report Equation:
5.28 cfs
30Q2 per Report Equation:
7.43 cfs
Continue
Drainage Area Ratio: 0.98 :1
[ new DA / Da at gage Continue
Weighted Ratio: 0.97 :1
Over -ride Inappropriate Site ( y ):
Drainage Area New Site: 21.60 miles squared
MAR New Site: 1
Weighted Qave per Report Equation: 22 cfs
Jeighted s7Q10 per Report Equation: 2.19 cfs
Jeighted w7Q10 per Report Equation: 6.60 cfs
Weighted 30Q2 per Report Equation: 7.14 cfs

PERMIT NUMBER: NCO071773
FACILITY NAME: Yadkin County Board of Education - Forbush High School WWTP
CITY: East Bend COUNTY: Yadkin
OUTFALL: 001 EFFLUENT
PERIOD ENDING MONTH: 12 - 2007
REGION: Winston-Salem
DMR 12 Month Calculated
PAGE 3 OF 4
00010
00310
00400
00530
00600
00610
00665
31616
deg c
mg/1
su
mg/l
mg/l
mg/l
mg/l
V 100ml
Temperature,
BOD, 5-Day (20
pH
Solids, Total
Suspended
Nitrogen, Total
(as N)
Nitrogen,
Ammonia Total
Phosphorus,
Total (as P)
Coliform, Fecal
MF, M-FC
Water Deg.
Centigrade
Deg. C)
(as N)
Broth,44.5C
30
30
1- 07
10.02
4.84
6.8 - 7.5
5.6
44•9
1
30
30
2-07
10.166667
7.7
7 - 7.7
7
60.7
60.433333
9.01
1
30
30
3-07
12.98
14.3
7.2 - 8
22.54
43.18
5.832581
30
30
4-07
17.066667
8.233333
7.2 - 7.6
3.666667
19.5
36.433333
3.5
1
30
30
5-07
121.12
9.72
6.5 - 8.1
13
51.7
28.24
7.43
2.390116
30
30
6-07
123
4.8
7.3 - 7.3
6
3
1
30
30
8-07
126.6
4.9
6.6 - 6.6
7
150.3
1 0.5
15.63
1 1
50050
50060
mgd
ug/l
Flow, in
Chlorine, Total
conduit or thru
Residual
treatment plant
0.015
1- 07
0.008
0.015
2-07
0.008

PERMIT NUMBER: NC0071773
FACILITY NAME: Yadkin County Board of Education - Forbush High School W WTP
CITY: East Bend
015
3-07
0.008
4-07
5-07
0.0252 Violation
6-07
0.008
8-07
0.008
COUNTY: Yadkin
PERIOD ENDING MONTH: 12 - 2007
REGION: Winston-Salem
DMR 12 Month Calculated
PAGE 4 OF 4

DIEHL & PHILLIPS.) P.A.
CONSULTING ENGINEERS
219 East Chatham Street
Cary, North Carolina 27511
Telephone [phone] — Fax [phone]
October 4, 2007
NPDES Unit
N.C. Division of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
WILLIAM C. DIEHL, P.E.
JOHN F. PHILLIPS, P.E.
ALAN R. KEITH, P.E.
D
OCT - 5 2001
nMR • WATER QUALITY
Re: Request for Permit Modification (Expansion) I FuI
NPDES Permit NCO071773 - Forbush High School (Yadkin County)
Dear Sir or Madam:
On behalf of the Yadkin County Board of Education, Diehl & Phillips, P.A. hereby submits
for your review and comment the following:
• Three copies of an Engineering Alternatives Analysis (EAA)
• Three copies of the NPDES Application Form — Form D (requesting expansion)
• Application fee check, in the amount of $260 (major modification, minor NPDES
permit)
• Letter from Permittee requesting expansion of their permit, based on the EAA
conclusions, and authorizing John F. Phillips, P.E. to act on their behalf in matters
related to this permit.
The enclosed EAA demonstrates that the expansion of the existing NPDES permit flow
limits, from 0.015 MGD to 0,026 MGD, is the only reasonably cost effective option of the
environmentally sound alternatives. This conclusion was reached after a thorough
evaluation of sub -surface and surface application non -discharge alternatives, possible
connections to privately and publicly owned treatment works, and possible reclaimed water
applications.
If the NPDES Unit has any questions or comments after reviewing this EAA, or if
additional information or copies of the EAA are required, please contact me.
Yours very truly,
Diehl & Phillips, P.A.
Enclosures John F. Phillips, P.E.
Cc: Mr. Donald Hawks
Mr. Eric Williams, County Manager
Dr. James Benfield
WSRO - DWQ

.t I
THE YADKIN COUNTY BO RD OF EDUCATION
TELEPHONE [phone] WASHINGTON STREET • YADKI LLE, NORTH CAROLINA 27055 • FAX [phone]
NTDES Unit
N.C. DivWon of Water Quality
1617 Mail Savice Center
Raleigh, NC 27699-1617
i
Re. Request for NPDES F=ii Expansion
Forbush l ish School — NC0071773
Starmount High School — NC4470459
Yadkin County
Dear Sir or Madam -
The Yadkin County Board of Education and School System hereby req
refereneed N.PIDES Perv%its be modified to atow increased wastowa
described in the Ea&vving Mternatives3 Andlyses prepared for the
and submiued with this letter. Further .ore, the School System authQ
Phillips, P.E.: of Diehl & Phillips, P.A. to act on behalf of the schao
chatters rolated to the two discharge permits.
Yours very truly,
D4:-o --� i
HELPING ALL STUDENTS DEVELOP TO THEIR
:s the two
flows, as
a permits
s John F.
I= in all

MR
Me
FM
P9
PAR
ENGINEERING ALTERNATIVES ANALYSIS
FOR
NPDES DISCHARGE PERMIT MODIFICATION (EXPANSION)
NPDES PERMIT NC0071773
FOR
FORBUSH HIGH SCHOOL WWTP
YADIKN COUNTY, NC
Prepared for:
Yadkin Board of Education
Prepared by:
Diehl & Phillips, P.A.
Consulting Engineers
219 E. Chatham Street
Cary, NC 27511
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Executive Summary
MR
This document examines seven alternatives for wastewater disposal at Forbush High
School, and presents concept designs and present worths of the costs of each
MOZI, alternative over a 20-year period. The alternatives are then compared and ranked
based on both environmental feasibility and cost effectiveness. The findings of this
study indicate the continued use of the existing treatment plant to discharge treated
wastewater into Forbush Creek (Alternative No. 5) is the only reasonably cost effective
alternative when compared to all of the land based disposal systems. The Present
worth of the cost of Alternative No. 5 is only 13% of the Present worth of the most
cost-efficient land based disposal option (37% if a tertiary filter is required for the
expanded NPDES permit). when compared to Alternative No. 7 (combination of
irrigation of reclaimed water and surface discharge), Alternative No. Ts PW is only
17% of the combination alternative (46% with filter added). As demonstrated by the
information included in this E.A.A. and the Appendices, the selection of the expanded
discharge alternative was made only after extensive consideration of all the other
alternatives. The Yadkin County Board of Education therefore requests approval of the
expansion of the existing discharge permit to a total permitted flow of 0.026 MGD.
FM
em
M
MR
FM
Contents
Executive Summary — (See above)
Engineering Alternatives Analysis
Appendix A - Detailed Description and
Present worth Calculations of the Alternatives
Appendix B - High School water Flow Documentation
Pages EAA — 1 to EAA — 10
Pages 1 - 22
Pages 1 - 4
Appendix C - Receiving Stream Low Flow Characteristic Data Pages 1 - 3
Appendix D - Spray Irrigation Water Balance Sheet - DWQ Format
RM

am
ENGINEERING ALTERNATIVES ANALYSIS TO SUPPORT
FM AN NPDES DISCHARGE PERMIT MODIFICATION
(EXPANSION REQUEST)
IM FORBUSH HIGH SCHOOL WASTEWATER TREATMENT PLANT
F-" A. GENERAL:
1. Introduction
This Engineering Alternatives Analysis (E.A.A.) is submitted in support of an application for a
modification of NPDES permit NC0071773. The modification would be an increase in the
permitted flow, from .015 MGD to .026 MGD. This proposal has been prepared in accordance
with 15A NCAC 2H.105(c)(1) through (7), and the Division of Water Quality's (DWQ)
"Guidance for the Evaluation of Wastewater Disposal Alternatives" (ver. June 23, 2005).
M,
The subject permit expansion is needed to serve a new middle school that is proposed to be
constructed adjacent to Forbush High School. As detailed below in 3. Project Description, and
in Appendix B, the wastewater flows have been estimated using water flow records, in
accordance with 15 NCAC 2T.0114 (f). The wastewater is and will be continue to be domestic
in nature.
2. Project Identification Information
Facility Name: Forbush High School VI WTP
f' County: Yadkin
Facility Address: Forbush High School
rA-9 1525 Falcon Road
East Bend, NC 27018
rM Yadkin County
Facility telephone number: [phone]
MR
Engineering Alternative Analysis author:
John F. Phillips, P.E.
IM Diehl & Phillips, P.A.
EAA preparer's address and telephone number:
FM Diehl & Phillips, P.A.
219 E. Chatham St.
Cary, NC 27511
[phone]
Forbush HS EAA-1

qW
No 3. Project Description
The treatment plant currently serves Forbush High School only. The proposed addition of a
new middle school adjacent to the High School will create a total wastewater flow that
exceeds the NPDES permit capacity of 15,000 gallons per day.
The current enrollment at the High School is approximately 1,080 students. The long-range
planning for the High School and Middle School indicates an ultimate student population of
1,300 students per school, or 2,600 students total.
The average water flow at Forbush High School was documented in January 2006 as less than
'R 5.0 gallons per day per student, based on the average of the three peak flow days recorded
during the 30 day period (see Appendix B). This flow rate is lower than the 9.9 gallons per day
per student that was measured at Starmount High School during the same time period. This
flow rate is also inconsistent with previous studies performed in various Yadkin County Schools
in 1990, when the flow per student was measured as 8.5 gpd/student at Starmount HS and
9.6 gpd/student at Forbush HS (ref: 1990 Wastewater Facilities Study prepared by Diehl &
Phillips, P.A., and submitted to the NC Division of Water Quality. Study identified the school
system's wastewater needs and alternative systems for schools that were discharging into
"zero -flow" streams). A partial explanation for this difference is that on -going conversion to
low -flow plumbing fixtures is more complete at Forbush High School than at Starmount. To be
more consistent with the flow rates measured at the majority of the schools, a flow of 10
gallons per day per student will be used to estimate the future flows at Forbush High School.
Based on an estimating value of 10 gallons per day per student, and the projected maximum
R" student population of 2,600 at the Forbush campus, the requested NPDES permit flow is
26,000 gallons per day. This flow total represents an increase of 11,000 gallons per day
FM from the currently permitted 15,000 gallons per day.
4. Existing Facilities
RM
The existing Forbush HS WWTP was constructed in 2006, replacing a pre -cast concrete
treatment plant that was approximately 38 years old. The new plant is a dual train extended
Im aeration WWTP. The plant is currently rated for a flow of 15,000 gpd, to match the NPDES
permit flow limitation. However, the plant was designed and constructed with the knowledge
that the campus might eventually be expanded with a second school. The constructed
treatment plant includes:
Influent bar rack (plant influent flow is via a gravity sewer line)
Influent flow control and splitter box
8,500-gallon flow equalization basin (33% of 26,000 gallons per day)
Duplex submersible flow equalization pumps with a peak flow rating of 57 gpm
Dual aeration basins, each with 13,000 gallons (24 hours hydraulic detention at 26,000
gallons per day)
s, Dual clarifiers, each with an overflow rate of 203 gallons per day per square foot at a
total flow of 26,000 gallons per day.
RO Forbush HS EAA-2

s.
Ultraviolet disinfection unit, rated for 0.10 mgd peak flow rate
Tablet chlorinator with 540-gallon chlorine contact chamber (30 minutes detention at
SM 26,000 gallons per day) — for backup of UV system
Tablet de -chlorinator with 200-gallon dechlorination chamber,* for use when chlorinating
Return sludge airlift pumps
Skimmer airlift pumps
Dual aerated sludge holding/thickening tanks, each with 3,250 gallons of volume
(combined volume of 6,500 gallons, or 25% of 26,000 gallons)
Swing —arm decant airlift pumps
Effluent flow meter
Aeration/sludge holding blowers — three total
Flow equalization blower — one each
The plant components are principally located below ground. Effluent is conveyed by gravity to
the discharge point on Forbush Creek.
The stream flow at the discharge point has been previously (January 1990) determined by
USGS. The tributary drainage area at the discharge point is 21.5 square miles. (See Appendix
C for additional information):
7Q10 flow = 2.1 cfs (cubic feet per second)
30Q2 flow = 7.1 cfs
REM Winter 7Q10 = 6.7 cfs
7Q2 flow = 5.6 cfs
IMM The existing treatment plant does not have any known deficiencies. The effluent has generally
been compliant with the existing permit limitations.
as 5. Phasin4
fm The existing Forbush WWTP is sufficiently sized to treat 26,000 gallons per day. Therefore,
there is no additional or phased construction planned if the NPDES permit is expanded from
0.015 MGD to 0.026 MGD. If the expanded NPDES permit is issued with more stringent limits,
F„ a tertiary filter rated for an average flow of 26,000 gpd would be added to the plant.
B. SUMMARY OF WASTEWATER TREATMENT AND DISPOSAL OPTIONS
Im CONSIDERED:
The results of this study clearly indicate that an expanded wastewater treatment plant
I' discharging into Forbush Creek is the most economically feasible of all the environmentally
feasible options. The various waste treatment and disposal alternatives considered and
investigated include:
1. Connection to a publicly owned treatment plant.
2. Connection to a privately owned treatment plant.
3. Subsurface system utilizing conventional nitrification lines.
Forbush HS EAA-3

o.
4. Surface Application Using Spray Irrigation.
5. Utilization of. the existing Wastewater Treatment plant, and discharge of treated effluent
to Forbush Creek.
6. Utilization of the existing Wastewater Treatment plant, modified by the addition of a
tertiary filter, and discharge of treated effluent to Forbush Creek.
7. Reuse of treated wastewater -in conjunction with surface water discharge.
All of the alternatives are environmentally feasible options that are routinely permitted in North
F-M Carolina. The ranking of the alternatives, in terms of environmental feasibility, will vary on a
case -by -case basis. For example, it is generally agreed that connection to a publicly owned
treatment works (POTW) would be the most desirable. An expanded discharge to surface
waters is not as environmentally desirable as a connection to a POTW, but an expanded
discharge remains an environmentally feasible option if the receiving stream has sufficient
assimilative capacity to accept the projected waste load. If the present worth values of the
IM connection to a POTW and the expanded discharge alternatives were equal, the POTW
connection should be selected, according to 15A NCAC 2H.105(c)(2). However, if the
connection to the POTW is not reasonably cost effective when compared to the cost of the
f-M-9 expanded stream discharge, then the POTW connection alternative must be discarded from
further consideration. 15A NCAC 2H.105(c)(2) states the selected alternative must be the
most environmentally sound alternative as selected from THE REASONABLY COST EFFECTIVE
o Lions. (Emphasis added.)
M
FM
The present worth values of the seven alternatives, are:
Alt.
Description
Present Worth
Number
of Costs
1
Connection to Publicly Owned Treatment Works
N/A
2
Connection to Privately Owned Treatment Plant
N/A
3
Subsurface system, utilizing conventional nitrification lines.
$ 694,998
4
Surface Application Using Spray Irrigation..
$ 766,239
5
Utilization of the existing Wastewater Treatment plant,
$ 87,485
and discharge of treated effluent to Forbush Creek.
6
Utilization of the existing Wastewater Treatment plant,
modified. by the addition of a tertiary filter, and discharge of
$ 239,731
treated effluent to Forbush Creek.
7
Reuse of treated wastewater in conjunction with surface water
$ 520,584
discharge.
MM Appendix A. includes a detailed explanation of each alternative, its capital cost and
operation/maintenance (0&M) costs, and its present worth.
MW
Forbush HS EAA-4
�-]

FM
fm
C. NARRATIVE DESCRIPTION OF THE PROPOSED TREATMENT WORKS:
1. Design Flows: 0.026 MGD
Peaking Factor — 2.5
Peak Flow = 2.5 x 0.026 mgd = 0.065 mgd = 45 gpm
2. Pretreatment: Manually cleaned trash rack with drying deck
3. Influent Pumps: Each rated for design peak flow of 0.082 MGD (57 gpm).
4. Treatment Plant:
Volumes:
Pumps:
Flow Equalization 8,500 gallons (33%)
Aeration Zone 26,000 gallons (24 hrs)
Sludge Holding 6,500 gallons (25% of 26,000 gallons)
Flow Equalization duplex submersible pumps with flow control box
Return Sludge air lift pump with a capacity of 27 gpm (minimum), or
F, 150% of design flow. Flow rate can be varied by
throttling the air supply.
Aeration: Each process train has one aeration basin and one sludge holding tank. A
total of three blowers are provided — one for each active train, and one
additional blower that serves as the back-up blower for the other two
blowers:
Aeration Zone Volume: 13,000 gallons per train
Sludge Holding Volume: 3,250 gallons per train
Total Volume Mixed by one blower: 16,250 gallons per train
Air required for mixing (exceeds process requirements).
30 SCFM/1,000 Cu Ft x 16,500 gal./7.48 gal. x 1 Cu Ft = 66 SUM
required to mix one aeration — sludge train.
Air required for airlifts increases air requirements to 80 scfm/train.
Plant has three positive displacement blowers, each rated for 80 SCFM.
The flow equalization basin is aerated by a separate positive displacement
blower, which is capable of operating with the varying pressures created
FW due to the liquid level fluctuations.
Flow Equalization Volume: 8,500 gallons
Forbush HS EAA-5

..o
Flow Equalization Air Requirements — 1.25 to 2.0 CF/1,000 gal to prevent
septic conditions
Im 8,500 gal x 2.0 Cu Ft/1,000 gal = 17 SCFM
Plant has one positive displacement blowers for the FE basin, rated for 25
SCFM. There is also a valved interconnection from the FE air piping
to the main blower air piping, to be used if the FE blower is
inoperable.
5. Clarifiers:
Dimensions — 8 ft. by 8 ft. at surface (each, two total)
Surface Overflow Rate at ADF - 203 gallons/day/SF
Dual hopper bottom clarifiers — approximately 9'6" water depth
Hydraulic detention time — 6.0 hours
Scum removed by airlift to aeration basin
Weir loading rate — 812 gallons/LF/Day
6. Tertiary Filter:
Plant does not currently have a tertiary filter. If an expanded permit is
issued with limits that require a filter, the following criteria describe the
filter that would be installed.
Filter area —12 square feet total, in two cells with 6.0 sf area in each
Filtration rate - 1.50 gpm/SF at ADF
Backwash return to the flow equalization basin
Backwash rate — up to 15 gpm/SF, with air scour provided by dedicated
blower
Media: 6" anthracite, 1.1-1.2 mm effective size, UC = 1.5
15" filter sand, .45 — .50 mm effective size, UC = 1.6
12" gravel of various graduations, with upper 3 inches having an
effective size of .80 — 1.20 mm, UC = 1.7
FM 7. U.V. Disinfection Unit:
Ultraviolet system has four modules with two bulbs each. System is rated
by the manufacturer for a peak flow rate of 100,000 gpd. System has
tablet chlorination — dechlorination systems for redundancy.
M 8. Effluent Flow Measurement:
Effluent flow measurement is by an ultrasonic level measurement head
FM and a 22.5 V-notch weir.
N"
Forbush HS EAA-6

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FORBUSH
FORBUSH'/ HIGH
} s� L MIDDLE MAP No. 1
� 4 _ _ r � -' ,/' ,-
SCHOOL _ _ y ' ,-' FORBUSH CAMPUS
GRAPHIC SCALE
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( 1N FEET }
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FORB U S H CAMPUS
VICINITY MAP
NO SCALE

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x — — - - — — -830— —
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AERATION BASIN
-834 (13,000 GAL. EA. TRAIN)
xi I I
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LDING EQUALIZATION � - - - -834-- -
(E5�N (8,000 GAL.) ' �— — —$35-
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PAD MOUNTED TRANSFORMER-,.
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837. FIGURE
No. 1
838--------- - - - - - - - - - - - - - - EXISTING FORBUSH WWTP
_-_ _ GRAPHIC SCALE
10 0 5 10 20
( IN FEET )
1 inch = IO ft.
40

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D. GENERAL LOCATION MAP: See Map No. 1 and Map No. 2.
E. SCALE SITE PLAN: See Figure No. 1.
F. - SPECIAL STUDIES OR MODELING WHERE DWQ CANNOT DETERMINE IMPACTS
OF DISCHARGE: Not required at this time.
G. FINANCIAL QUALIFICATIONS/ SUBSTANTIAL PREVIOUS COMPLIANCE
M-9 STATEMENT:
The Yadkin County Board of Education and Yadkin County government are in sound financial
condition and have a record of consistent environmental compliance.
H. OTHER POSSIBLE COMBINATIONS OF ALTERNATIVES:
Alternatives No. 1 through No. 7 address the wastewater treatment and disposal alternatives
for the subject project, as required by the DWQ Guidance for the Evaluation of Wastewater
Disposal Alternatives.
I. POTENTIAL ACQUISITION OF ADDITIONAL LAND:
The potential acquisition of land to provide the required treatment capacity for the land based
disposal systems (Alternatives No. 3 and No. 4) was considered as a part of this E.A.A. The
Forbush campus property owned by the School Board will not have any usable land left for
land based disposal systems, following the construction of the middle school. It will be
assumed that the required additional suitable land can be purchased from an adjacent
FMI property owner. If this assumption causes one of the non -discharge alternatives to have a
present worth less than the PW of the discharge alternative after the initial calculation, then a
more specific location of the required off -site property will be defined.
3. CONCLUSION:
'AR Of the environmentally sound alternatives, continued use of the existing treatment
plant to discharge treated wastewater into Forbush Creek (Alternative No. 5) is the
only reasonably cost effective alternative when compared to all of the land based
disposal systems. The Present Worth of the cost of Alternative No. 5 is only 130/o of the
Present Worth of the cost of the most cost-efficient land based disposal option (34% if a
tertiary filter is required for the expanded NPDES permit). When compared to Alternative No.
7 (combination of irrigation of reclaimed water and surface discharge), Alternative No. 5's PW
is only 17% of the combination alternative (46% with filter added). As demonstrated by the
information included in this E.A.A. and the Appendices, the selection of the expanded
discharge alternative was made only after extensive consideration of all the other alternatives.
On behalf of the applicant, we request approval of the expansion of the existing discharge
permit to a total permitted flow of 0.026 MGD.
FM
Forbush HS EAA-10

ow
°" GENERAL INFORMATION REGARDING THE ALTERNATIVES INCLUDED IN THIS
ENGINEERING ALTERNATIVES ANALYSIS
The alternatives presented below represent ' the various general categories of wastewater
disposal options available for Forbush High School. The subsurface disposal alternative was
developed using conventional nitrification trenches. Other types of sub -surface disposal, such
as low-pressure pipe distribution or subsurface drip irrigation, could have been evaluated
instead of conventional nitrification trenches, but these systems will typically have a higher
capital cost than conventional nitrification trench systems. Therefore, the EAA author selected
the most cost effective type of system to represent each category of on -site wastewater
disposal.
Spray irrigation was. similarly selected to represent surface application of wastewater, as
opposed to surface drip irrigation, due to the lesser cost of spray irrigation. Spray irrigation
generally has a lesser capital cost than drip irrigation, even when the increased land
requirements (due to the larger setback requirements for spray irrigation) are included in the
analysis.
The existing treatment plant at Forbush High School is sized to treat 26,000 gpd of domestic
wastewater, which is the flow limitation requested for the expanded NPDES permit. Therefore,
the treatment plant is included in all the alternatives to provide the wastewater treatment prior
to effluent disposal. Because the existing treatment plant is a common element in each
alternative, there is no capital cost included in the alternatives for the plant. The inclusion of
the plant's capital cost in each alternative would not alter the comparative ranking of the
alternatives or the magnitude of the differences in the present worths of the alternatives.
The capital, O&M (operations and maintenance), and replacement costs for all new equipment
added to the treatment system are included in each alternative. Alternative No. 5 is the
alternative that proposes to use the existing plant, with no modifications. The only cost
associated with this alternative is the present worth of 20 years of effluent testing. This cost is
included because it is not common to all the alternatives (the non -discharge alternatives will
have less frequent testing).
,1M The alternatives examined in this EAA do not include standby power generators because the
water system for the school utilizes a booster pumping system to maintain adequate pressure
for the plumbing fixtures. If there is a power outage at the school, the booster pumping
system is without power, and there is no potential for wastewater flow to the plant. The new
school that is planned for the campus will have a booster pumping system similar to the
existing high school. Even if generators were to be included in the alternatives, the electrical
EM load for each of the alternatives is approximately the same, and the present worth of the
generators for each alternative would be approximately equal (the irrigation pumps for
Alternative No. 4 represent larger motor loads than are in the other alternatives, but the
No irrigation pumps would not be served by a standby power system due to the storage capacity
provided by the effluent holding pond).
'� Appendix A-1

Finally, the economic analyses presented herein were made using an annual interest rate of
5.0%. This is the rate that the County anticipates paying when the bonds are sold. A 20-year
period is used in the evaluations, which matches the maturity period of the bonds.
OR
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MM
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MM
°'' Appendix A-2

'M ALTERNATIVE NO. 1 .
CONNECTION TO PUBLICLY OWNED TREATMENT WORKS
Forbush High School is located more than five miles from any wastewater collection system
that is associated with a Publicly Owned Treatment Works. Due to the distance and potential
costs of a connection to a wastewater collection system, this Alternative is not a feasible
option for Forbush High School.
FM
ALTERNATIVE NO. 2
CONNECTION TO A PRIVATELY OWNED TREATMENT PLANT
MW
There are not, to the best of the author's knowledge, any privately owned treatment plants
within a five mile radius of Forbush High School that have sufficient capacity to accept a
`M 26,000 gpd flow from the school. Therefore, connection to a privately owned wastewater
treatment plant in not considered for in this E.A.A.
MR
ALTERNATIVE NO. 3
IM SUB -SURFACE SYSTEM UTILIZING CONVENTIONAL NITRIFICATION LINES
Under this alternative one large subsurface disposal system would be constructed to provide
Ina wastewater disposal for the school. It will be assumed under this alternative that the existing
wastewater treatment plant will treat all the school's wastewater. A new effluent holding tank
will be required to accumulate a sufficient volume of effluent for a dose to one of the
nitrification fields, and duplex pumps will be required to dose the fields. Due to the size of the
proposed disposal system, the nitrification field will be divided into sub -fields, to limit the size
of the effluent holding tank and pumps. Flow to the sub -fields will be controlled by solenoid
valves and automated controls that will rotate the doses sequentially to each sub -field.
The Long Term Acceptance Rate (LTAR) for the nitrification trench bottoms is estimated to be
0.30 gallons per day per square foot. This value is based on the general soil characteristics in
the central portion of Yadkin County, and on actual Yadkin County sub -surface systems
designed by the EAA author.
The sizing of the nitrification field and related system components is as follows:
26,000 gallons per day in soils with an LTAR of 0.30 gpd/sf =
86,667 sq. feet of trench bottom required
With standard 3 foot wide trenches, 86,667 SF/3 Ft = 28,889 linear feet of trench
Limit lines to 200 LF length; 28,889 LF/200 LF = 144 trenches at 200 LF each
Create 8 sub -fields, each with 18 trenches. Using a pressure manifold with 1/2 inch taps
for flow distribution for each sub -field will require a dosing flow of 126 gallons
per minute per manifold.
RM Appendix A-3

Dose volume to one sub -field is to be 2/3 to 3/4 of the volume in the field pipes; dose
should be between 1,566 and 1,764 gallons, per DEH. To provide the minimum
pump submergence, dose volume, and emergency storage volume (4 hours), an
8,000 gallon precast concrete dosing tank is proposed.
The forcemain from the pumps to the manifolds will be 4 inches in diameter, to
maintain a 3-ft./sec. velocity in -the pipe. There will be solid 3-inch PVC pipes
from the manifold taps to each nitrification trench.
The total land requirements for this system are as follows:
28,889 LF of trench at 9 foot minimum spacing = 260,000 SF minimum for initial
system
100% repair area requirement is therefore 260,000 SF
30% layout inefficiencies for initial and repair areas adds 156,000 SF
Approximate area of required 25-foot setback is 51,000 SF (minimum)
Total land required for this Alternative = 260,000 + 260,000 + 1561000 + 51,000 =
727,000 SF
"' 727,000 SF = 16.7 acres — total land area required
School has no land available for subsurface disposal. All required property will be
purchased (See Figure No. 2).
'M Initial system installation will require approximately 7.75 acres to be cleared and
disturbed.
The components of this system and their estimated installed cost are as follows:
One 4,000 gallon precast pump tank
$ 8,000
28,944 LF of nitrification trench at $7.50/LF
$ 217,080
Duplex effluent pumps and control panel, including irrigation controller
to rotate nitrification sub -field dosing
$ 24,000
Eight pressure manifolds for flow distribution to nitrification
lines in each sub -field, at $4,000/each
$ 32,000
F" Eight solenoid sub -field valves, wiring, and boxes at $900 each
$ 7,200
14,400 LF of 3" PVC supply lines from manifolds to
nitrification lines at $2.00/LF (common trench)
$ 28,800
41000 LF of 4" PVC force main from effluent pumps to pressure
manifolds at $10.00/LF
$ 40,000
Erosion control, clearing, landscaping, seeding, etc.
(7.75 acres at $5,000/ac.)
$ 38,750
Electrical Construction
t 20.000
Mm
Subtotal, Estimated Construction Cost
$ 415,830
Soil Scientist Fees (5%)
$ 20,790
Engineering Fees (7%)
t 29 080
Total Estimated Wastewater System Project (Alternative No. 3):
$ 4651700
�, Appendix A-4

1 1 \
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` � /� � ! 1 ! ! � ! �v i° a ,u � ; ,�- _ \ '� i4 �, \ 1\11 \ \♦\`� / // \1 11 1 ���� 1\ `\ I
\\\ i ►! ! i w \ 11`1 / I \ 1 11 �11r \� 1} 11
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y d 1 L \\ `� `-_ ��� 1 ti_/, ± _ ♦ ;\\\Iltil l r \\ `'1 ' ,/'
T.
r
i Q
♦ \ 1 r ' r�crsrr FORBUSH 11
FIGURE No. 2 r
FORBUSH '-� �'�'' HIGH /'
MIDDLE
SCHOOL
NO AVAILABLE ON -SITE AREA FOR
SUBSURFACE DISPOSAL. ALL LAND
REQUIRED WILL BE PURCHASED.
CAMPUS AREA ASSUMED TO BE
SUITABLE FOR SUBSURFACE DISPOSAL
GRAPHIC SCALE
240 0 S20 240 480 960
( IN FEET )
I inch = 240 M

ras -
Other CostsiSavings
am Cost of land purchase required for the initial and repair systems:
MM
16.7 acres (minimum) to be purchased at $10,000 per acre: $ 167,000
Operation and Maintenance Costs
FM Field Maintenance:
The existing treatment plant is operated by an operator that is also licensed for sub-
surface systems, so there would be no additional operator cost. The field would require
mowing 6 times per year, at $500 per cutting, for a total of $3,000.
Power Costs:
The annual power costs for the dosing pumps are estimated as follows (treatment plant
power is constant for all alternatives, and is therefore not included in the economic
FM comparison of alternatives):
Dosing Pump Station:
Design pump rate: 126 GPM
TDH: 60 feet assumed
26,000 gal per day/126 gal per min
= 206 minutes pumping per day = 3.44 hours per day
Brake horsepower required: 2.65 BHP (60% efficiency)
KW input to motor: 2.33 KW (85% motor efficiency)
Power consumption per day: 2.33 KW x 3.44 hours per day = 8.0 KWH per day
Power consumption per year: = 8.0 KWH per day x 5 days per week x 38 weeks
per year = 1,520 KWH per year
Power costs per year = $152
Equipment Repair/Replacement:
Assume 15 year life for pumps and motors, yielding an annual replacement charge of
6.67% (1/15) of equipment cost. Use an additional 5% of equipment cost to represent
the annual cost of routine maintenance and repairs.
GM Approximate equipment costs are $ 11,200
Replacement costs at 6.67% of $11,200 = $ 747
rom Maintenance at 5.0% of $11,200 = 560
Total annual replacement/repair charge = $ 1,307
sm
�- Appendix A-6

�.
Lab Analyses:
The following tests and testing frequencies will be used for this Alternative
(Type VI-B subsurface system):
Test
Cost
Frequency
Annual Cost
BOD-5
$25
4/year
$ 100
NH3-N
$20
4/year
$ 80
TSS
$15
4/year
$ 60
Fecal Coliform
$20
4/year
$ 80
Total N
$35
4/year
$ 140
,W
Tota l P
$20
4/year
80
Annual Testing Costs
$ 540
RM
The annual 0&M costs for this alternative are summarized as follows:
Field Maintenance
$ 3,000
rim
Power costs
$ 152
Equipment/replacement repair
$ 1,307
Testing Costs
540
FM
Total Annual 0&M Costs
$ 41999
`m
Present Worth Analysis
Year 0 Costs
'-'
Wastewater System Construction
$ 465,700
Land Acquisition
167 000
Total Year 0 Costs
$ 632,700
Annual O&M Costs
Year 1-20
$ 41999
FM
Present Worth of Alternative,
FM
Year 0:
$ 632,700
Year 1-20: (4,999) (P/A,5%,20)=
(41999)(12.4622) =
62 298
Present Worth of Alternative 3:
$ 694,998
am Appendix A-7

am
ALTERNATIVE NO.4
SPRAY IRRIGATION SYSTEM
This alternative utilizes the existing wastewater treatment system to provide wastewater
treatment and disinfection. The disinfected wastewater would be surface applied through
solid set sprinkler heads following treatment in the plant. The wastewater cannot be applied
when there is a chance of runoff, such as when the ground is saturated by rainfall. To
address this requirement, a storage lagoon is proposed to provide the volume required to
meet the storage demands of a wetter than average winter. The system operator will
generally operate the irrigation system in accordance with the calculated water balance to
insure the system's storage needs do not exceed the lagoon volume.
Spray irrigation systems utilize pressurized spray nozzles to emit a relatively constant flow.
The sprinkler layout is controlled by regulatory setbacks from property lines (150 feet), off -site
houses (400 feet), streams, lakes, and similar considerations. The estimated annual average
irrigation rate for this site is 0.40 inches per week (20.8 inches per year) for the soils that are
,-, suitable for spray. The lagoon storage volume is estimated be equivalent to 81 days of the
design wastewater flow, based on calculations utilizing the DWQ Water Balance spreadsheet
(See Appendix D).
MM
The design flow for this alternative is 26,000 gpd for five days per week, 38 school weeks per
12-month period, or 4,940,000 gallons per year. The minimum irrigation area required is 13.0
fm acres, based on an annual average application rate of 20.8 inches per year. There will be an
estimated 20% layout inefficiencies, increasing the required area by 2.6 acres. The layout
inefficiencies are typically due to topography, shape of suitable soil areas and setback
'-' requirements. The minimum amount of additional land required to satisfy the property line
setback requirements for the spray irrigation zone is 10.07 acres. Approximately 1.0 acre
would be required for the storage lagoon and irrigation pump station, creating the need for a
'"M total of 26.67 acres to support the sprayfield system and storage lagoon. All of the required
land will be provided by purchase of adjacent property, as the proposed school construction
FM will leave no areas on the current School property available for spray irrigation (See Figure No.
3).
For the purposes of this analysis, it will be assumed that the treated effluent can flow by
gravity from the treatment plant to the effluent storage lagoon.
I,
IM
13M Appendix A-8

10
LA
N.
E%IS11HG
sar 4SdCCr
Of
)60
9�
+
4 r ! .l •1 / \, \ \ \ D� .' a E+ ►1 11 \\''y 1 �� /�_1 V1
\
r
1 E
`--
1 ay1+ , /r ♦ 0 \ \1 �14 /
=fir '" r•1 \ '+ !1 ` '1 /
J.
a
- ' _, / 4�r� r x ' - F ALCON f\
♦
A- e • -'.'� Gam-
%
% FORBUSH J� r _ FIGURE No. 3
FORBUSH �' {' f '�� -- / HIGH � ,�
MIDDLE SCL-_ y}'} ,- CAMPUS AREA ASSUMED TO BE
SCHOOL �
J
-'/ -'' SUITABLE FOR SPRAY IRRIGATION
NO AVAILABLE ON -SITE AREA FOR GRAPHIC SCALE
240 0 In 240 460 860
SPRAY IRRIGATION. ALL LAND `- /.--___-_
REQUIRED WILL BE PURCHASED.
( IN FEET )
1 inch = 240 M

The wastewater system components for this alternative include:
One lined lagoon (81 days storage) with bottom dimensions of 80 Ft x 160 Ft,
3:1 side slopes, 10 ft. max. water level, two feet of freeboard:
11,271 CY cut to fill at $3.50/CY
$39,448
35,300 SF of 30 mil HDPE liner at $1.70/SF installed
$60,010
Spray irrigation system with 4 zones & 64 heads/zone (50' grid spacing):
4 x 64 3/4" risers w/nozzles and support pipe at $60/each
$15,360
4 x 800 LF of 3/a" PVC pipe per zone at $1.90/LF
$6,080
4 x 1,600 LF of 1" PVC pipe per zone at $2.25/LF
$14,400
4 x 400 LF of 1 1/2" PVC per zone at $3.50/LF
$5,600
4 x 50 LF of 2" PVC per zone at $4.80/LF
$960
4 x 100 LF of 3" PVC per zone at $7.20/LF
$2,880
4 x 100 LF of 4" PVC per zone at $10.00/LF
$4,000
4 x 100 LF of 6" PVC per zone at $13.50/LF
$5,400
1,600 LF of 6" force main from irrigation pump station to the
4 zones at $13.50/LF
$21,600
4 solenoid zone valves at $450 each
$1,800
Irrigation pump station with duplex 200 gpm pumps and zone controller
$85,000
800 LF chain link fence at $12.00/LF (lagoon and irrigation pump
station area)
$9,600
31400 LF barbed wire fence at $3.25/LF (spray field area)
$11,050
Electrical
$24,000
Erosion control, clearing, seeding, etc. (8.0 acres at $5,000/ac.)
40 000
Subtotal, Estimated Construction Cost
$347,188
Soil Scientist Fees (5%)
$17,362
Engineering Fees (7%)
24 300
Total Estimated Project Cost
$388,850
M"
Other Costs/Savings
Cost of land purchase required for spray irrigation system and buffer:
26.67 acres (minimum) at $10,000 per acre
Operation and Maintenance Costs
$ 266,700
Field Maintenance:
The existing treatment plant is operated by an operator that is licensed for surface
discharge and sub -surface systems. It is assumed, for this alternative, that the operator
MW would obtain the necessary spray irrigation license and that there would be no
additional operator cost. The spray field would require mowing 6 times per year, at
$1,000 per cutting, for a total of $6,000.
FW
OR Appendix A-10

a.
Power Costs:
The annual power costs for the spray irrigation pumps are estimated as follows
(treatment plant power is constant for all alternatives, and is .therefore not included in
on the economic comparison of alternatives):
Irrigation Pump Station:
Design pump rate: 200 GPM
TDH: 135 feet assumed
4,940,000 gallons per year of treated wastewater plus 284,820 gallons per year
of net gain in lagoon = 5,224,820 gallons per year to be applied
5,224,820 gallons per year/200 gpm
= 26,124 minutes pumping per year = 435.4 hours per year
Brake horsepower required: 11.4 BHP (60% efficiency)
KW input to motor: 9.97 KW (85% motor efficiency)
Power consumption per year: 9.97 KW x 435.4 hours per year =
41341 KWH per year
Power costs per year = $434
Equipment Repair/Replacement:
Assume 15 year life for pumps and motors, yielding an annual replacement charge of
'M 6.67% (1/15) of equipment cost. Use an additional 5% of equipment cost to represent
the annual cost of routine maintenance and repairs.
Approximate equipment costs are $17,500
I, Replacement costs at 6.67% of $17,500 =
$ 11168
Maintenance at 5.0% of $17,500 =
875
Total annual replacement/repair charge =
$ 21043
Lab Analyses:
The following tests and testing frequencies will be used for this Alternative
(Spray irrigation system):
Test Cost
FrequenQ�
Annual Cost
BOD-5 $25
3/year
$ 75
NH3-N $20
3/year
$ 60
TSS $15
3/year
$ 45
Fecal Coliform $20
3/year
$ 60
Total N $35
3/year
$ 105
Total P $20
3/year
60
Annual Testing Costs
$ 405
M
Im Appendix A-11

°-
The annual 0&M costs for this alternative are summarized as follows:
Field Maintenance
$ 6,000
Power costs
$ 434
Equipment repair/replacement
$ 2,043
Testing Costs
405
Total Annual 0&M costs
$ 8,882
SO
Present Worth Analysis
Im
Year 0 Costs
Wastewater System Construction
$ 388,850
Land Acquisition
266 700
M
Total Year 0 Cost
$ 655,550
"'
Annual 0&M Costs
Year 1-20
$ 8,882
MW
Present Worth of Alternative
Year 0:
$ 655,550
Year 1-20: (8,882) (P/A,5%,20)=
(81882)(12.4622) =
110 689
Present Worth of Alternative 4:
$ 766,239
FM
RM
Im
no
Appendix A-12

-- ALTERNATIVE NO.5
UTILIZATION OF EXISTING WASTEWATER TREATMENT PLANT WITH DISCHARGE
TO FORBUSH CREEK
Alternative No. 5 utilizes the existing extended aeration wastewater treatment plant to treat
26,000 gpd of wastewater to a level that is suitable for discharge to surface waters. The
existing plant was over -sized when it was constructed, and is capable -of treating 26,000 gpd
with no modifications or additional expenditures. The alternative requires no additional
construction or land to be functional at 26,000 gpd.
The annual 0&M costs for the treatment plant are the same for Alternatives No. 3, 4 and 5 as
the plant is used to treat the wastewater in each alternative. These 0&M costs are not
included in this EAA because this is a comparative analysis of the alternatives, and the
inclusion or omission of costs that are identical in each alternative does not alter the relative
ranking of the alternatives. The one facet of the 0&M costs that will vary between these three
alternatives is the required effluent testing. The NPDES permit will require effluent testing for
Alternative No. 5. Effluent testing will also be required for Alternatives 3 and 4, but the
frequency and quantity of testing required for those alternatives will be substantially less than
required for Alternative No. 5. The testing costs under alternative no. 5 will be included as
detailed below:
Lab Analyses:
Is" The following tests and
testing frequencies will be used
for this Alternative (Surface
Discharge):
FM Test
Cost
Frequency
Annual Cost
BOD-5
$25
Weekly
$1,300
NH3-N
$20
Weekly
$1,040
TSS
$15
Weekly
$780
Fecal Coliform
$20
Weekly
$1,040
Total N
$35
Weekly
$1,820
'-' Total P
$20
Weekly
1 040
Annual Testing Costs
$7,020
MM Present Worth Analysis
RIM Annual 0&M Costs
Year 1-20 $ 7,020
Present Worth of Alternative
Year 1-20: (7,020)(P/A,5%,20)=
(7,020)(12.4622) = 87 485
Present Worth of Alternative 5. $ 87,485
Appendix A-13

ALTERNATIVE NO. 6
UTILIZATION OF EXISTING WASTEWATER TREATMENT PLANT, MODIFIED BY THE
ADDITION OF A TERTIARY FILTER. WITH DISCHARGE TO FORBUSH CREEK
Alternative No. 6 addresses the possibility that the stream wasteload modeling for the
expansion of the NPDES permit may indicate a limits reduction in the concentration of some of
effluent parameters is required. If this were the case, a tertiary filter would be added to the
existing wastewater treatment plant. The filter would be rated for an average daily flow of
PER 26,000, and would include two filter cells, each with 6 square feet of surface area. The filter
would include duplex wastewater (mudwell) pumps, backwash pumps, and a positive
displacement blower for air scouring the filter. The existing UV system from the plant would be
relocated to the effluent line from the filter.
The wastewater treatment system components for this alternative and their estimated installed
``M costs are as follows:
Excavation for tertiary filter
$4,300
Construction of concrete base slab (10' x 15' x 8")
$ 1,800
New tertiary filter, installed on base slab
$80,825
Relocation of existing UV system
$8,350
60 LF of chain line fence at $12.00/1-F
$ 720
Yard piping additions
$7,200
Electrical construction
$ 16,000
Erosion control, clearing, landscaping,
2 800
seeding, etc.
Subtotal, Estimated Construction Cost
$121,995
Soil Scientist Fees
$ 0
Engineering Fees (7%)
8 505
Total Estimated Project Cost
$130,500
rM Operation and Maintenance Costs
The annual O&M costs for the treatment plant are the same for Alternatives No. 3 through 6,
with the exception of O&M cost associated with the filter. The O&M costs that are common to
all the alternatives are not included for the previously stated reasons.
Power Costs:
For the tertiary filter included in this Alternative, the power costs are estimated as
�^ follows:
Filter backwash pumps:
Design flow rate: 120 GPM (20 gpm/SF times 6 Sq. ft. per cell)
TDH: 25 feet
Brake horsepower required: 1.26 BHP (60% efficiency)
KW input to motor: 1.10 KW (85% motor efficiency)
Assume 10 minutes per day per cell, two cells total.
"' Appendix A-14

Pump run time is 0.33 hours per day.
Power consumption per year: 1.10 KW x 0.33 hours per day x 6 days per week
x 38 weeks days per year = 82.7 KWH per year
Power costs per year = $8.27
Wastewater (mudwell) pumps:
Design flow rate: 30 GPM
TDH : 20 feet
Brake horsepower required: 0.38 BHP (40% efficiency)
KW input to motor: 0.33 KW (85% motor efficiency)
1,200 gallons per BW, times two per day = 2,400 gallons/day
21400 gpd/30 gpm = 80 minutes
Pump run time is 1.33 hours per day.
Power consumption per year: 0.33 KW x 1.33 hours per day x 6 days per week
x 38 weeks days per year = 100.1 KWH per year
Power costs per year = $10.00
Lab Analyses:
The following tests and testing frequencies will be used for this Alternative (Surface
Pin Discharge):
Test
Cost
Freque�
Annual Cost
ME BOD-5
$25
Weekly
$ 1,300
NH3-N
$20
Weekly
$ 1,040
TSS
$15
Weekly
$ 780
Fecal Coliform
$20
Weekly
$ 1,040
Total N
$35
Weekly
$ 1,820
Total P
$20
Weekly
1 040
Annual Testing Costs
$ 7,020
FW Equipment Repair/Replacement:
Assume 15 year life for pumps and motors, yielding an annual replacement charge of
6.67% (1/15) of equipment cost. Use an additional 5% of equipment cost to represent
,M the annual cost of routine maintenance and repairs.
Approximate equipment costs are $14,800
Replacement costs at 6.67% of $14,800 = $ 987
Maintenance at 5.0% of $14,800 = 740
Total annual replacement/repair charge = $1,727
The annual O&M costs for this alternative are summarized as follows:
Equipment/replacement repair $ 11727
Power costs $ 18
Lab Analysis costs 7,020
Total Annual O&M Costs $ 8,765
FM Appendix A-15

r
Present Worth Analvsis
Year 0 Costs
Wastewater System Construction $ 130,500
Annual 0&M Costs
Year 1-20 $ 81765
Present Worth of Alternative
FM
Year 0: $ 130,500
Year 1-20: (8,765) (P/A, 5%, 20)=
FM (81765)(12.4622) _ I 109 231
Present Worth of Alternative 6: $ 239,731
F"
IM
M"
IM
fm
Appendix A-16

i.n
® ALTERNATIVE NO. 7
UTILIZATION OF EXISTING WASTEWATER TREATMENT PLANT WITH DISCHARGE
TO FORBUSH CREEK, IN CONJUNCTION WITH RE -USE SPRAY IRRIGATION
This Alternative examines the implementation of a reuse system as described in 15 NCAC
,., 2T.0904, .0907, and .0910. Reuse as the only managed option was previously examined in the
land based treatment systems of Alternatives No. 3 and No. 4. Alternative No. 7 examines
whether there are any opportunities in the Project area for a combination of reclaimed effluent
utilization and a discharge to Forbush Creek (during wet weather or plant dormant seasons).
The environmental benefits of a combination reuse system have been previously established
by the Environmental Management Commission's published intent to encourage the use of
such systems.
The only potential opportunity to use reclaimed wastewater on the school campus would be to
RM irrigate the athletic fields. This Alternative is included in accordance with the EAA Guidance
Document provided by DWQ. While the application of reclaimed wastewater onto high school
athletic fields may be allowable under the rules of the NC Administrative Code, the Yadkin
F' County Board of Education stipulates that there may be reluctance by the public, as well as
the Board, to implement such a system.
Im
The potential area for irrigation would be approximately 9.8 acres (See Figure No. 4). The
irrigation period would be typically be limited to seven months of the year, with the amount of
fm irrigation controlled by the agronomic needs of the grass crops. It is assumed for this analysis
that the natural rainfall would, on average, need to be supplemented by approximately 0.50
inches per week of irrigation for the seven month period. For the 9.8 acres that could be
Im irrigated, this would represent 4,036,290 gallons, or approximately 82% of the effluent
produced during the 38 week, 5 days per week, school year. Due to a substantial portion of
the irrigation season occurring during the summer when the school is not in operation, and
due to some of the effluent being discharged to the receiving stream in the winter and in wet
weather, the actual percentage of effluent that could be irrigated is more realistically 30%.
For the purposes of calculating the power costs, 50% of the total volume of effluent, or
2,470,000 gallons, will be applied in this analysis.
", Alternative No. 7 would require the same tertiary filter described in Alternative No. 6, to allow
the reclaimed wastewater standards to be consistently met. Additionally, the disinfection
system would have to be modified to provide the reduced fecal coliform count required by the
M, standards. For this system, tablet chlorination would be added to the effluent stream that is
used for irrigation, to maintain a chlorine residual and prevent bacteriological re -growth in the
irrigation system. The plant would have automated controls to divert chlorinated effluent to
the storage tank when the tank was less than full, and to divert UV -disinfected effluent to
Forbush Creek when either the storage tank was filled or the effluent turbidity was elevated
above 10 NTU (indicated a failure to meet the reclaimed water standard). The filter would also
have a continuously recording turbidity meter.
The reclaimed wastewater irrigation system would consist of a 70,000 gallons storage tank,
MM sufficient to hold enough effluent to allow a 1/4 inch irrigation session on 9.8 acres, an
irrigation control and pump system, and an irrigation pipe and nozzle network installed on the
�- Appendix A-17

r
RM
M"
MR
RM
FM
M
M,
am
FMM
Mm
fields. The irrigation piping network required for this system would utilize larger diameter
piping and larger nozzle spray heads than used in Alternative No. 4, in order to provide the
flows and pressures required to project the water for the longer distances required on athletic
fields (the 50 foot grid spacing used in Alternative No. 4 is not practical for athletic fields).
no Appendix A-18

o.
0
0
0
0
0
0
0
0
r
0
0
0
0
0
0
0
0
}�~
` \\
...��i EX NG \\
tj
A ikk
r 7
\�\mot\` \�
- '
obd
J.
\
Cps RD. 1
p _ F AL , 1
FORBUSH ,�' , ' 7% '
MIDDLE f
SCHOOL
,- FIGURE No. 4
CAMPUS AREAS TO RECEIVE
RECLAIMED WASTEWATER IRRIGATION
GRAPHIC SCALE
9.8 ACRES OF ATHLETIC FIELD AREAS 240 120 240 .ao gso
AVAILABLE FOR IRRIGATION WITH
RECLAIMED WASTEWATER
( IN FEET )
1 inch = 240 ft.

a'
..
The wastewater treatment system components for this alternative and their estimated installed
costs are as follows:
Excavation for tertiary filter
Construction of concrete base slab (10' x 15' x 8")
New tertiary filter, installed on base slab
Relocation of existing UV system
60 LF of chain line fence at $12.00/1-F
Yard piping additions
Turbidimeter, chlorinator, and automated controls to direct
reclaimed effluent to the storage tank or to discharge
70,000 gallon effluent storage tank and foundation slab
Irrigation pump station with duplex 100 gpm pumps and zone
controller
'm Irrigation system for athletic fields
Electrical construction
Erosion control, clearing, landscaping,
seeding, etc. (3 acres at $5,000/ac.)
Subtotal, Estimated Construction Cost
Soil Scientist Fees (5%)
Engineering Fees (7%)
Total Estimated Project Cost
Operation and Maintenance Costs
$4,300
$1,800
$80,825
$8,350
$ 720
$7,200
$8,000
$41,620
$55,000
$92,000
$35,000
15 000
$349,815
$17,385
24 500
$391,700
The annual O&M costs for the treatment plant for this Alternative are the same as for
Alternatives No. 3 through 6, with the exception of 0&M cost associated with the filter and the
M-W reclaimed water irrigation system. The O&M costs that are common to all the alternatives are
not included for the previously stated reasons.
'-' Power Costs:
The power cost for all equipment that is unique to this alternative is included in the
present worth analysis below. For the tertiary filter included in this Alternative and
reclaimed water irrigation system, the power costs are estimated as follows:
Filter backwash pumps:
Design flow rate: 120 GPM (20 gpm/SF times 6 Sq. ft. per cell)
TDH: 25 feet
Brake horsepower required: 1.26 BHP (60% efficiency)
KW input to motor: 1.10 KW (85% motor efficiency)
Assume 10 minutes per day per cell, two cells total.
Pump run time is 0.33 hours per day.
Power consumption per year: 1.10 KW x 0.33 hours per day x 6 days per week
x 38 weeks days per year = 82.7 KWH per year
Power costs per year = $8.27
Appendix A-20

Wastewater (mudwell) pumps:
FM Design flow rate: 30 GPM
TDH: 20 feet
Brake horsepower required: 0.38 BHP (40% efficiency)
F, KW input to motor: 0.33 KW (85% motor efficiency)
1,200 gallons per BW, times two per day = 2,400 gallons/day
2,400 gpd/30 gpm = 80 minutes
® Pump run time is 1.33 hours per day.
Power consumption per year: 0.33 KW x 1.33 hours per day x 6 days per week
x 38 weeks days per year = 100.1 KWH per year
Power costs per year = $10.00
Irrigation Pump Station:
Design pump rate: 100 GPM
TDH: 155 feet
2,470,000 gallons per year of reclaimed effluent to be applied/100 gpm
= 24,700 minutes pumping per year = 412 hours per year
Brake horsepower required: 6.5 BHP (60% efficiency)
,M KW input to motor: 5.7 KW (85% motor efficiency)
Power consumption per year: 5.7 KW x 412 hours per year =
21348 KWH per year
RM Power costs per year = $235
Lab Analyses:
MM The following tests and testing frequencies will be used for this Alternative (Conjunctive
Use — Discharge and Reclaimed Water Irrigation):
'm Test Cost Frequency Annual Cost
BOD-5 $25 Weekly $ 1,300
NH3-N $20 Weekly $ 1,040
TSS $15 Weekly $ 780
Fecal Coliform $20 Weekly $ 1,040
Total N $35 Weekly $ 1,820
Total P $20 Weekly 1 040
Annual Testing Costs $ 7,020
Equipment Repair/Replacement:
PER Assume 15 year life for pumps and motors, yielding an annual replacement charge of
6.67% (1/15) of equipment cost. Use an additional 5% of equipment cost to represent
the annual cost of routine maintenance and repairs.
Approximate equipment costs are $26,300
Replacement costs at 6.67% of $26,300 = $ 1,754
Maintenance at 5.0% of $26,300 = 1.31
Total annual replacement/repair charge = $ 31069
Appendix A-21

f
1.
The annual 0&M costs for this alternative are summarized as follows:
Equipment/replacement repair
$ 31069
Power costs
$ 253
Lab Analysis costs
7 020
Total Annual 0&M Costs
$ 10,342
Present Worth Analysis
Year 0 Costs
Wastewater System Construction
$ 391,700
Annual 0&M Costs
Year 1-20
$ 10,342
Present Worth of Alternative
Year 0:
$ 391,700
Year 1-20: (10,342) (P/A, 5%, 20)=
(10,342)(12.4622)=
$128,884
Present Worth of Alternative 7:
$ 520,584
�° Appendix A-22

4M
LOW STREAM FLOW ESTIMATES FOR THE DISCHARGE SITE:
FM
A request was submitted to the NC offices for USGS for an update of the low
flow estimate previously issued for the receiving stream for the discharge of the
F" Forbush High School WWTP in Yadkin County.
I"
MW
FM
M
FM
M
FM
I
The response issued by USGS was by e-mail, a copy of which is included in this
Appendix. The response can be summarized as follows:
FORBUSH HIGH SCHOOL:
The low flow estimates provided for Forbush Creek, at the point of discharge of
the Forbush High School WWTP, were as follows:
7Q10 flow =
30Q2 flow =
Winter 7Q10 =
7Q2 flow =
Drainage Area =
2.1 cfs
7.1 cfs
6.7 cfs
5.6 cfs
21.6 square miles
The e-mail states that these estimates were prepared in 1990, based on the flow
characteristics of Forbush Creek, as measured at a continuous record gaging
station that is no longer in use. The period of record for this station was 1940 to
1971, and the station location was 0.6 miles downstream of the discharge point.
The 7Q10 and 30Q2 flows are also positive for this location. Because these
estimates were derived from same -stream gaging records, they would be
considered more accurate than the estimates that might be derived from the
methods presented in "Low -flow Characteristics of Streams in North Carolina".
on Appendix C - 1

.. Page 1 of 2
John F. Phillips
no From: "John C Weaver" <[e-mail]>
To: <[e-mail]>
Cc: "John C Weaver" <[e-mail]>; "Jeanne C Robbins" <[e-mail]>
fm Sent: Monday, September 24, 2007 4:56 PM
Subject: Low flow estimates for selected Yadkin basin sites
Sm John,
During the latter part of August, you submitted formal low -flow requests for 3 sites in Yadkin River basin,
requesting the full range of flow statistics typically provided in response to formal requests. Due to other items
requiring my focus these day — particularly the drought — I have been unable to spend time on your requests until
this afternoon. The purpose of this email is to provide you with some information that may be helpful to you at this
time and to confirm your need for a formal response.
FM
The "most recent" low -flow information published for this area is in a statewide report completed in the early
1990's. It is USGS Water -Supply Paper 2403, 'Low -flow characteristics of streams in North Carolina" (Giese and
Mason, 1993). An online version of the report is available through
http://pubs.er.usgs.gov/usgspubs/wsp/wsp2403. The report provides the low -flow characteristics (based on data
through 1988) via regional relations and at site values for sites with drainage basins between 1 and 400 sgmi and
not considered or known to be affected by regulation and/or diversions.
If you access the report, please note the online report files are provided in the ".DJVU" format and require a
particular Lizardtech plug-in, also available through a link displayed on the page. Or you can click an adjacent
link that will allow you to view the report as a group of images without the need for a plug-in.
A check of the low -flow files here at the USGS North Carolina Water Science Center for each of your sites
indicates the following:
(1) Your site of interest on South Deep Creek tributary (adjacent to Starmount High School) is identical to a site
where low -flow estimates have previously been determined — South Deep Creek tributary near Wagoner (station
`� id 02115541, drainage area 0.53 sgmi). The following estimates were determined in June 1987 based on the flow
characteristics at a nearby partial -record site on North Deep Creek near Yadkinville (station id 02115610):
FM Average flow = 0.7 cfs (1.03 cfsm)
7Q10 = 0.06 cfs (0.109 cfsm)
30Q2 = 0.2 cfs (0.383 cfsm)
winter 7Q10 = 0.15 (0.290 cfsm)
7Q2 = 0.16 cfs (0.293 cfism)
MM (2) Your site of interest on Forbush Creek is almost identical to another site where low -flow estimates have
previously been determined — Forbush Creek above gaging station near Forbush (station id 0211549820,
drainage area 21.6 sgmi). The following estimates were determined in January 1990 based on the flow
characteristics at a discontinued continuous -record gaging station located 0.6 mile downstream from your point of
MM interest — Forbush Creek near Yadkinville (station id 02115500, period of record in 1940-71):
Average flow = 22 cfs (1.03 cfsm)
7Q10 = 2.1 cfs (0.098 cfsm)
30Q2 = 7.1 cfs (0.330 cfsm)
winter 7Q10 = 6.7 (0.307 cfsm)
7Q2 = 5.6 cfs (0.262 cfsm)
MM 10/3/2007

Page 2 of 2
s-
Please note the low -flow yields (expressed as flow per sqmi drainage area, or cfsm) at the above two sites are
very comparable for each statistic.
(3yfzQQour site of interest on th a difference in drainage areas between your location aDd4t
gaging sta t is negligible such that flow cha tstics a
the gage can be co red applicable to your site.
Average flow = 2,440 cfs
7Q10 = 550 cfs
30Q2 = 1,140 cfs
winter 7Q 10 = 860 cfs N , f
7Q2 = 990 cfs N/A
Please note e-66ove statistics are based on the 1965 to 2006 climatic years, which reflect�Wilke
of
re the gaging station and the regulated flow releases from W. Kerr Scott Reservoir ne
Note: The climatic year is the standard annual period used for low flow analyses at continuous -record gaging
stations. It runs from April 1 through March 31 and is designated by the year in which the period begins.. For
example, the 2006 climatic year is from April 1, 2006, through March 31, 2007.
In some of the western basins in North Carolina, the low -flow conditions observed during .the 1998 2002 drought
have resulted in lower low flow statistics. No formal statewide investigation has been completed to document the
changes in low -flow statistics since the drought. However, where updated analyses have been completed for
selected stations, the changes in pre- versus post -drought 7Q10 discharges have been on the order of about 10
to 25 percent. For example, the 7Q10 discharge estimated for the Enon gaging station as of 1998 was about 620
cfs. The updated value is about 12 percent lower that the 1998 value. However, with no additional data from the
discontinued gaging station on Forbush Creek, there no means other than a "guess estimate" to consider what an
updated 7Q10 discharge might be at this location.
If using this email as a means to provide you with the low -flow estimates is not sufficient -or- if you still want the
formal response completed for each site, the let me know. I have been using email as the primary means of
providing low flow information (at no charge) to help facilitate more rapid responses. Again, if you need the
formal responses, then I will attempt to complete these by mid- to late October (charge of $150 per site).
Thank you for you patience ... hope this information is helpful.
Curtis Weaver
J. Curtis Weaver, Hydrologist, PE
USGS North Carolina Water Science Center
3916 Sunset Ridge Road
Raleigh, NC 27607
Telephone: [phone] H Fax: [phone]
E-mail address —[e-mail]
Internet address — httpJ/nc.water_usgs.gov/
10/3/2007