NC0086550_Authorization to Construct_20000407

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State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Bill Holman, Secretary
Kerr T. Stevens, Director
April 7, 2000
Mr. Jeffrey Lewis
Town of Fairmont
P.O. Box 248
Fairmont, North Carolina 28340
erfill
NCDENR
Subject: Authorization to Construct
ATC No. 086550ACA
NPDES Permit No. NCO086550
Fairmont Regional WWTP
Robeson County
Dear Mr. Lewis:
The Division of Water Quality's NPDES Unit has reviewed the Town of Fairmont's request for an
Authorization to Construct a new regional wastewater treatment facility near Boardman. the new
Fairmont Regional WWTP. The Division finds the proposed design to be satisfactory and hereby grants
authorization for construction of a 1.75 MGD activated sludge treatment facility including the following:
• Headworks:
• Two 1.0 MGD bar screens, one manually cleaned, one mechanically cleaned
• Aerated grit chamber
• Activated sludge system:
• Two 724,000 gallon rectangular aeration basins,
• Two 75 ft. diameter clarifiers (octagonal),
• Coarse -bubble diffused aeration system with three 3200 scfm centrifugal blowers,
• Blowerbuilding,
• Disinfection system:
• Gaseous chlorination and two 170,600 gallon chlorine contact chambers
• Gaseous sulfur dioxide dechlorination and 35,900 gallon contact chamber
Chlorine and sulfur dioxide feed building,
• One cascade aerator,
• Solids handling facilities:
• One 30 ft. diameter gravity thickener
• Two aerated digesters, 376,000 gallons total volume
• One 444,400 gallon sludge holding tank
• One sludge loading station
• Laboratory and control building, and
• All associated structures, pumps, motors, valves, piping, wiring, controls, and other
appurtenances as described in the subject plans and specifications.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer Internet: http://h2o.enr.state,nc.us/

•.r
Fairmont Regional WWTP
ATC No. 086550ACA
z Page 2
This Authorization to Construct is issued in accordance with NPDES Permit No. NC0086550, issued
June 9, 1999. The Division issued Wastewater Collection Permit No. WQ0015382 in January 1999,
authorizing construction of related facilities:
• Pump Station No. 1 and force main to pump the Town's wastewaters from the current
treatment plant site to the new treatment facilities and
• Pump Station No. 2 and force main to discharge treated wastewater to the Lumber River.
Upon submittal of Engineer's Certification(s) of completion for the entire project (see below), the Town
shall be authorized to discharge up to 1.75 MGD of treated wastewater to the Lumber River in
accordance with the conditions and limitations specified in its NPDES permit. The Division understands
that, upon start-up of the regional facility, the Town's NPDES permit for the existing Fairmont WWTP
(N00021059) will no longer be needed and can be rescinded.
The key issue with the proposed design is that the 1.75 MGD average design flow is considerably higher
than the sum of current flows, around 0.5 MGD, that will be pumped to the new plant. Because the plant
is designed with only two treatment trains, operators could face a significant challenge in meeting permit
limits across the full range of flows. The design addresses this issue to a certain degree: it provides for
operating just one of the two treatment trains at the lower flows and using an operating mode better
suited to those conditions. In addition, the prospects for connecting other wastewater sources to the plant
seem to be improving, and the added connections could shorten the time that the plant has to operate
under low flow conditions. Still, the approach is less than optimal. The Town should consider whether a
design change, such as converting to a three- or four -train configuration, is appropriate at this time in
order to enhance the plant's ability to reliably meet permit limits over the wide range of expected flows.
Fairmont is understandably interested in attracting industry in order to boost the area's economy, and the
regional plant design includes some capacity for industrial wastewater flows. The Town should be aware,
however, that the new plant is specifically designed to treat domestic wastewater. Many industrial
wastewaters are not suitable for treatment in this type of facility. Without special pretreatment, they can
exert toxic effects in the plant, upsetting the biological treatment processes and causing violations of the
NPDES permit limit for toxicity. Before committing to accept any significant industrial flows, the Town
must be convinced and demonstrate to the Division that the new wastewater is compatible with its
treatment plant. The Town must also develop and implement a local pretreatment program, approved by
the Division, to control the industrial source(s) discharging to its treatment plant.
Engineer's Certification
Upon completing construction of all components of the regional project approved under this ATC and the
Wastewater Collection Permit No. WQ0015382 and prior to operation of the new facilities, the Permittee
shall provide the Division with a certification from a professional engineer certifying that the permitted
facilities have been installed in accordance with the NPDES Permit, the Authorizations to Construct, and
the approved plans and specifications.
The Certification should be mailed to:
NCDENR/ DWQ/ NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Additional Conditions
In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions,
the Permittee shall take immediate corrective action, including those as may be required by this Division,
such as the construction of additional or replacement wastewater treatment or disposal facilities.

•_o
Fairmont Regional WWTP
ATC No. 086550ACA
Page 3
The Permittee shall notify the Fayetteville Regional Office, telephone number [phone], at least
forty-eight (48) hours in advance of operation of the installed facilities, so that an in -place inspection can
be made. Such notification to the regional supervisor shall be made during the normal office hours of
8:00 a.m. until 5:00 p.m. on Monday through Friday, excluding State Holidays.
The Permittee shall employ a certified wastewater treatment plant operator to be in responsible charge
(ORC) of the wastewater treatment facilities. The operator must hold a certificate of the type and grade at
least equivalent to or greater than the classification assigned to the wastewater treatment facilities by the
Certification Commission. The Permittee must also employ a certified back-up operator of the
appropriate type and grade to comply with the conditions of Title 15A, Chapter 8G, .0200. The ORC of
the facility must visit each Class I facility at least weekly and each Class II, III, and IV facility at least
daily, excluding weekends and holidays; and must properly manage and document daily operation and
maintenance of the facility and comply with all other conditions of Title 15A, Chapter 8G, .0200.
The Operational Agreement between the Permittee and the Environmental Management Commission is
incorporated herein by reference and is a condition of this Permit. Noncompliance with the terms of the
Operational Agreement shall subject the Permittee to all sanctions provided by G. S. 143-215.6 for
violation of or failure to act in accordance with the terms and conditions of this Permit.
Failure to abide by the requirements contained in this Authorization to Construct may subject the
Permittee to an enforcement action by the Division of Water Quality in accordance with North Carolina
General Statute 143-215.6A to 143-215.6C.
The issuance of this Authorization to Construct does not preclude the Permittee from complying with any
and all statutes, rules, regulations, or ordinances which may be imposed by other government agencies
(local, state, and federal) which have jurisdiction.
The Permittee shall maintain a copy of the approved plans and specifications on file for the life of the
facility. One (1) copy of the approved plans and specifications is enclosed for your records.
If you have any questions about this Authorization to Construct, please contact Mike Templeton, at (919)
733-5083, extension 541.
Sincerely,
Y71,6`rr T. Stevens
Director
Enclosures: Project Plans and Specifications
Engineer's Certification Form
cc: Mr. William R. Lester, Hobbs, Upchurch & Associates (w/ certification form)
Fayetteville Regional Office, Water Quality
Technical Assistance and Certification Unit
Central Files
NPDES Unit Files

ATC SUMMARY
Town of Fairmont - Regional WWTP
ATC No. 086550ACA
Lumber River, Class C-Sw
Lumber River Basin, 030751
Robeson County
SCOPE
The Town of Fairmont proposes to construct a 1.75 MGD regional wastewater treatment facility near
Boardman. The Town will abandon its existing treatment plant (NC0021059), convert it to a central lift
station, and pump its wastewater to the new plant. Treated effluent from the new plant will be pumped to
the Lumber River. The project involves approximately 11 miles of force main in all.
The influent and effluent pump stations and the influent and effluent force mains were permitted under
permit number WQ0015832, issued January 11, 1999. The scope of the current review is limited to the
new treatment facilities.
The ATC was originally received July 27, 1998, and returned until the NPDES permit for the facility was
issued on June 9, 1999.
RECOMMENDATIONS
1. Approve the revised ATC request as submitted, in consideration of
additional information provided by the design engineer.
2. Add comments to the approval letter linking it with the pump
station/ force main project and addressing design capacity and
industrial connection issues.
REVIEW SUMMARY
General
The key issue in the design review is that the 1.75 MGD average design flow is considerably higher than
current flows, which are around 0.5 MGD on a monthly average. Because the plant is designed with only
two treatment trains, operators could face a significant challenge to meet permit limits across the full
range of expected flows.
The,flow projection for Fairmont was over -estimated in past planning efforts; DWQ issued speculative
limits for 2.0 MGD in 1995. The flow was reduced to 1.75 MGD, and the Town received a FONSI for
the new plant at that flow. Later reviews revealed that even the reduced flow was more than needed for
the Town. Fairmont's plant is now being promoted as a regional treatment facility, with our support
and consistent with more recent wastewater planning efforts in Robeson County and surrounding
areas.
The Town is having some success recruiting other communities to connect to the regional plant, and it
now appears more likely that committed flows will approach a more comfortable 0.7-0.8 MGD by start-
up.

Design Issues
The main issues with the plant design are:
1. The facility design appears reasonable for a plant treating 1.75 MGD of domestic wastewater.
Current flows from committed contributors are approximately 0.5 MGD, and the design calculations
look at both Year 1 and Average Design Flow conditions.
2. Having only two treatment trains limits the operators' options for running the plant at low initial
flows. Even with only one train in operation and in extended aeration mode, the plant will be lightly
loaded. The main challenge in the new plant may be in managing the biological solids: maintaining a
healthy sludge in the system and keeping enough solids in the aeration basin to achieve adequate
treatment.
UNRESOLVED ISSUES
It remains to be seen whether the Town can collect enough treatable wastewater to feed the plant at a
reasonable level. As domestic -type flows approach and exceed 0.7 - 0.8 MGD, the operation of the plant
should become relatively routine.
The Town is recruiting industries, marketing the available capacity of the new plant. The initial design
assumes that all of the wastewater to the plant is domestic in nature. DWQ should allow an industry to
connect to the Town only after the industry has demonstrated that its wastewater is compatible with the
treatment system. If the industry is a Significant Industrial User, the Town must develop and implement a
local pretreatment program.
- end -
-2-

ATC Review Notes
Town of Fairmont - Regional WWTP
ATC No. 086550ACA
NPDES No. NCO086550
Lumber River, Class C-Sw
Lumber River Basin, 030751
Robeson County
A. PROJECT OVERVIEW
The Town of Fairmont proposes to build a 1.75 MGD activated sludge wastewater treatment plant to
treat wastewaters from Fairmont, Orrum, Proctorville, Boardman, and future municipal and/or
industrial connections to be defined. The regional plant will be built to the south and west of the US
Highway 74 crossing of the Lumber River near Boardman. The project is being funded by a $6-7M
Farmer's Home Rural Development grant.
Fairmont's existing treatment plant will be abandoned and converted to a central lift station.
Wastewaters will be pumped to the new plant through approx. 11 miles of 12" 0 force main. Other
pump stations will be added as needed for other planned and future connections. Treated effluent
from the new plant will be pumped to the Lumber River through approx. mile of 12" 0 force main.
The influent pump station and the influent and effluent force mains were already permitted under
permit number WQ0015832, issued January 11, 1999. The scope of the current project includes the
treatment facilities and the effluent pump station.
A key issue in the design review is that the design flows are considerably higher than initial flows (1.75
vs. 0.5 MGD, monthly average values). The plant is designed with only two treatment trains, and the
operators will face a significant challenge to meet permit limits through the full range of expected
flows.
The following is a compilation of design information for the new plant.
B. PROCESS DESCRIPTION
The proposed process consists of an activated sludge system (w/o primary clarification), chlorine
disinfection w/ SO2 dechlorination, and cascade re -aeration. Waste sludge is thickened and
aerobically digested, then held in a storage basin until trucked to a disposal site.
During the first years of the plant's operation, when wastewater flows will be low, only one train of the
activated sludge process will be operated, in extended aeration mode. As flows increase, operations
will evolve to conventional mode using both treatment trains. The exact progression will be up to the
judgment of the operators.
The hydraulic capacity of the plant is adequate to allow nitrification, and this is included in the design.
With addition of mixers at the influent end of the aeration basin(s), the plant could also provide
denitrification, but the design does not address this possibility.

C. DESIGN ASSUMPTIONS
Year 1
Design Year
NPDES Permit
Monthly
Hourly
Monthly
Hourly
Effluent
Average
Maximum
Average
Maximum
Limitations*
WASTEWATER & EFFLUENT CHARACTERISTICS
Flow (MGD)
0.5
1.25
1.75
4.375
1.75
BOD (mg/L)
200
200
200
200
15
TSS (mg/L)
200
200
200
200
30
TKN (mg/L)
50
50
50
50
—
NH3-N (mg/L as N)
--
--
—
--
4
Fecal Coliform (#/100rnQ
--
--
--
--
200
Residual Chlorine (ug/L)
--
--
--
--
28
Dissolved Oxygen (mg/L)
--
--
--
--
5
PROCESS ASSUMPTIONS
MCRT (d)
20
--
10
--
--
lb BOD/1,000 ft3
15
--
15
--
--
RAS, WAS TSS (mg/L)
8,000
--
8,000
--
--
Qr/Q ratio
--
up to 200%**
--
up to 57%**
--
MLVSS:MLSS ratio
0.65
--
.65
--
--
PLANT SITE
Temp (degC) 27 27 27 27 Site elevation (ft) 100 100 100 100 --
Monthly average values, except residual chlorine (daily maximum)
*' 1.0 MGD pumping capacity
D. HEADWORKS
Bar Screen one manually cleaned unit, one mechanically cleaned, both rated at 1.0 MGD
(2.5 MGD peak), w/ SS grates and 1/2" openings
Grit Chamber =* aerated grit chamber w/ rolling aeration action
-2-

E. ACTIVATED SLUDGE
Aeration Basins =* 2 rectangular basins @ 362,000 gal each = 724,000 gal total
Coarse air diffusers w/ dome deflectors
=> 3 - 3,200 scfm blowers for entire plant; wide use of airlift pumps; 6,400 scfm
reserved for aeration
Given Calculated
Typical Values
Year 1 Design Year 1 Design
(M&E, 3rd)' Results
MLSS, mg/L 2,300 4,020 2,800 2,800
1,500-5,000 / See comment
1,200-3,000 below
Hydraulic Retention Time (hrs) 21 *' 12* 17 9
4-8 / 18-36 '
Organic Loading
F/M (IbBOD /lb MLVSS-d) 0.08 0.08 0.15*** 0.27***
0.05-0.15 / 0.2-0.4 °
lb BOD/ 1,000 U 15 15 17.2 30.2
10-25 / 20-40 °
Sludge Wastage (gpd @ 4,620**** 8,140**** 9,380 32,800
8,000 mg/L TSS)
MCRT (days) 20 10 11.3 6.4
20-30 / 5-15 °
AOTR 1,100 7,740
SOTR 1,690 11,840
Aeration HP req'd 21 145
Aeration Rate (scfm/1,000 ft3) -- -- -- 29.4
OK
* Given as extended air/ conventional values; Table 10-5.
*' Basin volume includes rapid mix and influent channel volumes
*** Assuming 2,800 mg/L MLSS,1,820 mg/L MLVSS
**** Calculation error as submitted
The aeration basins were originally sized (8/18/97 calcs in EAA) based on a 10-day MCRT and an
MLSS of 2,800 mg/L. The current design (7/98 calcs) uses that same volume, assumes MCRTs of 20
and 10 days (initial and design flows), and back -calculates the MLSS.
The plant is described as starting in extended air mode, due to low organic loading rates, and
converting to conventional activated sludge process as loadings increase. Most design values for the
design year still fall into the range that is considered the extended air mode.
Clarifiers 2 center -feed, peripheral -draw octagonal clarifiers, vacuum withdrawal of
sludge thru rake arms.
Dimensions:
Diameter:
Area:
Side -Water Depth:
Volume:
75 ft (approx.)
4,880 ft2
15.25 ft
557,000 gal each
-3-

. /A,
Given
Calculated
Typical Values
Year 1
Design
Year 1
Design
Results
Surface Loading (gpd/ft2)
113
<350
102
179
200-400 / 400-800
Low
990 @ peak
600-800 /
OK
1,000-1,200
Solids Loading (lb/02)
® 0.35 & 1 MGD recycle
3.7
26
3.7
6.1
4.8 -24
Low end
Recycle Rate (MGD)
0.35
1.0
0.27
0.78
N
70
200
53
45
50-150 / 25-100
OK!
Additional capacity to recycle mixed liquor would enhance denitrification capability.
F. DISINFECTION
Chlorine gas in 1-ton cylinders. Sulfur
dioxide in
lb cylinders. Both are dual -tank systems w/
automatic switch -over and alarms.
Chlorine Contact Chamber =>
Dimensions:
two chambers, each approx.
20.6 x 42.6 x 13 avg. depth
Volume:
approx. 85,300 gal each, 170,600 total
Given
Calculated
Year 1 Design
Year 1 Design Typical Values Results
Detention Time, avg. (min)
110 64
245 140 30 std. OK
Dechlorination Chamber =>
Dimensions:
one chamber, approx.
20.6 x 19.4 x 12 avg. depth
Volume:
approx. 35,870 gal
Given
Calculated Typical Values
Year 1 Design
Year 1 Design & Source Results
Detention Time (min)
-- --
103 30 30-60 OK
-4-

G. SOLIDS HANDLING
Waste activated sludge is pumped continuously to a 30' 0 gravity thickener. Design calls for 8,000
mg/L TSS in, 2.5% solids out to digesters. The two square digesters operate in series. Sludge will
periodically be decanted in the second digester cell and drained by gravity to the adjoining sludge
storage basin.
Given
Calculated Typical Values
Year 1 Design
Year 1 Design & Source
Results
Gravity Thickener
Solids Loading (Ib/02)
-- 2.9
-- 3.1
OK
Digesters Nos.1 & 2
Volume (gal)
-- 376,000
-- --
--
HRT (days)
-- 41
-- 36
OK
Solids Loading
-- 26
8.1 33
(lb VSS/1,000 ft3)
Aeration
•• --
-- 29.4
OK
(scfm/1,000 ft3)
Sludge Storage
Volume (gal)
-- 444,400
-- 454,400
OK
Detention
-• 73'
-- 69'
OK
At 4% solids
H. OTHER
Design includes back-up power source: 500 KW (670 HP) unit. Total load for all three blowers plus all
three effluent pumps is 435 HP.
Plans, specs, and initial design calculations are stamped by Will Buie, no longer with Hobbs
Upchurch. No revisions were made to the plans and specs, so new P.E. stamp is not required.
Did not look at D.O. levels predicted at the outfall
I. COMMENTS
Main issue with the design is the under -loading in first years of operation, until flows reach 0.7-0.8
MGD. Controlling the sludge age (MCRT) and managing the solids inventory in the activated sludge
system will probably be especially challenging during this time.
DESIGN REFERENCES
1) Metcalf and Eddy, Inc. Wastewater Engineering, Treatment, Disposal, Reuse (3ro Ed.). McGraw-Hill, Inc., New York, N.Y.,
1991
2) Great Lakes -Upper Mississippi Rive Board of State Public Health and Environmenal Managers, Recommended Standards
for Wastewater Facilities (Ten States Standards, Health Education Services, Albany, N.Y., 1990 Edition.
-5-

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EPMRONMEW AND Nxru ResouRGes BY 1AIV
DATE CHKD BY DATE
3,4JE0 Jp 4 @ Z.s
bo
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* \J ' = 37-6,oM 4 4w oAA

Job Name:
Town of Fairmont W WTP
HUANo.
FR9605
Date:
I8-Aug-97
Description:
Aeration Basin Sizing and Parameter Calculation Worksheet
Formulas:
Sludge Age (days) = Suspended Solids In Aeration
Suspended Solids To Aeration
MLSS (mg/1) =
Desired Suspended Solids In Aeration
Weight Of Water In Aeration
MCRT (days) =
Suspended Solids In Aeration
SS In WAS +SS In Effluent
Food To Microorganism Ratio = BOD To Aeration
- MLVSS in Aeration
,r l
Input Parameters:
Calculated Parameters:
Wastewater Flow & Influent Conditions:
Calculated Parameter:
Peak Wet Weather Flow(mgd)=
4.375
ADF BOD5 Deslmyed(Ibday)=>
2,700
Design Year Flow, ADF (mgd) =
1.750
ADF Ammonia -Nitrogen Destroyed (Ibday)=>
671
Stan-Up'Anticipated Flow(mgd)-
0.500
Yr.l B0D5Destmyed(Ib/day)=>
771
Design Sludge Return Rate (mgd) =
1.000
Yr.l Ammonia -Nitrogen Destroyed (IWday) =>
192
Influent BOD5 (mg/1) =
200
Influent TSS(mg/1)=
200
Oxygen Rain
Influent TKN(mgtl)=
50
ADF Actual sfer Rete,AOTR(Ibtday)=> �.
7,138
Effluent BODS Required(mg1I)=
IS
ADF Standaansfer Rate, SOTR(IWday)->
/0"
I0,926
E(Bueml TSS Required(mg/1)=
30
Yr.l Actualmfer Rare, AOTR(lb/day)=>
2,040
Emuent NHS-N(mg/1)=
4
Yc1 Standaransfer Rate, SOTR(lbtday)�
3,122
Max Temperature (deg C) =
27
Site Elevation=
too
HP Required
Temperature Correction Them
1.024
HP At Av eDaily Flow=>
182
Satiation D.O. at Temp, Elev Cst (mg/I) =
7.99
HP At Y 1 Flow->
52
Design Assumptions
Reactor Basin Volume (Based on IbBOD/1000 euft)
P/I)=
Desig/WAS
2,800
Volume Required (gols) —> -
673,219
Yr.l I)=
2,800
Detention Time (hrs)=>
9.23
RASoncentation(mg1l)=
8,000
Transfer Alpha Value =
0.90
System Mass Requirements
Transfer Beta Value =
0.95
System Man ZBOD x MCRT x Yield (lb)
20,251
Mean C/Residence Time (days)
10
Volume Required (gal)
967,199
Operatin Dissolved Oxygen, Cis(mg/1)=
lb BO1000 cut R Aeration Vol -
2.00
30
Detention Time (hrs)=>
11.89
r-a o+o w..}I98 C.0-LA
Sludge Yield (lb TSS/Ib BOD5 Destroyed) =
0.75
Selected Volume- Input Value (gals) r
87, 0
Volatile SS Fraction (h4,VSSMB.SS)-
0.65
-+J' a
Selected Basin Evaluation 1/
Rate Coemclents
� 000 T
ADF Detention Tim (hrs)�> �
I1.93
Its Oxygen/lb BOD5 Applied =
1.50
ta
Yr.I Detention T' e(hrs)Y>
41.76
Its Oxygen/lb NH3-N Applied =
4.60
Mixing HPRcq red =>
174
ADF Process Required
52
HP Coefficients
ADFFood Mass(Ib BOD/Ib MASS)=>
0.20
Its 02B r=
2.50
YcIII F oMass(Ib BODAb MLSS)=>
•O.00'
BHP/1 Cu Ft=
1.5
ADF SI ge Wasting Rate (gpd)=>
23,888
Yr.IS ge Wasting Rate(gpd)=>
28,575

Hobbs, Upchurch & Associates, P.A.
Consulting Engineers
290 S.W. Broad Street a Post Office Box 1737 • Southern Pines, NC 28388
March 30, 2000
Mr. Mike Templeton
N.C. Department of Environment & Natural Resources
Division of Water Quality
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Re: Fairmont Wastewater Treatment Plant
ATC No. 086550ACA
HUA No. FR9605.G
Dear Mr. Templeton:
�®
FAX: [phone]
Total 34 pages including cover
Attached is the design and performance calculations for the diffused air system for the Fairmont
Regional Wastewater Treatment Plant.
Should you have any questions, please do not hesitate to contact our office.
Sincerely,
HOBBS, UPCHURCH & ASSOCIATES, P.A.
Bill Lester, Jr., P.E.
Governmental Division Manager
p L��1OdL� n
Ili
APR 3 - 2000
BENR - WATER QUALITY
POINT S011RCE BRANCH
Southern Pines, NC • Telephone [phone] • Fax [phone] • e-mail: [e-mail]
Myrtle Beach • Kill Devil Hills • Raleigh

WATER POLLUTION CONTROL CORP.
June 25, 1998
Tony Combs
Combs & Associates, Inc.
P.O. BOX 32185
Charlotte, NC 28232-2185
RE: Fairmont, NC
WPCC Project # 9770-97S
Dear Tony,
Attached is a revised design for the above mentioned project. Please note
that the design contains performance calculations for the following
basins. These performance calculations are based on supplying SD 1000
single drop diffusers in quantities equal to the indicated number on the
drawings. The basin and number of diffusers indicated on the drawings
are as follows:
Aeration Basins # 1 &2
Aerobic Digesters # 1 &2
Sludge Holding Basin
Thickener Pre -Mix Basin
Rapid Mix Basin
Aerated Influent Channel
96 Diffusers per Basin, 192 Diffusers Total
40 Diffusers per Basin, 80 Diffusers Total
104 Diffusers
8 Diffusers
10 Diffusers
60 Diffusers
There are also five (5). single droplegs with single diffusers. One (1) in
Aerobic Digester #2, one (1) in Clarifier Loading Basin # 1, one (1) in the
Grit Chamber and two (2) in Clarifier Loading Basin #2. WPCC intends
to supply these diffuser assemblies as shown on the drawings.
There are also several airlift pumps shown on the drawings. These are
located in the following basins and are sized as shown on the drawings.
Basin Number of Airlift Pumps Diameter of Airlift Pump
Rapid Mix Basin
Aerobic Digester # 1
Aerobic Digester #2
0
SANITAIR EO
al
2
C:
Clarifier Loading Basin #2 3
10
6
4
16
9333 N. 49th Street Brown Deer, WI 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abjwastewater.com

SANITAIRE\ABJ
All dimensions for the basins are consistent with the dimensions on the
drawings and the previous design that I sent you. The loadings for the
aeration basins and the air rates for the other basins are the same as the
previous design.
The only parameters that have changed for the aeration basins is Alpha
(a) and Beta (R). Since we are providing a coarse bubble system, these
values need to be adjusted to reflect the change in diffuser selection.
Also, only the AVE and PEAK conditions are included for the aeration
basins. The AVE2 condition no longer applies to a coarse bubble
application.
There are detail drawings included of the single drop diffuser that WPCC
proposed to supply for this project. The dropleg material is stainless
steel and the deflector plate is PVC.
If you have any questions, please give Jon Butt or me a call.
Sincerely,
WATER POLLUTION CONTROL CORP.
Christopher J. Tippery
Sales Technician
C: Hobbs, Upchurch & Associates, Inc.
290 SW Broad Street
Southern Pines, NC 28388
ATTN: Will Buie

r
. a
SANRAIR EO
WATER POLLUTION CONTROL CORP.
GBANITAIRE0
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Aeration Basins #1 &2
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 25, 1998
cjt Osetupsftr3
9333 N. 49th Street Brown Deer. WI 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abiwastewater.com

<TAN`KAGE 2 TRAINS EACH CONSISTING OF:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
•:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME .
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
..............................................................................
1 1 AEROBIC 15.50 80.00 L X 36.67 W X 16.50 D 48.40:
.............................................................................
TOTAL VOLUME PER TRAIN 48.4004
AERATED VOLUME PER TRAIN 48.4004
DESIGN DATA
--------
:COND. NO.
BOD
NH3-N
OXYGEN
------------------•
AIR WATER TEMP.:
TRAINS
(#/DAY)
(#/DAY)
(#/DAY)
(SCFM) (DEG. C. )
:AVE 2
2921
511.087
6732.5 A
@20
:PEAK 2
5842
1022.17
13464 A
@20
DESIGN PARAMETERS
-----------------
--------------------- ------------------------------------------------!
! COND. AOR/SOR ALPHA BETA THETA D.O.
AMB.
02/
02/ SRT !
! (ppm)
!---------------------------------------------------------------------!
( PS IA)
BOD5
NH3 ( DAYS) !
!AVE @.90 @.95 @1.024 @2.0
14.6
1.5
4.6 !
!PEAK @.90 @.95 @1.024 @2.0
14.6
1.5
4.6 !
NOTES: @-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
Pa e 2 of 5

PERFORMANCE SUMMARY
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 6
NUMBER DIFFUSERS/ASSEMBLY: 32
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT CENTER OF 26.67 FEET WIDE AERATION BAND AND 15.50 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME -
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
---------------------------------------------
CONDITION:
AVE
PEAK
---------------------------------------------
TANKAGE:
.
NO. TANKS
2
2
VOLUME/TANK (KCF)
: 48.4
48.4
TOTAL VOLUME (KCF)
96.8
96.8
OXYGEN TRANSFER:
02 (#/DAY) AOR
6732.5
13464
AOR/SOR
: .67764
.67764
02 (#/DAY) STD. COND.
9935.1
19870
02 (#/DAY/KCF) STD.CND.
102.6
205.2
STD. COND. EFF. (o)
10.3
11.6
SAFETY FACTOR (o)
10
10
AIR RATES:
TOTAL SCFM
3839.6
6780.1
SCFM/ASSEMBLY
639.9
1130.0
SCFM/KCF
39.6
70.0
SCFM/DIFFUSER
19.9
35.3
PSIG REQUIRED AT
6.9
7.2
TOP OF DROPLEG
POWER ESTIMATES:
:
*TOTAL BHP REQUIRED
148.2
271.3
STD. COND.(#02/BHP/HR)
2.79
3.05
SITE (#02/BHP/HR)
----------------------------------------------
1.89
2.06
NOTE: BHP QUOTED ASSUMES ADIABATIC COMPRESSION, 70% MECHANICAL
EFFICIENCY AND
0.3 PSI AIR
MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER WILL DEPEND ON ACTUAL BLOWER, MOTOR, AND
PLANT PIPING DESIGN.
Page 3 of 5

9
OXYGEN TRANSFER CORRECTION FACTOR: AOR/SOR
------------------------------------------
THE RATIO OF ACTUAL SITE OXYGEN TRANSFER TO STANDARD CONDITION
OXYGEN TRANSFER, (AOR/SOR), IS DEPENDENT ON A NUMBER OF FACTORS:
20 STANDARD CONDITION
TEMPERATURE (DEG.C)
T : OPERATING WATER
TEMPERATURE (DEG. C)
BETA : FIELD/STD.COND. 02 SATURATION RATIO
THETA : OPERATING WATER TEMPERATURE FACTOR
D.O. : OPERATING OXYGEN CONCENTRATION (MG/L)
P : STD. COND. AMBIENT C SURF : CLEARWATER SURFACE 02 SATURATION
Sc PRESSURE (1 ATMOSPHERE) T AT OPERATING TEMPERATURE (MG/L)
P : OPERATING AMBIENT 9.07 : CLEARWATER SURFACE 02 SATURATION
SITE PRESSURE (PSIA) AT 20 DEG. C. (MG/L)
*
ALPHA : FIELD/STD.COND. C SAT : STD. COND. AERATED 02 SATURATION
KLA RATIO 20 IN THE TANK (MG/L)
T-20 * .
(THETA) (ALPHA) [ (BETA) (C SAT ) (CSURF /9.07) (P /P ) - (D.O.) ]
20 T SITE SC
:AOR/SOR= -----------------------------------------------------------------
(C SAT )
20
---------------------------------------------------------------------------
WATER * .
:COND. ALPHA BETA THETA DO P
TEMP. C SAT C SURF AOR/SOR:
ppm site
:----------------------------------------------------------------------------:
deg.0 20 T
:AVE @.90 @.95 @1.024 @2.0 14.6
@20 10.245 9.070 0.6776
:PEAK @.90 @.95 @1.024 @2.0 14.6
@20 10.245 9.070 0.6776
NOTE: @-PRECEEDING A VALUE INDICATES AN ASSUMPTION
STANDARD CONDITIONS FOR OXYGEN TRANSFER IMPLIES: CLEARWATER AT
20 DEG. C.,• ZERO DISSOLVED OXYGEN AND 1 ATMOSPHERE AMBIENT PRESSURE.
Page 4 of 5

c
ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE AVE CONDITION
AIR RATE PER ASSEMBLY= 639.93 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 6.911 PSIG
DIFFUSER CONNECTORS SPACED AT 1.125 FT CENTERS
HEADER 1 IS APPROX. 34.9 FT LONG WITH 32 DIFFUSER CONNECTORS
-------------------
NODE APP. EQU DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
--------------------------------------------
1 E 6.3 10 639.9 462.3 14.8 2.44E-03 3.14E-04 6.911 6.909
2 17.5 10 639.9 462.3 14.8 2.44E-03 8.72E-04 6.910 6.908
3 T 25.8 10 639.9 462.4 14.8 2.44E-03 1.29E-03 6.909 6.907
***** HEADER 1 *****
4 36.8 10 0.0 0.0 0.0 0.00E+00 4.58E-04 6.909 6.909
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 1.98E-03 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY = 6.9076 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 3.922E-03 PSI
B: DIFFUSER HEADLOSS= 1.412E-01 PSI
AT 19.998 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 15.500 FEET OF SUBMERGENCE= 6.7115 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 6.8566 PSIG
(FRICTION HEADLOSS (A+B) = 1.451E-01 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
Pacie 5 of 5

ri
9ANrrA1RBll
WATER POLLUTION CONTROL CORP.
riBANITAIRE'9
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Aerobic Digester#1
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 25,1998
cjt c:lsetupslfairl
9333 N. 49th Street Brown Deer, WI 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abjwastewater.com

='I'ANKAGE 1 TRAINS EACH CONSISTING OF:
..............................................................................
.:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME :
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
..............................................................................
1 1 AEROBIC 15.50 42.25 L X 36.75 W X 16.50 D 25.62:
................. .................. ..........................................
:
TOTAL VOLUME PER TRAIN 25.6193
AERATED VOLUME PER TRAIN 25.6193
DESIGN DATA
.-----------------------------------------------------------:
:COND. NO. BOD NH3-N OXYGEN AIR WATER TEMP.:
TRAINS (#/DAY) (#/DAY) (#/DAY) (SCFM) (DEG. C. )
:.25 FT 1 310.538 @20
:20 S/K 1 512.3 @„_
DESIGN PARAMETERS
-----------------
---------------------------------------------------------------------
! COND. AOR/SOR ALPHA BETA THETA D.O. AMB. 02/ 02/ SRT
(ppm) (PSIA) BOD5 NH3 (DAYS)
---------------------------------------------------------------------
l.2S/FT 14.6
!20 S/K 14.6
i
NOTES: @-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
lPacre 2 of-4

PERFORMANCE SUMMARY
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 2
NUMBER DIFFUSERS/ASSEMBLY: 20
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT CENTER OF 21.13 FEET WIDE AERATION BAND AND 15.50 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME.
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
---------------------------------------------
CONDITION:
. .2S/FT
20 S/K
---------------------------------------------
TANKAGE:
NO. TANKS
1
1
VOLUME/TANK (KCF)
: 25.6
25.6
TOTAL VOLUME (KCF)
25.6
25.6
OXYGEN TRANSFER:
02 (#/DAY) AOR
AOR/SOR
02 (#/DAY) STD. COND.
603.0
1056.6
02 (#/DAY/KCF) STD . CND . 23.5
41.2
STD. COND. EFF. (%)
7.75
8.23
SAFETY FACTOR ( %)
10
10
AIR RATES:
TOTAL SCFM
310.5
512.3
SCFM/ASSEMBLY
155.2
256.1
SCFM/KCF
12.1
20
SCFM/DIFFUSER
: 7.76
12.8
PSIG REQUIRED AT
6.9
7.1
TOP OF DROPLEG
POWER ESTIMATES:
*TOTAL BHP REQUIRED
11.9
20.2
STD. COND.(#02/BHP/HR)
2.09
2.17
SITE ( #02 /BHP/HR)
---------------------------------------------
NOTE: BHP QUOTED
ASSUMES ADIABATIC COMPRESSION, 70%; MECHANICAL
EFFICIENCY AND 0.3 PSI AIR
MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER WILL DEPEND ON ACTUAL BLOWER, MOTOR, AND
PLANT PIPING
DESIGN.
Pa e 3 of 4

ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE .2S/FT CONDITION
AIR RATE PER ASSEMBLY= 155.27 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 6.911 PSIG
DIFFUSER CONNECTORS SPACED AT 1.750 FT CENTERS
HEADER 1 IS APPROX. 33.3 FT LONG WITH 20 DIFFUSER CONNECTORS
NODE APP. EQU. DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
1 E 4.6 4 155.3 112.2 24.0 6.43E-03 1.33E-03 6.910 6.904
2 17.5 4 155.3 112.2 24.0 6.43E-03 5.04E-03 6.905 6.899
3 T 15.5 4 155.3 112.2 24.0 6.43E-03 4.46E-03 6.901 6.894
***** HEADER 1 *****
4 34.0 4 0.0 0.0 0.0 0.00E+00 2.45E-03 6.898 6.898
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 3.98E-03 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY - 6.8962 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 1.527E-02 PSI
B: DIFFUSER HEADLOSS= 9.094E-02 PSI
AT 7.763 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 15.500 FEET OF SUBMERGENCE= 6.7115 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 6.8177 PSIG
(FRICTION HEADLOSS (A+B)= 1.062E-01 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
[page 4 of 4

a.
sANrrAlvi F-0
WATER POLLUTION CONTROL CORP.
ri SANITAIFIE0
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Aerobic Digester #2
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 26,1998
cjt cAsetupsVairl
9333 N. 49th Street Brown Deer, WI 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abjwastewater.com

c
TANKAGE 1 TRAINS EACH CONSISTING OF:
..............................................................................
:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME .
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
..............................................................................
1 1 AEROBIC 15.50 40.66 L X 36.75 W X 16.50 D 24.65:
..............................................................................
TOTAL VOLUME PER TRAIN 24.654
AERATED VOLUME PER TRAIN 24.654
DESIGN DATA
:-----------------------------------------------------------:
:COND. NO. BOD NH3-N OXYGEN AIR WATER TEMP.:
TRAINS (#/DAY) (#/DAY) (#/DAY) (SCFM) (DEG. C. )
:.25 FT 1 298.838 @20
:20 S/K 1 493.0 @_
DESIGN PARAMETERS
-----------------
!---------------------------------------------------------------------!
! COND. AOR/SOR ALPHA BETA THETA D.O. AMB. 02/ 02/ SRT !
! (ppm) (PSIA) BOD5 NH3 (DAYS) !
!---------------------------------------------------------------------!
!.2S/FT 14.6 !
!20 S/K 14.6 !
r r
NOTES: @-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
Pacre 2 of 4

PERFORMANCE SUMMARY
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 2
NUMBER DIFFUSERS/ASSEMBLY: 20
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT CENTER OF 20.33 FEET WIDE AERATION BAND AND 15.50 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME.
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
---------------------------------------------
CONDITION:
: .2S/FT
20 S/K
---------------------------------------------
TANKAGE:
NO. TANKS
1
1
VOLUME/TANK (KCF)
24.6
24.6
TOTAL VOLUME (KCF)
24.6
24.6
OXYGEN TRANSFER:
02 ( #/DAY) AOR
AOR/SOR
02 (#/DAY) STD. COND.
580.2
1029.5
02 (#/DAY/KCF) STD.CND.
23.5
41.7
STD. COND. EFF. (o)
7.75
8.33
SAFETY FACTOR (%}
10
10
AIR RATES:
TOTAL SCFM
298.8
493.0
SCFM/ASSEMBLY
149.4
246.5
SCFM/KCF
12.1
20
SCFM/DIFFUSER
7.47
12.3
PSIG REQUIRED AT
6.9
7
TOP OF DROPLEG
POWER ESTIMATES:
*TOTAL BHP REQUIRED
11.5
19.2
STD. COND.(#02/BHP/HR)
2.09
2.22
SITE (#02/BHP/HR)
---------------------------------------------
NOTE: BHP QUOTED ASSUMES ADIABATIC
COMPRESSION, 70% MECHANICAL
EFFICIENCY AND
0.3 PSI
AIR MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER WILL DEPEND
ON ACTUAL BLOWER, MOTOR, AND
PLANT PIPING DESIGN.
Page 3 of 4

ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE .2S/FT CONDITION
AIR RATE PER ASSEMBLY= 149.42 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 6.911 PSIG
DIFFUSER CONNECTORS SPACED AT 1.750 FT CENTERS
HEADER 1 IS APPROX. 33.3 FT LONG WITH 20 DIFFUSER CONNECTORS
-----------------------------------
NODE APP. EQU. DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
1 E 4.6 4 149.4 107.9 23.1 5.95E-03 1.23E-03 6.910 6.904
2 17.5 4 149.4 108.0 23.1 5.96E-03 4.67E-03 6.906 6.900
3 T 15.5 4 149.4 108.0 23.1 5.96E-03 4.13E-03 6.901 6.896
***** HEADER 1 *****
4 33.3 4 0.0 0.0 0.0 0.00E+00 2.22E-03 6.899 6.899
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 3.74E-03 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY = 6.8974 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 1.412E-02 PSI
B: DIFFUSER HEADLOSS= 8.629E-02 PSI
AT 7.471 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 15.500 FEET OF SUBMERGENCE= 6.7115 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 6.8119 PSIG
(FRICTION HEADLOSS (A+B)= 1.004E-01 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
Page 4 of 4l

r
WATER POLLUTION CONTROL CORP.
ri SANITAIRE'9
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Sludge Holding Tank
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 26,1998
cjt Osetupsftr4
9333 N. 49th Street Brown Deer, Wt 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abiwastewater.com
SANrrAiR F-0
ABJ"4

.,s TANKAGE 1 TRAINS EACH CONSISTING OF:
.......................................................0......0........
:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME��:
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
..................................... ....... ................ ................ .
1 1 AEROBIC 15.50 56.79 L X 64.83 W X 16.50 D 60.75:
.................................................0....0....0....0.............
TOTAL VOLUME PER TRAIN 60.7497
AERATED VOLUME PER TRAIN 60,7497
DESIGN DATA
:-----------------------------------------------------------•
:COND. NO. BOD NH3-N OXYGEN AIR WATER TEMP.:
TRAINS (#/DAY) (#/DAY) (#/DAY) (SCFM) (DEG. C. )
:.25 FT 1 736.364 @20
:20 S/K 1 1214.9 @20
DESIGN PARAMETERS
-----------------
!---------------------------------------------------------------------!
! COND. AOR/SOR ALPHA BETA THETA D.O. AMB. 02/ 02/ SRT !
! (ppm) (PSIA) BOD5 NH3 (DAYS) !
!---------------------------------------------------------------------!
!.2S/FT 14.6 !
!20 S/K 14.6 !
r r
NOTES: @-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
Pa e 2 of 4

r
. .
PERFORMANCE SUMMARY
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 3
NUMBER DIFFUSERS/ASSEMBLY: 35
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT CENTER OF 18.93 FEET WIDE AERATION BAND AND 15.50 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME.
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
---------------------------------------------
CONDITION: :
.2S/FT
20 S/K
---------------------------------------------
TANKAGE: .
NO. TANKS :
1
1
VOLUME/TANK (KCF)
60.7
60.7
TOTAL VOLUME (KCF)
60.7
60.7
OXYGEN TRANSFER:
02 (# /DAY) AOR
AOR/SOR
02 (#/DAY) STD. COND.
1429.9
2595.8
02 (#/DAY/KCF) STD.CND.
23.5
42.7
STD. COND. EFF. (%)
7.75
8.52
SAFETY FACTOR (o)
10
10
AIR RATES:
TOTAL SCFM
736.3
1214.9
SCFM/ASSEMBLY
245.4
404.9
SCFM/KCF
12.1
20
SCFM/DIFFUSER
7.01
11.5
PSIG REQUIRED AT
6.9
7
TOP OF DROPLEG
POWER ESTIMATES:
*TOTAL BHP REQUIRED
28.4
47.4
STD. COND. (##02/BHP/HR)
2.09
2.27
SITE (#02/BHP/HR)
---------------------------------------------
NOTE: BHP QUOTED ASSUMES ADIABATIC COMPRESSION, 700-, MECHANICAL
EFFICIENCY AND 0.3 PSI AIR MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER
WILL DEPEND
ON ACTUAL BLOWER, MOTOR, AND
PLANT PIPING DESIGN.
Page 3 of 4

ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE .2S/FT CONDITION
AIR RATE PER ASSEMBLY= 245.45 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 6.911 PSIG
DIFFUSER CONNECTORS SPACED AT 1.900 FT CENTERS
HEADER 1 IS APPROX. 64.6 FT LONG WITH 35 DIFFUSER CONNECTORS
---------------------------------------------------
NODE APP. EQU. DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
1 E 5.4 6 245.5 177.3 16.2 2.94E-03 4.92E-04 6.911 6.908
2 17.5 6 245.5 177.3 16.2 2.94E-03 1.60E-03 6.909 6.906
3 T 19.7 6 245.5 177.4 16.2 2.94E-03 1.80E-03 6.908 6.905
***** HEADER 1 *****
4 20.0 6 168.3 121.6 11.1 1.38E-03 1.30E-03 6.906 6.905
5 R 5.1 4 168.3 121.6 26.0 7.56E-03 1.73E-03 6.905 6.897
6 82.7 4 0.0 0.0 0.0 0.00E+00 7.00E-03 6.898 6.898
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 7.91E-03 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY = 6.8996 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 1.186E-02 PSI
B: DIFFUSER HEADLOSS= 7.927E-02 PSI
AT 7.013 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 15.500 FEET OF SUBMERGENCE= 6.7115 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 6.8026 PSIG
(FRICTION HEADLOSS (A+B)= 9.113E-02 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
Page 4 of 4

C
rj
SAwrAiR E10
WATER POLLUTION CONTROL CORP.
OBANITAIRF.'9
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Thickener Pre -Mix Basin
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 25,1998
cjt OsetupslfaW
9333 N. 49th Street Brown Deer, Wl 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abjwastewater.com
ABI"A

r
°'TANKAGE 1 TRAINS EACH CONSISTING OF:
..............................................................................
:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME .
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
..............................................................................
1 1 AEROBIC 13.00 30.00 L X 4.00 W X 14.00 D 1.68:
.............................................................................
TOTAL VOLUME PER TRAIN 1.68
AERATED VOLUME PER TRAIN 1.68
DESIGN DATA
•-----------------------------------------------------------•
:COND. NO. BOD NH3-N OXYGEN AIR WATER TEMP.:
TRAINS (#/DAY) (#/DAY) (#/DAY) (SCFM) (DEG. C. )
:.25 FT 1 24 @20
:20 S/K 1 33.6 @_
DESIGN PARAMETERS
-----------------
!---------------------------------------------------------------------!
! COND. AOR/SOR ALPHA BETA THETA D.O. AMB. 02/ 02/ SRT !
(ppm) (PSIA) BOD5 NH3 (DAYS) !
!---------------------------------------------------------------------!
l.2S/FT 14.6 !
!20 S/K 14.6 !
!
NOTES: @-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
lPacre 2 of 4

PERFORMANCE SUMMARY
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 1
NUMBER DIFFUSERS/ASSEMBLY: 8
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT SIDE OF 4.00 FEET WIDE AERATION BAND AND 13.00 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME.
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
---------------------------------------------
CONDITION:
. .2S/FT
20 S/K
---------------------------------------------
TANKAGE:
.
NO. TANKS
1
1
VOLUME/TANK (KCF)
1.68
1.68
TOTAL VOLUME (KCF)
1.68
1.68
OXYGEN TRANSFER:
02 (#/DAY) AOR
AOR/SOR
02 (#/DAY) STD. COND.
39.0
54.7
02 (#/DAY/KCF) STD.CND.
23.2
32.5
STD. COND. EFF. (OU
6.5
6.5
SAFETY FACTOR M
10
10
AIR RATES:
TOTAL SCFM
23.9
33.6
SCFM/ASSEMBLY
23.9
33.6
SCFM/KCF
14.2
20
SCFM/DIFFUSER
2.99
4.2
PSIG REQUIRED AT
5.8
5.9
TOP OF DROPLEG
POWER ESTIMATES:
*TOTAL BHP REQUIRED
.80117
1.13
STD. COND.(#02/BHP/HR)
2.03
2.00
SITE (#02/BHP/HR)
---------------------------------------------
NOTE: BHP QUOTED ASSUMES ADIABATIC COMPRESSION, 70% MECHANICAL
EFFICIENCY AND
0.3 PSI AIR
MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER WILL DEPEND ON ACTUAL BLOWER, MOTOR, AND
PLANT PIPING DESIGN.
Pa e 3 of 4

ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE .2S/FT CONDITION
AIR RATE PER ASSEMBLY= 24.00 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 5.829 PSIG
DIFFUSER CONNECTORS SPACED AT 4.000 FT CENTERS
HEADER 1 IS APPROX. 28.0 FT LONG WITH 8 DIFFUSER CONNECTORS
--- --------------------------------------------------
NODE APP. EQU. DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
1 E 4.6 4 24.0 18.3 3.9 1.62E-04 3.34E-05 5.829 5.829
2 15.0 4 24.0 18.3 3.9 1.62E-04 1.09E-04 5.829 5.829
3 T 15.5 4 24.0 18.3 3.9 1.62E-04 1.12E-04 5.829 5.829
***** HEADER 1 *****
4 28.0 4 0.0 0.0 0.0 O.00E+00 5.07E-05 5.829 5.829
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 1.11E-04 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY = 5.8286 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 3.600E-04 PSI
B: DIFFUSER HEADLOSS= 1.273E-01 PSI
AT 3.000 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 13.000 FEET OF SUBMERGENCE=
5.6290 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 5.7567 PSIG
(FRICTION HEADLOSS (A+B)= 1.277E-01 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
Pa e 4 of 4

{
WATER POLLUTION CONTROL CORP.
SANITAIRE°
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Rapid Mix Basin
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 25, 9 998
cjt c:%setupsVair6
9333 N. 49th Street Brown Deer. WI 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abiwastewater.com
8ANMAIR F-e .
ABJ 7M

i
.r TANKAGE 1 TRAINS EACH CONSISTING OF:
..............................................................................
:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME .
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
.............................................................................:
1 1 AEROBIC 16.80 25.17 L X 10.00 W X 17.80 D 4.48:
..............................................................................
TOTAL VOLUME PER TRAIN 4.47954
AERATED VOLUME PER TRAIN 4.47954
DESIGN DATA
------------
:COND. NO. BOD NH3-N OXYGEN AIR WATER TEMP.:
TRAINS (#/DAY) (#/DAY) (#/DAY) (SQFM) (DEG. C. )
:40 S K 1 179.1 @20
DESIGN PARAMETERS
-----------------
!---------------------------------------------------------------------!
! COND. AOR/SOR ALPHA BETA THETA D.O. AMB. 02/ 02/ SRT !
(ppm) (PSIA) BODS NH3 (DAYS) !
!---------------------------------------------------------------------!
!40 S/K 14.6 !
i i
NOTES: @-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
Wage 2 of L4J

PERFORMANCE SUMMARY
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 1
NUMBER DIFFUSERS/ASSEMBLY: 10
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT SIDE OF 10.00 FEET WIDE AERATION BAND AND 16.80 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME.
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
------------------------------------
CONDITION: :
40 S/K
------------------------------------
TANKAGE:
NO. TANKS
1
VOLUME/TANK (KCF)
4.47
TOTAL VOLUME (KCF)
4.47
OXYGEN TRANSFER:
02 ( # /DAY) AOR
AOR/SOR
02 (#/DAY) STD. COND.
532.0
02 (#/DAY/KCF) STD.CND.
118.7
STD. COND. EFF. (%)
11.8
SAFETY FACTOR (o)
10
AIR RATES:
TOTAL SCFM
179.1
SCFM/ASSEMBLY
179.1
SCFM/KCF
40
SCFM/DIFFUSER
17.9
PSIG REQUIRED AT
7.5
TOP OF DROPLEG
POWER ESTIMATES:
*TOTAL BHP REQUIRED
7.41
STD. COND.(#02/BHP/HR)
2.98
SITE (#02/BHP/HR)
------------------------------------
NOTE: BHP QUOTED ASSUMES ADIABATIC COMPRESSION, 70% MECHANICAL
EFFICIENCY AND 0.3
PSI AIR MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER
WILL DEPEND ON ACTUAL BLOWER, MOTOR, AND
PLANT .PIPING DESIGN.
Pacre 3 of 4

ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE 40 S/K CONDITION
AIR RATE PER ASSEMBLY= 179.18 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 7.474 PSIG
DIFFUSER CONNECTORS SPACED AT 2.500 FT CENTERS
HEADER 1 IS APPROX. 22.5 FT LONG WITH 10 DIFFUSER CONNECTORS
NODE APP. EQU. DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
1 E 4.6 4 179.2 126.1 26.9 8.34E-03 1.72E-03 7.473 7.464
2 18.8 4 179.2 126.2 27.0 8.35E-03 7.03E-03 7.466 7.457
3 T 15.5 4 179.2 126.2 27.0 8.35E-03 5.79E-03 7.460 7.452
***** HEADER 1 *****
4 22.5 4 0.0 0.0 0.0 0.00E+00 2.10E-03 7.458 7.458
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 6.25E-03 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY - 7.4546 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 1.977E-02 PSI
B: DIFFUSER HEADLOSS= 1.164E-01 PSI
AT 17.918 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 16.800 FEET OF SUBMERGENCE= 7.2744 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 7.4106 PSIG
(FRICTION HEADLOSS (A+B)= 1.362E-01 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
Page 4 of 41

WATER POLLUTION CONTROL CORP.
ri SANITAIRE'o
SINGLE DROP DIFFUSER AERATION EQUIPMENT
for
Fairmont, NC
Aerated Influent Channel
CONSULTING ENGINEER:
Hobbs, Upchurch & Associates
SANITAIRE #9770-97S
June 25,1998
cjt cAsetupsftr5
9333 N. 49th Street Brown Deer. WI 53223 phone: [phone] fax: [phone]
Web Sites: http://www.sanitaire.com http://www.abjwastewater.com
ABI TM
BANrrAsR E0

:.;TANKAGE 1 TRAINS EACH CONSISTING OF:
..............................................................................
:PASS PARALLEL ZONE SUBMERGENCE REACTOR VOLUME .
:NO. REACTORS PROCESS (FEET) DIMENSIONS (FEET) (KCF/PASS):
..............................................................................
1 1 AEROBIC 16.80 177.00 L X 4.00 W X 17.80 D 12.60:
..............................................................................
TOTAL VOLUME PER TRAIN 12.6024
AERATED VOLUME PER TRAIN 12.6024
DESIGN DATA
:-----------------------------------------------------------:
:COND. NO. BOD NH3-N OXYGEN AIR WATER TEMP.:
TRAINS (#/DAY) (#/DAY) (#/DAY) (SCFM) (DEG. C. )
:3 S LF 1 531 @20 .
DESIGN PARAMETERS
-----------------
---------------------------------------------------------------------!
! COND. AOR/SOR ALPHA BETA THETA D.O. AMB. 02/ 02/ SRT !
(ppm) (PSIA) BODS NH3 ( DAYS) !
---------------------------------------------------------------------!
!3 S/LF 14.6
NOTES: Q-PRECEDING A VALUE INDICATES AN ASSUMPTION BY SANITAIRE
A -INDICATES ACTUAL (AOR) OXYGEN REQUIREMENT
S-INDICATES STANDARD CONDITION (SOR) OXYGEN REQUIREMENT
ROUND TANKS ARE EVALUATED AS SQUARE TANKS OF EQUAL SURFACE AREA
IF THE AOR/SOR PARAMETER IS NOT GIVEN, THEN ITS VALUE WILL BE
CALCULATED LATER IF SUITABLE ALPHA, BETA, D.O., THETA, PRESSURE
AND TEMPERATURE DATA IS SUPPLIED.
INDICATED PRESSURE IS EQUIVALENT TO SITE ELEVATION OF 60 FEET
Pacre 2 of 4

PERFORMANCE SUMMARY
-------------------
EQUIPMENT:
TYPE: SINGLE DROP DIFFUSER
NUMBER OF ASSEMBLIES: 1
NUMBER DIFFUSERS/ASSEMBLY: 60
OXYGEN TRANSFER PERFORMANCE BASED ON:
EACH HEADER AT SIDE OF 4.00 FEET WIDE AERATION BAND AND 16.80 FEET
OF SUBMERGENCE. OXYGEN PERFORMANCE IS CORRELATED TO PLACEMENT GEOMETRY,
DIFFUSER SUBMERGENCE, AND AIR RATE PER UNIT TANK VOLUME.
(NOTE: SCFM/DIFFUSER DOES NOT DISPLAY SIGNIFICANT CORRELATION TO
COARSE BUBBLE DEVICE PERFORMANCE USING THESE PARAMETERS)
------------------------------------
CONDITION: :3 S/LFT
------------------------------------
TANKAGE:
NO. TANKS 1
VOLUME/TANK (KCF) 12.6
TOTAL VOLUME (KCF) 12.6
OXYGEN TRANSFER:
02 (#/DAY) AOR
AOR/SOR
02 (#/DAY) STD. COND. 1616.9
02 (#/DAY/KCF) STD.CND. 128.3
STD. COND. EFF. (%) 12.1
SAFETY FACTOR (%) 10
AIR RATES: .
TOTAL SCFM 530.9
SCFM/ASSEMBLY 530.9
SCFM/KCF 42.1
SCFM/DIFFUSER 8.84
PSIG REQUIRED AT 7.4
TOP OF DROPLEG
POWER ESTIMATES:
*TOTAL BHP REQUIRED 21.7
STD. COND.(#02/BHP/HR) 3.09
SITE (#02/BHP/HR)
------------------------------------
NOTE: BHP QUOTED ASSUMES ADIABATIC COMPRESSION, 70o MECHANICAL
EFFICIENCY AND 0.3 PSI AIR MAIN HEADLOSS. MORE ACCURATE
VALUES FOR POWER WILL DEPEND ON ACTUAL BLOWER, MOTOR, AND
PLANT PIPING DESIGN.
Pa e 3 of 4

ONE AERATION ASSEMBLY HEADLOSS
CALCULATED FOR THE 3 S/LFT CONDITION
AIR RATE PER ASSEMBLY= 531.00 SCFM
ASSUMED OPERATING TEMPERATURE= 100 DEG F.
ASSUMED TOTAL PRESSURE AT TOP OF DROPLEG= 7.474 PSIG
DIFFUSER CONNECTORS SPACED AT 2.900 FT CENTERS
HEADER 1 IS APPROX. 171.1 FT LONG WITH 60 DIFFUSER CONNECTORS
NODE APP. EQU. DIA. SCFM CFM VEL. VEL. HEADLOSS TOTAL STATIC
* LENGTH PRESS. PRESS. PRESS. PRESS.
(FT) (IN) (FPS) (PSI) (PSI) (PSIG) (PSIG)
1 E 5.9 8 531.0 373.8 18.9 4.09E-03 5.90E-04 7.474 7.470
2 18.8 8 531.0 373.9 18.9 4.09E-03 1.88E-03 7.472 7.468
3 T 23.0 8 531.0 373.9 18.9 4.09E-03 2.30E-03 7.470 7.466
***** HEADER 1 *****
4 80.0 8 283.2 199.4 10.1 1.16E-03 4.70E-03 7.465 7.464
5 R 4.5 6 283.2 199.5 18.2 3.82E-03 5.37E-04 7.464 7.461
6 254.0 6 0.0 0.0 0.0 0.00E+00 7.56E-03 7.457 7.457
----------------------------------------------------------------------------
(STATIC HEADER PRESSURE DIFFERENTIAL IN ASSEMBLY= 8.71E-03 PSI)
(AVERAGE HEADER PRESSURE IN ASSEMBLY - 7.4615 PSIG)
----------------------------------------------------------------------------
A: NET AVERAGE HEADLOSS FROM TOP OF DROPLEG TO HEADER= 1.292E-02 PSI
B: DIFFUSER HEADLOSS= 1.066E-01 PSI
AT 8.850 SCFM/DIFF, ONE SD1000 DIFFUSER PER DROP
C: 16.800 FEET OF SUBMERGENCE= 7.2744 PSIG
----------------------------------------------------------------------------
TOTAL PRESSURE REQ'D AT TOP OF DROP, (A+B+C)= 7.3940 PSIG
(FRICTION HEADLOSS (A+B)= 1.196E-01 PSI)
NOTE: * -LABELS FOR APPURTENANCES-
------------------------
R-REDUCER, T-BRANCH FLOW TEE, RT-LINE FLOW TEE, E-90 DEG. ELBOW
B-WIDE OPEN BUTTERFLY VALVE, S-SWING PEDESTAL & KNEE JOINTS.
Pa e 4 of 74

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p AIR MAIN
T.O.T. EL.
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1
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SANITAIRE TO HERE
3/4- SCH. 40
SEE DETAIL 63
I" SCH. 40
S.S. DROPLEG
3 X 3 X 1/4'
S.S. ANGLE (TYP)
18"o PVC DEFLECTOR PLATE
37 REOUIRED
ALTERNATE HEIGHT OF PLATE
FOR EVERY OTHER OROPLEC.
DROPLECS NEXT TO WALL OR
COLUMN DO NOT HAVE PLATE.
SD 1000 DIFFUSER
SEE DETAIL NS-1
SHEET -27
AIR RELEASE EL.
FLOOR EL.
TION TA
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/ 8 SPACES 0 1'-0' f. 8--0-
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WASTEWATER TREATMENT PLANT
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F
Hobbs, Upchurch & Associates, P.A.
Consulting Engineers
290 S.W. Broad Street • Post Office Box 1737 , Southern Pines, NC 28388
March 19, 2000
Mr. Michael E. Templeton
NCDENR Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Re: Town of Fairmont
Wastewater Treatment Plant
ATC No. 021059ACA
HUA No. FR9605.p
Dear Mike:
Fax: [phone]
n� 6 IS
Li L____.J
Per our telephone conversation Thursday, I have summarized a list of equipment with
specification reference. I will gladly add detail to this if that is what you need. I also
discovered the same discrepancy in aeration volume as you mentioned. The specifications
appear to be more accurate with a volume of 47,147 cf each. This does not appear to
change the outcome of the design calculation results with respect to concept and
feasibility.
As you know, I am faced with a serious funding issue with Rural Development and I
appreciate your assistance and cooperation in the approval of this project. If you should
have any additional questions regarding this project, please do not hesitate to contact this
office.
Sincerely,
HOBBS, UPCHUBLU AND ASSOCIATES, P.A.
Bill Lester, Jr., P.E.
Governmental Division Manager
Cc: Ben Hill, Town Manager, Fairmont
Southern Pines, NC a Telephone [phone] • Fax [phone] • e-mail: [e-mail]
Myrtle Beach • Kill Devil Hills • Raleigh

Town of Fairmont, Robeson County, NC
Wastewater Treatment Plant
Summary of Design Elements
Description
Mechanical Cleaned Bar Screen
Manual Bar Screen
Grit Removal & Dewatering Equipment
Aeration System
Circular Clarifier Equipment
Centrifugal Air Blower
Sludge Thickener
Pumps — Sludge Loading
Pumps — Existing WWTP
Pumps — Effluent Pump Station
Pumps — Treatment Plant
Instrumentation
Refrigerated Sampler
Airlift Pumps
Flow Control Equipment
Clorination/Dechlorination Equipment
Dimensions/Capacity
1.0 mgd / 2.5 mgd max.
1.0 mgd / 2.5 mgd max.
Rolling grit aeration
Diffused Air System
6388 scfin total airflow
SOTR = 215.8 lb/hr
75'0" dia. (octagonal basin)
3 ea @ 3200 scfin / 150 hp
30'0" dia., 15'6" s.w. depth
Centrifugal Solids Handling
1 ea — 225 gpm @ 13.1' TDH
Submersible Centrifugal
2 ea - 720 gpm @ 153' TDH, 75 hp
1 ea —1020 gpm @ 218' TDH, 125 hp
Submersible Centrifugal
2 ea — 750 gpm @ 62' TDH, 25 hp
1 ea — 2000 gpm @ 108' TDH, 100 hp
Submersible Centrifugal
2 ea — 250 gpm @ 35' TDH, 5 hp
As Noted
As Noted
RAS — 4 ea @ 900 gpm (10")
WAS/Scum — 4ea @ 140 gpm (4")
Thick. Scum — 2 ea @ 250 gpm (6")
Thick. Sludge — 2 ea @ 250 gpm (6")
Relift — 3 ea @ 1200 gpm (12")
Pivot Gates, Weir Gates, Inlet Stacks
Chlorine/Sulfur Dioxide
Reference
Section 19 Page 1
Section 19 Page 1
Section 20 Page 1
Section 21 Page 1
Section 22 Page 1
Section 23 Page 1
Section 24 Page 1
Section 25 Page 4
Section 25 Page 6
Section 25 Page 7
Section 25 Page 7
Section 26
Page 1
Section 27
Page 1
Section 28
Page 1
Section 29 Page 1
Section 30 Page 1

c�!
TOWN OF FAIRMONT
P.O. Box 248, FAIRMONT, N.C. 28340, PHONE (91 O) 628-9766
FAX (91 O) 628-9584
March 9, 1999
Mr. Dave Goodrich, P.E.
North Carolina Department of Environment and Natural Resources
Division of Water Quality
P.O. Box 29535
Raleigh, North Carolina 27626-0535
Re: Town of Fairmont Wastewater Treatment Plant, Robeson County
Request for Authorization to Construct Facilities
NPDES Permit No. NCO021059
Dear Mr. Goodrich,
Please find the attached materials for your use in review of the referenced project:
1. Three (3) sets of plan drawings
2. Three (3) sets of project specifications
3. Three (3) sets of project design calculations
4. Check in the amount of $200.00 for the permit application fee
When completed, this new regional wastewater treatment facilit� will serve the Town of
Fairmont, and the Orrum Middle School, eliminating. both of their current discharges as a
result. This plant also has the potential to serve several towns and communities in
Robeson County and Columbus County. By action of this submittal, we are requesting
that the Division of Water Quality grant formal Authorization to Construct this new
Wastewater Treatment Plant.
Please contact Mr. Bill Lester, P.E. at Hobbs, Upchurch & Associates, P.A. (910-692-
5616) should there be questions comments, or if additional information is needed for
project review. We appreciate your cooperation in this matter.
Sincerely
TOWN OF FAIRMONT
Ben Hill
Town Manager
cc: Bill Lester, Hobbs, Upchurch & Associates, P.A.