NC0020443_Permit Issuance_20090721

NPDES DOCUMENT SCANNING COVER SHEET
Permit:
NC0020443
Columbia WWTP
NPDES
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Speculative
Limits
201 Facilities Plan
Instream Assessment (67B)
Environmental
Assessment (EA)
Permit
History
Document Date:
July 21, 2009
This document is printed on reuse paper - ignore any
content on the re'erse side

ATA
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
Mr. Rhett White
Town Manager
P. O. Box 361
Columbia, NC 27925
July 21, 2009
Subject: Issuance NPDES Permit Modification
Permit Number NC0020443
Town of Columbia WWTP
Tyrrell County
Dear Mr. White:
Division personnel have reviewed and approved your application for the modification of the subject
permit. Accordingly, we are forwarding the attached NPDES discharge permit. This 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).
This final permit includes no major changes from the draft permit sent to you on April 22, 2009.
If any parts, measurement frequencies or sampling requirements contained in this permit are
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 150E 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 Ron Berry at telephone number
[phone],
Sincerely,
Coleen H. S „ins
Attachments
Cc: Washington Regional Office/Surface Water Protection Section
Central Files
NPDES Unit
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone] Customer Service: 1-877-623.6748
Internet: http:/ / h2o.state.nc.us /
An Equal Opportunity \ Affirmative Action Employer
One
NorthCarolina
Naturally

-, I
Permit NC0020443
t
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF ENVIRONMENTAL MANAGEMENT
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 regulatioins promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act, as amended,
Town of Columbia
is hereby authorized to discharge wastewater from a facility located at the
Columbia WWTP
NCSR 1219
Tyrrell County
to receiving waters designated as the Scuppernong River in the Pasquotank 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 September 1, 2009.
This permit and authorization to discharge shall expire at midnight on December 31, 2012.
Signed this day July 21, 2009.
Coleen H. Sullins, Director
Division.of Water Quality
By Authority of the Environmental Management Commission

Permit NC0020443
14. i _.
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 Town of Columbia
is hereby authorized to:
1. Continue to operate an existing 0.30 MGD wastewater treatment plant consisting of the following:
0 Stand by power
0 Bar screen
0 Grit removal chamber
0 Influent meter
0 Influent composite sampler
0 1 - 375,000 gallon Oxidation ditch
0 Clarifier flow splitter
0 2 - 65,000 gallon Secondary clarifiers
0 Effluent collection well and pumping facilities
0 Chlorination
0 14,600 gallon Dechlorination/Post aeration chamber with blower
0 Effluent composite sampler
0 Effluent meter
0 Sludge collection well and transfer pumping facility
0 52,000 gallon Sludge digestion tank
0 154,000 gallon Sludge holding tank
0 Sludge load out facilities
This facility is located at the Town of Columbia Wastewater Treatment Plant off NCSR1219 near
Columbia in Tyrell County.
2. After receipt of an Authorization to Construct and submittal of the Engineering Certificate for
expansion to 0.6 MGD, with 12 inch multiport effluent diffuser, and expanded wastewater treatment
plant consisting of the following:
0 Stand by power
0 Bar screen
0 Grit removal chamber
0 Influent meter
0 Influent composite sampler
0 Influent flow splitter
0 2 - 375,000 gallon Oxidation ditches
0 Clarifier flow splitter
0 4 - 65,000 gallon Secondary clarifiers
0 Effluent collection well and transfer pumping facilities
0 Chlorination
0 23,000 gallon post aeration sump with dual blowers
0 Effluent composite sampler
0 Effluent meter
0 Dechlorination system
0 Effluent collection well and outfall pumping facilities

r
. Permit NC0020443
0 12 inch multiport effluent diffuser system
p Sludge collection well and transfer pumping facility
p 194,400 gallon aerated Sludge digestion tank
9 52,000 gallon aerated Sludge holding tank
p 154,000 gallon aerated Sludge holding tank
0 Sludge Ioa out facilities
This facility is located at the Town of Columbia Wastewater Treatment Plant off NCSR1219 near
Columbia in Ty ell County.
3. Discharge from said treatment works at the location specified on the attached map into the
Scuppernong River, classified SC waters in the Pasquotank River Basin.

.
•
7
i
‘.
Downstream Sample *1 own o. Colurrbia
Point NC0020443 P NC0020443
Foul r,
•.
NC0020443
0.6 MGD DiFfuser
•
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•
•
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til
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C OLU M B I Al't* 1
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+ A 1
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Bridge1, e IP"; ' ir -4 • , • , *0 . dit W.
•. •• • 1 • • • !�.. ',di — • 'j i Si ; . JO • • 1 64 ;'.
1'.. . ,.: 1•,". .� V.sit • 'ww
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Upstream Sample : ._ • �.. �' . ► � . ; :,_`--=`
Point NC0020443 ' •.... .,,.' ,- ..,4i...14:-
... 0t 7IP e. (..\.
-
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NC0020443
0.3 MGD Out -Fall
s
1'. •
1-
�.� yam. ..� •
_ Co"pin ght (C1) 21001, M. Fitecfi', inc.
• s
USGS Quad: D33NE Columbia West, NC
0.3 MGD Outfall 0.6 MGD Diffuser
Latitude: 35° 55' 18.3" N Latitude: 35° 55' 17.6" N
Longitude: 76° 15' 27" W Longitude: 76° 15' 28.6" W
Facility Stream Class: SC.
Latitude: 35° 55' 36.3" W
Longitude: 76° 14' 42.2" W Subbasin: 03-01-53
Receiving Stream: Scuppernong River ,
North
•
Town of Columbia WWTP
Tyrrell County

Permit NC0020443
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period tbeginning on the effective date of this permit and lasting until expiration, or receipt of
an Authorization o Construct and submittal of the Engineering Certificate for expansion to 0.6 MGD
with a 12 inch mu tiport effluent diffuser, the Permittee is authorized to discharge from outfall 001. Such
discharges shall b limited and monitored by the Permittee as specified below:
•
EFFLUENT
CHARACTERISTICS
LIMITS -
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location
Flow
0.3 MGD
Continuous
Recording
Influent or Effluent
Temperature, °C
Monitor & Report
Daily
Grab
Effluent
Temperature, °C
(June 1- September 30)
Monitor & Report
Weekly
See Note 1
See Note 1
Total Residual Chlorine (TRC) 2
13 µg/L
2/Week
Grab
Effluent
BOD, 5 day, 20°C 3 1
15.0 mg/L
22.5 mg/L
Weekly
Composite
Influent & Effluent
Total Suspended Solids (TSS) 3
30.0 mg/L
45.0 mg/L
Weekly
Composite
Influent & Effluent
Ammonia as Nitrogen i(NH3-N)
4.0 mg/L
12.0 mg/L
Weekly
Composite
Effluent
Ammonia as Nitrogen;
(NH3-N)
(June 1- September 30)
mg/L
Monitor & Report
2/Month
See Note 1
See Note 1
Dissolved Oxygen (DO)
Not less than 6.0 mg/L daily average
Weekly
Grab
Effluent
Dissolved Oxygen, mg/L (DO)
(June 1- September 30)
Monitor & Report
Weekly •
See Note 1
See Note 1
Entero(geometric
(geometric mean)
35/100 ml
276/100 ml
Weekly
Grab
Effluent
PH
Not more than 8.5 s.u. nor less than
6.8 s.u.
Weekly
Grab
Effluent
pH, s.u.
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1
Salinity, ppt
(June 1- September 30)
Monitor & Report
Weekly
See Note 1
See Note 1
Conductivity , µohms
(June 1- September 30)
Monitor & Report,
P
Weekly
See Note 1
See Note 1
Total Phosphorus, mg/L (TP)
Monitor & Report
Quarterly
Composite
Effluent
Total Phosphorus, mg/i. (TP)
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1
Total Nitrogen, mg/L (TN)
TN = (NO2-N + NO3-N) + TKN
Monitor & Report
Quarterly
Calculated
Effluent
Kjeldahl Nitrogen, mg/Iii (TKN)
Monitor & Report
Quarterly
Composite
Effluent
Nitrite/Nitrate Nitrogen', mg/L
(NO2-N + NO3-N)
Monitor & Report
Quarterly
Composite
Effluent
Total Nitrogen, mg/L (TN)
TN = (NO?-N + NO3-N) + TKN
(June 1- September 30)
Monitor & Report
2/Month
Calculated
See Note 1
Kjeldahl Nitrogen, mg/l (TKN)
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
•
See Note 1
Nitrite/Nitrate Nitrogen, mg/L
(NO2-N + NO3-N)
(June 1- September 30)
Monitor & Report
2/Month '
See Note 1
See Note 1
Chlorophyll -a, µg/L
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1

Permit NC0020443
1 w J
(Continued A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS)
Notes:
1. Monitoring requirements must be followed as stated in Special Condition A. (4.).
2. Total Residual Chlorine compliance is required for chlorine or chlorine derivative used for disinfection. The
Division shall consider all effluent TRC values reported below 50 ug/I to be in compliance with the permit.
However, the Permittee shall continue to record and submit all values reported by a North Carolina certified
laboratory (including field certified), even if these values fall below 50 ug/I.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15 percent of
the respective influent value (85 percent removal).
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NC0020443 .
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period, beginning on the receipt of the Authorization to Construct and submittal of the
Engineering Certificate for the expansion to 0.6 MGD with a 12 inch multiport effluent diffuser 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:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS •
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location
Flow
0.6 MGD
Continuous
Recording
Influent or Effluent
Temperature, °C
Monitor & Report
Daily
Grab
Effluent
Temperature, °C j
(June 1- September 30)
Monitor & Report
Weekly
See Note 1
See Note 1
Total Residual Chlorine (TRC) 2
13 pg/L
3/Week
Grab
Effluent
BOD, 5 day, 20°C 3
7.0 mg/L
10.5 mg/L
3/Week
Composite
Influent & Effluent
Total Suspended Solids (TSS) 3
30.0 mg/L
45.0 mg/L
3/Week
Composite
Influent & Effluent
Ammonia as Nitrogen (NH3-N)
2.0 mg/L
6.0 mg/L
3/Week
Composite
Effluent
Ammonia as Nitrogen,
(NH3-N)
(June 1- September 30)
mg/L
Monitor & Report
2/Month
See Note 1
See Note 1
Dissolved Oxygen (DO)
Not Tess than 6.0 mg/L daily average
3/Week
Grab
Effluent
Dissolved Oxygen, mg1L (DO)
(June 1-September 30)
Monitor & Report
Weekly
See Note 1
See Note 1
Enterococci
(geometric mean)
35/100 ml
276/100 mi
3/Week
Grab
Effluent
pH
Not more than 8.5 s.u. nor less than
6.8 s.u.
3/Week
Grab
Effluent
pH, s.u.
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1
Salinity, ppt
(June 1- September 30)
Monitor & Report
Weekly
See Note 1
See Note 1
Conductivity , pohms
(June 1- September 30)
Monitor & Report,
P
Weekly
See Note 1
See Note 1
Total Phosphorus, mg/ (TP)
Monitor & Report
Quarterly
Composite
Effluent
Total Phosphorus, mg/L (TP)
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1
Total Nitrogen, mg/L (TN)
TN = (NO2-N + NO3-N) - TKN
Monitor & Report
Quarterly
Calculated
Effluent
Kjeldahl Nitrogen, mg/L (TKN)
Monitor & Report
Quarterly
Composite
Effluent
Nitrite/Nitrate Nitrogen; mg/L
(NO2-N + NO3-N)
Monitor & Report
Quarterly
Composite
Effluent
Total Nitrogen, mg/L (TN)
TN = (NO2-N + NO3-N) + TKN
(June 1- September 30) .
Monitor & Report
2/Month
Calculated
See Note 1
Kjeldahl Nitrogen, mg/L (TKN)
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1
Nitrite/Nitrate Nitrogen, mg/L
(NO2-N + NO3-N)
(June 1- September 30)'
Monitor & Report
2/Month
See Note 1
' See Note 1
Chlorophyll -a, pg/L
(June 1- September 30)
Monitor & Report
2/Month
See Note 1
See Note 1

• Permit NC0020443
J
(Continued A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS)
Notes:
1. Monitoring requirements must be followed as stated in Special Condition A. (4.).
2. Total Residual Chlorine compliance is required for chlorine or chlorine derivative used for disinfection. The
Division shall consider all effluent TRC values reported below 50 ug/I to be in compliance with the permit.
However, the Permittee shall continue to record and submit all values reported by a North Carolina certified
laboratory (including field certified), even if these values fall below 50 ug/I.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15 percent of
the respective influent value (85 percent removal). •
There shall be no discharge of floating solids or visible foam in other than trace amounts.

s•
• Permit NC0020443
A. (3.) Nutrient Condition
This permit may be modified, or revoked and reissued to include an effluent limitation for
nutrients depending upon the following:
> The f ndings of a study by the Division of Water Quality determine nutrient control is
nece�sary.
➢ Local actions do not successfully reduce the nutrient loading on the receiving waters.
➢ The nset of problem conditions in the receiving waters.
A. (4.) Instream Monitoring Requirements
lnstream samples shall be collected between June 1 and September 30 each year. See
attached map for sample locations:
➢ Upstream at U.S. Highway 64 Bridge;
> Downstream at marker number 10;
➢ End of pipe (mid point of diffuser).
Physical Parameters:
Parameter
Sample Type
Frequency
Dissolved Oxygen, mg/L (DO) 1
Instantaneous
Weekly
Temperature, °C 1
Instantaneous
Weekly
Salinity, ppt 1
Instantaneous
Weekly
pH s.u. 1
Instantaneous
2/Month 2
Notes: ,
1. The above parameters shall be collected as grab samples at one -meter intervals
vertically throughout the water column.
2. pI- shall be sampled only when Chlorophyll -a is sampled.
Chemical Parameters:
Parameter
Frequency
Kjeldahj Nitrogen, mg/L (TKN) 1
2/Month
Ammonia as Nitrogen, mg/L (NH3-N) 1
2/Month
Nitrite/Nitrate Nitrogen, mg/L (NO2-N + NO3-N) 1
2/Month
Total Nitrogen, mg/L (TN) TN = (N0 -N + NO3-N) + TKN 1
2/Month
Total Phosphorus, mg/L (TP) 1
2/Month
Chlorophyll -a, pg/L 1
2/Month
Notes:
1. TKN, NH3-N, (NO2-N + NO3-N), TN, TP, and Chlorophyll -a shall be collected by a
spatial composite throughout the photic zone (defined as twice the secchi depth).
Reporting Requirements:
Data results must be entered on a form approved by the Division and summarized in an
annual report. This report is due on January 1 immediately following the summer period
when sampling occurred. This report must.be sent to the following address:
NC DENR / DWQ / Central Files
1617 Mail Service Center
Raleigh, North Carolina 27626-0535

NoT1CC. OA) AP2, L 227 zoact
Rowan County
The Division has made an attempt to post notices in the following newspaper(s):
Charlotte Observer
I MAY 2 6 2009 IIE-j
I
DMF - HABITAT PROTECTION
The Rowan -Salisbury Schools [515 North Clay Street, Salisbury, NC 28144] have applied for
renewal of NPDES permit NC0034703 for the Knollwood Elementary School WWTP in Rowan
County. This permitted facility discharges treated domestic wastewater to Little Creek in the Yadkin -
Pee Dee River Basin. Currently ammonia nitrogen, fecal coliform and total residual chlorine are
water quality limited. This discharge [like any permitted discharge] may affect future allocations in
Stanly County
The Division has made an attempt to post notices in the following newspaper():
Charlotte Observer
David & Cynthia Amaral applied for renewal of NPDES permit NC0041718 for the Davidcyn
Apartments WWTP in Stanly County. This permitted facility discharges treated domestic wastewater
to Curl Tail Creek in the Yadkin -Pee Dee River Basin. Currently, BOD, ammonia nitrogen, and
total residual chlorine are water quality limited. This discharge may affect future allocations in this
Tyrrell County
The Division has made an attempt to post notices in the following newspaper(s):
Coastland Times
The Town of Columbia (P. O. Box 361, Columbia, NC 27925) requested modification of permit
NC0020443 for its WWTP in Tyrrell County, this permitted discharge is treated domestic wastewate
to the Scuppernong River in the Pasquotank River Basin. Currently BOD, ammonia nitrogen,
enterococci, dissolved oxygen, and total residual chlorine are water quality limited. This discharge
may affect future allocations in this segment of the Scuppernong River.
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Page 5of5

PUBLIC NOTICE
STATE OF NORTH CAROLINA
ENVIRONMENTAL MANAGEMENT COMMISSION/NPDES UNIT
1617 MAIL SERVICE CENTER
RALEIGH, NC 27699-1617
NOTIFICATION OF INTENT TO ISSUE A NPDES WASTEWATER PERMIT
The North Carolina Environmental Management Commission proposes to issue a
NPDES wastewater discharge permit to the person(s) listed below.
Written comments regarding the proposed permit will be accepted until 30 days after
the publish date of this notice. The Director of the NC Division of Water Quality (DWQ)
may hold a public hearing should there be a significant degree of public interest.
Please mail comments and/or information requests to DWQ at the above address.
Interested persons may visit the DWQ at 512 N. Salisbury Street, Raleigh, NC to review
information on file. Additional information on NPDES permits and this notice may be
found on our website: www.ncwaterquality.org, or by calling [phone].
Wednesday, April 22, 200.9 Page I of 5

PUBLIC NOTICE
NORTH CAROLINA ENVIRONMENTAL MAN-
AGEMENT COMMISSION/NPDES UNIT
1617 MAIL SERVICE CENTER
RALEIGH, NC 27699-1617
Notice of Intent to Issue a NPDES
Wastewater Permit
The North Carolina Environmental Man-
agement Commission proposes to issue a
NPDES wastewater discharge permit to the
person(s) listed below.
Written comments regarding the proposed
permit will be -accepted until 30 days after
the publish date of this notice. The Director
of the NC Division of Water Quality (DWQ)
may hold a public hearing should there be a
significant degree of public interest. Please
mail comments and/or information requests
to DWQ at the above address. Interested
persons may visit the DWQ at 512 N. Salis-
bury Street, Raleigh, NC to review informa-
tion on file. Additional information on NPDES
permits and this notice may be found on our
website: www.ncwaterquality.org, or by
calling [phone].
The Town of Columbia requested modifi-
cation of permit NC0020443 for its WWTP in
Tyrrell County; this permitted discharge is
treated domestic wastewater to Scupper-
nong River, Pasquotank River Basin.
4-26c
NORTH CAROLINA
DARE COUNTY.
AFFIDAVIT OF PUBLICATION
Before the undersigned, a Notary Public of said County
and State, duly commissioned, qualified, and authorized
by law to administer oaths, personally appeared
Bats,` al, 5ta s.�-'Qas.�'2�-
who being
first duly sworn, deposes and says: that he (she) is of The
Times Printing Co., Inc., engaged in the publication of a
newspaper known as TI-IE COASTLAND TIMES, pub-
lished, issued, and entered as second class mail in the Town
of Manteo, in said County and State; that he is authorized to
make this affidavit and sworn statement; that the notice or
other legal advertisement, a true copy of which is attached
hereto, was published in THE COASTLAND TINS on the
following dates:
vL 7 Ce. ( '1
and that the said newspaper in which said notice, paper,
document, or legal advertisement was published was, at
the time of each and every such publication, a newspaper
meeting all of the requirements and qualifications of Sec-
tions 1-596 and 1-597 of the General Statutes of North Caro-
lina and was a qualified newspaper within the meaning of
Section 1-General Statutes of North Carolina.
This
, 2009
Sworn to and subscribed to befor1(0
day of
/ l s Ct ! , 2009
Notary Publi
My Commission expires:....J. c'.. .1. 3 ..2Q i 3...
KIMBERLY A. SIMPSON
Notary Public
Dare County, North Carolina

Date:4/6/09
pb: rdb
DMR Data NC0020443
Town of Columbia WWTP
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Date:4/6/09
pb: rdb
DMR Data NC0020443
Town of Columbia WWTP
• Effluent —$— Upstream -- Downstream
60
50
a1
40
m
> 30
Q.
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0 20
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10
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• Effluent —13-- Upstream —6—Downstream
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Lo T co co O A • N Z7) r- 4 N N 4 cO N
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✓ co
• Effluent —a— Upstream - Downstream
•
CO
_7 ¢ ¢ ¢ ¢ cn u> cn cn
c� r v ao 4 m u)
N N - r N

ti r
PHONE CONSERVATION 2-27-09 3:30 PM Town of Columbia WWTP Mod (expansion)
NC0020443
Caller: Cecil G. Madden, Jr. P.E., consultant McDavid Associates, Inc.
Original January 16, 2009 letter did not have the attachment. Agreed to fax the missing attachment.
Follow up note: Fax system not working, sent attachment via an email to [e-mail]
(Feb 27, 2009 with return receipt requested).
Mr. Madden waned to know if the diffuser was required since existing discharge did not have diffuser.
Explained that this discharger upon any expansion would be required to install a diffuser. This mod
application is an expansion.
Informed Mr. Madde'that the CORMIX model is not longer a public domain so therefore as a state
agency I can only provide an example of what is need. In this case it is a CORMIX model or equivalent.
Specifically need mixing field information to develop the permit. Mr. Madden asked about using the
EPA plume model or other equations. No problem as long as they met the requirements. He also asked
about using the 7010 data in a tidal design. Replied that the CORMIX model had the ability to handle
tidal effects so its equivalent should have the same ability. Mr. Madden started asking more questions in
regards to if he designed the diffuser. I suggested he really needed to see the missing attachment because
it provides the information he probably needed. If after reviewing the missing page he need to discuss
then call me back. He agreed.
Ron Berry

Cecil G. Madden, Jr., PE
McDavid Associates, Inc.
P. O. Box 1776
Goldsboro, NC 27533
Subject:
Beverly Eaves Perdue, Govemor
State of North Carolina
Dee Freeman, Secretary
Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
January 16, 2009
Request for more information for Modification NPDES Permit
Permit No. NC0020443
Town of Columbia WWTP
Tyrell County
Dear Mr. Madden
The Division has reviewed the January 6, 2009 Modification application and support documents.
We require additional information before we can proceed with this application:
1. There is no mention of an automated influent sampler in the documentation. Please provide a
description of the location in the treatment process, the type sampler, and the sampler
features.
2. The effluent composite sampler location is listed but for clarity please provides a more
detailed description of the composite sampler features.
3. There are some effluent grab samples required for various parameters. Please provide a
description of where in the process this sample is taken.
4. It is assumed the backup power system extents to both the influent and effluent composite
samplers and meters. Please confirm.
5. Please confirm whether the new and upgraded lift stations will have back up power.
6. A very detailed discussion was provided on the sludge control and disposal options. As part
of the permit application a formal written "Sludge Plan" must be included. There should
already be a Sludge Plan in place. Please provide a Sludge Plan for the expansion.
7. Are any other chemicals projected for use, for example for pH control? If yes please list and
indicate point of entry into process.
8. The application requires a diffuser as part of the expansion which requires the permittee to
conduct a CORMIX model. The limited details listed on the application are unusual and
insufficient. Attached is a more detailed list of questions and support documentation that
must be provided from the diffuser design and CORMIX model.
9. Why is the proposed diffuser not symmetrical, more ports downstream than upstream?
It will not be necessary to resubmit a revised application with support documents. It is preferred
a letter with the required information and attached documents be submitted in triplicate. In turn these
copies will be added to the current three application as addendums.
Page 1 of 2
Division of Water Quality, Point Source Branch Telephone [phone]
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 FAY( [phone]
•
512 N. Salisbury Street, Raleigh, North Carolina 27604 On the Internet at http://h2a.enr.state.nc.us/
An Equal opportunity/Affirmative Action Employer
No `hCarolina
A7aiura l%

If you have any questions you can contact Ron Berry at [phone] or by email at
[e-mail].
Ron Berry
NPDES Eastern Unit
Attachments:
cc: NPDES File
Central File
Al Hodge/Washington Regional Office/Surface Water Protection
Rhett White
Town Manager
Town of Columbia
P. O. Box 361
Columbia, NC 27925
Page 2 of 2

,'
DIFFUSER DESIGN EVALUATION INFORMATION — NC0020443 EXPANSION
The Divisions supports, in this case requires, the installation of a properly designed diffuser to optimize
or enhance the' minimal impact of the permitted discharge to the Scuppermong River. To assist the
Division in its evaluation and development of the NPDES permit, the permittee must demonstrate
through a CORMIX model provided by the permittee, that the proposed diffuser design is acceptable.
The following information is obtainable from the CORMIX model and recognized experts.
Diffuser design conditions:
1) Diffuser ports upstream/downstream not aligned to maximizes mixing area
2) Diffuser located to point further from shore to maximize dispersion
3) Diffuser ports oriented to offset any scouring of surrounding terrain
4) Diffuser port anchored to guarantee no movement and diffuser always submerged.
Required information:
1) What major effluent pollutants are addressed by the diffuser design?
2) What are the CORMIX model inputs?
3) What assumptions are made in the CORMIX model?
4) How was the CORMIX model calibrated?
5) What is till size, shape, and location of the area of mixing during critical conditions?
6) What is the amount of dilution occurring at critical conditions at various points throughout the
plume?
7) What is the area of near field delineation where induced mixing ceases?
8) Does the p ume exhibit shore hugging?meriv
er Does the p exhibit interaction with thebottom?
10) Does the discharge location impact any aquatic life, biological communities, promote
dominance lof a nuisance species, impact any endangered species, or threatens any critical
habitats?
11) Does the discharge interfere with the designated use of the receiving stream or downstream
waters?
12) Is the mixing zone within or adjacent to any recreational areas?
Required support documents:
1) Mechanical drawing of diffuser including installation details, scaled view of layout in receiving
stream
2) Scheduled maintenance to diffuser
3) CORMIX Session Report for design.
Note: Some of this information may be addressed in the January 6, 2009 document. However, the
diffuser is only mentioned in the application and it is not included in any of the other documentation. If
included you may indicate the exact location of pertinent details that address any of the requested
information.
pb: rdb
1/16/09

MCDAVID ASSOCIATES, INC.
INC. Engineers • Planners • Land Surveyors
CORPORATE OFFICE
[phone] • Fax [phone]
E-mail: [e-mail]
3714 N. Main Street • P.O. Drawer 49
Farmville, NC 27828
Mr. Ron Berry
NPDES Eastern Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Dear Mr. Berry:
GOLDSBORO OFFICE
[phone] • Fax [phone]
E-mail: [e-mail]
109 E. Walnut Street • P.O. Box 1776
Goldsboro, NC 27533
March 12, 2009
RECENED
Subject:
MAR 1 6 2009
DENR - WATER QUALITY
POINT SOURCE BRANCH
Town of Columbia
NPDES Permit Modification
Permit No. NC0020443
Tyrell County
We have received comments by phone on March 11, 2009. This letter is written in
response to your comments.
Your comments are stated and our responses follow.
1. The anticipated low flow condition should be considered where the stream velocity is
only 0702 Ft/Sec. Provide two model runs using the following:
Velocity = 0.02 Ft/Sec
Ammonia = 4 mg/1
Flow = 0.6 MGD
Flow = 2 MGD
Check to make sure that the stream bottom is not disturbed.
The two model runs are included as Attachment No. 1. It is clear from the graph of the
plume that the stream bottom is not disturbed even at essentially zero flow conditions.
2. What is the definition of the phrase "matched energy radial velocity" used to support the
position that the water surface will not be disturbed?
\\G-PC1 \D1005\CGM\2009\COLUMBIA
2-06-6062-8004-COLUMBIA-NPDES-PERMIT-2 °-RESPONSES

The phrase was obtained from the model's text output. Reviews of the model's manual
and the model's help files yielded no definition of the phrase. EPA was approached to
determine the author's meaning of the phrase. The model's author has retired, and EPA
no longer provides support for the software.
We attempted to force the model to give notice when the water surface is disturbed, by
placing the diffuser one foot under the water surface. However no specific warning was
issued in the text. See Attachment No. 2. A warning is specifically provided when the
plume hits the stream bottom.
We have reviewed the effects of depth on the diffuser to determine if increasing the
diffusor depth would provide more protection of the water surface. Attachment No. 3
provides a graph showing the effects of diffuser depth on the plume. Providing more
depth than 8 or 9 feet does not significantly change the shape of the plume.
There is some potential for variability of salinity in the ambient river condition. Most of
the modeling was done using an ambient salinity of 10 psu. Because of the difference
between the salinity of the wastewater and the ambient salinity, there is a buoyant force
on the plume. The Washington Regional office has advised that values for salinity range
from 5 to 8 psu. Attachment No. 4 provides a graph that shows the relationship of the
plume with a change in ambient salinity.
With this information we are unable to definitively state that there will be no disturbance
of the water surface. However, the diffusers have a velocity of only 4.2 Ft/Sec. With a
diffuser depth of at least 8 feet, and a diffuser angle of only 15 degrees, it is not
anticipated that the water surface will be disturbed. This appears to be a reasonable
assumption.
3. Consider using Tide -Flex Valves on each diffuser to reduce fouling of the diffuser and to
potentially aid in flattening out the plume.
The Town can provide Tide -Flex valves if required by the State. However, we consider
this an unjustified expense. Velocity through the diffuser is expected to be 4.2 Ft/Sec.
Resuspension velocity is for sediment is only 3 feet per second. When the pumps come
on, anything that settles in the diffuser will be resuspended and driven out. Should this
not be the case, a diver can remove the plate on the end of the diffuser header and blow
out the accumulation of solids.
Plume rise in this case is primarily a function of the differences in salinity. The shape of
the orifice will have little if any effect on the rise of the plume.
1\G-PC 1113 I 005\CGM12009\COLUMBIA
2-06-6062-8004-COLU M BI A-NPDES-PERMIT-2d-RESPONSES
INC

Should you have any questions regarding this transmittal. do not hesitate to contact me.
Sincerely,
Mc David Associates, Inc.,
ecil 9 Madden, Jr(, P.
Goldsboro Office
CGM:
Attachments
cc: Town of Columbia (without Attachments)
\\G-PC 1 \D 1005\CGM120091COLUMBIA
2-06-6062-8004-COL UMB IA-NPDES-PERMIT-2nd-RESPONSES

4T7qCff,14)T
Diffuser: VP plume 6.vpp.db 1 Ambient: c:\plumesWVP plume 6.001.db 1 Special Settings 1 Text Output I Graphical Output 1
Project jc:\plumes\« plume 6
Notes: Columbia Diffuser Design with
River Velocity = 0.02 Ft/Sec,
WWTP Flow = 0.6 MGD_- &
Sonia = 4 mg.&
Ambient file list
Filename C ses
c:\plumesWVP plume 6.001.db 1 1
c:lplumes4VP plume 6.001.db 1 1
— After run go to tab
Diffuser
1- Ambient
r Special
ir Text
C Graphics
Units Conversion
} C Convert data
Label only
UM3
I Port
diameter
Diffuser, Flow,'Niiaing Zone Inputs
Model Configuration
Brooks far -field solution
C_. Graph effective dilution
.. Average plume boundary
- Amb. current vector averaging
Tidal pollution buildup
Same -levels time -series input
Case selection
a Base or selected case
Sequential, all ambient list
" Sequential, parse ambient
All combinations
in
nlr 1Port Vertical I Hor 1Num of 1Port I nir
elevation angle angle ports spacing
m ft deg deg ft s
2 15 Gr 15 2
In/r Infr (Acute (Chronic Port
mix zone mix zone depth
s s m m ft
10 50
Effluent
flow
Effluent 1 Effluent lEffluent
salinity() I temp conc
MGD psu C
0.6 1.1
Parameters for selected row I Time Series -Files (optional)
Froude number
Eff density fkg/m31
Port vel fm/sl
P-dia fm1
0.0762
P•dia f inl
3.0
Case No.
1.0
Time -series filename
Time increment fhrsl
ppm
23
Borrow time -series from project: Ic:\plumeswVP plume 6
Time cycling period
Measurement unit
Port
depth.
-..ck for fde
E ffluent
flow
click for file
Effluent
salinity[ x1
click for file
'Effluent
temp
click for file
Effluent
conc
click for file

Diffuser: VP plume 6.vpp.db Ambient: c:tplumesWP plume 6.001.db
Special Settings 1 Text Output 1 Graphical Output I
Ambient Inputs
Depth or Height 1 U
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit
UM3
Hrnbienk file list TM
Filename _
VP plume 6.001.db 1 1
1
ft
depth
depth
constant constant
linear to zero constant
ft/s deg
0
O. L_
8
0_02
G
depth
constant
constant
psu
depth depth
constant constant
extrapolated constant
C ppm
depth
constant
constant
s-1
depth depth depth _ _
constant constant constant
extrapolated extrapolated constant
ftis deg m0.671s2
10 25 0 0 0.5 0 0_0003
10 25
10
0.5 0 0.0003
Time -Series Files (optional)
Borrow time -series files from project: lc: \plumes \VP plume 6
Time -series filename 1
Time increment [hrs) j
Cycling period
.File measurement unit,
click for rile click for file click for file click for file click for file click for file click for file click for file click for file

Diffuser: VP plume 6.vpp.db ! Ambient: c:lplumes\VP plume 6.001.db
1113 tidal pollutant buildup parameters
Channel width (m)
,„
Special Settings
Text Output Graphical Output
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
(1
10.16
Farfield increment (m) 1200
UM3 aspiration coefficient
jo_i
Bacteria model on solar radiation input
C% Mancini (1978) coliform model
r 301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
C 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
�PDS sfc. model heat transfer
C Low Medium
r High
Graphics settings
Style
s 4-panel
C dilution
C concentration
C custom
— Custom graph coords. —
Abscissa (x)
Ordinate 1 (y)
t' Ordinate 2 (y)
Start case for graphs
Custom variables
Max detailed graphs
NRFIELD/FRFIELD input variables
Text output settings
Output medium —
t: Text tab (ambient filled) C File (ambient filled)
Text tab (ambient as is) C' File (ambient as is)
r Show changed Diffuser and Ambient tab variables only
Selection List
1
Reset Default List (
Selected Variables
Depth
Amb-cur
P-dia
Pohrtnt
Dilutn
x-posn
y-posn
UM3 output each?? steps 1100
UM3 maximum dilution reported 110000
UM3 max vertical reversals—
" to max rise or fall
t: to second trap level
C' to 2nd max rise or fall
UM3 text output format
6 Standard output
C Brief output
E Stop on maximum dilution
Close panel

01414)151 JE_Ii
Diffuser: VP plume 6.vpp.db I Ambient c:tplumesWVP plume 6.001.db I Special Settings
w ear text�ispla�l
Clear + I Output options I Numerical only
Text Outpu
Graphical Output 1
/ UM3. 3/12/2009 3:04:16 PM
Case 1; ambient file c:\plumes\VP plume 6.0 01. db; Diffuser
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal
m m/s deg- psu
0.0 0.0061 0.0 10.0
2.438 0.0061 0.0 10.0
3.048 0.0 0.0 10.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
table
Amb-tem Amb-pol
C kg/kg
25.0 0.0
25.0 0.0
25.0 0.0
Ports Spacing AcuteMZ ChrncHZ
() (ft) (m) (m)
15.0 2.0 10.0 50.0
Simulation:
Froude number: 5.433; effleunt densi
Depth Amb-cur P-dia Polutnt
Step (ft) (ft/s) (in) (ppm)
0 8.0 0.02 3.0 4.0
100 6.183 0.02 15.18 0.584
140 3.275 0.02 24.22 0.265
157 0.919 0.02 30.22 0.189
162-0.00214 0.02 32.46 0.171
Const Eddy Diffusivity. Farfield dispers
conc dilutn width distnce time
(ppm) (m) (m) (hrs)
0.16842 23.6 11.52 50.0 0.0884
count: 1
3:04:16 PM. amb fills: 2
ty (sigma-T) -2.
Dilutn x-posn
() (ft)
1.0 0.0
6.808 2.573
15.03 4.0
21.04 4.732
23.23 4.971
ion based on vastef
(ppm)
0.0
record 1:
Decay Far-spd
s-1 m/s
0.0 0.152
0.0 0.152
0.0 0.152
P-depth
(ft)
8.0
Tt 1-f to
(MGD)
0.6
Fardir-_ Dispr_sn Density
-
deg m0.67/s2 sigma-T
0.0 0.0003 4.618
0.0 0.0003 4.618
0.0 0.0003 4.618
Ef f -sal
(psu)
1.1
Temp Polutnt
(C) (ppm)
25.0 4.0
064; effleunt velocity 0.384(m/s);
y-posn
(ft)
0.0;
0.0;
0.0; merging;
0.0; matched energy radial vel = 0.0607m/s;
0.0; surface;
ield vidth of 9.36 m
(s-1) (ft/s)(m0.67/s2)
0.0 0.5 3.00E-4

Diffuser: VP plume 6.vpp.db I Ambient: c:\plumes\VP plume 6.001.db I Special Settings I Text Output Graphical Output )
Help
Clear + I
Clear all'
iCTear ia)
Clear rb l
Clear bal
Clear bbl
Clear gal
Clear gbl
Clr Verify'
— Style—
O. 4•pI
✓ diln
✓ con
cus
0
t.
Scale I
Thick I
To File I
Verify I
s
0
Plume Ele-, aticn
0 2 4 6 8 10 12 14 16 18 20 22 24
Horiz. Distance from Source (ft)
— Centerline
— Centerlme
— Centerline
• Plume Bndry
. Plume Bndry
• Plume Bndry
— Verification
50
Plan View
40 -
30- -
20— -
r 10= -
-c
z 0= -
;
0-10-
w •
-20=
-30-
-40
-200 -150 -100 -50 0 8.0 100 150 200 250
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
• Outline
• Outline
— Verification
Ambient Properties
0 1 2 3 4 5 6 7 8
Density (sigma-T)
Plumes Dilution Prediction
9 10
— Amb. density
— Amb. density
— Amb. density
• Plume density
• Plume density
• Plume density
— Verification
------------- L---J-------- 1----
t � �
0 2 4 6 8 10 12 14 16 18 20 22 24
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
• Centerline
• Centerline
— Verification

LEI
{10
Diffuser: VP plume 6.vpp.db Ambient: c:lplumeslVP plume 6.001.db I Special Settings Text Output I Graphical Output I
Project
Ic:\plumes\VP plume 6
Notes: Coiumbia Diffuser Design with
River Velocity = 0.02 Ft/Sec,
WWTP Flow = 2 TGD_ &
Ammonia = 4 me_
Ambient file list
Filename Cases_
c:lplumes \VP plume 6.001.db 1 1
c:\plumesWP plume 6.001.db 1 1
— After run go to tab
Diffuser
C Ambient
!. Special
Text
Graphics
-Units Conversion —
Convert data
( Label only
IGL
UM3
Diffuser, Flow, Mixing Zone Inputs
Model Configuration
C Brooks far -field solution
C Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
C Tidal pollution buildup
G Same -levels time -series input
— Case selection
r Base or selected case
C Sequential, all ambient list
(' Sequential, parse ambient
C All combinations
1Port
diameter
in
n/r 'Port
Vertical I Hor I Num of 1Port I n/r
elevation angle angle ports spacing
m ft deg deg ft s
2 15 0 15 2
Parameters for selected row I
Froude number
Eff density (ka/m3)
Port vel (m/s)
P•dia (ml
0.0762
P-dia fin)
3.0
Case No.
1
I n/r in/r 'Acute 1Chronic
mix zone mix zone
s s m m
10 50
Time Series -Files (optional)
Port
depth
ft
Effluent Effluent Effluent
flow salinity(") I temp lEffluent
conc
MGD psu C ppm
1.1 25
Borrow time -series from project: (caplumes\VP plume 6
1 Port Effluent
depthaleillik flow
Time -series filename ACME click for file
Time increment (hrsl
Time cyclino period
Measuren-ient unit
Effluent
salinity(')
click for file
Effluent
temp
click for file
Effluent
conc
click for file

CS; Cam; f ) H I AI @
Diffuser: VP plume 6.vpp.db Ambient: c:lplumesWP plume 6.001.db 1 Special Settings I Text Output I Graphical Output
Depth or Height
Extrapolation [sfc]
Extrapolation (btm) j
Measurement unit
UM3
pr-Ambien
Filenam
VP plume 6.001. db 1 1
depth
Ambient Inputs
Ambient ;I
temperature U apeed irect o
depth depth depth depth depth
constant constant constant constant constant constant
linear to zero constant constant extrapolated constant constant
ft/s deg psu C ppm s-1
depth depth depth_
constant constant constant
extrapolated extrapolated constant
ft/s
deg m0.67/s2
o
0_02
0
S
0.02
0
10 25
0 0
0.5
10
25
0
0
03
0.0003
0_0003
10
Time -Series Files (optional)
nme•sernes iilenamet
Time increment (hrs)]
Cycling period ]
File measuremmtaii
chck for file
Sorrow time -series files from project: l c:\plumeslVP plume 6
click for file
click for file j click for file click for file click for file click for file click for file click for file

Diffuser. VP plume 6.vpp.db I Ambient: c:\plumes\VP plume 6.001.db
12413 tidal pollutant buildup parameters
Channel width (m)
100
Graphics settings
Style
r: 4-panel
( dilution
( concentration
. custom
Custom graph coards. —
6 Abscissa (x)
C Ordinate 1 (y)
t' Ordinate 2 (y)
Custom variables
Start case for graphs Max detailed graphs
iI J
Special Settings Text Output Graphical Output 1
Additional model input
Diffuser port contraction coefficient 11
Light absorption coefficient
Farfield increment (m)
UM3 aspiration coefficient
I0-16
I200
Ia-1
Bacteria model on solar radiation input
6' Mancini (1978) coliform model
C' 301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
( 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
rPDS sfc. model heat transfer
C Low Medium
c High
NRFIELD/FRFIELD input variables
Text output settings
Output medium
Text tab (ambient filled) ( File (ambient filled)
C Text tab (ambient as is) (' File (ambient as is)
(— Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Depth
Anlb - cur
P-dia
Poh]tnt
Dilutn
x-posn
\'-poSIl
Reset Default List (
UM3 output each ?? steps I100
UM3 maximum dilution reported I10000
UM3 max vertical reversals —
to max rise or fall
to second trap level
C to 2nd max rise or fall
— UM3 text output format
Standard output
C Brief output
E Stop on maximum dilution
Close panel

Diffuser VP plume 6.vpp.db I Ambient c:tplumesWP plume 6.001.db I Special Settings Text Output 1 Graphical Output I
Near text d�spfa��
Clear + _ ..
Output options I Numerical only I
/ UM3. 3/12/2009 3:01:52 PM
Case 1; ambient file c:\plumes\VP plume
Ambient Table:
Depth Amb-cur
m m/s
0.0 0.0061
2.438 0.0061
3.048 0.0
Amb-dir
deg
0.0
0.0
0.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
Amb-sal
psu
10.0
10.0
10.0
6.001.db; Diffuser table
Amb-tem Amb-pol
C kg/kg
25.0 0.0
25.0 0.0
25.0 0.0
record 1:
Decay Far-spd
s-1 m/s
0.0 0.152
0.0 0.152
0.0 0.152
Ports Spacing AcuteMZ ChrncMZ P-depth
() (ft) (m) (m) (ft)
15.0 2.0 10.0 50.0 8.0
Simulation:
Froude number: 18.11; effleunt density (
Depth Amb-cur P-dia Polutnt Di
Step (ft) (ft/s) (in) (ppm)
0 8.0 0.02 3.0 4.0
100 6.8 0.02 20.6 0.552
109 6.44 0.02 24.22
154 1.579 0.02 47.91
160 0.294 0.02 51.8
Const Eddy Diffusivity. Farfield
0.462
0.244
0.224
dispersion
conc dilutn width distnce time
(Prom) (m) (m) ()
0.22113 17.98 11.98 50.0 0.0851
count: 1
3:01:52 PM. amb fills: 2
sigma-T) -2.
lutn x-posn
() (ft)
1.0 0.0
7.203 3.589
8.607 4.339
16.29 9.881
17.75 10.81
based on wastef
(Op ) 0
Far-dir Disprsn Density
deg m{I : fr 7/s2 sigma-T
0.0 0.0003 4.618
0.0 0.0003 4.618
0.0 0.0003 4.618
Tt l-f to Ef f -sal
(MGD) (psu)
2.0 1.1
Temp Polutnt
(C) (Prom)
25.0 4.0
064; effleunt velocity 1.281(m/s);
y-posn
(ft)
0.0;
0.0;
0.0; merging;
0.0; matched energy radial vel = 0.0838m/s;
0.0; surface;
ield width of 9.85 m
(s-1) (ft/s)(m0.67/s2)
0.0 0.5 3.00E-4

Diffuser: VP plume 6.vpp.db 1 Ambient: c:\plumes\VP plume 6.001.db 1 Special Settings 1 Text Output
Help I
Clear +
Clear alll
Clear !all
Clear rb I
Clear bal
Clear bbl
Clear gal
Clear gb1
Clr Verify'
— Style
( dln'
(' con
r cus
Scale I
Thick I
To File I
Verify
0.
0
0
Plume Elevation
0
10n
0 2 4 6 8 10 12 14 16 18 20 22 24
Horiz. Distance from Source (ft)
Graphical Output
— Centerline
— Centerline
— Centerline
• Plume Bndry
x Plume Bndry
• Plume Bndry
— Verification
0
Ambient Properties
10
r , '
0 1 2 3 4 5 6 7
Density (sigma-T)
8
10
— Amb. density
— Amb. density
— Amb. density
• Plume density
x Plume density
• Plume density
— Verification
• 10— - - -
S
z 0-- - < ,
o -10-
cn
- 20-
- 30-
40----
Plan View
50
40— - - -
30— - -1 -
20---
•
-200 -150 -100 -50 0 50 100 150 200 250
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outline
• Outline
— Verification
Plumes Motion Prediction
24 -
22=
4_
2=
0;
0
r
•
✓
---- i-
4 6 8 10 12 14 16 18 20 22 24
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerlin e
x Centerlin e
• Centerline
— Verification

:o:IebI WIiaI$101x1[Na1
• 7-7-4cif A)o .2-
Diffuser. VP plume 6.vpp.db I Ambient: c:lplumesAVP plume 6:001.db I Special Settings
• . .... .. .. . ..... . .
Clear + I Output options I Numerical only
=Ciea texi displa}�
Text Output I Graphical Output
/ UM3. 3/12/2009 4:34:07 PM
Case 1; ambient file c:\plumes\VP plume 6.001.db; Diffuser table record 1:
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal
m m/s deg psu
0.0 0.0061 0.0 6.0
2.438 0.0061 0.0 6.0
3.048 0.0061 0.0 6.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 9.0 15.0 0.0
Step
0
77
85 0
1 Amb-tem Amb-pol Decay-Far-spd Far-dr Disprsn
C kg/kg s-1 m/s deg m0.67/s2
25.0 0.0 0.0 0.152 0.0 0.0003
25.0 0.0 0.0 0.152 0.0 0.0003
25.0 0.0 0.0 0.152 0.0 0.0003
Ports Spacing AcuteMZ ChrncMZ P-depth
() (ft) (m) (m) (ft)
15.0 2.0 10.0 50.0 1.0
Simulation:
Froude number: 24.39; effleunt density (sigma-T) -2.
Depth Amb-cur P-dia Polutnt Dilutn x-posn
(ft) (ft/s) (in) (prom)
1.0 0.02 3.0 4.0
0.4 0.02 13.45 0.871
()
1.0
4.581
5.367
(ft)
0.0
2.122
2.581
Plumes not merged, Brooks method may be overly conservative.
Const Eddy Diffusivity. Farfield dispersion based on vastef
conc dilutn width distnce time
(ppm) (m) (m) (hrs) (ppm) (s-1) (
0.72937 5.468 11.09 50.0 0.0897 0.0 0.0
count: 1
4:34:07 PM. amb fills: 2
Ttl-f to
(HGD)
2.0
Ef f-sal
(psu)
1.1
064; effleunt velocity
y-posn
(ft)
0.0;
0.0; matched energy
0.0; surface;
ield width of
ft/s)(m0.67/s2)
0.5 3.00E-4
Density----
sigma-T
1.619
1.619
1.619
Temp Polutnt
(C) (PPm)
25.0 4.0
1.281(m/s);
radial vel 0.2m/s;
8.93 m
lt)f4E-10 Yosc�,t-
► F-Fti g g_. ?' ®for P-E-77-11-
i toD e c f t 0.'J yet, /
5 P DUO
die°" r•

_Ed 6-- FF ev—of p r F-Fu.
Diffuser: VP plume 6.vpp.dbAmbient: c:lplumes\VP plume 6.001.db Special Settings Text Output Graphical Output
Help
Clear +
Clear all
Near ra
Clear rb I
Clear bal
Clear bbl
Clear gal
Clear gb)
Clr Verify
— Style-
• 4-pl
C clan
✓ con
✓ cus
Scale I
Thick I
To File I
Verify I
30
40
501
xr,
Plume Elevation
I I
44-
f 'ire-"
I I I
1 1
25t'
PL'5 is l
L = m, 0Zi6/5
lv � C
6
0 5 10 15 20 25 30 35
Horiz. Distance from Source (ft)
— Centerline
— Centerline
— Centerline
• Plume Bndry
• Plume Bndry
• Plume Bndry
— Verification
AFF C3-r�JN
40 45 50
Plan View
50
30— --- - - -- ----
20— _ .1- ;
10— -
-
z < :
0 _-
o40
co
l
-30-
-40' -
-200 -150 -100 -50 0 50 100 150 200 250
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outline
• Outline
— Verification
10-
- 20-
v
Z.
Ambient Properties
° 30-
50
y
- y
0 1 2 3 4 5 6 7 8 9 10
Density (sigma-1)
50
Plumes Dilution Prediction
— Amb. density
— Amb. density
— Amb. density
• Plume density
Plume density
• Plume density
— Verification
I
45
40=
-
I
I ▪ I
I I I LJ/ I I I I
- � I I I I 1
30- , ,
o
c - I
1
525 = l e,
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I I • i � T� I I I I I ,,
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
• Centerline
• Centerline
— Verification

@1rat;'L
521 ! E c s oF-- i2M13r' /v J S 79 L rA_.) € N Pc ME -
Diffuser: VP plume 6.vpp.db I Ambient: c:\plumes\VP plume 6.001.db I Special Settings I Text Output Graphical Output I
Help
Clear + I
Clear all l
Clear ra l
Clear rb l
Clear bal
Clear bbl
Clear gal
Clear gip'
Clr Verify)
— Style
0
Plume Elevation
— Centerline
— Centerline
— Centerline
• Plume Bndry
x Plume Bndry
• Plume Bndry
— Verification
vNr)
10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
• 4-pl
diln
r. con 50
cus l
Scale
Thick
To File I
Verify I
Plan View
40----
30 -
20 - I- I- I- --1
i
la—
z D—,�•
.510-
-30
-40—
-200 -150 -100 -50 0 50 100 150 200 250
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outline
• Outine
— Verification
0
0
Ai 59C10,r .car » ,
Ambient Properties
10-
0
3 4 5 6 7
Density (sigma-T)
8
9
10
— Amb. density
— Amb. density
— Amb. density
• Plume density
x Plume density
• Plume density
— Verification
0
0
D
Plumes Dilution Prediction
24:
22
•
L
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
x Centerline
• Centerline
— Verification

fI®lad `III
Diffuser: VP plume 6.vpp.db 1 Ambient: c:\plumesWVP plume 6.001.db I Special Settings 1 Text Output 1 Graphical Output f
Project
Ic:\plumes\VP plume 6
Notes: Columbia Diffuser Design with
River Velocity ty = 0.02 Ft' S ec=
WWTP Flow = 2 MGD_ &
Ammonia = 4 mg&
Graphing Changes with Ambient Saliriit)y
c:\plumeslVP plume 6.001.db 1 1
c:iplumesWVP plume 6.001.db 1 1
- After run go to tab -
Diffuser
(' Ambient
C Special
C Text
* Graphics
[Units Conversion
( Convert data
C Label only
UM3
Model Configuration
❑ Brooks far -field solution
❑ Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
El Tidal pollution buildup
G Same -levels time -series input —
Case selection
Base or selected case
C Sequential, all ambient list
(' Sequential, parse ambient
C All combinations
Diffuser, Flow, Miring Zone Inputs
Port
diameter
3
nir
rn
Port Vertical Hor
elevation angle I angle
ft deg deg
1 15 0
1Num of
ports
Port ( Or
spacing
ft
15 _2
I
nlr
s
In/r (Acute
mix zone
s m
IChronic Port Effluent
mix zone depth flow
m ft MGD
10 50
9
Effluent Effluent Effluent
salinity[") temp conc
psu C ppm
2 1.1 25
Parameters for selected row
Froude number
Eff density f ko/mil
Port vel frnlsl
P-dia fml
0.0762
P-dia f inl
3.0
Case No.
1 0
Time Series -Files (optional)
Borrow time -series from project: lc:\plumesWVP plume 6
Port Effluent
depth flow
Time series filename221231111111111 click for file
Time increment f hrsl
Time cycling period
Measurement unit.
Effluent
salinity(x)
1 Effluent
temp
Effluent
conc
click for file
click for file
click for file

g
EN15til EJ
Diffuser: VP plume 6. vpp.db Ambient: cAplumes\VP plume 6.001.db I Special Settings I Text Output I Graphical Output
Ambient Inputs
re
Far -field
current dife-ot11.111
Depth or Height -1
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit
UM3
Ambient Neal
Filenam .
'VP plume 6.001.db 1 1
1111
-"•Mir
deptl depth !depth depth depth depth depth depth depth
constant I constant ; constant constant constant constant constant constant Iconstant
linear to zero ' constant constant extrapolated constant constant I
extrapolated extrapolated ;constant
ftls deg psu C ppm s-1 ftis deg I m0.67/s2
0 0.02
8 0.02
10
0 1.1
0 1.1
0
0 0.3 0
0
0.0003
0 0.5 0 0.0003
Time -Series Files (optionaD Borrow time -series files from project:
Time-teriFarename
Time increment (hrs)
Cycling period
File measurement unit
c: \ plumes WP plume 6
click for file click for fie click for file click for file click for file click for file click for file click for file click for file
1

Diffuser: VP plume 6.vpp.db Ambient: c:lplumesWP plume 6.001.db
LM3 tidal pollutant buildup parameters
Channel width (m)
Graphics settings
— Style
C 4-panel
C' dilution
C concentration
( custom
— Custom graph coords. —
(. Abscissa (x)
Ordinate 1 (y)
(' Ordinate 2 (y)
Custom variables
Start case for graphs Max detailed graphs
Th J
Special Settings I Text Output l Graphical Output 1
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
I
I0.16
Farfield increment (m) 1200
UM3 aspiration coefficient
lo_ 1
— Bacteria model on solar radiation input
61 Mancini (1978) coliform model
r 301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
C 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
PDS sfc. model heat transfer
r Low ( Medium
( High
'_\'RFIELD/FRFIELD input variables
Text output settings
Output medium
Text tab (ambient filled) r File (ambient filled)
C - Text tab (ambient as is) f ' File (ambient as is)
r Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Reset Default List I
Depth
Amb-cur
P-dia
Pohrtnt
Diln
x-posn
}r-posn
UM3 output each ?? steps 1100
UM3 maximum dilution reported 110000
n UM3 max vertical reversals-
- to max rise or fall
6' to second trap level
C to 2nd max rise or fall
— UM3 text output format
Standard output
C. Brief output
I- Stop on maximum dilution
Close panel

0
xI[aI5D)
Diffuser. VP plume 6.vpp.db I Ambient c:lplumesWVP plume 6.001.db l Special Settings
Clear + I Output options I Numerical only I
ear text displaii
Text Output I Graphical Output 1
/ UH3. 3/12/2009 3:20:45 PH
Case 1; ambient file c:\plumes\VP
plume 6.001.db; Diffuser table record 1:
Ambient Table:
Depth_- Amb-cur Amb-dir Amb-sal Amh-tem Amb-pol Decay Far-spd Far-dir Disprsn Density
m m/s deg psu C kg/kg s-1 m/s deg m0.67/s2 sigma-T
0.0 0.0061 0.0 10.0 25.0 0.0 0.0 0.152 0.0 0.0003 4.618
2.438 0.0061 0.0 10.0 25.0 0.0 0.0 0.152 0.0 0.0003 4.618
3.048 0.0 0.0 10.0 25.0 0.0 0.0 0.152 0.0 0.0003 4.618
Diffuser table:
P-dia P-elev \-angle H-angle
(in) (ft) (deg) (deg)
3.0 1.0 15.0 0.0
Simulation:
Froude number:
Depth
Step (ft)
0 9.0
100 7.791
Ports Spacing AcuteMZ ChrncMZ
() (ft) (m) (m)
15.0 2.0 10.0 50.0
18.11; effleunt density (sigma-T) -2.
Amb-cur P-dia Polutnt Dilutn x-posn
(ft/s) (in) (ppm) () (ft)
0.01 3.0 4.0 1.0 0.0
0.02 20.65 0.552 7.203 3.593
109 7.426 0.02 24.27 0.462
159 1.47 0.02 51.1 0.227
164 0.193 0.02 54.72 0.21
Const Eddy Diffusivity. Farfield dispersion
conc dilutn width distnce time
(PPm) (m) (m) (hrs)
0.20787 19.12 12.06 50.0 0.0848
count: 1
3:20:45 PM. amb fills: 2
/ UM3. 3/12/2009 3:22:12 PH
Case 1; ambient file c:`plumes`VP plume 6.001.db; Diffuser table record 1:
P-depth Tt 1-f to Ef f -sal
(ft) (HGD) (psu)
9.0 2.0 1.1
Ambient Table:
Depth Amb-cur
m/s
0.0 0.0061
2.438 0.0061
3.048 0.0
8.607 4.345
17.49 10.63
18.89 11.46
based on wastef
(Op0) (0 0) (
Amb-dir Amb-sal Amb-tem Amb-pol
deg psu C kg/kg
0.0 6.0 25.0 0.0
0.0 6.0 25.0 0.0
0.0 6.0 25.0 0.0
Temp Polutnt
25�0 (p4m0
064; effleunt velocity 1.281(m/s);
y-posn
(ft)
0.0;
0.0;
0.0; merging;
0.0; matched energy radial vel = 0.0961m/s;
0.0; surface;
ield width of 9.92 m
ft/s)(m0.67/s2)
0.5 3.00E-4
Decay Far-spd Far-dir Disprsn Density
s-1 m/s deg m0.67/s2 sigma-T
0.0 0.152 0.0 0.0003 1.619
0.0 0.152 0.0 0.0003 1.619
0.0 0.152 0.0 0.0003 1.619

MCDAVID ASSOCIATES, INC.
Engineers • Planners • Land Surveyors
CORPORATE OFFICE
[phone] • Fax [phone]
E-mail: [e-mail]
3714 N. Main Street • P.O. Drawer 49
Farmville, NC 27828
March 10, 2009
Mr. Ron Berry
NPDES Eastern Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Subject:
Dear Mr. Belly
GOLDSBORO OFFICE
[phone] • Fax [phone]
E-mail: [e-mail]
109 E. Walnut Street • P.O. Box 1776
Goldsboro, NC 27533
Town of Columbia
NPDES Permit Modification
Permit No. NC0020443
Tyrell County
We have received written comments from your office dated January 16, 2009. Please
find the following items provided in response to your comments:
1. Three copies of point for point written responses to the nine comments found in the
body of your letter.
2. Three copies of the Residuals Management Plan.
3. Three Copies of thee point for point response to the Diffuser Design Evaluation
comments.
4. Three copies of the Plumes model output.
5. Three copies of the diffuser construction detail including a scale sketch for the
diffuser plan and profile.
6. Three copies of Google aerial photographs showing the relationship of the diffuser to
the river.
11G-PC11D10051CGM120091COLUMBIA
2-06-6062-8004-COL U M B I A-N P D E S-PERMIT-RESPONSES

Should you have any questions regarding this transmittal, do not hesitate to contact me.
Sincerely,
Mc David Associates, Inc.,
Cecil C. Madden, Jr., P.
Goldsboro Office
CGM:
Attachments
cc: Town of Columbia (w/Attachments 1, 2, & 3)
\\G-PC 1 \D 10051CGM12009\COLUMBIA
2-06-6062-8004-COLU MBIA-NPDES-PERMIT-RESPONSES
rft

RESPONSES to NORTH CAROLINA
NPDES STAFF COMMENTS
Dated January 16, 2009
The original State's Review Comment is stated and the engineer's response follows:
1. There is no mention of an automated influent sampler in the documentation. Please
prov de a description of the location in the treatment process, the type sampler, and
the sampler features.
A refrigerated composite influent sampler is provided at the influent to the aerated grit
removal facility. The sampler shall be able to collect sample increments at timed or
prop rtional to flow as measured by a flow meter. The sampler shall deposit collected
sam le into a single container for collection and off site analysis. The refrigerated
sam ler is to be housed in a weatherproof housing. The sampler shall be Model 3710FR
by ISCO, Model 900AWRS by American Sigma or equal.
2. The effluent Composite sampler location is listed but for clarity sake please provide
a more detailed description of the composite sampler features.
A refrigerated composite effluent sampler is provided at the effluent to the post aeration
facility. The sampler shall be able to collect sample increments at timed or proportional
to flow as measured by a flow meter. The sampler shall deposit collected sample into a
single container for collection and off site analysis. The refrigerated sampler is to be
housed in a weatherproof housing. The sampler shall be Model 3710FR by ISCO, Model
900AWRS by American Sigma or equal.
3. There are several effluent grab samples required for various parameters. Please
provdde a description of where in the process these samples are taken.
Based on the current permit, grab samples are needed for the following parameters and
suggested sampling locations are as follows:
Parameter Suggested Sample Location
Diss lved Oxygen At the discharge from the post aeration structure
Ente occi At the discharge from the post aeration structure
Tota Residual Chlorine A sample tap will be placed in the effluent outfall
Tem erature At the discharge from the post aeration structure
pH At the Discharge from the post aeration structure
11G-PC 11D 10051CGM120091COLUMBIA
2-06-6062-8004-COLUMBIA-NPDES-PERM IT -RESPONSES

4. It is issumed the backup power system extends to both the influent and effluent
com If
osite samplers and meters. Please confirm.
The assumption is correct.
5. Please confirm whether the new and upgraded lift stations will have backup power.
Yes they will have backup power.
6. A very detailed discussion was provided on the sludge control and disposal options.
As a part of the permit application a formal written sludge plan must be included.
Thee should already be a Sludge Plan in place. Please provide a Sludge Plan for the
expansion.
A copy of the Residuals Management Plan is attached.
7. Are any other chemicals projected for use, for example pH control? If yes please list
and indicate point of entry into the process.
No other chemicals should be needed other than sodium hypochlorite for disinfection and
calcium thiosulfate for dechlorination. Alkalinity should be satisfactory, so pH
adjustment should not be required.
8. The Application requires a Diffuser as part of the expansion which requires the
permittee to conduct a CORMIX model. The limited details listed on the
application are unusual and insufficient. Attached is a more detailed list of
questions and support documentation that must be provided from the diffuser
design and CORMIX model.
Currentlyi The Town of Columbia operates a 300,000 gpd extended air oxidation ditch
• with a 10" gravity outfall and a single point discharge about 10 or so feet off the bank
into the Scuppernong River. The existing gravity outfall is located in the bank of the boat
channel on its way, out to the river. Due to erosion much of the existing gravity outfall is
exposed. The proposed effluent outfall is going to be a 12" HDPE force main that will be
10 feet south of the existing gravity outfall and will be installed by directional bore.
Based on Google Earth the width of the river at this location is about 1,100 feet. The
Town of Columbia has surveyed the bottom of the river to a point approximately 300 feet
beyond the existing discharge. It has been previously requested that the Town find a
11G-PC 11D 10051CGM120091COLUMBIA
2-06-6062-8004-COLUMBIA-NPD ES -PERMIT -RESPONSES

diffuser location with at least 6 feet of cover over the diffuser. It is proposed to place the
diffuser approximately 220 feet off the bank of the stream. The diffuser design provides
8 feeti)f cover.
In lieu of a CORMIX model, we have elected to use a PLUMES model. The PLUMES
modeling software is available from EPA, while CORMIX is a proprietary software.
A copy of the model results, and responses to the more detailed Diffuser Design
Evaluation Comments are attached.
9. Why s the diffuser not symmetrical, more ports upstream than upstream.
The diffuser provides 15 ports. They are placed 2 feet on center. Ports alternate with
first and last ports facing downstream. Eight ports face downstream, and 7 ports face
upstream. Upstream and downstream ports are staggered to achieve maximum mixing.
11G-PC 11D 10051CGr20091COLUMBIA
2-06-6062-8004-COLU MB1 A-NPDES-PERM IT -RESPONSES

Town of Columbia's WWTP
Residuals Management Plan
Per 15 NCAC 02T .0507
By Cecil G. Madden, Jr., P.E.
McDavid Associates, Inc.
Goldsboro, North Carolina
January 23, 2009
(1) Detailed explanation as to how the residuals will be collected, handled,
processed, stored and disposed;
The Town of Columbia's WWTP has three sources of residuals. They include the
screenings from the bar screen, grit from the aerated grit removal chamber, and waste
sl�}dge that is generated in the activated sludge process. The screenings are to be
co lected with a mechanical bar screen, washed, compacted, and deposited into a
co tainer for disposal at the County Landfill. A manual bar screen is available as a
b ckup to the mechanical screen. The grit is collected in a 10' X 10' aerated grit
removal chamber. A grit classifier is used to dewater and wash the grit. The grit is
deiposited into a container for disposal at the County Landfill. Grit removal is not
c9nsidered an essential process and duality is not required by regulation. The existing
1.
oxidation ditch and proposed oxidation ditch produce activated sludge. Two existing
clarifiers and two proposed clarifiers allow the sludge to settle and be removed from
t e system. Sludge is wasted from the activated sludge WWTP to the newly
proposed third digester. Digested decanted sludge can then be directed to the existing
atIrated tanks awaiting land application. The stored sludge can be further decanted
and land applied by a residuals contractor.
(2) Evaluation of the residuals storage requirements for the treatment facility.
Storage shall be calculated based upon the maximum anticipated residuals
production rate and ability to remove residuals;

Residuals production is based on the following assumptions:
Influent BOD5 = 225 mg/1
Dgsign Flow = 600,000 gpd
No residuals are discharged in the effluent.
Sludge yield = 0.6 lbs / lbs of BOD5 removed.
Therefore:
Slidg a Production = .6 MGD x 8.34 x (225 mg/1— 0 mg/1) x 0.6 lbs/lbs
= 676 lbs/day
= 3242 gpd @ 2.5% solids.
pie newly proposed digester is 54 feet in diameter with a 4 foot cone and has a 10
foot side water depth. This provides 194,520 gallons of capacity or 60 days of
storage. A 30 HP floating aerator is proposed for mixing/ aeration.
With digestion solids reduction occurs.
Assume 38% reduction in VSS within the aerobic digester.
Assume 70% of sludge is volatile.
3242 gpd — [(3242 x .7 x .38)] = 2380 gpd
The existing two tanks are as follows:
Tank No. 1 is 28 feet in diameter with a 10 foot side water depth and a 4 foot cone. It
has a capacity of 52,673 gallons. Tank No. 2 is 48 feet in diameter with a 10 foot side
ater depth and a 4 foot cone. It has a capacity of 154,186 gallons.
olding capacity of digested sludge = (52,673 + 154,186) / 2380
= 87 days
(3) P
rmit for residuals utilization, a written commitment to the Permittee of a
Department approved residuals.disposal/utilization program accepting the
residuals which demonstrates that the approved program has adequate capacity
to accept the residuals, or that an application for approval has been submitted;

Atlantic Sewage Control provides residualsmanagement services for the ultimate
disposal of the Town's sludge. A copy of the existing contract is attached.
(4) I oil, grease, grit, and screenings removal and collection is a designed unit
p ocess, a detailed explanation as to how the oil/grease will be collected, handled,
processed, stored and disposed.
Scum oil and grease are floatables that are removed from the top of the clarifier by
simmers. This is recycled back to the head of the plant or directed to the digester
where they are ultimately discharged with the other digested residuals.
Grit and screenings are removed and carried to the County Landfill.

02/20/2007 12:
FRCt1 : io-ise T'C
•
4 20000000000
SEJAGE CONTROL.
E`OL.UM 1 I 1
r.RA 110. : 25225510702 Feb. 22 2007 09:45AM F�
PAGE 01
ATLANTIC SEWAGE CONTROL
At11 .1 '•:1 4 5' .r % DCYwf. :!(•.1i t.
�i.
fa>. (252) 25S.O/0:
CONTRACT FOR SERVICES
This contract is by and between Atlantic Sewage Control and the Town of
Columbia for the following services:
Adana Sewage Control (ASC) will aontiaue.to provide residuals management
services as has been done since 1994. Whim residuals need to removed from the
wastewater treatment facility, the Town's operator will call ASC to schedule a. mutually
agreed upon date for bailing to continence. The Town's operawr will be responsible for
satisfying the stabilization and vector attraction reduction requirements, usually by
tiding a sufficient amount of lime to the residuals and recording the pH of the mixture st
appropriate timed. ASC will remove the residuals/lime minute and land apply in
accordance with the Division of Waste Quality (DWQ) Permit. The Towns is responsible
fo prcrvidhig ASC a residuals analysis each year as required by the DWQ permit. ASC
is responsible for satiating the DWQ conditions including an Annual wort. to DWQ.
The fee for these services and other services as may be required from time to '
dins will be mutually agreed upon by both parties prior to the commencement of such
service. This agreement shall remain in effect until either patty cancels with 60 days
written notice.
Risen White. Town
Town of Columbia
lkfiarcus Felton, Jr., P. ' ., ' ent
lantic Sewage Control
een �"'/ �/
Date
Dena

RESPONSES to NORTH CAROLINA NPDES STAFF'S QUESTIONS
Titled
DIFFUSER DESIGN EVALUATION INFORMATION — NC0020443 EXPANSION
The original diffuser design evaluation comment is stated and the engineer's response follows:
The Division supports, in this case requires, the installation of a properly designed diffuser to
optimize or enhance the minimal impact of the permitted discharge to the Scuppermong River.
To assist the Division in its evaluation and development of the NPDES permit, the permittee
must demgnstrate through a CORMIX model provided by the permittee, that the proposed
diffuser design is acceptable The following information is obtainable from the CORMIX
model and recognized experts.
In lieu of a CORMIX model, we have elected to use a PLUMES model. The PLUMES
modeling sofware is available from EPA, while CORMIX is a proprietary software.
Diffuser design conditions:
1) Diffuser ports upstream/downstream not aligned to maximize mixing area.
Diffusers are oriented alternating, starting with downstream, moving to upstream and
back io downstream in a repeating fashion in order to maximize mixing area.
2) Diffuser located to point further from shore to maximize dispersion.
II
The 30 foot long diffuser is placed approximately 200 feet off shore to enhance
dispersion.
3) Diffuser ports oriented to offset any scouring of surrounding terrain.
The diffuser ports are designed with a 15 degree vertical angle off of the horizontal plane.
This prevents bottom scour. Additionally, the diffuser is located 200 feet off the bank of
the river.
4) Diffuser port anchored to guarantee no movement and diffuser always submerged.
Concrete collar anchors are provided to prevent flotation and movement due to the thrust
from the diffusers.
11G-PC 11D 10051CGM120091COLUMBIA
2-06-6062-8004-COLUMB IA-NPD ES -PER MIT -RESPONSES

5) Diffuser ports oriented to prevent disturbance of the water surface. (Added by
phone on March 5, 2009.)
The model demonstrates the water surface is not disturbed. The potential of surface
distulbance would most likely occur at the pumping rate of 2.0 mgd. By reviewing the
text output for each model run, (page four of each run), it can be seen that the matched
energy radial velocity is achieved prior to the plume reaching the surface. Therefore,
there should be no water surface disturbance.
Required information:
1) Wha major effluent pollutants are addressed by the diffuser design?
As requested by the reviewer, ammonia and total residual chlorine have been addressed.
Starting with an initial ammonia concentration of 4 mg/1, the concentration 3.38 feet from
the diffuser would be 0.552 mg/1. The concentration of ammonia, 20.64 feet out from the
diffu er, would be 0.0825 mg/1.
Starting with an initial total residual chlorine concentration of 17 ppb, the concentration
3.38 feet from the diffuser would be 2.347 ppb. The concentration of total residual
chlorine, 20.64 feet out from the diffuser, would be 0.351 ppb.
2) What are the CORMIX model inputs?
Port diameter
Port levation off the bottom of the stream
Vertical angle off of the horizontal plane (angle of diffuser)
Horizontal angle with respect to main river channel
Number of ports
Spacing of ports
Acutc mixing zone
Chronic mixing zone
Port depth
Total effluent flow
Effluent salinity
Effluent temperature
Effluent concentrations for Ammonia and TRC
Current velocity
Current direction
Ambent salinity
Ambent temperature
Background concentration
11G-PC I1D 10051CGM120091COLUMBIA
2-06-6062-8004-COLUMBIA-NPDES-PERMIT-RESPONSES

Pollutant decay rate
Far -field current velocity
Far -field current direction
Far -field current coefficient
3) What assumptions are made in the CORMIX model?
Port diameter = 3"
Port elevation off the bottom of the stream = 2'
Vertical angle off of the horizontal plane (angle of diffuser) = 15 degrees
Horizontal angle with respect to main river channel = 0 degrees
Number of ports = 15
Spaciig of ports = 2'
Acute mixing zone 10 meters or 32.808 feet
Chronic mixing zone 50 meters of 164.04 feet
Port dgpth = 8'
Total effluent flow ADF = 0.6 MGD, pumping rate = 2 MGD
Effluent salinity = 1.1 PSU
Effluent temperature = 25 degrees C
Effluent concentrations for Ammonia = 4 mg/1, and TRC = 17 PPB
Current velocity = 0.5 ft/sec low flow and 2 ft/s normal flow
Curre>it direction = 0 degrees
Ambient salinity = 10 PSU
Ambient temperature = 25 degrees C
Background concentration Ammonia = 0 PPM, TRC = 0 PPB
Pollutant decay rate = 0
Far -field current velocity = 0.5 ft/sec, and 2.0 ft/sec
Far-fild current direction = 0 degrees
Far -field diffusion coefficient = 0.0003
One conservative assumption not addressed above is that the model assumes all diffusers
are pointed downstream. The actual design proposed aims a portion of the diffusers
upstream which helps to accomplish mixing in a smaller zone.
4) How ras the CORMIX model calibrated?
As requested by the reviewer the following runs were conducted for each of the two
pollutants of concern:
2 MGD (Pumping Rate) with a Stream Velocity of .5 ft/sec
2 MGD (Pumping Rate) with a Stream Velocity of 2 ft/sec
0.6 MGD (ADF) with a Stream Velocity of 0.5 ft/sec
0.6 MGD (ADF) with a Stream Velocity of 2 ft/sec
5) What is the size, shape, and location of the area of mixing during critical conditions?
11G-PC 11D 10051CGM120091COLUMBIA
2-06-6062-8004-C9L UMBIA-N PDES-PERMIT-RESPONSES

A review of the fifth page of the model run has a graph that shows the profile and plan
views1 of the plume for a port. The plume starts from a point at the port and grows to
about 5 feet of depth at a location 25 feet out from the port. With 15 diffusers 2 feet on
center, the width grows from 30 feet at the diffuser header to 44.9 feet
(13.69 meters) at the location where point of constant dilution. (This is about 25 feet out
from the diffuser.)
6) What is the amount of dilution occurring at critical conditions at various points
throughout the plume?
Distance
Diffuser
from
Dilution Factor
Ammonia
Concentration
Total Residual
Chlorine
0 Feet
1
4.0 mg/1
17 PPB
3.385, Feet
7.203
0.552 mg/1
2.347 PPB
5.607 Feet
12.54
0.317 mg/1
1.348 PPB
20.64 Feet
48.17
0.825 mg/1
0.351 PPB
22.24 Feet
52.14
0.0762 mg/1
0.324 PPB
24.45 Feet
57.57
0.069 mg/1
0.293 PPB
50 Meters
57.90
0.0686 mg/1
0.2917 PPB
7) What is the area of near field delineation where induced mixing ceases?
Essentially 24.43 feet from the diffuser.
8) Does
the plume exhibit shore hugging?
No. At a point 50 meters from the diffuser the plume is only 45 feet wide and the
diffuser is located 200 feet out into the stream.
9) Does
the plume exhibit interaction with the river bottom?
No. jFhe profile view of the plume shows that there is no interaction with the river
bottom.
10) Does the discharge location impact any aquatic life, biological communities,
promote dominance of a nuisance species, impact any endangered species, or
threatens any critical habitats?
The proposed discharge location does not impact any aquatic life, or biological
communities. Nor does the proposed location promote dominance of a nuisance species.
Nor Yvi11 it impact any endangered species. The proposed discharge location does not
threaten any critical habitat. This has already been addressed by the environmental
assessment which was reviewed and approved by the Construction Grants and Loans
Section of the Division of Water Quality. A copy of the Engineering Report with its
11G-PC 11D 10051CGM120091COLUMBIA
2-06-6062-8004-COLU M BIA-NPDES-PERMIT-RESPONSES

Environmental Assessment and the approval were provided with the original permit
application.
11) Does the discharge interfere with the designated use of the receiving stream or
downstream waters?
The Scuppernong River is Class SC. The designated best uses include Aquatic life
propagation; and Secondary Recreation including recreational fishing, boating, and water
related activities involving minimal skin contact. The proposed discharge does not
interfere with such uses here or downstream.
12) Is the mixing zone within or adjacent to any recreational areas?
No. The proposed discharge location is approximately 1,600 feet downstream from the
Towns marina. The discharge location is approximately 6,600 feet upstream from
another marina. The discharge plume would have no affect on either marina.
Navigational aids will be placed in the river near each end of the diffuser to warn boaters
and fishermen. However, with 8 feet of cover over the diffuser there should be no issues.
Required support documents:
1) Mechanical drawing of diffuser including installation details, scaled view of layout
in re eiving stream
2)
Attached is a drawing of the proposed diffuser including installation details and a scaled
view of the diffuser layout with respect to the river.
Scheduled maintenance to diffuser
A pressure gauge is to be installed on the force main in the pump station building. In the
event the pressure rises too high this would be an indication of diffuser blockage. In the
even that the pressure decreases significantly, this would be an indication of the diffuser
being disconnected. In the event of either condition a diver will be sent to conduct an
inspection. In addition, the town is willing to have a diver inspect the diffuser at least
one time per year.
3) CO MIX Session Report for design.
Attached are three copies of the model results.
Note: Some of this information may be addressed in the January 6, 2009 document.
However, the diffuser is only mentioned in the application and it is not included in
any of the other documentation. If included you may indicate the exact location of
pertinent details that address any of the requested information.
11G-PC 11D 10051CGM120091COLUMBIA
2-06-6062-8004-COLUMBI A-NPDES-PERMIT-RESPONSES

Details were not originally provided for the diffuser. We anticipated that the diffuser
design would be addressed during the Authorization to Construct review to be Conducted
by thei Construction Grants & Loans Section.
11G-PC I\D10051CGM120091COLUMBIA
2-06-6062-8004-COLUMBIA-NPDES-PERMIT-RESPONSES

r e»I Nall
Diffuser: VP plume 4.vpp.db !Ambient: c:\plumes\VP plume 4.001.db 1 Special Settings 1 Text Output 1 Graphical Output 1
Project Ic:\plumes\\'P plume 4
Ammonia = 4 mg''1 & Effluent Salinity = 1.1 psu
Ambient Velocity = .5 ft's & Salinity = 10 psu
AAfrint f
Filename Cases
— After run go to tab -
Diffuser
( Ambient
✓ Special
C Text
C Graphics
rUnits Conversion
r; Convert data
( Label only
UM3
Model Configuration
❑ Brooks far -field solution
❑ Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
❑ Tidal pollution buildup
❑ Same -levels time -series input
Case selection ------
t+ Base or selected case
C Sequential, all ambient list
(' Sequential, parse ambient
C All combinations
Diffuser, Flow, Mixing Zone Inputs
I Port
diameter
n/r
Port Vertical Hor Num of n/r
elevation angle angle ports 1Port
spacing
I n/r n/r lAcute
[Chronic
mix zone mix zone
Port
depth
E ffluent
flow
Effluent
salinity(1
Effluent Effluent
temp conc
ppm
251 4i
in m ft deg deg
3 2 15
0 15
ft
s
s
ft ft ft
32.808 164.04
MGD psu C
0.6 1.1
Parameters for selected row 1
Froude number
Eff densit k■/m3
Port vel m/s
P-dia (ml
0.0762
P-dia in
3.0
Case No.
1.0
Time Series -Files (optional)
Port
depth
Time -series filename
Time increment (Hs]
Time cycling period
Measurement_unit
click for file
Borrow time -series from project: lc:\plumes\VP plume 4
Effluent
flow
click for file
(Effluent
salinity(%)
click for file
'Effluent
temp
click for file
Effluent
conc
click for file

Ero
C 0
EN 5:11 la]
Diffuser VP plume 4.vpp.db Ambient: c:\plumesWP plume 4.001.db I Special Settings' Text Output 1 Graphical Output I
Depth or Height
Extrapolation (sic)
Extrapolation ibtmj
Measurement unit
UM3
agilent fill.
:enam
Ambient Inputs
lent all ac ro I uOnt 1 Far field Far -field Farfield
drnperatur - rater) current speed current direiidiffusion co
iilail
depth depth depth depth depth depth depth depth depth
----1 constant constant— constant constant constant constant • constant constant constant
extrapolated extrapolated constant extrapolated constant Iconstant extrapolated Lextrapolated constant
deg psu C ppm _ s-1 fth deg m0.671s2
0.5 0 10 25
01 0 , 0.5 0 0.0003
0
s
10
Time -Series Files (optional)
' Time -series filename .
Time increment (hrs)1
Cycling period
File measurement unii
0.5 0 10 25
. ...
click for file
0 0 0.5 0 0.0003
Borrow time -series files from project: lc: \plumes\VP plume 4
click for file click for file click for file click for file I click for file click for file click for file click for file

r
0
Diffuser: VP plume 4.vpp.db 1 Ambient: c:\plumes\VP plume 4.001.db
' 1-71,13 tidal pollutant buildup parameters
Channel width (m)
100
Graphics settings
Special Settings 1 Text Output' Graphical Output I
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
10.16
Farfield increment (m) 1200
UM3 aspiration coefficient
10.1
— Bacteria model on solar radiation input -
i: Mancini (1978) coliform model
C' 301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
C 301(h) TSD (1994) enterococcus (for saltwater, Eqn B•69)
FDS sfc. model heat transfer
Loa! Medium C' High
— Style
4: 4-panel
i dilution
( concentration
i custom
— Custom graph coords.
C: Abscissa (x)
r Ordinate 1 (y)
( Ordinate 2 (y)
Custorn variables
Start case for graphs Max detailed graphs
N FIELDfERFIELD input variables
Text output settings
Output medium
Text tab (ambient filled)
C' Text tab (arnbient as is)
C File (ambient filled)
C' File (ambient as is)
j— Show changed Diffuser and An-rbient tab variables only
Selection List
Reset Default List I
Selected Variables
Depth
Amb-cur
P-dia
Polutnt
Dilutn
x-posn
y-posn
UM3 output each ?? steps
1100
UM3 maximum dilution reported 110000
UM3 max vertical reversals
a to max rise or fall
( to second trap level
( to 2nd max rise or fall
UM3 text output format
i• Standard output
i� Brief output
I— Stop on maximum dilution
Close panel I

ril�lelr �'01�Imlml J
Diffuser. VP plume 4.vpp.db I Ambient: cA lumesWP plume 4.001.db I Special Settings
[leaf textislal
Clear + I Output options I Numerical only
ext Output 1 Graphical Output 1
/ UH3. 3/5/2009 11:00:40 AM
Case 1; ambient file c:\plumes\VP plume 4.001.db; Diffuser table record 1: ------
Ambient Table:
Depth Amb-cur
m/s
0.0 0.152
2.438 0.152
3.048 0.152
Amb-dir Amb-sal Amb-tem Amb-pol
deg psu C--kg/kg
0.0 10.0 25.0 0.0
0.0 10.0 25.0 0.0
0.0 10.0 25.0 0.0
Decay Far-spd Far-dir Disprsn Density
s-1 - m/s--- deg---m0.6-7-/s2 srgma- T
0.0 0.152 0.0 0.0003 4.618
0.0 0.152 0.0 0.0003 4.618
0.0 0.152 0.0 0.0003 4.618
Diffuser table:
P-dia P-elev V-angle H-angle Ports Spacing AcuteHZ ChrncHZ P-depth
(in) (ft) (deg) (deg) () (ft) (ft) (ft) (ft)
3.0 2.0 15.0 0.0 15.0 2.0 32.808 164.04 8.0
Simulation:
Froude number:
Depth
Step (ft)
0 8.0
Tt l-f to Ef f -sal
(MGD) (psu)
0.6 1.1
Temp Polutnt
(C) (PPm)
25.0 4.0
5.433; effleunt density (sigma-T)-2.064; effleunt velocity 0.384(m/s);
Amb-cur P-dia Polutnt Dilutn x-posn
(ft/s) (in) (PPm) ( ) (ft)
0.5 3.0 4.0 1.0 0.0
100 7.448 0.5
168 6.639 0.5
200 5.87 0.5
251 2.985 0.5
259 2.203 0.5
Const Eddy Diffusivity.
conc dilutn width
(PPm) (m)
2.36E-2 168.4 13.55
count: 1
11:00:40 AM. amb fills: 2
11.52 0.552 7.203
24.24 0.144 27.67
39.23 0.0762 52.14
102.8 0.0278 143.1
120.3 0.0237 167.7
Farfield dispersion based
distnce time
(m) (hrs)
50.0 0.0726
2.244
6.339
10.9
y-posn
(ft)
0.0;
0.0;
0.0; merging;
0.0;
28.54 0.0; matched energy
33.33 0.0; surface, acute
on wastefield width of 11.59
(ppm) (s-1) (ft/s)(m0.67/s2)
0.0 0.0 0.5 3.00E-4
radial
zone;
vel 0.112m/s;

Diffuser: VP plume 4,vpp.db Ambient: c:\plumesWP plume 4,001.db I Special Settings I Text Output Graphical Output I
• Help
Clear + I
Clear all
10
20
Clear rb I
t
Clear bet o
30
Clear bbl
Clear gal
Clear gbl
Clr Verify)
— Style
4-pI
C diln
con
r cus
Scale
Thick
To File I
Verify I
40
Plume Elevation
10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Centerline
— Centerline
— Centerline
• Plume Bndry
• Plume Bndry
• Plume Bndry
— Verification
South -North
100
Plan View
0 5 10 15
20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
• Outline
• Outline
— Verification
a
m
0
Ambient Properties
10
20—
40
-y
-y
0 5 10 15 20 25 30 35 40 45 50
Densely (sigma-T)
— Amb. density
— Amb. density
— Amb. density
• Plume density
= Plume density
• Plume density
— Verification
1,000 _
Plumes Dilution Prediction
900=
SOO= -
700
500= -- -
t 500
O -
400_
300---- ---- - 1
200—__-_ ___
100 - _ _
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
• Centerline
• Centerline
— Verification

ro�I � � el xl. 1. [I _l
Q
Diffuser. VP plume 4.vpp.db I Ambient: c:\plumes\VP plume 4.001.db I Special Settings I Text Output I Graphical Output I
Project
ic:plumes VP plume 4
Notes:Cohunbia Diffuser With WWTP Flow = 2.0 mgd &
Ammonia = 4 mg 1 & Effluent Salinity = 1.1 psu
Ambient Velocity = 2 ftls & Salinity = 10 psu
— After run go to tab -
C D iffuser
C Ambient
T Special
( Text
r' Graphics
Units Conversion
( Convert data
C Label only
UM3
Model Configuration
Brooks far -field solution
Graph effective dilution
Average plume boundary
Amb. current vector averaging
Tidal pollution buildup
Same -levels time -series input
— Case selection
a* Base or selected case
(- Sequential, all ambient list
( Sequential, parse ambient
<• All combinations
Diffuser, Flow, Mixing Zone Inputs
Port
diameter
in
n/r
m
'Port !Vertical IHor INumof
elevation angle angle ports
ft deg deg
Port In/r
spacing
ft s
n/r
I n/r {Acute 1Chronic
mix zone mix zone
s ft ft
Port
'depth
ft
E ffluert
flow
MGD
Effluent
salinity(")
psu
Effluent Effluent
temp conc -„al
C ppm
.1I
3
2 15 0 15
Parameters for selected row I
Froude number
Eff density f kq,'rr 31
Port vel (m/sl
P-dia fml
0.07E2
P-dia fin'
3.0
Case No.
1.0
Time Series -Files (optional)
Time -series filename
32.808 164.04
Borrow time -series from project:
Port Effluent
depth flow
click for file
Time increment fhrsl
Time cycling period
Measurement unit
Effluent
salinity(')
click for file
2
1
25 4
c:lplumes\VP plume 4
Effluent
temp
click for file
ffluent
conc
click for file

Diffuser: VP plume 4.vpp.db Ambient: c:\plumes\VP plume 4.001.db 1 Special Settings 1 Text Output I Graphical Output 1
Measurement
depth or height
(Current
speed
Current
direction
Ambient Inputs
Ambient Ambient
salinity(%) temperature
Background Pollutant Far
concentration decay rater) t
depth
constant
constant extrapolated extrapolated
Depth or Height depth depth depth depth depth
Extrapolation (sfc) r constant constant constant constant constant
Extrapolation (btm) extrapolated extrapolated constant extrapolated constant
Measurement unit ft - deg psu C ppm
UM3
Ambient file"
Filenaffre.
10
depth
cot
depth
constant
s-1
ft/s deg
'Far -field
diffusion coeff
depth
constant
constant
m0.671s2
0
2 0 0.0003
15 0 0 2 0 0.0003
Time -Series Files (optional) Borrow time -series files from project
c:lplumesWVP plume 4
Time -series filename_
Time increment (hrs)]
Cycling period
File measurement unii
click for file
click for file click for file click for file , click for file click for file click for file !click for file click for file

— [ _ = _ _ I 0
Diffuser: VP plume 4.vpp.db I Ambient: c:\plumes\VP plume 4.001.db
L-113 tidal pollutant buildup parameters
Channel width (m) 1 1
Special Settings 1 Text Output I Graphical Output I
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
10.16
Farfield increment (m) 1200
U M3 aspiration coefficient
I0.1
— Bacteria model on solar radiation input
t+ Mancini (1978) coliform model
C 301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
r 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
�PDS sfc. model heat transfer —
C Low a Medium
High
Graphics settings
— Style
C: 4-panel
C' dilution
( concentration
C custom
— Custom graph coords.
( Abscissa (x)
C Ordinate 1 (y)
( Ordinate 2 (y)
Custom variables
iI
Start case for graphs Max detailed graphs
NRFIELDIFRFIELD input variables
Text output settings
- Output medium
r: Text tab (ambient filled) r File (ambient filled)
Text tab (ambient as is) File (ambient as is)
I— Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Reset Default List I
Depth
Arab -cur
P-dia
Pohrtnt
Diatn
x-posn
y-posn
UM3 output each ?? steps 1100
UM3 maximum dilution reported I10000
— UM3 max vertical reversals
a to max rise or fall
C to second trap level
C to 2nd max rise or fall
rUM3 text output format
1+ Standard output
C Brief output
I— Stop on maximum dilution
Close panel

'.0a0 E. 01xle15:11 J )
Diffuser: VP plume 4.vpp.db 1Ambient: caplumesWP plume 4.001.db 1 Special Settings Text Output I Graphical Output
Bat t�is��a�1
Clear + I
Output options 1 Numerical only
/ UM3. 3/5/2009 10:41:39 AM
Case 1; ambient file c:\plumes\VP plume 4.001.db; Diffuser table record 1:
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal
m m/s-- deg --psu
0.0 0.61 0.0 10.0
2.438 0.61 0.0 10.0
3.048 0.61 0.0 10.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
Simulation:
Froude number:
Depth
Step (ft)
0 8.0
100 7.569
175 6.832
200 6.327
204 6.219
18.11
Amb-cur
(ft/s)
2.0
2.0
2.0
2.0
Amb-tem Amb-pol Decay Far-spd Far-dir Disprsn Density
C kg/kg s 1 m/s deg m0-.67/s2 _sigma-T
25.0 0.0
25.0 0.0
25.0 0.0
Ports Spacing AcuteMZ ChrncMZ
() (ft) (ft) (ft)
15.0 2.0 32.808 164.04
effleunt densi
P-dia Polutnt
(in) (PPm)
3.0 4.0
10.89 0.552
24.11 0.125
34.27 0.0762
2.0 36.63 0.0704 56.44
262 3.093 2.0
269 2.405 2.0
Const Eddy Diffusivity.
conc dilutn width
(PPm)
1.94E-2 205.0
count: 1
(m)
11.8
10:41:39 AM. amb fills: 2
124.2 0.0194 204.4
Farfield dispersion based
distnce time
(m) (hrs)
50.0 0.00393
(ppm)
0.0
0.0 0.61 0.0 0.0003 4.618
0.0 0.61 0.0 0.0003 4.618
0.0 0.61 0.0 0.0003 4.618
P-depth Ttl-flo Eff-sal Temp Polutnt
(ft) (MGD) (psu) (C) (ppm)
8.0 2.0 1.1 25.0 4.0
ty (sigma-T)-2.064; effleunt velocity 1.281(m/s);
Dilutn x-posn y-posn
( ) (ft) (ft)
1.0 0.0 0.0;
7.203 3.256 0.0;
31.78 17.24 0.0; merging;
52.14 30.01 0.0;
32.85 0.0; acute zone;
117.2 0.0; matched energy radial vel = 0.447m/s;
135.8 0.0; surface;
on wastefield width of 11.69 m
(s-1) (ft/s)(m0.67/s2)
0.0 2.0 3.00E-4

Y1 V
I pi
Diffuser: VP plume 4.vpp.db 1 Ambient: c:lplumesWVP plume 4.001.db 1 Special Settings
Help
Clear + 1
Clear all'
Clear'ra
Clear rb
Clear bal
Clear bbl
Clear gal
Clear gb1
CIr Verify'
— Style-
0
10
20
30
40
LPturneflevaron.
50
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
•
Text Output Graphical Output 1
0
10-
- Centerline
— Centerline
— Centerline
• Plume Bndry
• Plume Bndry
Plume Bndry
— Verification
Ambient Properties
20-
30-
40•
y
50
0 5 10 15 20 25 30 35 40 45 50
Density (sigma-T)
— Amb. density
— Amb. density
— Amb. density
• Plume density
x Plume density
• Plume density
— Verification
4-pI
✓ diln
(' con 100
• cus
Scale I
Thick J
To File I
Verify 1
South -North (it)
Ma View
SO—
60. --
40— - -- ,
0...»..'--
I I I
0 5 10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• 0utline
x 0uthne
• Outline
— Verification
1'000-
Plumes Dilution Prediction
900= ;
I I
800
700
I 1
600- _ • ,
500=
0
400 = - -
300— -• 4 a
I I I
100- - -
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
x Centerline
• Centerline
— Verification

cal 6I 0 ` LI
Diffuser: VP plume 4.vpp.db I Ambient: c:\plumes\VP plume 4.001.db 1 Special Settings' Text Output I Graphical Output 1
Project Ic:lplumes\VP plume 4
Notes:Columbia Diffuser With WWTP Flow = 2.0 mgd &
Ammonia = 4 mg'1 & Effluent Salinity = 1.1 psu
Ambient Velocity = 0.5 $/s & Salinity = 10 psu
— After run go to tab
�* Diffuser
C Ambient
C Special
Text
C Graphics
—Units Conversion
Convert data
C Label only
UM3
Model Configuration
C Brooks far -field solution
L Graph effective dilution
❑ Average plume boundary
Amb. current vector averaging
❑ Tidal pollution buildup
CO -Same -levels time -series input
— Case selection
(T Base or selected case
C Sequential, all ambient list
( Sequential, parse ambient
(- All combinations
Diffuser, Flow, Ming Zone Inputs
Port In/r
diameter
tin m
3
1Port (Vertical 1Hor
elevation l angle angle
ft deg deg
15
Num of Port nlr
ports spacing
ft s
0 15
Parameters for selected row I
Froude number
ER density fkg/mil
Port vel f m/sl
P-dia fml
0.0762
P-dia fin)
3.0
Case No.
1.0
I n/r
Time Series -Files (optional)
Time -series filename
n/r Acute Chronic Port
mix zone mix zone I depth
s ft ft
32.308 164.04
Port
depth
click for file
Time increment fhrsl
Time cuclino period
Measurement unit
Effluent
flow
Effluent Effluent
salinity(") temp temp lEfflueni
conc
MGD psu C
2 1.1
ppm
4
Borrow time -series from project: ic\plumes lliP plume 4
Effluent
flow
Effluent (Effluent
salinity(") temp
!Effluent
conc
click for file
click for file click for file
click for file

,(Y' Q I OI db L FBI
Diffuser: VP plume 4,vpp,db Ambient: c:\plumesWP plume 4.001.db 1 Special Settings 1 Text Output 1 Graphical Output 1
Ambient Inputs
Measureme
depth or height speed
Depth or Height l Th depth depth depth depth depth depth depth depth depth
Extrapolation (sfc) I 111 constant L: is istant constant constant constant constant constant constant constant
Extrapolation (btm) 1 I extrapolated extrapolated constant extrapolated constant constant extrapolated extrapolated constant
Measurement unit I ,- ;AI _AIM deg psu C ppm s•1 ftls deg m0.67/s2
OS
8
10
UM3
f Ambient file list
Imo_ Filename
0.5
0
0
10
10
25
25
0
0
0
0.5 0 0.0003
0.5 0 0.0003
Time -Series Files (optional) Borrow time -series files from project: lc: \plumes\VP plume 4
Time -series filename
Time increment (hrs) j
Cycling period
File measuren-ient uni�k
click for file
click for file click for file click for file click for file click for file click for file click for file click for file

elf r I o1
Diffuser: VP plume 4.vpp.db 1 Ambient: c:\plumes\VP plume 4.001.db
1113 tidal pollutant buildup parameters
Channel width (m)
Graphics settings
- Style
6' 4-panel
C' dilution
t - concentration
( custom
- Custom graph coords. -
Abscissa (x)
C' Ordinate 1 (y)
(' Ordinate 2 (y)
Custom variables
Start case for graphs Max detailed graphs
J
Special Settings 1 Text Output] Graphical Output 1
Additional model input
Diffuser port contraction coefficient 11
Light absorption coefficient
10.16
Farfield increment (m) _1200
UM3 aspiration coefficient
I0.1
- Bacteria model on solar radiation input
C: Mancini (1978) coliform model
( 301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
C 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
- PDS sfc. model heat transfer --
C Low Medium
C' High
INRFIELDIFRFIELD input variables
Text output settings
- Output medium
r: Text tab (ambient filled) C File (ambient filled)
C' Text tab (ambient as is) r File (ambient as is)
E Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Reset Default List I
Depth
Amb-cur
P-dia
Pohrtnt
Dilutn
x-posn
y-posn
UM3 output each ?? steps I
UM3 maximum dilution reported 1
UM3 max vertical reversals--
( to max rise or fall
C to second trap level
( to 2nd max rise or fall
- UM3 text output format
( Standard output
C' Brief output
100
10000
(- Stop on maximum dilution
Close panel I

0:1Egilpl6 01IEnlml J ) )
- Diffuser. VP plume 4.vpp.db I Ambient: c:\plumesWVP plume 4.001.db 1 Special Settings
ear tsxt��sp�a�
Clear + I Output options I Numerical only I
Text Output I Graphical Output I
/ UH3. 3/5/2009 10:17:15 AM
Case 1; ambient file c:\plumes\VP plume 4.001.db; Diffuser table record 1:
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal Amb-tem Amb-pol Decay Far-spd Far-dir Disprsn Density
m m/s deg psu C kg•ekg s-1 m/s deg m- : 6 7-/s2 - - sigma-T
0.0 0.152 0.0 10.0 25.0 0.0 0.0 0.152 0.0 0.0003 4.618
2.438 0.152 0.0 10.0 25.0 0.0 0.0 0.152 0.0 0.0003 4.618
3.048 0.152 0.0 10.0 25.0 0.0 0.0 0.152 0.0 0.0003 4.618
Diffuser table:
P-dia P-elev V-angle H-angle Ports Spacing AcuteMZ ChrncIZ P-depth Ttl-flo Eff-sal Temp Polutnt
(in) (ft) (deg) (deg) () (ft) (ft) (ft) (ft) (MGD) (psu) (C) (ppm)
3.0 2.0 15.0 0.0 15.0 2.0 32.808 164.04 8.0 2.0 1.1 25.0 4.0
Simulation:
Froude number: 18.11; effleunt density (sigma-T)-2.064; effleunt velocity 1.281(m/s);
Depth Amb-cur P-dia Polutnt Dilutn x-posn y-posn
Step (ft) (ft/s) (in) (ppm) () (ft) (ft)
0 8.0 0.5 3.0 4.0 1.0 0.0 0.0;
100 7.207 0.5 16.3 0.552 7.203 3.385 0.0;
128 6.721 0.5 24.25 0.317 12.54 5.607 0.0; merging;
196 3.102 0.5 99.24 0.0825 48.17 20.64 0.0; matched energy radial vel = 0.12m/s;
200 2.68 0.5 108.3 0.0762 52.14 22.24 0.0;
205 2.102 0.5 120.6 0.069 57.57 24.43 0.0; surface;
Const Eddy Diffusivity. Farfield dispersion based on wastefield width of 11.60 m
conc dilutn width distnce time
(ppm) (m) (m) (hrs) (ppm) (s-1) (ft/s)(m0.67/s2)
6.86E-2 57.9 13.69 50.0 0.0776 0.0 0.0 0.5 3.00E-4
count: 1
10:17:15 AM. amb fills: 2

Diffuser: VP plume 4.vpp.db1 Ambient: c:\plumes\VP plume 4.001.db I Special Settings! Text Output Graphical Output
Help I
Clear + I
Clear alll
Clear rb l
Clear bal
Clear bbl
Dear gal
Clear gbl
Clr Verify'
—Style
C: 4•pl
• d1n
con 100
• cus
0
Plume Elevation
10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Centerline
— Centerline
— Centerline
• Plume Bndry
x Plume Bndry
• Plume Bndry
— Verification
1?
0
10
0 ?
y
30
40
50
0
Ambient Properties
10 15 20 25 30 35 40 45 50
Density (sigma-T)
— Amb. density
— Amb. density
— Amb. density
• Plume density
x Plume density
• Plume density
— Verification
Scale I
Thick
To File
Verify I
South -North (ft)
80
60
.0
20
0
- 20
-40
-60
- 80
LPlaa Yie_1w d
10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plum path
• 0utline
x Outfne
• Outline
— Verification
1.000 _
Plumes Dilution Prediction,
900 = - -
700=
600 ------ --- -
c - 1
500---- - -- --- - -1
400 = - -
300 = -
100= a ;- +,-
0 5 10 15 20 25 30 35
Horiz. Distance from Source (ft)
40 45 50
— Average
— Average
— Average
• Centerline
x Centerline
• Centerlin e
— Verification

talk 01 `gl
Diffuser: VP plume 4,vpp.db 1 Ambient: c:\plumes\VP plume 4.001.db I Special Settings I Text Output I Graphical Output I
Project
Ic:lplumesVVP plume 4
Notes:Columbia Diffuser With WWTP Flow = 0.6 mgd &
Ammonia = 4 mg.11 & Effluent Salinity = 1.1 psu
Ambient Velocity = 2 Ns & Salinity = 10 psu
f Port In/r
I diameter
Port
elevation
— After run go to tab -
Diffuser
Ambient
C Special
C Text
C Graphics
— Units Conversiori
Ci Convert data
t' Label only
UM3
Model Configuration
Brooks far -field solution
L, Graph effective dilution
C] Average plume boundary
❑ Amb. current vector averaging
❑ Tidal pollution buildup
❑ Same -levels time -series input
— Case selection
C' Base or selected case
✓ Sequential, all ambient list
(' Sequential, parse ambient
✓ All combinations
Diffuser, Flow, Mixing Zone Inputs
Vertical Hot Nurn of Or
angle angle ports 1Port
spacing
n/r
In/r (Acute (Chronic
mix zone mix zone
Port Effluent
depth flow
Effluent
salinity(x)
Effluent
temp
Effluent
conc
in m ft deg deg
3 2 15
0 15
ft
Parameters for selected row I
Froude number
Eff densit k•/m3
Port vel m/s
P-dia f m
0.0762
P-dia in
3.0
Case No.
1.0
Time Series -Files (optional)
s
Port
depth
ft ft ft
32.S0S 164.04
MGD psu C
S 0.6 1.1
Borrow time -series from project:
Effluent
flow
Time -series filename click for file
Time increment f hrsl
Time cycling period
Measurement unit
Effluent
salinity(x)
click for file
ppm
,5
4
caplumesAVP plume 4
Effluent
temp
Effluent
conc
click for file
click for file

12Ife6A0g 5iI� )
Diffuser: VP plume 4.vpp.db
Ambient: c:lplumesWP plume 4.001.db I Special Settings 1 Text Output 1 Graphical Output 1
Depth or Height _
Extrapolation (sfc)'
Extrapolation (btm)
_Measurement unit
UM3
Ambient Inputs
Ambient
temperature.
depth depth depth
constant constant constant
extrapolated extrapolated constant
deg psu
Backgro �.
conce.
..
Pollutant
decay rater).
•
Far -field
'11111
current speed icrarrent rt
depth depth depth depth depth depth
constant constant_ constant constant constant constant
extrapolated constant constant extrapolated extrapolated constant
C ppm s•1 ftls deg m0.671s2
o z u
8
10
0
25 0 0 2 0 0.0003
10 25
0
0 0.0003
Time -Series Files (optional) Borrow time -series files from project: ic:\plumesWP plume 4
Time -series filename',
Tirne increment (hrs)I
Cycling period
File measurement IA
click for file
click for file click for file click for file t click for file click for file !click for file i click for file !click For file

Diffuser. VP plume 4.vpp.db 1 Ambient: c:\plumesWP plume 4.001.db
Special Settings 1 Text Output 1 Graphical Output I
1.M13 tidal pollutant buildup parameters Additional model input
Channel width (m)
100
Diffuser port contraction coefficient
Light absorption coefficient
I0-16
Farfield increment (m) -- -- -1200
UM3 aspiration coefficient
(o-1
Bacteria model on solar radiation input
Mancini (1978) coliform model
301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
PDS sfc. model heat transfer
LowMedium
C. High
Graphics settings
— Style
;- 4-panel
C' dilution
( concentration
C custom
— Custom graph coords. —
G' Abscissa (x)
Ordinate 1 (y)
C Ordinate 2 (y)
Custom variables
Start case for graphs Max detailed graphs
NRFIELD/FRFIELD input variables
Text output settings
— Output medium
0" Text tab (ambient filled)
C Text tab (ambient as is)
(' File (ambient filled)
C File (ambient as is)
r Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Reset Default List I
Depth
Amb-cur
P-dia
Pohrtnt
Mum
x-posn
y-posn
UM3 output each ?? steps 1100
UM3 maximum dilution reported 110000
r UM3 max vertical reversals--
to max rise or fall
<' to second trap level
C to 2nd max rise or fall
_ UM3 text output format
Standard output
C Brief output
E Stop on maximum dilution
Close panel I

0:1 all .01 E.
0
ci]
Diffuser VP plume 4.vpp.db l Ambient c.\plumesWVP plume 4.001.db 1 Special Settings Text Output Graphical Output
dear text�ispla�
Clear + I Output options I Numerical only
/ UM3. 3/5/2009 10:50:45 AM
Case 1; ambient file c:\plumes\VP plume 4.001.db; Diffuser table
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal Amb-tem
m m/s deg - psu C
0.0 0.61 0.0 10.0 25.0
2.438 0.61 0.0 10.0 25.0
3.048 0.61 0.0 10.0 25.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
Simulation:
Froude number:
Depth
Step (ft)
0 8.0
100 7.791
200 7.135
222 6.868
234 6.695
300 4.524
307 4.081
321 2.988
328 2.317
Outside chronic
•
Ports
()
15.0
record 1:
Amb-pol Decay Far-spd Far-dir Disprsn Density
kg/kg--- s-1-m/s deg m0.67/s2 sigma-T
0.0 0.0 0.61 0.0 0.0003 4.618
0.0 0.0 0.61 0.0 0.0003 4.618
0.0 0.0 0.61 0.0 0.0003 4.618
Spacing AcuteHZ ChrncMZ P-depth Ttl-flo
(ft) (ft) (ft) (ft) (HGD)
2.0 32.808 164.04 8.0 0.6
5.433; effleunt density (sigma-T) -2
Amb-cur P-dia Polutnt Dilutn x-posn
(ft/s) (in) (ppm) () (ft)
2.0 3.0 4.0 1.0 0.0
2.0 6.572 0.552 7.203 2.762
2.0 17.26 0.0762 52.14 22.66
2.0 21.43 0.0493 80.61 33.07
2.0 24.13 0.0389 102.2 40.38
2.0 70.31 0.0105 377.7 142.9
2.0 80.34 0.00916 433.9 164.4
2.0 105.3 0.00694 572.5 217.5
2.0 120.6 0.00604 657.6 250.2
zone
10:50:45 AM. amb fills: 2
Ef f -sal
(psu)
1.1
Temp Polutnt
(C) (ppm)
25.0 4.0
064; effleunt velocity 0.384(m/s);
y-posn
(ft)
0.0;
0.0;
0.0;
0.0; acute zone;
0.0; merging;
0.0;
0.0; chronic zone;
0.0; matched energy radial vel = 0.447m/s;
0.0; surface;

Q
: e ' i I o
Diffuser: VP plume 4.vpp.db 1 Ambient: c:\plumesWP plume 4.001.db 1 Special Settings' Text Output
Help I
Clear + I
Clear all
Dear ra'
Clear rb l
Clear bal
Clear bbl
Clear gal
Clear gbl
CIr Verify
— Style
0
10
Plume Elevation
50,.
0 5 10 15 20 25 30 35 40 4E E0
Horiz. Distance from Source (ft)
Graphical Output
— Centerline
— Centerline
— Centerline
• Plume Bndry
x Plume Bndry
• Plume Bndry
— Verification
4-pl!
• diln'
• con; 100
• cusl
Ram .View.
Scale I
Thick
To File
Verify
South -North (it)
60— ---------
40—
20—` -
0 1�4'-w♦ ♦ • 1 ♦ 1
— 20---- ---
-40— -
-60— -
- 80 -
• . $
10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outfine
• 0utfne
— Verification
Ambient Properties
10------
20
eer
30
40
0 5 10 15 20 25 30 35 40 45 50
Density (sigma-T)
— Amb. density
— Amb. density
— Amb. density
• Piume density
x Plume density
• Plume density
— Verification
0
0
Plumes Dilution Prediction
1.000 _
900=---- -- ---
S00- ;
700
600 -
500
400
300 -
200=--- - -- ---
100
0
I see eee:
eeee
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
x Centerline
Centerline
— Verification

0I»IEI
Diffuser: VP plume 4.vpp.db I Ambient: c:tplumesWVP plume 4.001.db Special Settings Text Output I Graphical Output I
Project
Jc:\plumesVVP plume 4
Notes:Columbia Diffuser With WWTP Flow = 2 mgd &
TRC = 17 ppb & Effluent Salinity = 1.1 psu
Ambient Velocity = .5 ft's & Salinity = 10 psu
— After run go to tab
( Diffuser
✓ Ambient
C Special
t' Text
✓ Graphics
Units Conversion
( Convert data
{' Label only
G:
UM3
Model Configuration
❑ Brooks far -field solution
❑ Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
❑ Tidal pollution buildup
❑ Same -levels time -series input
— Case selection
C Rase or selected case
✓ Sequential, all ambient list
( Sequential, parse ambient
✓ All combinations
Diffuser, Flow, Mixing Zone Inputs
Port n/r
diameter
in m
Port Vertical Hor
elevation angle angle
ft deg deg
1Num of
ports
Port
spacing
ft
n/r n/r lAcute 1Chronic
mix zone mix zone
s s ft ft
Port
depth
ft
Effluent
flow
Effluent
salinityr)
Effluent !Effluent
temp conc
MGD psu
15
5
Parameters for selected row I Time Series -Files (optional)
Froude number
Eff density (kq/m31
Port vel (m/s]
P-dia fml
0.0762
P-dia fin]
3.0
Case No.
1.0
32.308 164.04
Borrow time -series from project:
23 i
lc:\plumesWP plume 4
Time -series filename
Time increment (his]
Port
depth
MIMS—
Time cycling period
Measurement unit
Effluent
flow
Effluent
salinity(')
lEffluent
temp
!Effluent
conc
click for file
click for file
click for file
click for file

:[ir:
0
ail
Diffuser: VP plume 4.vpp.db Ambient: c:\plumes\VP plume 4.O01.db 1 Special Settings 1 Text Output' Graphical Output I
Measurement
depth or height
Depth or Height
Ambient Inputs
Current
speed
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit ft
UM3
Ambient file list
Filename
depth depth depth
constant constant constant
extrapolated extrapolated constant
ft!s deg psu
depth depth
constant constant
extrapolated constant
C
0 0.5 0 10 25
8 0.3 : 0 10 25
10
depth depth
constant constant
ppb
0
0
depth
depth
constant constant
constant extrapolated extrapolated constant
s-1 ftls deg m0.67/s2
0 0.3
0 0.0003
0.5
0.0603
Time -Series Files (optional) Borrow time -series files from project:
Ic:\plumes\VP plume 4
Time -series filename
Time increment (hrs) _
Cycling period
File measurement unit_ •
II MI
r
click for file click for file click for file click for file click for file click for file click for file click for file click For file

Diffuser: VP plume 4.vpp.db 1 Ambient: c:\plumes\VP plume 4.001.db
L-113 tidal pollutant buildup parameters
Channel width (m)
Special Settings 1 Text Output I Graphical Output 1
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
Farfield increment (m)
1
(0-16
1200
UM3 aspiration coefficient
Bacteria model on solar radiation input
G Mancini (1978) coliform model
301(h) TSD (1994) coliform (for saltwater, Eqn B-68)
(' 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
— PDS sfc. model heat transfer
C Low ( Medium i High
Graphics settings
- Style
a' 4-panel
C dilution
— Custom graph coords. -
( Abscissa (x)
C Ordinate 1 (y)
C Ordinate 2 (y)
Start case for graphs
C concentration
C custom
Custom variables
Max detailed graphs
NRFIELD/FRFIELD input variables
Text output settings
-- Output medium
Text tab (ambient filled)
r Text tab (ambient as is)
( File (ambient filled)
r File (ambient as is)
I— Show changed Diffuser and Ambient tab variables only
Selection List
Reset Default List I
Selected Variables
Depth
Amb-cur
P-
Pohltnt
Dilutn
x-posn
y-posn
UM3 output each ?? steps 1 100
UM3 maximum dilution reported
UM3 max vertical reversals-
(;" to max rise or fall
� to second trap level
( to 2nd max rise or fall
-- UM3 text output format —
t� Standard output
in Brief output
►l0000
(— Stop on maximum dilution
Close panel I

Airy
E.
}3it 0[ Eb
Diffuser VP plume 4.vpp.db 1 Ambient: c \plumesWP plume 4.001.db I Special Settings Text Output I Graphical Output
[Clear text displa�
....................................
Clear + I Output options I Numerical only
Step
0
100
128
196
200
205
Const
/ UM3. 3/5/2009 1:20:46 PM
Case 1; ambient file c:`plumes\VP plume 4.001.db; Diffuser table record 1:
Ambient Table:
Depth Amb-cur
m/s
0.0 0.152
2.438 0.152
3.048 0.152
Amb-dir
deg
0.0
0.0
0.0
Diffuser table:
P-dia P-elev \-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
Simulation.
Froude number:
Depth
(ft)
8.0
7.207
6.721
3.102
2.68
Eddy Diffusivity.
conc dilutn width
(PPb) (m)
0.2917 57.9 13.69
count: 1
1:20:46 PH. amb fills: 2
Amb-sal
psu
10.0
10.0
10.0
Amb-tem Amb-pol
C kg/kg
25.0 0.0
25.0 0.0
25.0 0.0
Ports Spacing AcuteHZ ChrncMZ
() (ft) (ft) (ft)
15.0 2.0 32.808 164.04
Decay Far-spd Far-dir Disprsn Density
s-1 m/s deg-m 0-: 6 7-/s-2 sigma-T
0.0 0.152 0.0 0.0003 4.618
0.0 0.152 0.0 0.0003 4.618
0.0 0.152 0.0 0.0003 4.618
P-depth Ttl-f to
(ft) (MGD)
8.0 2.0
Ef f -sal
(psu)
1.1
Temp Polutnt
(C) (ppb)
25.0 17.0
18.11; effleunt density (sigma-T)-2.064; effleunt velocity 1.281(m/s);
Amb-cur P-dia Polutnt Dilutn
(ft/s) (in)
0.5 3.0
0.5 16.3
0.5 24.25
0.5 99.24
0.5 108.3
0.5 120.6
Farf iel
distnce
(m)
50.0
(PPb) ()
17.0 1.0
2.347 7.203
1.348 12.54
0.351 48.17
0.324 52.14
0.293 57.57
d dispersion based
time
(hrs) (ppb)
0.0776 0.0
x-posn y-posn
(ft) (ft)
0.0 0.0;
3.385 0.0;
5.607 0.0; merging;
20.64 0.0; matched energy radial vel = 0.12m/s;
22.24 0.0;
24.43 0.0; surface;
on vastefield width of 11.60 m
(s-1) (ft/s)(m0.67/s2)
0.0 0.5 3.00E-4

ritil QJ
Diffuser: VP plume 4.vpp.db Ambient: c:\plumes\VP plume 4.001.db 1 Special Settings Text Output Graphical Output
Help
Clear +
Clear all'
�Teairai
Clear rb I
Clear ba)
Clear bbl
Clear gal
Clear gb)
Clr Verify'
10
— 20
-5.
0
3
50
0
Style
4-PI
C din
✓ con 100
Plume Elevation
— Centerline
— Centerline
— Centerline
• Plume Bndry
. Plume Bndry
• Plume Bndry
— Verification
10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
Ambient Properties
10-
20— -,
42)
30— -�
<` cus
s0- -,
1
40
Scale
Thick I
To File I
Verify I
South -North (ft)
- 40
-60
- S0
Plan View
ir
10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
• Outline
• O utlin
— Verification
40-
0 5 10 15 20 25 30 35 40 45 50
Density (sigma-T)
1.000 _
Plumes Dilution Prediction
400- *- -
300- �- 1,
1
200: __ _ _•_-__.I _ _--1
-
I I 1
100 - • T.1 _ -1
1
— Amb. density
— Amb. density
— Amb. density
• Plume densiity
. Plume density
• Plume density
— Verification
0:1 t.
0 5 10 15 20 25 30 35 40
Horiz. Distance from Source (ft)
,
45
50
— ;rverage
— Average
— Average
• Centerlin e
Centerlin e
• Centerline
— Verification

i6 @
811)
}
Diffuser: VP plume 4.vpp.db 1 Ambient: c:\plumes\VP plume 4.O01.db 1 Special Settings' Text Output 1 Graphical Output I
Project
Ic:\pinmes\VP plume 4
Notes:Columbia Diffuser With WWTP Flow = 2 mgd &
TRC = 17 ppb & Effluent Salinity = 1-1 psu
Ambient Velocity = 2 ft's & Salinity = 10 psu
— After run go to tab -
Diffuser
C Ambient
Special
C Text
t~ Graphics
-Units Conversion
( Convert data
( Label only
UM3
Model Configuration
Brooks far -field solution
L Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
❑ Tidal pollution buildup
D Same -levels time -series input
— Case selection
R Base or selected case
( Sequential, all ambient list
C Sequential, parse ambient
C All combinations
Diffuser, Flow, Mixing Zone Inputs
Port In/r
diameter
,I in m
3
Port Vertical
elevation angle
ft deg deg
. 15
I H or
angle
Num of n.r
ports 1Port
spacing
ft
15
I n/r In/r lAcute Chronic Port
mix zone mix zone depth.
s s ft ft ft
32.SOS 164.04
Parameters for selected row
Froude number
Eff density fk./m31
Port vel f misl
P-dia fml
0.0762
P•dia fin
3.0
Case No.
1.0
Time Series -Files (optional)
Effluent
flow
MGD
Effluent
salir-iity(xl
psu
2 1.1
Effluent
temp
C
Effluent
conc
25 1-
Borrow time -series from project: lc: \plumes\VP plume 4
Port
depth
Effluent
flow
Effluent
salinityM
Effluent
temp
Effluent
conc
Time -series filename
Time increment lhrsl
Time cycling period
Measurement unit
dick for file
click for file
click for file
click for file
click for file

alQE. !OXLrI 0
Diffuser. VP plume 4.vpp.db Ambient: c:\plumes\VP plume 4.001.db I Special Settings I Text Output I Graphical Output I
Depth or Height
Extrapolation (sfc)
Extrapolation (btm)
Measuren-ient unit
UM3
Measurement
depth or height
Current
speed
depth
constant
extrapolated
ft?s
8 2
10
Ambient Inputs
depth
constant
extrapolated
deq
depth depth
constant constant
constant extrapolated
psu C
0
10 25
10 25
depth
constant
constant
ppb
depth depth depth depth
constant constant constant constant
constant extrapolated extrapolated constant
s-1 ft/s deg m0.67ls2
0 0
0 0
0 0.0003
0 0.0003
Time -Series Files (optional)
Borrow time -series files from project: lc: \plumesWP plume 4
Time -series filename w click for file € click for file click for file click for file click for file click for file click for file click for file click for file
Time increment (hrs)
Cycling period
File measurement r.riii IF
r

0
Diffuser: VP plume 4,vpp.db 1 Ambient c:\plumes\VP plume 4,001,db
I:11I3 tidal pollutant buildup parameters
Channel width (m)
100
Graphics settings
Special Settings 1 Text Output 1 Graphical Output 1
Additional model input
Diffuser port contraction coefficient
11
Light absorption coefficient
10.16
Farfield increment (rn) 1200
UM3 aspiration coefficient
0.1
— Bacteria model on solar radiation input
C: Mancini (1978) coliform model
C 301(h) TSD (1994) coliforrn (for saltwater, Eqn B-68)
C 301(h) TSD (1994) enterococcus (for saltwater, Eqn B-E9)
- PDS sfc. model heat transfer
C Low Mediuni
C High
Style
C- 4-panel
f " dilution
C concentration
C custom
— Custom graph coords. —
C•' Abscissa (x)
Ordinate 1 (y)
C Ordinate 2 (y)
Start case for graphs
Custom variables
I�1
Max detailed graphs
1`-RF'IELDJVR}lELD input variables
Text output settings
Output medium
{: Text tab (ambient filled) C" File (ambient filled)
C Text tab (ambient as is) C File (ambient as is)
r Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
J
Reset Default List I
Depth
Amb-cur
P-dia
Polutnt
Du
x-posn
y-posn
UM3 output each ?? steps 11C1IQ
LIM3 maximum dilution reported 110000
UM3 max vertical reversals --
to max rise or fall
to second trap level
to 2nd max rise or fall
UM3 text output format
r: Standard output
C Brief output
I Stop on maximum dilution
Dose panel I

*lfi ):1101glm1ml J
Diffuser. VP plume 4.vpp.db 1 Ambient: cAplumes\VP plume 4.001.db 1 Special Settings Text Output 1 Graphical Output 1
Clear + I Output options I Numerical only I
��ear text�rspl
/ UM3. 3/5/2009 1:30:35 PM
Case 1; ambient file c:\plumes\VP plume 4.001.db; Diffuser table record 1:
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal Amb-tem
m/s deg psu C
0.0 0.61 0.0
2.438 0.61 0.0
3.048 0.61 0.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
Simulation:
Froude number:
Depth
Step (ft)
0 8.0
100 7.569
175 6.832
200 6.327
204 6.219
18.11
Amb-cur
(ft/s)
2.0
2.0
2.0
2.0
2.0
262 3.093 2.0
269 2.405 2.0
Const Eddy Diffusivity.
conc dilutn width
(ppb) (m)
8.24E-2 205.0 11.8
count: 1
1:30:36 PM. amb fills: 2
3.0 17.0 1.0
10.89 2.347 7.203
24.11 0.531 31.78
34.27 0.324 52.14
36.63 0.299 56.44
108.2 0.0949 178.0
124.2 0.0826 204.4
Farfield dispersion based
distnce time
(m) (hrs) (ppb)
50.0 0.00393 0.0
10.0 25.0
10.0 25.0
10.0 25.0
Amb-pol Decay Far-spd Far-dir Disprsn Density
kg/kg s-1 mzs deg m0.67/s2- sigma-T
0.0 0.0 0.61 0.0 0.0003 4.618
0.0 0.0 0.61 0.0 0.0003 4.618
0.0 0.0 0.61 0.0 0.0003 4.618
Ports Spacing AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal
() (ft) (ft) (ft) (ft) (MGD) (psu)
15.0 2.0 32.808 164.04 8.0 2.0 1.1
; effleunt density (sigma-T)-2.064; effleunt
P-dia Polutnt Dilutn x-posn y-posn
(in) (ppb) () (ft) (ft)
0.0 0.0;
3.256 0.0;
17.24 0.0;
30.01 0.0;
32.85 0.0; acute
117.2 0.0; matched energy
135.8 0.0; surface;
on wastefield width of 11.69
Temp Polutnt
(C) (ppb)
25.0 17.0
velocity 1.281(m/s);
merging;
(s-1) (ft/s)(m0.67/s2)
0.0 2.0 3.00E-4
z one ;
radial vel = 0.447m/s;

Dittmar: VP plume 4.vpp.db Ambient: c:\plumes\VP plume 4.001.db I Special Settings I Text Output Graphical Output l
Help
Clear + I
Clear all I
CINLig
Clear rb
Clear bal
Clear bbl
Clear gal
Clear gbl
CIr Verify)
— Style --
0
Plume Elevation
omMft2'24-
10------
40 -•
50
•
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Centerline
— Centerline
— Centerline
• Plume Bndr},
x Plume Bndry
= Plume Bndry
— Verifcatic n
; 4-pl
diln
✓ con 100
<` cus
•
f
Scale
Thick
To File I
Verify I
South -North (it)
80----
60=---
40--
20—
Plan View
er
-20— i- • -
I
— — —
�.-—_--�-—— ▪ _____—
0 —
-50— —
0 5 10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outline
• Outline
— Verification
0
Ambient Properties
•••4
10
20 —
ra
30-
40-
50
0
10 15 20 25 30 35 40 45 50
Density (sigma-1)
— Amb. density
— Amb. density
— Amb. density
• Plume density
x Plume density
• Plume density
— Verification
0
0
5
1,000 _
Plumes Dilution Prediction
900er
700 - _ 1- ,
600- --; -
500- - - —
400---- -- - *- •-
I I I I I I I
300--_--•--_- ---- ------- 1- .
= I 1 I
200— h1 I----• -
I
100= •- ,
- —
0 5 10 15 20 25 30 35 • 40 45 50
Horiz. Distance from Source (ft)
— Averace
— Averace
— Average
• Centerline
x Centerlin e
• Centerlin e
— Verification

Qik 01x1IA111 0 ) )
Diffuser: VP plume 4.vpp.db
1 Ambient: c:\plumes\VP plume 4.001.db I Special Settings Text Output 1 Graphical Output I
Project
Ic:lplumes\VP plume 4
Notes:Columbia Diffuser With WWI? Flow = _6 mgd &
TRC =17 ppb & Effluent Said' = 1.1 psu
Ambient Velocity = .5 ft's & Salinity = 10 psu
Ambient file
Filename Case
Diffuser, Flow, Xticing Zone Inputs
— After run go to tab
6 Diffuser
C Ambient
C Special
(' Text
< Graphics
—Units Conversion--
6 Convert data
(' Label only
UM3
Model Configuration
Brooks far -field solution
❑ Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
❑ Tidal pollution buildup
❑ Same -levels time -series input
— Case selection
6 Base or selected case
( Sequential, all ambient list
C Sequential, parse ambient
All combinations
Port n/r
diameter
in
!Port Vertical 1Hor Num of Port ln/r
elevation angle angle ports spacing
ft deg deg ft s
I n/r In/r
s s
Acute Chronic Port
mix zone mix zone depth
ft ft ft
Effluent Effluent x, Effluent
flow salinity(' temp
MGD psu C
Effluent,
conc
3
2 15 0 15 2
32.808 164.04
8 0.6 1.1 25 17
Parameters for selected row 1
Froude number
Elf density fkg/m31
Port vel (m/s)
P•dia (m)
0.0762
P-dia fin)
3.0
Case No.
1.0
Time Series -Files (optional) Borrow time -series from project:
Time -series filename
Port
depth
Effluent
flow
Effluent
salinity(x)
click for file
Time increment fhrs)
Time cycling period
M easutemerlt_unit..___
click for file click for file
c: \plumes\VP plume 4
Effluent
temp
Effluent
conc
click for file click for file

17510a1k [01A1[a
Diffuser: VP plume 4. upp.db Special Settings 1 Text Output I Graphical Output 1
Depth or 1-74111111111111
ExtrapolationW-1
Extrapolation (btm)
Measurement unit
UM3
Ambient Inputs
ack round
ation
depth depth 1 depth
constant constant constant
extrapolated , extrapolated constant
deg psu
0
10
depth depth
constant constant
extrapolated constant
10
ppb
0
Pollutant
decay rate[]
depth
constant
constant
s-1
----111111111111
Far -field cF
current speed
depth
constant
extrapolated
Vs
0 0.5
depth constant- I dcoepntshtant extrapolated constant
deg m0.67/s2
0
0.0003
0
0.3
0
0.0003
Time -Series Files (optional)
Borrow time -series files from project:
lc: \ plumes WP plume 4
Time -series filenamel
Time increment (Firs]
Cycling period
411measurement unit
click for file click for file click for file click for file jclick for file click for file
click for file click for file

Diffuser: VP plume 4.vpp.db Ambient: c:\plumes\VP plume 4.001.db
L110 tidal pollutant buildup parameters
Channel width (m)
100
Special Settings Text Output 1 Graphical Output 1
Additional model input
Diffuser port contraction coefficient 11
Light absorption coefficient
10.16
Farfield increment (m) - 1200
UM3 aspiration coefficient
lo.1
Bacteria model on solar radiation input
Mancini (1978) coliform model
( 301(h) TSD (1994) coliform (for saltwater. Eqn B-69)
C" 301(h) TSD (1994) enterococcus [for saltwater, Eqn 8.69)
— PDS sfc. model heat transfer
i Low Medium
( High
Graphics settings
Style
17i. 4•panel
( dilution
concentration
custom
— Custom graph coords.
Abscissa (x)
( Ordinate 1 (y)
C- Ordinate 2 (y)
Custom variables
Start case for graphs Max detailed graphs
NRFIELDIFRFIELD input variables
Teat output settings
Output medium
s� Text tab (ambient filled) C File (ambient filled)
C Text tab (ambient as is) C File (ambient as is)
E Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Reset Default List 1
Depth
Arab -cur
P-dia
Polutnt
Dilum
a -posh
V-posn
UM3 output each ?? steps
I100
Ut\13 maximum dilution reported
10000
UM3 max vertical reversals
C% to max rise or fall
C to second trap level
( to 2nd max rise or fall
UM3 text output format
C: Standard output
C' Brief output
I— Stop on maximum dilution
Close panel I

*101xIENmI
Diffuser. VP plume 4.vpp.db I Ambient c:\plumes\VP plume 4.001.db 1 Special Settings f Text Output Graphical Output 1
Clear text display Clear + Output options I Numerical only I
/ M. 3/5/2009 1:49:49 PM
Case 1; ambient file c:\plumes\VP plume
Ambient Table:
Depth Amb-cur Amb-dir
m_ - m/s deg
0.0 0.152 0.0
2.438 0.152 0.0
3.048 0.152 0.0
Amb-sal
psu
10.0
10.0
10.0
4.001.db; Diffuser table record 1:
Amb-tem
C
25.0
25.0
25.0
Amb-pol
kg/kg
0.0
0.0
0.0
Diffuser table:
P-dia P-elev V-angle H-angle Ports Spacing AcutelZ ChrncMZ
(in) (ft) (deg) (deg) () (ft) (ft) (ft)
3.0 2.0 15.0 0.0 15.0 2.0 32.808 164.04
Simulation:
Froude number:
Depth
Step (ft)
0 8.0
100 7.448
168 6.639
200 5.87
251 2.985
259 2.203
Const Eddy Diffusivity.
conc dilutn width
(ppb) (m)
0.10026 168.4 13.55
count: 1
1:49:49 PM. amb fills: 2
Decay Far-spd
-1 m/s
0.0 0.152
0.0 0.152
0.0 0.152
P-depth Ttl-f to
(ft) (HGD)
8.0 0.6
Far-dir
deg
0.0
0.0
0.0
Ef f -sal
(psu)
1.1
5.433; effleunt density (sigma-T)-2.064; effleunt velocity
Amb-cur P-dia Polutnt Dilutn x-posn y-posn
(ft/s) (in) (ppb) () (ft) (ft)
0.5 3.0 17.0 1.0 0.0 0.0;
0.5 11.52 2.347 7.203 2.244 0.0;
0.5 24.24 0.61 27.67 6.339 0.0; merging;
0.5 39.23 0.324 52.14 10.9 0.0;
0.5 102.8 0.118 143.1 28.54 0.0; matched energy
0.5 120.3 0.101 167.7 33.33 0.0; surface, acute
Farfield dispersion based on wastefield width of
distnce time
(m) (hrs) (ppb) (s-1) (ft/s)(m0.67/s2)
50.0 0.0726 0.0 0.0 0.5 3.00E-4
Disprsn Density
m0 67/s2---sigma-T
0.0003 4.618
0.0003 4.618
0.0003 4.618
Temp Polutnt
(C) (ppb)
25.0 17.0
0.384(m/s);
radial vel = 0.112m/s;
zone;
11.59 m

Diffuser. VP plume 4.vpp-db 1 Ambient: c:\plumes\VP plume 4.001.db 1 Special Settings] Text Output
Help I
Clear + I
Clear ad
Clear rat
Clear rb I
Dear bal
Clear bbl
Clear gal
Clear gbl
Clr Verif
Style —
0
Plume Elevation
10-
-20
11
30
40
•
50
0
10 15 20 25 30 35 40 45
Horiz. Distance from Source (ft)
50
Graphical Output
— Centerline
— Centerline
— Centerline
• Plume Bndry
• Plume Bndry
• Plume Bndry
— Verification
0
, Ambient Properties
t44•
10---
.. 70
m
30
40
50..,��„,„,,,,,
0 5 10 15 20 25 30 35 40 45 50
Density (sigma-T)
— .Amb. density
— Amb. density
— Amb. density
Plume density
• Plume density
• Plume density
— Verification
4-pl
{� diln
con 100
cus
Scale
Thick I
To File I
Verify I
South -North (It)
60—
-t0
Plar► View
T.
•
0
5 10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outline
▪ Outline
— Verification
Plumes Dilution Prediction
1.000 _
900: -_- -;- -;
8O0
Sao---------------------;--- .----,----,
600_
oc
O
509
0_
409
300
200
100
0 5 10 15 20 25 30 35 40 45
Horiz. Distance from Source (ft)
50
— Average
— Average
— Average
• Centerline
x Centerline
• Centerline
— Verification

[ $'
�xI rn
�I J
Diffuser: VP plume 4.vpp.db I Ambient: c:Iplumes\VP plume 4.001.db 1 Special Settings Text Output I Graphical Output
Project Ic:lplumesliP plume 4
Notes:Cohimbia Diffuser With WWTP Flow _ .6 mgd &
TRC =17 ppb & Effluent Salinity = 1.1 psu
Ambient Velocity = 2 ft's & Salinity = 10 psu
r After run go to tab
Diffuser
C Ambient
C Special
C Text
C Graphics
-Units Conversion
f: Convert data
Label only
UM3
Model Configuration
C Brooks far -field solution
❑ Graph effective dilution
❑ Average plume boundary
❑ Amb. current vector averaging
❑ Tidal pollution buildup
E Same -levels time -series input
— Case selection
a Base or selected case
C Sequential, all ambient list
C Sequential, parse ambient
C All combinations
Diffuser, Flow, Mixing Zone Inputs
Port
diameter
n/r
I
Port
I elevation
Vertical
I angle
1Hor angle 'ports-
Num of
1Port
spacing
nir
I
n/r
n/r
Acute
mix zone
Chronic Port
mix zone depth
Effluent
flow
in
3
m
ft
deg deg
15
15
ft
s
s
s
ft ft ft
32.808 164.04
Effluent Effluent (Effluent
salinityf'j temp conc
MGD psu C:
3 0.6 1.1 25 17
Parameters for selected row I
Froude number
E ff density f kq/m31
Port vel fmisl
P-dia fml
0.0762
P-dia fin)
3.0
Case No.
1 0
Time Series -Files (optional)
111111111
Time -series filename
click for file
Time increment fhrsl
Time cycling period
Measurement unit
Borrow time -series from project: lc:\plumes\VP plume 4
Effluent
flow
click for file
Effluent
salinity[')
click for file
(Effluent !Effluent
temp conc
click for file click for file

I tI- *►eIg►7,Ed i
Diffuser: VP plume 4.vpp.db Ambient: c:lplumes`VP plume 4.001.db I Special Settings 1 Text Output I Graphical Output I
Measurement
depth or height
Depth or Height
Extrapolation (sfc)
Current
speed
depth
constant
Extrapolation (btm)
Ambient Inputs
bient
Far-fie'Far
I
fief
1F'ar field'.
direction
salinity(')
empe
current speed
current_ direct
:diffusion coeff
depth
constant
depth
constant
depth 'depth
constant---- -constant
extrapolated extrapolated constant
Measurement unit f
UM3
111111111111
ftls deg
extrapolated constant
psu
ppb.
depth
constant -
depth
constant constant— constant
depth
depth
constant
s-1
extrapolated extrapolated constant
ft/s
deg
m0.671s2
x
8
10
10
10
2s
25
0
0
2
0 0.0003
0 0_0003
Time -Series Files (optional)
Time -series filename
Time increment (firs)]
Cycling period ]
Alaimsurement uni$
click for file
Borrow time -series files from project:
c:\plumes\VP plume 4
click for file click for file click for file click for file click for file click for file click for file click for file

I
Diffuser: VP plume 4.vpp.db 1 Ambient: c:\plumes\VP plume 4.001.db Special Settings
Csi3 tidal pollutant buildup parameters
Channel width (m)
Text Output 1 Graphical Output I
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
Farfield increment (m)
UM3 aspiration coefficient
1
10.16
1200
lo_1
Bacteria model on solar radiation input
Mancini (1978) coliform model
C 3O1(h) TSD (1994) coliform (for saltwater, Eqn B-68)
C 3O1(h) TSD (1994) enterococcus (for saltwater, Eqn B-69)
— PDS sfc. model heat transfer
C' Low Medium rs High
Graphics settings
Style
(: 4-panel
C' dilution
r concentration
C custom
r Custom graph coords.
s' Abscissa (x)
r, Ordinate 1 (y)
Ordinate 2 (y)
Start case for graphs
Custom variables
Max detailed graphs
YRFIELDTRF"IELD input variables
Text output settings
Output medium
is Text tab (ambient filled)
(• Text tab (ambient as is)
C File (ambient filled)
C File (ambient as is)
r Show changed Diffuser and Ambient tab variables only
Selection List Selected Variables
Reset Default List I
Depth
Arab -cur
P-dia
Polutnt
Dihrtn
x-posn
Y-posn
UM3 output each ?? steps
UM3 maximum dilution reported
UM3 max vertical reversals
0- to max rise or fall
C- to second trap level
r to 2nd max rise or fall
UM3 text output format
R Standard output
C Brief output
100
10000
E Stop on maximum dilution
Close panel I

al�le54 1eII4 J
Diffuser. VP plume 4.vpp.db I Ambient c:tplumesWP plume 4.001.db I Special Settings
Clear + I Output options I Numerical only I
tsar text�cs�l�
Text Output I Graphical Output 1
/ UM3. 3/5/2009 2:08:45 PM
Case 1; ambient file c:\plumes\VP plume 4.001.db; Diffuser table
Ambient Table:
Depth Amb-cur Amb-dir Amb-sal
m m/s deg psu
0.0 0.61 0.0 10.0
2.438 0.61 0.0 10.0
3.048 0.61 0.0 10.0
Diffuser table:
P-dia P-elev V-angle H-angle
(in) (ft) (deg) (deg)
3.0 2.0 15.0 0.0
Simulation.
Froude number:
Depth Amb-cur P-dia
Step (ft) (ft/s)
0 8.0 2.0
100 7.791 2.0
200 7.135 2.0
222 6.868 2.0
234 6.695 2.0
300 4.524 2.0
307 4.081 2.0
321 2.988 2.0
328 2.317 2.0
Outside chronic zone
2:08:45 PM. amb fills: 2
(in)
3.0
6.572
17.26
21.43
24.13
70.31
80.34
105.3
120.6
Ports
()
15.0
Amb-tem Amb-pol
C-- kg/kg
25.0 0.0
25.0 0.0
25.0 0.0
record 1:
Decay
-1
0.0
0.0
0.0
Spacing AcuteMZ ChrncHZ P-depth
(ft) (ft) (ft) (ft)
2.0 32.808 164.04 8.0
Far-spd Far-dir Disprsn Density
m/s deg m0-6-7/s2 sigma-T
0.61 0.0 0.0003 4.618
0.61 0.0 0.0003 4.618
0.61 0.0 0.0003 4.618
Ttl-f to
(HGD)
0.6
Ef f-sal
(psu)
1.1
Temp Polutnt
(C) (ppb)
25.0 17.0
5.433; effleunt density (sigma-T) -2 064; effleunt velocity 0.384(m/s);
y-posn
(ft)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Polutnt Dilutn x-posn
(ppb) () (ft)
17.0 1.0 0.0
2.347 7.203 2.762
0.324 52.14 22.66
0.21 80.61 33.07
0.165 102.2 40.38
0.0447 377.7 142.9
0.0389 433.9 164.4
0.0295 572.5 217.5
0.0257 657.6 250.2
acute zone;
merging;
chronic zone;
matched energy radial vel = 0.447m/s;
surf ace;

:,Cfj25 C3 v. t10, _.
1
Diffuser: VP plume 4.vpp.dbI Ambient: c:\plumes\VP plume 4.001.dbI Special Settings Text Output Graphical Output
Help I
Clear + I
Clear all)
Mar ra
Clear rb
Clear bal
Clear bbl
Clear gal
Clear gbl
Clr Verify)
- Style 1
4-pl
C diln
t con
cus.
•
Scale I
T hick I
T o File II
Verify I
10
20
• ,
Plume Elevation
50
•
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Centerline
— Centerline
— Centerline
• Plume Bndry
Plume Bndry
• Plume Bndry
— Verification
0
10
20
Ambient Properties
50 -
0
10 15 20 25 30 35 40 45 50
Density (sigma-T)
— Amb. density
— Amb. density
— Amb. density
• Plume density
• Plume density
▪ Plume density
— Verification
South -North (ft)
100
Plan View
•
g0 ----
60 — -
• -
?4- ;
Ow•--• = - , _ _ , i
-20-
-4.0
-80
5 10 15 20 25 30 35 40 45 50
West -East (ft)
— Plume path
— Plume path
— Plume path
• Outline
x Outline
• 0 utlin e
— Verificaticn
0
0
5
0
1�000 -
Plumes Dilution Prediction
900 -
800---- ---- - 7
700 : T, ---- -
600 = T. -
500= T - ,
400- -
.
30D 1 7--- ---
200----- -,---- ,
•
100-—
0 5 10 15 20 25 30 35 40 45 50
Horiz. Distance from Source (ft)
— Average
— Average
— Average
• Centerline
• Centerline
• Centerline
— Verification

INC.
MCDAVID ASSOCIATES INC.
Engineers • Planners • Land Surveyors
CORPORATE OFFICE
[phone] • Fax [phone]
E-mail: [e-mail]
3714 N. Main Street • P.O. Drawer 49
Farmville, NC 27828
Mr. Gil T. Vinzani, Jr., P.E.
Supervisor, Eastern NPDES Unit
Division of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
SUBJECT:
Dear Mr. Vinzani:
January 6, 2009
NPDES Permit Expansion
NC0020443
Town of Columbia
Tyrrell County, NC
GOLDSBORO OFFICE
[phone] • Fax [phone]
E-mail: [e-mail]
109 E. Walnut Street • P.O. Box 1776
Goldsboro, NC 27533
The Town of Columbia intends to expand its WWTP capacity from 300,000 GPD to 600,000 GPD.
The proposed project is being funded through the Construction Grants and Loans Section of the
Division of Water Quality. The Engineering Alternatives Analysis, Engineering Report and
Environmental Assessment have been reviewed and approved by the Construction Grants and Loans
Section. A determination of minor construction activity was provided.
Enclosed please find the following items:
1. Check in the amount of $260.00 for a major modification of a minor NPDES Permit
2. Completed NPDES Form 2A Application
3. Supporting Engineering Report, including Alt i s •
4. Approval of Engineering Report
5. Determination of Minor Construction Activity
6. Topographic Map
7. Flow Diagram JAN - 7 2009
8. Copy of existing NPDES Permit
9. Speculative Limits for 600,000 GPD (� [�Q �/ Fj� (� �'}y
We ask that you review the Town's request and provide c"ri�diligied' eri tf. SAtS u' have any
questions regarding this matter don't hesitate to call me. POINT SOURCE BRANCH
Regards,
McDAVID ASSOCIATES, INC.
Cecil -. Madden,
Golds ' oro Offic
CGM:
Enclosures
cc: Rhett White
\\G-PC 1 \D 1005\FTL12009
COLUM BIA-DWQ-N PDES-PERM IT-EXP-LTR.doc
090106

BURIED
2 EA CONCRETE BALLASTS WITH
3 EA 12" HOPE WALL ANCHORS
(TYPICAL 7 LOCATIONS)
PARTIALLY
BURIED
DIFFUSER PIPE
12" HDPE DR11
Be
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I
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WASHERS
4'
#4 REBAR NOTCH FOR BOLTS (TYP.)
LIFTING HANDLE
13" --� HOLES FOR 1/2"0 BOLTS (TYP.)
2' 1"
BALLAST ASSEMBLY
SHALL HAVE A MINIMUM
WEIGHT OF 300 LBS.
PER ASSEMBLY.
CONCRETE SHALL BE NORMAL WEIGHT
CONCRETE HAVING A MINIMUM COMPRESSIVE
STRENGTH OF 2500 PSI 0 28 DAYS.
1' 0"
BOLT BALLAST SECTIONS TOGETHER WITH 1/2"0
STAINLESS STEEL BOLTS, NUTS & WASHERS.
12" STAINLESS STEEL
BLIND FLANGE
CONCRETE BALLAST
1" = 1'-0"

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