NC0025071_Authorization to Construct_20041229

O� WAT�c Michael F. Easley, Governor
�Q State of North Carolina
William G. Ross, Jr., Secretary
r- Department of Environment and Natural Resources
,y O Alan W. Klimek, P.E., Director
Division of Water Quay
December 29, 2004
Mr. Dennis Asbury, Director
City of Eden
191 Mebane Bridge Road
Eden, North Carolina 27288
Subject: Authorization to Construct
ATC No. 025071A01
NPDES Permit No. NCO025071
City of Eden, Mebane Bridge WWTP
Rockingham County
Dear Mr. Asbury:
The Division of Water Quality's NPDES Unit has reviewed your request for an Authorization to
Construct at the Mebane Bridge WWTP. The Division finds the proposed improvements to be satisfactory
and hereby grants authorization for the following:
• Construction of pump station with a 12' diameter wetwell and overflow to the head of the WWTP;
• Installation of 12" gravity sewer to redirect flow from the water treatment plant to the pump station;
• Installation of 6" force main to divert flows;
• Construction of a Lamella type gravity settler, and;
• All related structures, equipment, piping, controls, and other appurtenances, as presented in the
proposed plans and specifications
This Authorization to Construct is issued in accordance with NPDES Permit No. NC0025071, issued
August 9, 2002, and shall be subject to revocation unless the wastewater treatment facilities are
constructed in accordance with the terms and conditions of the permit.
Notification
The Permittee shall notify the Water Quality Supervisor of the Winston-Salem Regional Office, telephone
number [phone], at least forty-eight (48) hours prior to operation of the installed facilities, so that
an in -place inspection can be made. Notification shall be made during the normal office hours of 8:00 a.m.
until 5:00 p.m., Monday through Friday.
Engineer's Certification
Upon completion of construction and prior to operation of the modified facility, the Permittee shall
provide the Division with a certification (copy enclosed) from a professional engineer registered in North
Carolina certifying that the permitted facility has been installed in accordance with the NPDES Permit,
this Authorization to Construct, and the approved plans and specifications. The Certification should be
submitted to: NCDENR / DWQ NPDES Unit,1617 Mail Service Center, Raleigh, North Carolina 27699-
1617.
Requirements for Certified Operator
The Permittee shall employ a certified wastewater treatment plant operator to be in responsible charge
(ORC) of the wastewater treatment facilities. The operator must hold a certificate of the type and grade at
least equivalent to or greater than the classification assigned to the wastewater treatment facilities by the
Certification Commission. The Permittee must also employ a certified back-up operator of the
appropriate type and grade to comply with the conditions of Title 15A, Chapter 8G, .0200. The ORC of
North Carolina Division of Water Quality [phone]
1617 Mail Service Center FAX [phone]
Raleigh, North Carolina 27699-1617 On the Internet at http://h2o.enr.state.nc.us/

Mr. Dennis Asbury
Mebane Bridge WWTP
Permit No. NC0025071
Page 2
the facility must visit each Class I facility at least weekly and each Class II, III, and IV facility at least
daily, excluding weekends and holidays; and must properly manage and document daily operation and
maintenance of the facility and comply with all other conditions of Title 15A, Chapter 8G, .0200.
Additional Requirements
The Operational Agreement between the Permittee and the Environmental Management Commission is
incorporated herein by reference and is a condition of this Permit. Noncompliance with the terms of the
Operational Agreement shall subject the Permittee to all sanctions provided by G. 5.143-215.6 for
violation of or failure to act in accordance with the terms and conditions of this Permit.
Failure to abide by the requirements contained in this Authorization to Construct may subject the
Permittee to an enforcement action by the Division of Water Quality in accordance with North Carolina
General Statute 143-215.6A to 143-215.6C.
The issuance of this Authorization to Construct does not preclude the Permittee from complying with
any and all statutes, rules, regulations, or ordinances which may be imposed by other government
agencies (local, state, and federal) which have jurisdiction.
The Permittee shall maintain a copy of the approved plans and specifications on file for the life of the
facility. One (1) copy of the approved plans and specifications is enclosed for your records.
If you have any questions about this Authorization to Construct, please contact Toya Fields, at (919) 733-
5083, extension 551.
Sincerely, dl��
Ian W. Klimek, P.E.
Enclosures: Project Plans and Specifications (approved)
Engineer's Certification Form
cc: Winston-Salem Regional Office, Water Quality
Technical Assistance and Certification Unit
Central Files
NPDES Unit Files
Mr. Gary Crouch, P.E. - Anderson & Associates
100 Ardmore Street
Blacksburg, VA 24060

ANDERSON
AlAND
ASSOCIATES, INC.
November 30, 2004 I
i
Ms. Toya Fields
North Carolina Department of Environment & Natural Resources ;
Division of Environmental Management
P.O. Box 29535
Raleigh, NC 27626-0535
104
Dear Ms. Fields:
Professional Design Services
DEC 9 2004 D
DENR - WAUP mw in
City of Eden
Mebane Bridge WWTP Solids
JN 21177
This letter is a follow-up to your request for documentation of performance on similar
solids concentration equipment (Lamella separator) to that proposed for the City of Eden's
Mebane Bridge Wastewater Treatment Plant. We obtained an updated list of supposedly
similar installations from the anticipated equipment manufacturer. We contacted most of the
facilities on the list. As we discussed by telephone, we were able to get good recommendations
and references from those we contacted, but little or no "hard data". It appears that little
quantitative monitoring is done under similar circumstances.
We also asked the manufacturer for information from prior pilot studies at similar
installations, but have not received any data. We recently became aware of a very similar
installation in Chapel Hill. The contact there was very pleased with the performance of his
Lamella separator for concentrating water treatment plant wash water. Again, real data were
not readily available. We just received the enclosed memorandum, which shows a removal rate
of suspended solids in the range of 87%. An installation in Windsor, Ontario reported NTU
reduction of 0-99% depending on influent concentration with a solids concentration of about 8%
in the concentrated sludge.
We have attached copies of our Records of Discussion with several similar facilities. As
we discussed, the purpose of the unit is to improve operations by concentrating the sludge
being deposited in the holding ponds. This process will not impact the overall plant discharge.
The exact performance of the unit is not critical in this case and we feel that a significant
concentration of solids will be achieved.
An Employee -Owned Company
100 Ardmore Street, Blacksburg, VA 24060 [phone] [phone] fax www.andassoc.com
Blacksburg, Fredericksburg, & Middletown, Virginia • Greensboro, North Carolina • Td-Cities, Tennessee

Ms. Toya Fields
November 30, 2004
Page 2 of 2
I apologize for taking so long to reply, but as you see we have had trouble obtaining the
desired data. If you have any questions, please let me know.
Sincerely,
ANDERSON & ASSOCIATES, INC.
G:Yy - Crpuc,Yi, PE
Vice res t for Engineering
GSClcmp
Enclosure
cc: Charles Van Zandt
021 \21177\geneml\21177111 _denr.doc

'11/29/04 MON 16:55 FAX
1J 001
Orange Water and Sewer Authority
Water Supply and Treatment
MEMORANDUM
Facsimfle Cover Page
To: Matt Gross
Phone:
Fax: [phone]
From: Orange Water and Sewer Authority
P. O. Box 366
Ca:rrboro, N.C. 27510
Douglas Terry, Manager of Water Supply and Treatment
Rhone: 919-537-4229
Fax: [phone]
E-Mail: [e-mail]
Date: November 29, 2004
Pages: 1 including Fax Cover Sheet
Mat
Listed below is the data you requested.
Influent solids to clarifier averages 800 to 1,000 mg/1 total solids
Effluent solids from clarifier averages 117 mg/1 total solids

Anderson & Associates, Consulting Engineers
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City of Eden
ft6Cu vtifities Department
April 7, 2004
Department of Environment & Natural Resources
Division of Water Quality
NPDES Unit
512 N. Salisbury Street, Suite 1219
Raleigh, NC 27604
Re: Mebane Bridge WWTF
Process Wastewater Pump Station
Dear Sir or Madame:
This letter is provided to inform the Department that Anderson & Associates, Inc has
been authorized by the City of Eden to act on our behalf, as agent, in matters to the design and
regulatory review of the Mebane Bridge Wastewater Facility, Process Wastewater Pump.
Station.
Sincerely,
City of Eden
'*'`
Dennis Asbury
Director
DA/bwj
191 Mebane Bridge Road * Eden, KC 27288-5346 * [phone] * Fax [phone]

IJI
cc: Technical Support Branch MAY 2 8 2004 J
County Health Department
I
Central Files
WSRO J
SOC PRIORITY PROJECT: YES NO a
To: Permits and Engineering Unit
Water Quality Section
Attention: (Ms. Toya Fields) +
AUTHORIZATION TO CONSTRUCT
NPDES PERMIT REPORT AND RECOMMENDATIONS
Date: May 12, 2004
County: Rockingham
NPDES Permit No. NC: 0025071
ATC Permit No. NC: 025071AOI
PART I GENERAL INFORMATION
1.
2.
3.
4.
Facility Name and Current Address: City of Eden
Mebane Bridge WWTP
191 Mebane Bridge Road
Eden, N.C. 272886
Date of most recent NPDES Staff Report: (attach copy) October 3, 1996
Changes since previous action on NPDES Permit: None
Verify Discharge Point(s) on plans with current NPDES Permit. List for all discharge points.
Latitude: 30' 28' 38"
Longitude: 79' 44' 21"
Attach a USGS map extract and indicate treatment facility site and discharge point on map.
U.S.G.S. Quad No. B20NW U.S.G.S. Name SE Eden
5. Treatment plant classification: (attach completed rating sheet) IV

A
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
(PROVIDE THE FOLLOWING INFORMATION IF IT IS NOT ON THE PREVIOUS NPDES
STAFF REPORT)
1. Existing treatment facility:
a. What is the current permitted capacity of the facility? 13.5 mgd
b. Date(s) and construction activities allowed by previous Authorizations to Construct
issued in the previous two (2) years: None
c: What is the actual treatment capacity of the current facility (design volume)? 13.5
2. Please provide a description of proposed wastewater treatment facilities:
Pump station to handle alum sludge from City's water plant. Sludge will be pumped via
pump station to a lamella separator. Sludge from separator will be pumped to sludge lagoon
for land disposal. Supernatant will go to head of WWTP.
3. Residuals handling and utilization/disposal scheme:
Sludge from WWTP is land applied under Permit WQ0003035
a. If residuals are being land applied, please specify DWQ permit no.
Residual Contractor: Synagro
PART III - EVALUATION AND RECOMMENDATIONS
The ATC is for the construction of a pump station to handle the alum from the City's water
plant. Presently, all waste from the water plant goes into the influent of the WWTP. As a result, the
solids in the WWTP are very high. From time to time solids are washed from the plant and limits
have been exceeded. Civil penalties have been accessed and paid.
The proposed pump station would collect and pump the alum sludge to a proposed Lamella
separator which will further concentrate the solids. The solids will go to the WWTP sludge lagoon
for land application, the supernatant will gravity flow back to the influent of the WWTP. The filter
back wash water from the water plant will continue to flow to the WWTP influent.
When completed, the project should greatly reduce the solids going to the WWTP. It is
recommended the ATC be issued.

Signature of report preparer
at
ater Quality Section Supervisor
�i�z..r-dam
Date

ANDERSON M
eqe�AND p u I Professional Design Services
ASSOCIATES, INC.
u APR 2 0 2004
April 8, 2004
- F{ECEIVED
NC Department of Environment and Natural Resources APR 13 2004
Division of Water Quality
NPDES Permitting Unit WATEBQUALM SEUIOI
512 N. Salisbury Street, Suite 1219 NonQsrna�Cempl (c
Raleigh, NC 27604 v
Re: City of Eden
Mebane Bridge WWTF
Process WW Pump Station
JN 21177
Dear Sir or Madam:
During 2001-2002, we conducted a study of solids handling in the City of Eden's
Mebane Bridge Wastewater Treatment Facility. The study reviewed solids sources, treatment,
and disposal, as well as, accumulation of solids in the treatment facilities. Water treatment plant
process wastewater flow streams (backwash water and sedimentation basin wastewater) were
found to be a significant source of solids passing through the wastewater treatment plant.
These inert (non -biodegradable) solids "take up space" in the treatment units; decreasing
detention times, increasing pumping, and making it difficult to monitor biological solids within the
wastewater plant.
The sedimentation basin and filter waste streams are segregated as they leave the
water treatment plant. Most of the solids (89%) are present in the sedimentation basin waste
stream, which is only 37% of the combined water plant waste flow. It is most cost effective to
divert the sedimentation basin waste stream around the wastewater treatment aeration basins,
clarifiers, return sludge system, and digesters while allowing the small mass of backwash solids
to continue through the wastewater plant.
This project diverts the water treatment sedimentation basin solids into a gravity sewer
line which flows to a new pump station located on the Mebane Bridge Wastewater Treatment
Facility site. The wastewater will accumulate in the wetwell, be equalized, and pumped to a
gravity settler where the solids will be further concentrated prior to discharge to the sludge
holding ponds. The effluent from the gravity settler now that the solids have been separated will
flow by gravity to the head of the existing treatment plant.
Enclosed with this submittal are the following:
1 copy — Authorization letter from Owner
3 copies - Plans (12 Sheets)
3 copies - Technical Specifications
2 copies - Design Calculations
An Employee -Owned Company
100 Ardmore Street, Blacksburg, VA 24060 [phone] [phone] fax www.andassoc.com
Blacksburg, Fredericksburg, Middletown 8 Richmond, Virginia • Greensboro, North Carolina • Tri-Cities, Tennessee

April 1, 2004
Page 2 of 2
A Construction Sequence Plan is included on Sheet C-2 of the plans. Since there is no
alteration of the WWTP piping or treatment units, so no flow schematic seemed warranted.
The work will take place within the confines of the existing water treatment plant and
wastewater treatment plant, with the exception of a road crossing by the gravity sewer in
between the two plants. The work falls below the minimum thresholds outlined in 15A NCAC
OIC.0408 MINOR CONSTRUCTION ACTIVITIES and thus no SEPA documentation appears to
be required.
Please contact me if you have any questions or comments regarding this project.
Please expedite whatever review is required as the City of Eden would like to bid this project as
soon as possible.
Sincerely,
TES, INC.
S. r ch, PE
3r s' ent for Engineering
GSC/kld
Enclosures
cc: Charles VanZandt
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