NC0020184_Authorization to Construct_19950106

State of North Carolina �C
Department of Environment,
Health and Natural Resources
Division of Environmental Management
&10
'^ James B. Hunt, Jr„ Governor©�
Jonathan B. Howes, Secretary f-7PI
A. Preston Howard, Jr., P.E., Director
January 6, 1995
Mr. Donald E. Carmichael, P.E.
Director of Public Works & Utilities
City of Gastonia
P. O. Box 1748
Gastonia, North Carolina 28053-1748
SUBJECT: City of Gastonia
Permit No. NCO020184
Authorization to Construct
Wastewater Treatment Facilities
Project No. CS370744-03
Gaston County
�'s Dear Mr. Carmichael:
The final plans and specifications for the subject project have been reviewed and
found to be satisfactory.
Authorization is hereby granted for the construction of additions and
modifications to upgrade and expand the City, of Gastonids Long Creek Wastewater
Treatment Plant from 8 MGD to 16 MGD to consist of a 3-barrel inverted siphon to
convey influent from the new Dillard Creek Outfall to head of plant; improvements to
the existing preliminary treatment facilities including addition of a course bar screen,
two (2) new rake -type mechanical bar screens, grit removal equipment, and a Parshall
flume; new 36 MGD (peak flow capacity) wet well/dry well influent pump station; a
new splitter box and influent piping to primary clarifiers; modifications to the existing
primary clarifiers to increase hydraulic capacity, installation of a doppler flow meter at
existing raw sludge pump station; new splitter boxes and piping to convey primary
clarifier effluent to two (2) parallel treatment basins of 7 MGD and 9 MGD capacity
designed for biological nutrient removal and sized for 7.3 hours total hydraulic
detention time at design flow, followed by a denitrification basin sized for 2.5 hours
hydraulic detention time at design flow; addition of five (5) new centrifugal blowers to
serve the BNR and denitrification basins; a screw -pump intermediate lift station with
three (3) 84-inch diameter open screws; splitter box and influent piping to four (4) new
P.O. Box 29535, Raleigh, North Carolina 27626.0535 Telephone [phone] FAX [phone]
An Equal opportunity Affirmative Action Employer 50%recycled/ 10%post-consumer paper

PAGE 2
120 ft. diameter by 14 ff. SWD final clarifiers; an 8-cell tertiary filter and back: wash
holding tank; new dual channel chlorine contact tank; chlorination/dechlorination /01*bN
facilities; dual static aerators for effluent reaeration; a new 7,300-linear foot, 54-inch
diameter effluent outfall to South Fork Catawba River with outlet structure for effluent
dispersion; a dissolved air flotation unit for sludge thickening; renovation of four (4)
existing anaerobic digesters; addition of a new anaerobic- digester and a sludge holding
tank; solids contact reactor for phosphorus removal from digester supernatant; chemical
storage and feed facilities for acid, caustic and alum; polymer mixing and feed
facilities for sludge conditioning; non -potable water pump station; new generator
facilities for standby power; and all associated site work, yard piping and electrical
work
Do not proceed with construction until the Authorization -to -Award package,
EEO, and MBE documentation/certification have been reviewed, and you are in receipt
of our approval, if funding is desired for project construction.
The Permittee shall employ an actively State certified wasteN ater treatment plant
operator to be in responsible charge of the wastewater treatment facilities. Such
operator must hold a valid State Certificate of the grade at least equivalent to the
classification assigned to the wastewater treatment facilities by the Certification
Commission. when a new chief operator must be obtained to be in responsible charge
of the new facilities, it is required that this be done by the time the construction of the
facilities is 50% complete.
The Authorization -to -Construct is issued in accordance with Part III, Paragraph C
of NPDES Permit No. NC0020184, issued April 7, 1994 and shall be subject to
revocation unless the wastewater treatment facilities are constructed in accordance with
the approved plans, specifications, and supporting documents; and are in compliance
with the conditions and limitations specified in Permit No. NC0020184.
The Permittee shall have an acceptable sludge analysis and a sludge toxicity
analysis which have been approved by the Division of Environmental Management,
Water Quality Section prior to the disposal of any sludge from the new wastewater
treatment plant. Copies of the analyses, supporting documents, and approvals shall be
submitted to the Division of Environmental Management's Mooresville Regional
Office.
The disposing, selling or free distribution of wet, dried, composted sludge or
sludge -like materials from wastewater facilities without prior review and approval by
this Division is illegal.

PAGE 3
During the construction of the proposed additions/modifications, the permittee
shallcontinue to properly maintain and operate the existing wastewater treatment
facilities at all tunes, and it such a manner, as necessary to comply with the effluent
limits specified in the NPDES Permit.
You are reminded that it is mandatory for the project to be constructed in
accordance with the North Carolina Sedimentation Pollution Control Act, and, when
applicable, the North Carolina Dam Safety Act. In addition, the specifications must
clearly state what the contractor's responsibilities shall be in complying with these
Acts.
One (1) set of final approved plans and specifications is to be forwarded to you
for your files. The copy of the approved plans and specifications shall be maintained
on file by the Owner for the life of the project.
Upon completion of construction and prior to operation of this permitted facility,
a certification must be received from a Professional Engineer certifying that the
permitted facility has been installed in accordance with the approved plans and
specifications. Mail the Certification to the Permits and Engineering Unit, P. O. Box
29535, Raleigh, North Carolina 27626-0535. (Engineer's Certification Form is
attached.)
If you have any questions or need additional information, please contact Mr. Bill
Hoffman, at [phone], extension 615.
Sincerely,
Presto oward, Jr., P.E.
Attachment
RPT:vk
cc: I N. Pease Associates
Mr. Don Safrit-
Mooresville Regional Office
Mr. Tom Fahnestock
Mr. Don Evans
Ms. Valerie Lancaster
Mr. Robert Teulings
Ms. Cindy Finan
DMU
�, SRF